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2020 Vol. 38, No. 11
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2020, 38(11): 1-5,43.
doi: 10.13205/j.hjgc.202011001
Abstract:
Based on the definition and judgment criteria of the carbon dioxide emissions peaking, an evaluation system for Chinese cities was proposed. In order for China to achieve the carbon dioxide emissions peak around 2030 or sooner, Chinese cities need to put forward clear peaking deadlines and peaking goals according to their actual conditions, and the qualified cities should reach the emissions peak as soon as possible. Besides, Chinese cities should develop refined road maps, including city-level annual and phased emissions targets, sectoral peaking deadlines, goals, and emission control plans before and after achieving the peak. In addition, a corresponding supervision mechanism is needed, requiring Chinese cities to strengthen the carbon emission statistical accounts, build the information platform, establish the accountability system and the reward and punishment mechanism.
Based on the definition and judgment criteria of the carbon dioxide emissions peaking, an evaluation system for Chinese cities was proposed. In order for China to achieve the carbon dioxide emissions peak around 2030 or sooner, Chinese cities need to put forward clear peaking deadlines and peaking goals according to their actual conditions, and the qualified cities should reach the emissions peak as soon as possible. Besides, Chinese cities should develop refined road maps, including city-level annual and phased emissions targets, sectoral peaking deadlines, goals, and emission control plans before and after achieving the peak. In addition, a corresponding supervision mechanism is needed, requiring Chinese cities to strengthen the carbon emission statistical accounts, build the information platform, establish the accountability system and the reward and punishment mechanism.
2020, 38(11): 6-11,202.
doi: 10.13205/j.hjgc.202011002
Abstract:
Coal is the main energy source in China. It is very important to analyze the changing trend of coal consumption in order to predict the emission of carbon dioxide and air pollutants. Based on the National Environmental Statistics Survey data, this paper analyzed the utilization of coal consumption in major cities from 2011 to 2018, as well as the coal consumption trends of industrial sources and living sources by clustering analysis of provincial capitals in China using the thermodynamic clustering map, and according to the eastern cities, central cities and western cities for regional comparison of coal consumption. The following conclusions were drawn: through cluster analysis, it was found that there was a certain similarity in the base and changing trend of the total coal consumption of industrial enterprises among the cities in the same cluster. Overall, the coal consumption of urban industrial enterprises showed a decreasing trend year by year. The total coal consumption of eastern cities was higher than that of central and western cities, and the decline of coal consumption in the eastern cities was generally better than that in the central and western cities. Except for a few cities such as Beijing, the annual coal consumption in the power and heat production and supply industries did not changed much. The trend of coal consumption of urban living source was decreasing year by year generally, and it was increasing in the west, decreasing in the east and the middle. The coal consumption peaking in eastern cities was better than that in central and western cities.
Coal is the main energy source in China. It is very important to analyze the changing trend of coal consumption in order to predict the emission of carbon dioxide and air pollutants. Based on the National Environmental Statistics Survey data, this paper analyzed the utilization of coal consumption in major cities from 2011 to 2018, as well as the coal consumption trends of industrial sources and living sources by clustering analysis of provincial capitals in China using the thermodynamic clustering map, and according to the eastern cities, central cities and western cities for regional comparison of coal consumption. The following conclusions were drawn: through cluster analysis, it was found that there was a certain similarity in the base and changing trend of the total coal consumption of industrial enterprises among the cities in the same cluster. Overall, the coal consumption of urban industrial enterprises showed a decreasing trend year by year. The total coal consumption of eastern cities was higher than that of central and western cities, and the decline of coal consumption in the eastern cities was generally better than that in the central and western cities. Except for a few cities such as Beijing, the annual coal consumption in the power and heat production and supply industries did not changed much. The trend of coal consumption of urban living source was decreasing year by year generally, and it was increasing in the west, decreasing in the east and the middle. The coal consumption peaking in eastern cities was better than that in central and western cities.
2020, 38(11): 12-18.
doi: 10.13205/j.hjgc.202011003
Abstract:
On the 2015 Paris Climate Change Conference, Chinese government put forward a series of new goals such as "peak carbon emissions around 2030 and accelerate their realization". Cities are main sources of energy consumption and carbon emissions, thus promoting low-carbon development of cities becomes a common challenge facing all countries. This study used the STIRPAT model to explore the development situation of Shanghai in the past 20 years, and analyzed the impact factors of its carbon emissions to identity whether Shanghai can peak carbon emissions in 2025. The results showed that shanghai could peak its carbon emissions by 2025 under either the baseline scenario or the ultra-low carbon scenario. It was also found that urbanization rate was the dominant impact factors for Shanghai’s carbon emissions, followed by the level of per capita GDP.
On the 2015 Paris Climate Change Conference, Chinese government put forward a series of new goals such as "peak carbon emissions around 2030 and accelerate their realization". Cities are main sources of energy consumption and carbon emissions, thus promoting low-carbon development of cities becomes a common challenge facing all countries. This study used the STIRPAT model to explore the development situation of Shanghai in the past 20 years, and analyzed the impact factors of its carbon emissions to identity whether Shanghai can peak carbon emissions in 2025. The results showed that shanghai could peak its carbon emissions by 2025 under either the baseline scenario or the ultra-low carbon scenario. It was also found that urbanization rate was the dominant impact factors for Shanghai’s carbon emissions, followed by the level of per capita GDP.
2020, 38(11): 19-24,77.
doi: 10.13205/j.hjgc.202011004
Abstract:
Based on the IPCC emission factors method, this article developed the 2015—2019 city level CO2 emission inventory for Beijing-Tianjin-Hebei(TBH) agglomeration in China, and adopt decoupling coefficient method to analyze the relationship between economic growth and carbon dioxide emission. Based on carbon dioxide emissions trends and decoupling situation, this paper made a prediction on the peak of CO2 emission in TBH agglomeration. The results showed that in the past five years, the carbon emissions of 7 cities including Baoding, Zhangjiakou, Qinhuangdao, Xingtai, Cangzhou, Langfang, and Hengshui have not reached the peak yet. While Beijing, Tianjin, Shijiazhuang, Chengde, Handan, and Tangshan have already reached the peak. The cities which have the fundation of reach the peak should promptly propose and carry out the action plan for the CO2 emission peaking goal.
Based on the IPCC emission factors method, this article developed the 2015—2019 city level CO2 emission inventory for Beijing-Tianjin-Hebei(TBH) agglomeration in China, and adopt decoupling coefficient method to analyze the relationship between economic growth and carbon dioxide emission. Based on carbon dioxide emissions trends and decoupling situation, this paper made a prediction on the peak of CO2 emission in TBH agglomeration. The results showed that in the past five years, the carbon emissions of 7 cities including Baoding, Zhangjiakou, Qinhuangdao, Xingtai, Cangzhou, Langfang, and Hengshui have not reached the peak yet. While Beijing, Tianjin, Shijiazhuang, Chengde, Handan, and Tangshan have already reached the peak. The cities which have the fundation of reach the peak should promptly propose and carry out the action plan for the CO2 emission peaking goal.
2020, 38(11): 25-32.
doi: 10.13205/j.hjgc.202011005
Abstract:
Based on the LEAP model (long-range energy alternatives planning system), this study evaluated the variation law of on-road vehicle greenhouse gases (GHGs) emissions in the historical stage of Beijing (2000—2018), and developed five different scenarios to predict the development trend of vehicle stock, energy demand and GHGs emissions in the future (2019—2030). In addition, we explored the peaking year of vehicle GHG emissions of Beijing, as well as the optimal development path. The results showed that the vehicle stock would continue to increase in the future, but the average annual growth rate would reduce to 1.63%. Total vehicle GHGs emissions peaked in 2013 at 21758563 t CO2e, corresponding to the energy consumption of 306383 TJ. In all future scenarios, vehicle GHGs emissions would decline. Improving the fuel efficiency of motor vehicles was the best way to reduce emission when implementing single emission reduction measures. And ODS (optimal development scenario) that integrated the three emission reduction measures was the optimal development path.
Based on the LEAP model (long-range energy alternatives planning system), this study evaluated the variation law of on-road vehicle greenhouse gases (GHGs) emissions in the historical stage of Beijing (2000—2018), and developed five different scenarios to predict the development trend of vehicle stock, energy demand and GHGs emissions in the future (2019—2030). In addition, we explored the peaking year of vehicle GHG emissions of Beijing, as well as the optimal development path. The results showed that the vehicle stock would continue to increase in the future, but the average annual growth rate would reduce to 1.63%. Total vehicle GHGs emissions peaked in 2013 at 21758563 t CO2e, corresponding to the energy consumption of 306383 TJ. In all future scenarios, vehicle GHGs emissions would decline. Improving the fuel efficiency of motor vehicles was the best way to reduce emission when implementing single emission reduction measures. And ODS (optimal development scenario) that integrated the three emission reduction measures was the optimal development path.
2020, 38(11): 33-38,59.
doi: 10.13205/j.hjgc.202011006
Abstract:
By utilizing the Cobb Douglas function and the impact of COVID-19 pandemic on GDP in China,the carbon dioxide emissions of the Yangtze River Delta urban agglomeration in 2025 were predicted. Based on historical trends and future projections of carbon dioxide emissions in the Yangtze River Delta, and integrated with relevant judgement criteria, the peaking of carbon dioxide emissions was evaluated for 41 cities in the Yangtze River Delta urban agglomeration. The results showed that some cities including Shanghai, Jiangsu (Nanjing, Suzhou, Wuxi, Changzhou, Zhenjiang), Zhejiang (Hangzhou, Jiaxing, Huzhou, Ningbo, Wenzhou), Anhui (Chizhou, Huangshan, Wuhu) were already qualified for reaching the emission peak. It was recommended that these cities came up with action plans to reach the peak during the 14th Five-Year Plan period and researched the mechanisms to control the carbon dioxide emissions.
By utilizing the Cobb Douglas function and the impact of COVID-19 pandemic on GDP in China,the carbon dioxide emissions of the Yangtze River Delta urban agglomeration in 2025 were predicted. Based on historical trends and future projections of carbon dioxide emissions in the Yangtze River Delta, and integrated with relevant judgement criteria, the peaking of carbon dioxide emissions was evaluated for 41 cities in the Yangtze River Delta urban agglomeration. The results showed that some cities including Shanghai, Jiangsu (Nanjing, Suzhou, Wuxi, Changzhou, Zhenjiang), Zhejiang (Hangzhou, Jiaxing, Huzhou, Ningbo, Wenzhou), Anhui (Chizhou, Huangshan, Wuhu) were already qualified for reaching the emission peak. It was recommended that these cities came up with action plans to reach the peak during the 14th Five-Year Plan period and researched the mechanisms to control the carbon dioxide emissions.
2020, 38(11): 39-43.
doi: 10.13205/j.hjgc.202011007
Abstract:
Based on the available urban SO2 and CO2 emission inventory data, from the perspective of data mining, we explored the similarities and differences between the two emission trends and found out the reference significance of analyzing the relationship for predicting the CO2 emission trends. DTW algorithm was used to realize the matching pattern of CO2 and SO2 on the time axis. Cities were classified as lag type, synchronous type and advanced type, based on DTW. The carbon emission peak year of cities were estimated due to emission path types. At last, suggestions were proposed for future carbon emission reduction of the cities.
Based on the available urban SO2 and CO2 emission inventory data, from the perspective of data mining, we explored the similarities and differences between the two emission trends and found out the reference significance of analyzing the relationship for predicting the CO2 emission trends. DTW algorithm was used to realize the matching pattern of CO2 and SO2 on the time axis. Cities were classified as lag type, synchronous type and advanced type, based on DTW. The carbon emission peak year of cities were estimated due to emission path types. At last, suggestions were proposed for future carbon emission reduction of the cities.
2020, 38(11): 44-52.
doi: 10.13205/j.hjgc.202011008
Abstract:
Tangshan, as an industrial-intensive city, accounted for about 15% of China’s iron, crude steel, and steel production in 2018, and emitted large amount of greenhouse gases and atmospheric pollutants. This paper took Tangshan as an example and studied trend of the production carbon emission of steel industry from 2010 to 2030 and determined the peak time. Based on the calculation method provided by Greenhouse Gas Emission Accounting and Reporting Requirements, in this paper, we preliminarily established a numerical formula that can calculate the enterprise’s CO2 emission based on the equipment scale, operating time, capacity utilization rate and unit product energy consumption parameters. Then we applied it into all enterprises of Tangshan in 2017, and the carbon emission was calculated as 140,425,200 tons, and the carbon emission coefficient was 1.616 t CO2/t steel. Compared with the literature and statistical yearbook data, the relative error was less than 10%, indicating that the numerical formula had a certain accuracy, which could provide references for the bottom-up rapid accounting of carbon emission from steel production in enterprises or regions. At the same time, we combined the historical production status, production status and future planning of the industry, an energy demand model was constructed by LEAP model to obtain the trends of fossil energy consumption and carbon emission of Tangshan’s iron and steel production from 2010 to 2030, and we find the carbon emission had already peaked in 2018.
Tangshan, as an industrial-intensive city, accounted for about 15% of China’s iron, crude steel, and steel production in 2018, and emitted large amount of greenhouse gases and atmospheric pollutants. This paper took Tangshan as an example and studied trend of the production carbon emission of steel industry from 2010 to 2030 and determined the peak time. Based on the calculation method provided by Greenhouse Gas Emission Accounting and Reporting Requirements, in this paper, we preliminarily established a numerical formula that can calculate the enterprise’s CO2 emission based on the equipment scale, operating time, capacity utilization rate and unit product energy consumption parameters. Then we applied it into all enterprises of Tangshan in 2017, and the carbon emission was calculated as 140,425,200 tons, and the carbon emission coefficient was 1.616 t CO2/t steel. Compared with the literature and statistical yearbook data, the relative error was less than 10%, indicating that the numerical formula had a certain accuracy, which could provide references for the bottom-up rapid accounting of carbon emission from steel production in enterprises or regions. At the same time, we combined the historical production status, production status and future planning of the industry, an energy demand model was constructed by LEAP model to obtain the trends of fossil energy consumption and carbon emission of Tangshan’s iron and steel production from 2010 to 2030, and we find the carbon emission had already peaked in 2018.
2020, 38(11): 53-59.
doi: 10.13205/j.hjgc.202011009
Abstract:
Natural graphite powder, tetraethylorthosilicate and pyrrole monomer were used as the raw materials to synthesize graphene/SiO2-polypyrrole nanocomposite (GS-PPy) through the sol-gel method and in situ precipitation method. And GS-PPy was used to remove Cr(Ⅵ) in the solution. The effects of solution pH, reaction time, solution concentration, and temperature on adsorption effect were investigated. Meanwhile, methods the removal mechanisms of Cr(Ⅵ) removal by GS-PPy were investigated by TEM, XPS, FTIR and other characterization. The results showed that the adsorption effect was the best at pH=2.0. The adsorption process conformed to the pseudo-second-order kinetic model and the Freundlich isotherm model, which was defined as multi-molecular layer chemical adsorption and endothermic reaction. The mechanisms of Cr(Ⅵ) removal by GS-PPy mainly includes electrostatic attraction, ion exchange and redox.
Natural graphite powder, tetraethylorthosilicate and pyrrole monomer were used as the raw materials to synthesize graphene/SiO2-polypyrrole nanocomposite (GS-PPy) through the sol-gel method and in situ precipitation method. And GS-PPy was used to remove Cr(Ⅵ) in the solution. The effects of solution pH, reaction time, solution concentration, and temperature on adsorption effect were investigated. Meanwhile, methods the removal mechanisms of Cr(Ⅵ) removal by GS-PPy were investigated by TEM, XPS, FTIR and other characterization. The results showed that the adsorption effect was the best at pH=2.0. The adsorption process conformed to the pseudo-second-order kinetic model and the Freundlich isotherm model, which was defined as multi-molecular layer chemical adsorption and endothermic reaction. The mechanisms of Cr(Ⅵ) removal by GS-PPy mainly includes electrostatic attraction, ion exchange and redox.
2020, 38(11): 60-65,52.
doi: 10.13205/j.hjgc.202011010
Abstract:
In this paper, micro-scale zinc-copper (mZn/Cu) bimetallic particles were prepared via replacement reaction and applied in the removal of Rhodamine B. The effects of initial pH, mZn/Cu dosage and initial concentration on the degradation of Rhodamine B were investigated. The optimal conditions for the degradation of of Rhodamine B was determined through single-factor experiment. As compared with single metals, the formation of microbatteries on mZn/Cu greatly improved its ability to provide electrons and its chemical activity, resulting in more efficient degradation of Rhodamine B. When N2 was bubbled into the reaction system to remove the dissolved oxygen and the scavengers such as tert-butyl alcohol (TBA) and benzoquinone (BQ) were introduced, the degradation of Rhodamine B was also greatly inhibited. This proved that under acidic and aerobic conditions, the dissolved oxygen could accepted electrons from the surface of mZn/Cu to produce ·OH and O2-· radicals responsible for the rapid removal of Rhodamine B. Thus, this study not only provided a low-cost and high-efficiency technology for the degradation of organic contaminants in aqueous solution, but also put insight into the mechanism of the reaction.
In this paper, micro-scale zinc-copper (mZn/Cu) bimetallic particles were prepared via replacement reaction and applied in the removal of Rhodamine B. The effects of initial pH, mZn/Cu dosage and initial concentration on the degradation of Rhodamine B were investigated. The optimal conditions for the degradation of of Rhodamine B was determined through single-factor experiment. As compared with single metals, the formation of microbatteries on mZn/Cu greatly improved its ability to provide electrons and its chemical activity, resulting in more efficient degradation of Rhodamine B. When N2 was bubbled into the reaction system to remove the dissolved oxygen and the scavengers such as tert-butyl alcohol (TBA) and benzoquinone (BQ) were introduced, the degradation of Rhodamine B was also greatly inhibited. This proved that under acidic and aerobic conditions, the dissolved oxygen could accepted electrons from the surface of mZn/Cu to produce ·OH and O2-· radicals responsible for the rapid removal of Rhodamine B. Thus, this study not only provided a low-cost and high-efficiency technology for the degradation of organic contaminants in aqueous solution, but also put insight into the mechanism of the reaction.
2020, 38(11): 66-71,156.
doi: 10.13205/j.hjgc.202011011
Abstract:
In view of the difficulties in long-term maintenance of the treatment effect of black odorous river and the problem of black and odorous repeatedly, an in-situ ecological restoration was carried out in a seriously polluted black odorous river course with severe internal pollution. In the first stage, ultrafine bubble oxygen enrichment (mobile aerator+fixed point aerator) and biological activation technology were used to restore water and sediment, reduce endogenesis pollution and improve living environment; in the second stage, the fixed point aerator, ecological floating island, purification of aquatic plants and diversity regulation of aquatic animals were applied, to restore and create a healthy and stable ecosystem. After nearly 4 months’ treatment, the water quality in the treated area stabilized from severe black odor to the surface V water standard, and the contents of COD, NH3-N and TP were 28.79, 0.36 and 0.19 mg/L, and the removal rates reached 45%, 98% and 85% respectively. After the treatment, the water was clarified and a variety of aquatic animals and submerged plants were visible. The channel sediment had a natural earthy color. The mud-water co-treatment effect was achieved without dredging treatment. The quality of the water environment was significantly improved and long-term governance aim was achieved.
In view of the difficulties in long-term maintenance of the treatment effect of black odorous river and the problem of black and odorous repeatedly, an in-situ ecological restoration was carried out in a seriously polluted black odorous river course with severe internal pollution. In the first stage, ultrafine bubble oxygen enrichment (mobile aerator+fixed point aerator) and biological activation technology were used to restore water and sediment, reduce endogenesis pollution and improve living environment; in the second stage, the fixed point aerator, ecological floating island, purification of aquatic plants and diversity regulation of aquatic animals were applied, to restore and create a healthy and stable ecosystem. After nearly 4 months’ treatment, the water quality in the treated area stabilized from severe black odor to the surface V water standard, and the contents of COD, NH3-N and TP were 28.79, 0.36 and 0.19 mg/L, and the removal rates reached 45%, 98% and 85% respectively. After the treatment, the water was clarified and a variety of aquatic animals and submerged plants were visible. The channel sediment had a natural earthy color. The mud-water co-treatment effect was achieved without dredging treatment. The quality of the water environment was significantly improved and long-term governance aim was achieved.
2020, 38(11): 72-77.
doi: 10.13205/j.hjgc.202011012
Abstract:
The nitrate removal performance from spent brine by electrolysis was investigated, with 10 g/L NaHCO3 added into 6 g/L NaCl regenerant as a pH buffer. Besides a stable pH level (8.3~9.1) during 8 h electrolysis of spent brine, there was a higher nitrate removal efficiency (i.e., 96%) achieved by the addition of NaHCO3 than those achieved by the addition of diluted HCl solution and even without pH adjustment. The addition of NaHCO3 also protected Fe cathodic plate from attacks of aggressive ions (e.g., chloride) in regenerant. The increase in NaCl concentration in regenerant from 6 g/L to 36 g/L led to a remarkable decrease in nitrate removal by 20%. Subsequently, this study investigated the long-term operation performance (i.e., 13 cycles) of the nitrate-selective ion exchange-regeneration-spent brine electrolysis process for nitrate-ridden groundwater treatment, with the addition of 10 g/L NaHCO3 into 6 g/L NaCl regenerant. There were no side effect on product water quality, resin nitrate selectivity, regenerant elution capacity, and nitrate accumulation characteristics in regenerant observed after the addition of NaHCO3. Nitrate concentration in product water stably met the required water quality standards for drinking water throughout the experimental periods.
The nitrate removal performance from spent brine by electrolysis was investigated, with 10 g/L NaHCO3 added into 6 g/L NaCl regenerant as a pH buffer. Besides a stable pH level (8.3~9.1) during 8 h electrolysis of spent brine, there was a higher nitrate removal efficiency (i.e., 96%) achieved by the addition of NaHCO3 than those achieved by the addition of diluted HCl solution and even without pH adjustment. The addition of NaHCO3 also protected Fe cathodic plate from attacks of aggressive ions (e.g., chloride) in regenerant. The increase in NaCl concentration in regenerant from 6 g/L to 36 g/L led to a remarkable decrease in nitrate removal by 20%. Subsequently, this study investigated the long-term operation performance (i.e., 13 cycles) of the nitrate-selective ion exchange-regeneration-spent brine electrolysis process for nitrate-ridden groundwater treatment, with the addition of 10 g/L NaHCO3 into 6 g/L NaCl regenerant. There were no side effect on product water quality, resin nitrate selectivity, regenerant elution capacity, and nitrate accumulation characteristics in regenerant observed after the addition of NaHCO3. Nitrate concentration in product water stably met the required water quality standards for drinking water throughout the experimental periods.
2020, 38(11): 78-84.
doi: 10.13205/j.hjgc.202011013
Abstract:
Low nucleic acid (LNA) and high nucleic acid (HNA) bacteria show different characteristics under different environmental conditions, and the effect of denitrification process on bacteria is still unclear. The variations of free-swimming LNA and HNA bacteria under different denitrification conditions and microbial community were thus investigated in this study, it was found that free-swimming bacteria increased rapidly during the denitrification process, and greater the denitrification rate resulted in a higher increase of free-swimming bacteria. It was evidenced that LNA bacteria moved faster than HNA bacteria at the beginning of the denitrification reaction. HNA bacteria showed a rapid increase, either the denitrification reached a certain level, or the floc structure loose or break, indicating that LNA bacteria was mainly on the surface of flocs and functioned as glue, or filling materials of the pores of flocs. HNA bacteria functioned as a backbone of flocs. When starch was used as the carbon source for denitrification, free-swimming bacteria were reduced due to the bridge-capture of starch. However the denitrification of sodium acetate had a more significant effect on free-swimming bacteria than the bridge-capture of starch. In addition, HNA bacteria had higher abundance and diversity than LNA bacteria, and was found out as the main functional bacteria. LNA bacteria can respond faster to denitrification and be used as a signal for denitrification initiation.
Low nucleic acid (LNA) and high nucleic acid (HNA) bacteria show different characteristics under different environmental conditions, and the effect of denitrification process on bacteria is still unclear. The variations of free-swimming LNA and HNA bacteria under different denitrification conditions and microbial community were thus investigated in this study, it was found that free-swimming bacteria increased rapidly during the denitrification process, and greater the denitrification rate resulted in a higher increase of free-swimming bacteria. It was evidenced that LNA bacteria moved faster than HNA bacteria at the beginning of the denitrification reaction. HNA bacteria showed a rapid increase, either the denitrification reached a certain level, or the floc structure loose or break, indicating that LNA bacteria was mainly on the surface of flocs and functioned as glue, or filling materials of the pores of flocs. HNA bacteria functioned as a backbone of flocs. When starch was used as the carbon source for denitrification, free-swimming bacteria were reduced due to the bridge-capture of starch. However the denitrification of sodium acetate had a more significant effect on free-swimming bacteria than the bridge-capture of starch. In addition, HNA bacteria had higher abundance and diversity than LNA bacteria, and was found out as the main functional bacteria. LNA bacteria can respond faster to denitrification and be used as a signal for denitrification initiation.
2020, 38(11): 85-90.
doi: 10.13205/j.hjgc.202011014
Abstract:
The purification abilities of ecofilter are affected by many factors. Different species of wetland plants may cause different purification abilities. For the improvement of applicability of ecofilter in Guizhou, we studied the purification abilities of main contaminants (COD, NH3-N,TN and TP) in ecofilter with three wetland plants in Guizhou (Canna indica L.,Cyperus alternifolius,Acorus calamus L.). Through a comparison of the removal efficiencies of main contaminants we selected the optimal plants combination that could achieve the best purification ability of ecofilter in Guizhou. The result showed that: The ecofilter planted with Canna indica L. achieved the best purification abilities of COD, NH3-N and TP, the removal efficiencies were up to 88% and 92% and 47%. The ecofilter planted with Canna indica L. and Cyperus alternifolius achieved the best purification ability of TN with the highest removal efficiency of 49%. The microbial community structures in different ecofilters were very similar. The main components were Proteobacteria, Chloroflexi and Acidobacteria. The biological diversity of nitrobacteria was low, mainly ammonia oxidizing bacteria. The biological diversity of denitrifying bacteria was high. The aerobiotic denitrifying bacteria was also detected.
The purification abilities of ecofilter are affected by many factors. Different species of wetland plants may cause different purification abilities. For the improvement of applicability of ecofilter in Guizhou, we studied the purification abilities of main contaminants (COD, NH3-N,TN and TP) in ecofilter with three wetland plants in Guizhou (Canna indica L.,Cyperus alternifolius,Acorus calamus L.). Through a comparison of the removal efficiencies of main contaminants we selected the optimal plants combination that could achieve the best purification ability of ecofilter in Guizhou. The result showed that: The ecofilter planted with Canna indica L. achieved the best purification abilities of COD, NH3-N and TP, the removal efficiencies were up to 88% and 92% and 47%. The ecofilter planted with Canna indica L. and Cyperus alternifolius achieved the best purification ability of TN with the highest removal efficiency of 49%. The microbial community structures in different ecofilters were very similar. The main components were Proteobacteria, Chloroflexi and Acidobacteria. The biological diversity of nitrobacteria was low, mainly ammonia oxidizing bacteria. The biological diversity of denitrifying bacteria was high. The aerobiotic denitrifying bacteria was also detected.
2020, 38(11): 91-97.
doi: 10.13205/j.hjgc.202011015
Abstract:
Biochar, as an environmentally friendly adsorbent, can effectively remove and recover phosphorus from water. Therefore, it has become the research hotspot. In this paper, the current research progress of phosphate adsorption and recovery at home and abroad were reviewed. Four main mechanisms for controlling the adsorption of phosphate by biochar were summarized, and the main influencing factors in the process of phosphorus removal by biochar were described. The direction of applied research was introduced and the problems of biochar in practical application were put forward. Suggestion on the future research was proposed in order to provide theoretical support for future research and application.
Biochar, as an environmentally friendly adsorbent, can effectively remove and recover phosphorus from water. Therefore, it has become the research hotspot. In this paper, the current research progress of phosphate adsorption and recovery at home and abroad were reviewed. Four main mechanisms for controlling the adsorption of phosphate by biochar were summarized, and the main influencing factors in the process of phosphorus removal by biochar were described. The direction of applied research was introduced and the problems of biochar in practical application were put forward. Suggestion on the future research was proposed in order to provide theoretical support for future research and application.
2020, 38(11): 98-102,109.
doi: 10.13205/j.hjgc.202011016
Abstract:
In order to study the effect of high concentration of phosphorus on anammox efficiency and sludge characteristics, a UASB reactor was used for continuous test to investigate the nitrogen removal efficiency of anammox at different phosphorus concentrations. The surface morphology and element composition of granular sludge were analyzed by SEM and EDS. The results showed that: when the phosphorus concentration reached 600 mg P/L, it began to inhibit the nitrogen removal efficiency of ANAMMOX, and 700 mg P/L inhibited 91.86% of the nitrogen removal efficiency of Anammox; NRR recovered completely after 10 days of phosphorus reduction; with the increase of phosphorus concentration in the influent, the retention of phosphorus in the reactor decreased. The high concentration of P resulted in the formation of white solid on the surface of granular sludge at the bottom of the reactor, which was composed of C, O, P and Ca, insoluble compounds such as hydroxyapatite and calcium phosphate. The results of EDS showed that the number percentage of O, P, C and Ca atoms in the solid was 41.89%, 21.78%, 14.41% and 10.82%, respectively.
In order to study the effect of high concentration of phosphorus on anammox efficiency and sludge characteristics, a UASB reactor was used for continuous test to investigate the nitrogen removal efficiency of anammox at different phosphorus concentrations. The surface morphology and element composition of granular sludge were analyzed by SEM and EDS. The results showed that: when the phosphorus concentration reached 600 mg P/L, it began to inhibit the nitrogen removal efficiency of ANAMMOX, and 700 mg P/L inhibited 91.86% of the nitrogen removal efficiency of Anammox; NRR recovered completely after 10 days of phosphorus reduction; with the increase of phosphorus concentration in the influent, the retention of phosphorus in the reactor decreased. The high concentration of P resulted in the formation of white solid on the surface of granular sludge at the bottom of the reactor, which was composed of C, O, P and Ca, insoluble compounds such as hydroxyapatite and calcium phosphate. The results of EDS showed that the number percentage of O, P, C and Ca atoms in the solid was 41.89%, 21.78%, 14.41% and 10.82%, respectively.
2020, 38(11): 103-109.
doi: 10.13205/j.hjgc.202011017
Abstract:
The microbial community structure of rhizosphere soils in four groups of constructed wetlands were analyzed by phospholipid fatty acid (PLFAs) biomarker method. The results showed that the total amount of phospholipid fatty acid biomarker (PLFAs) in rhizosphere soil of four groups varied from 1322 μg/g to 2769 μg/g, and the range of PLFAs sorts number varied from 18 to 30. PLFAs in wetland plant rhizosphere soil mainly contained saturated fatty acids and monounsaturated fatty acids. The content of bacteria in plant rhizosphere soil was the highest, and the content of well-nourished bacteria was significantly higher than that of anaerobes. The total amount of PLFAs and the design and operation parameters of wetland were analyzed by Pearson correlation analysis. The results showed that the content of PLFAs was positively correlated with matrix porosity and influent water quality.
The microbial community structure of rhizosphere soils in four groups of constructed wetlands were analyzed by phospholipid fatty acid (PLFAs) biomarker method. The results showed that the total amount of phospholipid fatty acid biomarker (PLFAs) in rhizosphere soil of four groups varied from 1322 μg/g to 2769 μg/g, and the range of PLFAs sorts number varied from 18 to 30. PLFAs in wetland plant rhizosphere soil mainly contained saturated fatty acids and monounsaturated fatty acids. The content of bacteria in plant rhizosphere soil was the highest, and the content of well-nourished bacteria was significantly higher than that of anaerobes. The total amount of PLFAs and the design and operation parameters of wetland were analyzed by Pearson correlation analysis. The results showed that the content of PLFAs was positively correlated with matrix porosity and influent water quality.
2020, 38(11): 110-116,134.
doi: 10.13205/j.hjgc.202011018
Abstract:
The effects of nitrogen and phosphorus concentrations on the growth, chlorophyll fluorescence parameters (Fv/Fm、α、rETRmax、IK) and the ratio of carotenoid to chlorophyll a of Pseudanabaena sp. were investigated. Moreover, the Pseudanabaena sp. growth kinetics utilizing nitrogen and phosphorus was demonstrated through Monod equation and Droop equation. The semi-saturation constants, KsP of total phosphorus, intracellular phosphorus share and the semi-saturation constants KsN of total nitrogen were calculated. The results showed that the effects of different nitrogen and phosphorus concentrations on the growth of Pseudanabaena sp. were significant(P<0.01). The chlorophyll a of Pseudanabaena sp. was positively correlated with nitrogen concentration ranging from 0 to 230.4 mg/L, and phosphorus concentration higher than 5.12 mg/L inhibited the growth of Pseudanabaena sp. The chlorophyll fluorescence parameters were significantly affected by different nitrogen concentrations (P<0.05). Concentrations of phosphorus had a significant effect on Fv/Fm、IK and no significant effect on rETRmax, α (P>0.05). KsP was far less than KsN, which proved that Pseudanabaena sp. had better affinity for phosphorus. The minimum share of intracellular phosphorus for Pseudanabaena sp. was 0.0486 μg/mg, under which the proliferation of algal cells will cease. The ratio of carotenoid to chlorophyll a was negatively correlated with the concentration of nitrogen and phosphorus.
The effects of nitrogen and phosphorus concentrations on the growth, chlorophyll fluorescence parameters (Fv/Fm、α、rETRmax、IK) and the ratio of carotenoid to chlorophyll a of Pseudanabaena sp. were investigated. Moreover, the Pseudanabaena sp. growth kinetics utilizing nitrogen and phosphorus was demonstrated through Monod equation and Droop equation. The semi-saturation constants, KsP of total phosphorus, intracellular phosphorus share and the semi-saturation constants KsN of total nitrogen were calculated. The results showed that the effects of different nitrogen and phosphorus concentrations on the growth of Pseudanabaena sp. were significant(P<0.01). The chlorophyll a of Pseudanabaena sp. was positively correlated with nitrogen concentration ranging from 0 to 230.4 mg/L, and phosphorus concentration higher than 5.12 mg/L inhibited the growth of Pseudanabaena sp. The chlorophyll fluorescence parameters were significantly affected by different nitrogen concentrations (P<0.05). Concentrations of phosphorus had a significant effect on Fv/Fm、IK and no significant effect on rETRmax, α (P>0.05). KsP was far less than KsN, which proved that Pseudanabaena sp. had better affinity for phosphorus. The minimum share of intracellular phosphorus for Pseudanabaena sp. was 0.0486 μg/mg, under which the proliferation of algal cells will cease. The ratio of carotenoid to chlorophyll a was negatively correlated with the concentration of nitrogen and phosphorus.
2020, 38(11): 117-122,129.
doi: 10.13205/j.hjgc.202011019
Abstract:
In order to analyze the fixation and oxidation reaction of SO2 in simultaneous removal of SO2 and NOx by Ca(OH)2, and the influence of O2 and NO2 on this progress, DRIFTS(diffuse reflectance infrared Fourier transform spectrometry) and fixed bed reactor were used respectively for composition changes of solid and gas phase at 100 ℃ and 0% RH. The results showed that firstly SO2 was rapidly adsorbed on Ca(OH)2 to form CaSO3, which could hardly be oxidized by O2, but could be oxidized to CaSO4 by NO2. CaSO3 showed selectivity during simultaneous removal process, of which the infrared absorption peak at the position of 930~936 cm-1 first increased and then decreased, while the peak at 980~995 cm-1 monotonically increased.When SO2 and O2 coexisted in the gas, it could react with Ca(OH)2 to form CaSO4. When NO2 and SO2 were simultaneously removed by Ca(OH)2 in the absence of O2, the ratio of produced NO/consumed NO2 was around 1:1, but in the presence of O2, the content of Ca(NO3)2 increased significantly, and the formation rate of CaSO4 was accelarated in the early stage of reation.
In order to analyze the fixation and oxidation reaction of SO2 in simultaneous removal of SO2 and NOx by Ca(OH)2, and the influence of O2 and NO2 on this progress, DRIFTS(diffuse reflectance infrared Fourier transform spectrometry) and fixed bed reactor were used respectively for composition changes of solid and gas phase at 100 ℃ and 0% RH. The results showed that firstly SO2 was rapidly adsorbed on Ca(OH)2 to form CaSO3, which could hardly be oxidized by O2, but could be oxidized to CaSO4 by NO2. CaSO3 showed selectivity during simultaneous removal process, of which the infrared absorption peak at the position of 930~936 cm-1 first increased and then decreased, while the peak at 980~995 cm-1 monotonically increased.When SO2 and O2 coexisted in the gas, it could react with Ca(OH)2 to form CaSO4. When NO2 and SO2 were simultaneously removed by Ca(OH)2 in the absence of O2, the ratio of produced NO/consumed NO2 was around 1:1, but in the presence of O2, the content of Ca(NO3)2 increased significantly, and the formation rate of CaSO4 was accelarated in the early stage of reation.
2020, 38(11): 123-129.
doi: 10.13205/j.hjgc.202011020
Abstract:
The particulate matters in the unorganized emission of flue gas from the blast furnace cast house has the characteristics of scattered pollution sources, wide pollution range, long time and strong paroxysmal occurrence. Because the hot plume that the airflow above the high-temperature molten iron was greatly affected by the ventilation airflow, the existing dust cover design method couldn’t effectively solve the pollution of high temperature smoke and dust. In this study, a two-phase flow model and a numerical simulation method for the diffusion and trapping process of high temperature smoke and dust, in China’s small and medium-sized blast furnace cast house were established. The simulation results showed that the rising velocity of air flow in front of blast furnace increased first and then decreased, forming a typical confined space thermal plume. Because of the gap between the blast furnace and the dust cover of the tapping hole, the bottom airflow produced upward high-speed airflow on the blast furnace wall under the suction action, which made the dust cover had no trapping effect on the airflow between the dust collector and the blast furnace. When only the roof ventilation was used, the heat that could be carried away by ventilation was reduced, because the roof ventilation volume was two-thirds less than that of natural ventilation, which led to the overall temperature in the cast house on the high side. The temperature of the cast house decreased obviously after adding the dust cover. The overall capture rate of particulate matter by the dust cover could reach 89.66%. However, a large number of particles in front of the main ditch escaped, and the capture rate was only 47.71%. The capture rate of particulate matter released from the rear of the hot metal was 86.34%, because it was far from the dust cover. It caused a wide range of pollution, resulting in the working environment of the cast house was not up to the standard at present.
The particulate matters in the unorganized emission of flue gas from the blast furnace cast house has the characteristics of scattered pollution sources, wide pollution range, long time and strong paroxysmal occurrence. Because the hot plume that the airflow above the high-temperature molten iron was greatly affected by the ventilation airflow, the existing dust cover design method couldn’t effectively solve the pollution of high temperature smoke and dust. In this study, a two-phase flow model and a numerical simulation method for the diffusion and trapping process of high temperature smoke and dust, in China’s small and medium-sized blast furnace cast house were established. The simulation results showed that the rising velocity of air flow in front of blast furnace increased first and then decreased, forming a typical confined space thermal plume. Because of the gap between the blast furnace and the dust cover of the tapping hole, the bottom airflow produced upward high-speed airflow on the blast furnace wall under the suction action, which made the dust cover had no trapping effect on the airflow between the dust collector and the blast furnace. When only the roof ventilation was used, the heat that could be carried away by ventilation was reduced, because the roof ventilation volume was two-thirds less than that of natural ventilation, which led to the overall temperature in the cast house on the high side. The temperature of the cast house decreased obviously after adding the dust cover. The overall capture rate of particulate matter by the dust cover could reach 89.66%. However, a large number of particles in front of the main ditch escaped, and the capture rate was only 47.71%. The capture rate of particulate matter released from the rear of the hot metal was 86.34%, because it was far from the dust cover. It caused a wide range of pollution, resulting in the working environment of the cast house was not up to the standard at present.
2020, 38(11): 130-134.
doi: 10.13205/j.hjgc.202011021
Abstract:
In winter, there are serious traffic congestion, high vehicle acceleration and deceleration frequency and high idle speed ratio of vehicles, harsh driving conditions and difficulty in spreading emissions in the cold regions in China. According to the above characteristics, this paper introduced the acceleration and deceleration emission parameters to improve the CAL3QHC model, and used the bench test to modify various basic emission rates under the low temperature condition. According to the field investigation of the urban road traffic characteristics in cold region, this paper revised the IVE model to get the comprehensive emission factors, acceleration emission factors and deceleration emission factors of NOx and PM. Then, the prediction of NOx and PM in the modified model was tested by field investigation and vehicle experiment analysis in Harbin in winter. The results indicated that the relative errors of NOx and PM were reduced by 9.2% and 19.4%.
In winter, there are serious traffic congestion, high vehicle acceleration and deceleration frequency and high idle speed ratio of vehicles, harsh driving conditions and difficulty in spreading emissions in the cold regions in China. According to the above characteristics, this paper introduced the acceleration and deceleration emission parameters to improve the CAL3QHC model, and used the bench test to modify various basic emission rates under the low temperature condition. According to the field investigation of the urban road traffic characteristics in cold region, this paper revised the IVE model to get the comprehensive emission factors, acceleration emission factors and deceleration emission factors of NOx and PM. Then, the prediction of NOx and PM in the modified model was tested by field investigation and vehicle experiment analysis in Harbin in winter. The results indicated that the relative errors of NOx and PM were reduced by 9.2% and 19.4%.
2020, 38(11): 135-139.
doi: 10.13205/j.hjgc.202011022
Abstract:
This study evaluated the environmental risk of lead (Pb) under wetting and drying (W-D) intermittent in fly ash from municipal solid waste incineration (MSWI), co-treated with cement and chelator. The results showed that the mineral composition of the co-treated fly ash kept stable and the hydration degree improved under W-D intermittent. Thus, the environmental risk of Pb got reduced due to the protection by more hydration products. In addition, compared with traditional cement-solidification method, co-treatment was more efficient in stabilizing Pb and easily made Pb meet the standard for pollution control of the landfill site of municipal solid waste (GB 16889—2008); compared with chelator-stabilization, the environmental risk of Pb under W-D intermittent was significantly reduced. Therefore, cement and chelator co-treatment was suitable for the stabilization of Pb in MSWI fly ash in areas with high W-D intermittent incidence.
This study evaluated the environmental risk of lead (Pb) under wetting and drying (W-D) intermittent in fly ash from municipal solid waste incineration (MSWI), co-treated with cement and chelator. The results showed that the mineral composition of the co-treated fly ash kept stable and the hydration degree improved under W-D intermittent. Thus, the environmental risk of Pb got reduced due to the protection by more hydration products. In addition, compared with traditional cement-solidification method, co-treatment was more efficient in stabilizing Pb and easily made Pb meet the standard for pollution control of the landfill site of municipal solid waste (GB 16889—2008); compared with chelator-stabilization, the environmental risk of Pb under W-D intermittent was significantly reduced. Therefore, cement and chelator co-treatment was suitable for the stabilization of Pb in MSWI fly ash in areas with high W-D intermittent incidence.
2020, 38(11): 140-144,151.
doi: 10.13205/j.hjgc.202011023
Abstract:
In order to explore the influence of NaOH dosage acting on the contents of SS, TS, oxytetracycline and COD during alkal-water heat treatment, the alkali dosage was controlled as 0.06 g NaOH/g TS, 0.08 g NaOH/g TS, 0.10 g NaOH/g TS, 0.12 g NaOH/g TS and 0.14 g NaOH/g TS respectively, reacting for 2 h at 120 ℃. Before and after reaction, we measured the contents of TS, SS, oxytetracycline, COD and pH value. It was found that reduction quantity rates of TS and SS in the miscible liquids all increased significantly with the increase of NaOH dosage at first, and then decreased slightly, and all reached the maximum(14.36% and 44.13% respectively ) when the alkali dosage was 0.12 g NaOH/g TS. The change trend of COD dissolution efficiency was similar to the removal efficiency of SS, and the maximum dissolution efficiency (45.82%) was achieved when the alkali dosage was 0.12 g NaOH/g TS. Therefore, the highest cytolytic decrease efficiency of bacterial residue was achieved when the alkali dosage was 0.12 g NaOH/g TS. But the change trend of oxytetracycline reduction efficiency was reversed, as the excessive alkali dosage was not conducive to the removal of oxytetracycline, and the reduction quantities of oxytetracycline reached the peak with an average value of 99.99% when the alkali dosage was 0.08 g NaOH/g TS. The pH value decreased significantly after the reaction, and its extent was positively related to the reduction rates of TS and SS.
In order to explore the influence of NaOH dosage acting on the contents of SS, TS, oxytetracycline and COD during alkal-water heat treatment, the alkali dosage was controlled as 0.06 g NaOH/g TS, 0.08 g NaOH/g TS, 0.10 g NaOH/g TS, 0.12 g NaOH/g TS and 0.14 g NaOH/g TS respectively, reacting for 2 h at 120 ℃. Before and after reaction, we measured the contents of TS, SS, oxytetracycline, COD and pH value. It was found that reduction quantity rates of TS and SS in the miscible liquids all increased significantly with the increase of NaOH dosage at first, and then decreased slightly, and all reached the maximum(14.36% and 44.13% respectively ) when the alkali dosage was 0.12 g NaOH/g TS. The change trend of COD dissolution efficiency was similar to the removal efficiency of SS, and the maximum dissolution efficiency (45.82%) was achieved when the alkali dosage was 0.12 g NaOH/g TS. Therefore, the highest cytolytic decrease efficiency of bacterial residue was achieved when the alkali dosage was 0.12 g NaOH/g TS. But the change trend of oxytetracycline reduction efficiency was reversed, as the excessive alkali dosage was not conducive to the removal of oxytetracycline, and the reduction quantities of oxytetracycline reached the peak with an average value of 99.99% when the alkali dosage was 0.08 g NaOH/g TS. The pH value decreased significantly after the reaction, and its extent was positively related to the reduction rates of TS and SS.
2020, 38(11): 145-151.
doi: 10.13205/j.hjgc.202011024
Abstract:
The machinery manufacturing industry was a pillar industry in China. Especially in the 21st century, machinery manufacturing industry developed rapidly. However, due to the large amount of wastewater, exhaust gas, solid waste and additional pollutants generated during the coating process of machinery equipment in machinery manufacturing, the treatment of manufacturing pollutants had always been the focus of the industry’s environmental governance. This article mainly introduced the solid waste treatment technology and its research progress during the coating process in machinery manufacturing industry. Finally, we believed that the utilization and the harmless treatment of organic solid wastes in coating porcess were the focus of future researches. Only the development model of circular economy could effectively alleviate the pressure on China ’s resource shortage and environmental pollution, and thus ensure the smooth realization of the overall goal of sustainable development.
The machinery manufacturing industry was a pillar industry in China. Especially in the 21st century, machinery manufacturing industry developed rapidly. However, due to the large amount of wastewater, exhaust gas, solid waste and additional pollutants generated during the coating process of machinery equipment in machinery manufacturing, the treatment of manufacturing pollutants had always been the focus of the industry’s environmental governance. This article mainly introduced the solid waste treatment technology and its research progress during the coating process in machinery manufacturing industry. Finally, we believed that the utilization and the harmless treatment of organic solid wastes in coating porcess were the focus of future researches. Only the development model of circular economy could effectively alleviate the pressure on China ’s resource shortage and environmental pollution, and thus ensure the smooth realization of the overall goal of sustainable development.
2020, 38(11): 152-156.
doi: 10.13205/j.hjgc.202011025
Abstract:
Dyeing industry is a traditional labor-intensive industry and with high water-consuming. In China, the dyeing industry is concentrated in Zhejiang and Jiangsu province. Based on the conventional plate-and-frame pressure filtration technology, the sludge of a dyeing industrial park in Wuxi, Jiangsu Province was studied experimentally. According to the research results, a 40 t/d demonstration project of sludge dewatering by high-pressure plate-and-frame pressure filtration was built. All the sludge of the dyeing industrial park were centralized treated and filtered. Sludge water content was less than 60%, which was subsequently sent to coal-fired power plant as the raw material to achieve the purpose of sludge reduction and heat resource recycling. At the same time, the wastewater after pressure filtration process was discharged to the wastewater treatment plant after coagulation sedimentation and three dimensional electrocatalysis, without secondary pollution.
Dyeing industry is a traditional labor-intensive industry and with high water-consuming. In China, the dyeing industry is concentrated in Zhejiang and Jiangsu province. Based on the conventional plate-and-frame pressure filtration technology, the sludge of a dyeing industrial park in Wuxi, Jiangsu Province was studied experimentally. According to the research results, a 40 t/d demonstration project of sludge dewatering by high-pressure plate-and-frame pressure filtration was built. All the sludge of the dyeing industrial park were centralized treated and filtered. Sludge water content was less than 60%, which was subsequently sent to coal-fired power plant as the raw material to achieve the purpose of sludge reduction and heat resource recycling. At the same time, the wastewater after pressure filtration process was discharged to the wastewater treatment plant after coagulation sedimentation and three dimensional electrocatalysis, without secondary pollution.
2020, 38(11): 157-162.
doi: 10.13205/j.hjgc.202011026
Abstract:
After the oil-bearing cuttings were extracted and degreased, the extracted raffinate cuttings were experimentally researched by the muffle furnace to simulate the co-processing of the cement kiln. Through the thermo-gravimetric analysis of the effect of extracted raffinate cuttings’ addition on the roasting process of cement, the results showed that after adding extracted raffinate cuttings, the decomposition temperature of calcium carbonate decreased by 13.2℃, and the addition of extracted raffinate cuttings was beneficial to making cement clinker. By measuring the content of f-CaO in cement clinker using ethylene glycol substitution method, it could be concluded that the proportion of solid waste added of 20% was the most suitable; the results of X-ray diffraction spectrum of cement clinker showed that the main mineral composition of cement clinker roasted with extracted raffinate cuttings was unchanged, but the addition of raffinate solids still affected the formation of cement minerals. At the same time, the results of XRD patterns of hydration samples of cement products showed that the addition of extracted raffinate cuttings would inhibit the cement hydration reaction rate, and the leaching concentration of heavy metals in cement co-processing products with extracted raffinate cuttings complied with safety limit of Technical Specification for Co-processing Solid Waste in Cement Kilns (GB 30760—2014), possessed no environmental safety risk of heavy metal leaching.
After the oil-bearing cuttings were extracted and degreased, the extracted raffinate cuttings were experimentally researched by the muffle furnace to simulate the co-processing of the cement kiln. Through the thermo-gravimetric analysis of the effect of extracted raffinate cuttings’ addition on the roasting process of cement, the results showed that after adding extracted raffinate cuttings, the decomposition temperature of calcium carbonate decreased by 13.2℃, and the addition of extracted raffinate cuttings was beneficial to making cement clinker. By measuring the content of f-CaO in cement clinker using ethylene glycol substitution method, it could be concluded that the proportion of solid waste added of 20% was the most suitable; the results of X-ray diffraction spectrum of cement clinker showed that the main mineral composition of cement clinker roasted with extracted raffinate cuttings was unchanged, but the addition of raffinate solids still affected the formation of cement minerals. At the same time, the results of XRD patterns of hydration samples of cement products showed that the addition of extracted raffinate cuttings would inhibit the cement hydration reaction rate, and the leaching concentration of heavy metals in cement co-processing products with extracted raffinate cuttings complied with safety limit of Technical Specification for Co-processing Solid Waste in Cement Kilns (GB 30760—2014), possessed no environmental safety risk of heavy metal leaching.
2020, 38(11): 163-167,174.
doi: 10.13205/j.hjgc.202011027
Abstract:
In this paper, the efficient separation and leaching of Ti, V and W elements in the waste SCR denitration catalyst were carried out by the dry-wet method, and the recovery technology of Ti, V and W in the waste SCR denitration catalyst was proposed. Taking waste SCR denitration catalyst as the research object, the leaching conditions of Ti, V and W elements were optimized, and the recovery rate and purity of TiO2 recovered by sulfuric acid dissolution method and V2O5 and WO3 recovered by organic extraction method were also researched. The results showed that the optimal process conditions for acid leaching and reduction of vanadium were temperature of 140 ℃, liquid-solid ratio of 30:1; and the optimal process conditions for sodium roasting and leaching of tungsten were roasting temperature of 750 ℃, reactants and Na2CO3 ratio of 1:1.5. Under the above reaction conditions, the leaching rates of V and W were 97.6% and 93.6%, respectively. The TiO2 product recovered by the sulfuric acid dissolution method mainly existed in the form of anatase crystal. At the optimum roasting temperature of 750 ℃, the recovery rate of TiO2 was 97.17% and the purity rate was 95.35%. The recovery and purity rate of the V2O5 and WO3 products recovered by the organic extraction method were 72.47%, 75.43%, and 93.25%, 78.26%, respectively.
In this paper, the efficient separation and leaching of Ti, V and W elements in the waste SCR denitration catalyst were carried out by the dry-wet method, and the recovery technology of Ti, V and W in the waste SCR denitration catalyst was proposed. Taking waste SCR denitration catalyst as the research object, the leaching conditions of Ti, V and W elements were optimized, and the recovery rate and purity of TiO2 recovered by sulfuric acid dissolution method and V2O5 and WO3 recovered by organic extraction method were also researched. The results showed that the optimal process conditions for acid leaching and reduction of vanadium were temperature of 140 ℃, liquid-solid ratio of 30:1; and the optimal process conditions for sodium roasting and leaching of tungsten were roasting temperature of 750 ℃, reactants and Na2CO3 ratio of 1:1.5. Under the above reaction conditions, the leaching rates of V and W were 97.6% and 93.6%, respectively. The TiO2 product recovered by the sulfuric acid dissolution method mainly existed in the form of anatase crystal. At the optimum roasting temperature of 750 ℃, the recovery rate of TiO2 was 97.17% and the purity rate was 95.35%. The recovery and purity rate of the V2O5 and WO3 products recovered by the organic extraction method were 72.47%, 75.43%, and 93.25%, 78.26%, respectively.
2020, 38(11): 168-174.
doi: 10.13205/j.hjgc.202011028
Abstract:
Ultrasound, microwave and alkali-thermal pretreatment were applied for enhancing biogas production by anaerobic co-digestion of garden waste, kitchen waste and fruit and vegetable waste. The experiment without pretreatment served as the control. The results showed that pH values of the four experiments rapidly decreased to 7.24~7.45 within 2 days and then increased to 7.7~8.0 at the end of reactions, indicating that anaerobic digestion systems were relatively stable. The concentrations of VFA reached the maximum within 2~4 days, of which acetic acid and propionic acid were the main components, accounting for more than 70%. After 13 days, VFA concentrations decreased to below 500 mg/L, and mainly acetic acid remained. There were some fluctuations of TAN concentrations during the first 4 days, which then gradually increased to 2190~2410 mg/L at the end. While the concentrations of FAN firstly decreased, then increased and stabilized to 144~209 mg/L after 13 days. The proportion of methane in biogas all exceeded 50% after the 2nd day and reached the maximum value of 61.4%~63.8% on the 11th~12th day. According to simulation results of the modified Gomperts model, pretreatments could shorten the adaption period and enhance gas production at early stage. Ultrasonic pretreatment and alkali-thermal pretreatment could significantly increase the methane yield, from 396 mL CH4/g VS to 601 mL CH4/g VS, 536 mL CH4/g VS, respectively, while microwave pretreatment slightly decreased the methane yield.
Ultrasound, microwave and alkali-thermal pretreatment were applied for enhancing biogas production by anaerobic co-digestion of garden waste, kitchen waste and fruit and vegetable waste. The experiment without pretreatment served as the control. The results showed that pH values of the four experiments rapidly decreased to 7.24~7.45 within 2 days and then increased to 7.7~8.0 at the end of reactions, indicating that anaerobic digestion systems were relatively stable. The concentrations of VFA reached the maximum within 2~4 days, of which acetic acid and propionic acid were the main components, accounting for more than 70%. After 13 days, VFA concentrations decreased to below 500 mg/L, and mainly acetic acid remained. There were some fluctuations of TAN concentrations during the first 4 days, which then gradually increased to 2190~2410 mg/L at the end. While the concentrations of FAN firstly decreased, then increased and stabilized to 144~209 mg/L after 13 days. The proportion of methane in biogas all exceeded 50% after the 2nd day and reached the maximum value of 61.4%~63.8% on the 11th~12th day. According to simulation results of the modified Gomperts model, pretreatments could shorten the adaption period and enhance gas production at early stage. Ultrasonic pretreatment and alkali-thermal pretreatment could significantly increase the methane yield, from 396 mL CH4/g VS to 601 mL CH4/g VS, 536 mL CH4/g VS, respectively, while microwave pretreatment slightly decreased the methane yield.
2020, 38(11): 175-179,186.
doi: 10.13205/j.hjgc.202011029
Abstract:
With electrolytic manganese slag as raw material, after the weak acid complexing, activation of alkali-melt, aging at room temperature and crystallization of hydrothermal synthesis system, analcite ANA-A and ANA-S was prepared by adding aluminum and silicon respectively. Performance of the two kinds of analcime such as chemical composition, crystal phase structure, microstructure, and specific surface area were analyzed by using characterization methods of XRF, XRD, SEM, EDS and BET. The results showed that the analcite could be successfully synthesized with both the addition of aluminum and silicon at the calcination temperature of 750 ℃, the synthesis temperature of 180 ℃, and the hydrothermal reaction time of 8 h. Further study on two kinds of zeolite Pb2+ in aqueous solution of static adsorption showed that ANA-A and ANA-S could fitting Langmuir isotherm model well, accorded to the monolayer adsorption. Their saturated adsorption capacity were 161.29 mg/g and 185.19 mg/g, and the initial concentration of 100 mg/L of Pb2+ removal rate reached 93.69% and 95.47% respectively, comlied with the lagergren quasi-second order kinetics model, and were defined as chemical adsorption. ANA-S has better adsorption effect between the two adsorbers.
With electrolytic manganese slag as raw material, after the weak acid complexing, activation of alkali-melt, aging at room temperature and crystallization of hydrothermal synthesis system, analcite ANA-A and ANA-S was prepared by adding aluminum and silicon respectively. Performance of the two kinds of analcime such as chemical composition, crystal phase structure, microstructure, and specific surface area were analyzed by using characterization methods of XRF, XRD, SEM, EDS and BET. The results showed that the analcite could be successfully synthesized with both the addition of aluminum and silicon at the calcination temperature of 750 ℃, the synthesis temperature of 180 ℃, and the hydrothermal reaction time of 8 h. Further study on two kinds of zeolite Pb2+ in aqueous solution of static adsorption showed that ANA-A and ANA-S could fitting Langmuir isotherm model well, accorded to the monolayer adsorption. Their saturated adsorption capacity were 161.29 mg/g and 185.19 mg/g, and the initial concentration of 100 mg/L of Pb2+ removal rate reached 93.69% and 95.47% respectively, comlied with the lagergren quasi-second order kinetics model, and were defined as chemical adsorption. ANA-S has better adsorption effect between the two adsorbers.
2020, 38(11): 180-186.
doi: 10.13205/j.hjgc.202011030
Abstract:
In this paper, On the basis of calculating the liquidus temperatures and viscosities of the slag system CaO-SiO2-Al2O3-MgO-FeO-Na2O-K2O, slag fiber was successfully prepared from blast furnace slag and coal ash by the high-speed air-injection method. The effect of factors such as mass ratio of blast furnace slag to coal ash (slag/coal), air-injection temperature and pressure was investigated in detail. While the air-injection experiment was carried out at 1450 ℃, the slag/coal was increased from 20% to 60%, the diameter of the slag fibers was subsequently decreased from 18.08 μm to 6.03 μm. the slag/coal was increased from 60% to 80%, the average fiber diameter was between 5 and 7 μm and the single fiber average tensile strength was about 1085 MPa. However, the glass beads, otherwise fibers, have been prepared if further increased the slag/coal. Hence, high quality mineral wool fibers could be obtained by controlling the addition ratio of the blast furnace slag between 60% and 80%, and the air-injection temperature between 1400 and 1500 ℃.
In this paper, On the basis of calculating the liquidus temperatures and viscosities of the slag system CaO-SiO2-Al2O3-MgO-FeO-Na2O-K2O, slag fiber was successfully prepared from blast furnace slag and coal ash by the high-speed air-injection method. The effect of factors such as mass ratio of blast furnace slag to coal ash (slag/coal), air-injection temperature and pressure was investigated in detail. While the air-injection experiment was carried out at 1450 ℃, the slag/coal was increased from 20% to 60%, the diameter of the slag fibers was subsequently decreased from 18.08 μm to 6.03 μm. the slag/coal was increased from 60% to 80%, the average fiber diameter was between 5 and 7 μm and the single fiber average tensile strength was about 1085 MPa. However, the glass beads, otherwise fibers, have been prepared if further increased the slag/coal. Hence, high quality mineral wool fibers could be obtained by controlling the addition ratio of the blast furnace slag between 60% and 80%, and the air-injection temperature between 1400 and 1500 ℃.
2020, 38(11): 187-195.
doi: 10.13205/j.hjgc.202011031
Abstract:
The presence of chromium in industrial wastes is a potential hazard to the environment and humans. Bioadsorption remediation technology has become one of the most promising technologies for removing toxic metals from contaminated sites for its technical feasibility, low cost and low environmental impact. This review introduced the source of chromium contamination, the main species of interest and their toxicity, and discussed the classification of chromium adsorption mechanism. The biosorption characteristics of chromium by bacteria, fungi, algae, plants and other modified materials were discussed, and their adsorption mechanism and main influencing factors were explained respectively. It was proposed that the research of biosorption mechanism, the optimization of biosorption parameters, and the chemical modification of biosorbents were the key points to realize the large-scale application of biosorption remediation technology.
The presence of chromium in industrial wastes is a potential hazard to the environment and humans. Bioadsorption remediation technology has become one of the most promising technologies for removing toxic metals from contaminated sites for its technical feasibility, low cost and low environmental impact. This review introduced the source of chromium contamination, the main species of interest and their toxicity, and discussed the classification of chromium adsorption mechanism. The biosorption characteristics of chromium by bacteria, fungi, algae, plants and other modified materials were discussed, and their adsorption mechanism and main influencing factors were explained respectively. It was proposed that the research of biosorption mechanism, the optimization of biosorption parameters, and the chemical modification of biosorbents were the key points to realize the large-scale application of biosorption remediation technology.
2020, 38(11): 196-202.
doi: 10.13205/j.hjgc.202011032
Abstract:
The effects of walnut shell biochar (BC400, BC500, BC600) on pH and Cd morphology distribution in artificial Cd-contaminated soil (20 mg/kg) were studied through laboratory simulation experiments, and possible repair mechanisms were investigated. The results showed that after 56 days of remediation, compared with the blank control group, with 10% dosage of walnut shell biochar BC400, BC500 and BC600, the soil pH increased by 1.07, 1.31 and 1.38, the content of extractable Cd decreased by 17.02%, 20.20% and 24.53%, the reducible Cd content decreased by 8.9%, 19.1% and 38.2%, the oxidizable Cd content increased by 44.83%, 78.45% and 100%, and the residual Cd content increased by 66.03%, 71.43%, 89.21%. At the same time, there was a significant negative correlation between soil pH and soil extractable Cd content (P<0.01). Walnut shell biochar was proved to have the performance in passivating and repairing Cd-contaminated soil.
The effects of walnut shell biochar (BC400, BC500, BC600) on pH and Cd morphology distribution in artificial Cd-contaminated soil (20 mg/kg) were studied through laboratory simulation experiments, and possible repair mechanisms were investigated. The results showed that after 56 days of remediation, compared with the blank control group, with 10% dosage of walnut shell biochar BC400, BC500 and BC600, the soil pH increased by 1.07, 1.31 and 1.38, the content of extractable Cd decreased by 17.02%, 20.20% and 24.53%, the reducible Cd content decreased by 8.9%, 19.1% and 38.2%, the oxidizable Cd content increased by 44.83%, 78.45% and 100%, and the residual Cd content increased by 66.03%, 71.43%, 89.21%. At the same time, there was a significant negative correlation between soil pH and soil extractable Cd content (P<0.01). Walnut shell biochar was proved to have the performance in passivating and repairing Cd-contaminated soil.
2020, 38(11): 203-210,195.
doi: 10.13205/j.hjgc.202011033
Abstract:
In recent years, the application of nano zero-valent iron (nZVI) on the treatment of Cr(Ⅵ) pollution attracted more and more attention. Biochar-loaded nano zero-valent iron (nZVI@BC), as one of the nano zero-valent iron modification technologies, is with the advantages of low cost, easy preparation and excellent remediation effect. However, the researches on its application on the Cr(Ⅵ) contaminated soil remediation were not sufficient. Plants straw were used in this study to prepare biochar (BC) by pyrolysis process. Biochar-supported nZVI was synthesized by liquid phase reduction or one-step pyrolysis with biochar and nano zero-valent iron. The synthesized nZVI@BC could effectively solve the relative disadvantages of nano-scale zero-valent iron, such as aggregation and passivation, and significantly increased the utilization of nano zero-valent iron (nZVI). In this research, the reaction mechanism and the research progress of nZVI@BC for remediation of Cr(Ⅵ)-contaminated soil, and the ways to improve the performance of the material were summarized as follows: improved BC performance by adjusting BC pyrolysis conditions and modifying BC, appropriate mass ratio (BC/nZVI), improved nZVI stability by polyethylene glycol (PEG), carboxymethyl cellulose (CMC), sludge-derived BC and tea polyphenols (TP). In addition, the material could increase the content of organic matters in the soil, and is with great application prospect in Cr(Ⅵ) remediation.
In recent years, the application of nano zero-valent iron (nZVI) on the treatment of Cr(Ⅵ) pollution attracted more and more attention. Biochar-loaded nano zero-valent iron (nZVI@BC), as one of the nano zero-valent iron modification technologies, is with the advantages of low cost, easy preparation and excellent remediation effect. However, the researches on its application on the Cr(Ⅵ) contaminated soil remediation were not sufficient. Plants straw were used in this study to prepare biochar (BC) by pyrolysis process. Biochar-supported nZVI was synthesized by liquid phase reduction or one-step pyrolysis with biochar and nano zero-valent iron. The synthesized nZVI@BC could effectively solve the relative disadvantages of nano-scale zero-valent iron, such as aggregation and passivation, and significantly increased the utilization of nano zero-valent iron (nZVI). In this research, the reaction mechanism and the research progress of nZVI@BC for remediation of Cr(Ⅵ)-contaminated soil, and the ways to improve the performance of the material were summarized as follows: improved BC performance by adjusting BC pyrolysis conditions and modifying BC, appropriate mass ratio (BC/nZVI), improved nZVI stability by polyethylene glycol (PEG), carboxymethyl cellulose (CMC), sludge-derived BC and tea polyphenols (TP). In addition, the material could increase the content of organic matters in the soil, and is with great application prospect in Cr(Ⅵ) remediation.
2020, 38(11): 211-217.
doi: 10.13205/j.hjgc.202011034
Abstract:
In order to prevent the expansion of the contaminated sites and pollution of groundwater, engineering measures can be taken to enclose the contaminated site around and below. The contaminated soil within the enclosure can be repaired by leaching. Taking the contaminated site left by Qingdao Steam Turbine Co., Ltd. as an example, visual MODFLOW was used to simulate the layout and hydraulic conditions of the optimized water injection and pumping wells, for remediation of contaminated leaching in the enclosed site. Through the technical and economic comparison of 9 groups of injection and pumping well combinations, the optimal spacing of injection and pumping wells was 27 m, the optimal water injection and pumping capacity was 200~300 m3, and the arrangement mode was one injection-five pumping. The economic comparison with the ectopic disposal scheme showed that 7000 m3 contaminated soil was cost limit for the two schemes: the project with earthwork of 7000 m3 above should adopt leaching repair scheme, otherwise, the ectopic treatment method should be considered.
In order to prevent the expansion of the contaminated sites and pollution of groundwater, engineering measures can be taken to enclose the contaminated site around and below. The contaminated soil within the enclosure can be repaired by leaching. Taking the contaminated site left by Qingdao Steam Turbine Co., Ltd. as an example, visual MODFLOW was used to simulate the layout and hydraulic conditions of the optimized water injection and pumping wells, for remediation of contaminated leaching in the enclosed site. Through the technical and economic comparison of 9 groups of injection and pumping well combinations, the optimal spacing of injection and pumping wells was 27 m, the optimal water injection and pumping capacity was 200~300 m3, and the arrangement mode was one injection-five pumping. The economic comparison with the ectopic disposal scheme showed that 7000 m3 contaminated soil was cost limit for the two schemes: the project with earthwork of 7000 m3 above should adopt leaching repair scheme, otherwise, the ectopic treatment method should be considered.
2020, 38(11): 218-225.
doi: 10.13205/j.hjgc.202011035
Abstract:
In order to elucidate the composition, distribution and source characteristics of soil dissolved organic matter (DOM) in coastal wetland, ultraviolet-visible absorption spectrum and excitation-emission matrix spectroscopy combined with parallel factor analysis (PARAFAC) were applied to investigate the DOM in the surface soil of Dongtan in Chongming District, Shanghai. The results indicated that the mean value of DOM absorption coefficient (a(355)) was (13.72±9.47) m-1, which showed a trend of decreasing from high tide beach to low tide beach. The mean value of the spectral slope (S275-295) was (15.22±2.07) μm-1 and it reflected that the soil DOM had a higher molecular weight in the south of the wetland, which was greatly affected by macromolecular organic matter. Three fluorescence components were identified by PARAFAC, including protein-like component named FC1, land-sourced humic-like component named FC2, and authigenic-source humic-like component named FC3. The contribution rates of FC1, FC2 and FC3 to total fluorescence intensity were 40.70%, 23.04% and 36.26%, respectively. Spatially, the peak values of the intensity of three components were observed in the Spartina alterniflora and Phragmites australis wetland, and gradually decreased from the north to the south. Fluorescence index (FI), biogenic index (BIX) and humification index (HIX) showed that the soil DOM in Dongtan was mainly derived from endogenous sources. The fluorescence components were significantly positively correlated with each other, and each component was closely related to the migration and transformation of carbon and nitrogen. Chromophores and fluorophores of DOM shared a common source.
In order to elucidate the composition, distribution and source characteristics of soil dissolved organic matter (DOM) in coastal wetland, ultraviolet-visible absorption spectrum and excitation-emission matrix spectroscopy combined with parallel factor analysis (PARAFAC) were applied to investigate the DOM in the surface soil of Dongtan in Chongming District, Shanghai. The results indicated that the mean value of DOM absorption coefficient (a(355)) was (13.72±9.47) m-1, which showed a trend of decreasing from high tide beach to low tide beach. The mean value of the spectral slope (S275-295) was (15.22±2.07) μm-1 and it reflected that the soil DOM had a higher molecular weight in the south of the wetland, which was greatly affected by macromolecular organic matter. Three fluorescence components were identified by PARAFAC, including protein-like component named FC1, land-sourced humic-like component named FC2, and authigenic-source humic-like component named FC3. The contribution rates of FC1, FC2 and FC3 to total fluorescence intensity were 40.70%, 23.04% and 36.26%, respectively. Spatially, the peak values of the intensity of three components were observed in the Spartina alterniflora and Phragmites australis wetland, and gradually decreased from the north to the south. Fluorescence index (FI), biogenic index (BIX) and humification index (HIX) showed that the soil DOM in Dongtan was mainly derived from endogenous sources. The fluorescence components were significantly positively correlated with each other, and each component was closely related to the migration and transformation of carbon and nitrogen. Chromophores and fluorophores of DOM shared a common source.
