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2020 Vol. 38, No. 12
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2020, 38(12): 1-5.
doi: 10.13205/j.hjgc.202012001
Abstract:
In order to solve the problems existing in traditional centralized treatment system, such as heavy workload, high maintenance cost and resource waste, hydrothermal carbonization in source separation treatment of toilet blackwater was studied. A treatment system of toilet black water based on hydrothermal carbonization was proposed. Subsequently, the test was set up at five temperature gradients of 200, 210, 220, 230, and 240 ℃, and two reaction residence times of 20 min and 30 min. The vacuum filtration time of the reaction product and the moisture content of the filter residue were analyzed and compared. The results showed that the time of vacuum filtration was longer than 3 minutes under the conditions of 200 ℃-20 min, 200 ℃-30 min and 210 ℃-20 min. The remaining reaction conditions were less than one minutes. With the increase of reaction temperature, the water content of filter residue decreased. The cost and energy consumption of the system were estimated with 200 person/day. The system cost and per capita processing cost were 103000 RMB and 0.08 RMB, respectively. Finally, it was pointed out that the solid products could be used as resources, the wastewater and exhaust gas could be treated by vacuum evaporation and catalytic combustion respectively.
In order to solve the problems existing in traditional centralized treatment system, such as heavy workload, high maintenance cost and resource waste, hydrothermal carbonization in source separation treatment of toilet blackwater was studied. A treatment system of toilet black water based on hydrothermal carbonization was proposed. Subsequently, the test was set up at five temperature gradients of 200, 210, 220, 230, and 240 ℃, and two reaction residence times of 20 min and 30 min. The vacuum filtration time of the reaction product and the moisture content of the filter residue were analyzed and compared. The results showed that the time of vacuum filtration was longer than 3 minutes under the conditions of 200 ℃-20 min, 200 ℃-30 min and 210 ℃-20 min. The remaining reaction conditions were less than one minutes. With the increase of reaction temperature, the water content of filter residue decreased. The cost and energy consumption of the system were estimated with 200 person/day. The system cost and per capita processing cost were 103000 RMB and 0.08 RMB, respectively. Finally, it was pointed out that the solid products could be used as resources, the wastewater and exhaust gas could be treated by vacuum evaporation and catalytic combustion respectively.
2020, 38(12): 6-12.
doi: 10.13205/j.hjgc.202012002
Abstract:
One of the main reasons for the blackness and odors of the river is the discharge pollution caused by the serious mixing of the diversion drainage system. An integrative bio-diatomite bioreactor was developed based on A1/O1/A2/O2 process and powdery microorganism technology. The removal efficiency of pollutants in the water was studied under different operation conditions, taking the intercepted sewage of pumping station with great fluctuation of water quality as raw water. Furthermore, we also compared the difference in microbial community structure for dry-weather sewage and wet-weather sewage treatment, respectively. When the concentration of diatomite was 3 g/L, the results indicted that the optimal operation conditions for dry-weather sewage treatment when the inlet sewage flow was 1.5 m3/h were as follows: the DO in the O1 tank between 1.5~2.5 mg/L, internal reflux of 50% and external reflux of 100%, the treated water reached the surface V standard of GB 3838—2002. However, for wet-weather sewage treatment when the inlet sewage was 1.5 m3/h, the optimal operation conditions were as follows: the DO in the O1 tank between 2.5~3.5 mg/L, internal reflux 200% and external reflux 100%, PAC addition amount 23 mg/L and carbon source addition amount equal to 60 mg/L COD, the treated effluent was up to discharge standards Table 2 of main water pollutants for urban sewage treatment plants (DB 33/2169—2018) of Zhejiang province. The results of high-throughput sequencing showed that the dominant phylum, class and species in dry-weather sewage treatment system were Proteobacteria (59.25%), Gammaproteobacteria (31.57%) and Dechloromona (7.76%), respectively. While, for wet-weather sewage treatment system, Proteobacteria (46.02%), Bacteroidia (32.71%), and norank-Saprospiracea (20.65%) were the dominant phylum, class and species. Diatomite played the role of microbial carrier and sink aid, increased the biological viscosity, improved the sludge concentration in the biochemical system, and expanded the treatment scope of the reactor. Bio-diatomite reactor had a good application prospect.
One of the main reasons for the blackness and odors of the river is the discharge pollution caused by the serious mixing of the diversion drainage system. An integrative bio-diatomite bioreactor was developed based on A1/O1/A2/O2 process and powdery microorganism technology. The removal efficiency of pollutants in the water was studied under different operation conditions, taking the intercepted sewage of pumping station with great fluctuation of water quality as raw water. Furthermore, we also compared the difference in microbial community structure for dry-weather sewage and wet-weather sewage treatment, respectively. When the concentration of diatomite was 3 g/L, the results indicted that the optimal operation conditions for dry-weather sewage treatment when the inlet sewage flow was 1.5 m3/h were as follows: the DO in the O1 tank between 1.5~2.5 mg/L, internal reflux of 50% and external reflux of 100%, the treated water reached the surface V standard of GB 3838—2002. However, for wet-weather sewage treatment when the inlet sewage was 1.5 m3/h, the optimal operation conditions were as follows: the DO in the O1 tank between 2.5~3.5 mg/L, internal reflux 200% and external reflux 100%, PAC addition amount 23 mg/L and carbon source addition amount equal to 60 mg/L COD, the treated effluent was up to discharge standards Table 2 of main water pollutants for urban sewage treatment plants (DB 33/2169—2018) of Zhejiang province. The results of high-throughput sequencing showed that the dominant phylum, class and species in dry-weather sewage treatment system were Proteobacteria (59.25%), Gammaproteobacteria (31.57%) and Dechloromona (7.76%), respectively. While, for wet-weather sewage treatment system, Proteobacteria (46.02%), Bacteroidia (32.71%), and norank-Saprospiracea (20.65%) were the dominant phylum, class and species. Diatomite played the role of microbial carrier and sink aid, increased the biological viscosity, improved the sludge concentration in the biochemical system, and expanded the treatment scope of the reactor. Bio-diatomite reactor had a good application prospect.
2020, 38(12): 13-18,85.
doi: 10.13205/j.hjgc.202012003
Abstract:
The simulated water-based ink wastewater was treated by micro nano bubble aeration. The effects of different initial pH value, NaCl dosage and H2O2 dosage on the treatment of ink wastewater by micro nano air floatation were discussed by taking the dye concentration, COD and ammonia nitrogen removal efficiency as the inspection indexes. The experimental results showed that the micro nano air flotation could achieve better results in the removal of ink wastewater pollutants, and different reaction conditions could effectively promote the aeration adsorption of micro nano bubbles, among which the treatment effect was the best under the condition of pH 5, the removal rate of dye concentration and COD were over 90.0%, and the removal rate of ammonia nitrogen was 75.4%.
The simulated water-based ink wastewater was treated by micro nano bubble aeration. The effects of different initial pH value, NaCl dosage and H2O2 dosage on the treatment of ink wastewater by micro nano air floatation were discussed by taking the dye concentration, COD and ammonia nitrogen removal efficiency as the inspection indexes. The experimental results showed that the micro nano air flotation could achieve better results in the removal of ink wastewater pollutants, and different reaction conditions could effectively promote the aeration adsorption of micro nano bubbles, among which the treatment effect was the best under the condition of pH 5, the removal rate of dye concentration and COD were over 90.0%, and the removal rate of ammonia nitrogen was 75.4%.
2020, 38(12): 19-25,31.
doi: 10.13205/j.hjgc.202012004
Abstract:
Extracellular polymeric substances (EPS) are the essential components of sludge, which influence sludge dewaterability and methane productivity. In this study, the roles played by different EPS fractions in methane production of sludge were investigated. Results demonstrated that combined acid-alkali microwave pretreatment dissolved the intracellular organic matters and changed the distribution of EPS, and furthermore enhanced methanogenesis. The optimal conditions were observed to be pH=10, 500 W microwave and 120 s, and then the concentration of soluble chemical oxygen demand (SCOD) in S-EPS reached 11460 mg/L, increased by 84.5% compared with the control. The accumulative methane production approached 89.08 mL/g-VS, whose increase rate was 59.9%. At pH=10, 12, the contribution of S-EPS to methane production accounted for 16.6% and 30.4%, respectively, much higher than LB-EPS and TB-EPS. During the anaerobic digestion process, the contribution of S-EPS rapidly increased in the first four days and then slightly and constantly decreased in the following days. Therefore, acid-alkali pretreatment combined with microwave accelerated the methane production of sludge by enhancing the release of polysaccharide and protein from sludge flocs into S-EPS fraction.
Extracellular polymeric substances (EPS) are the essential components of sludge, which influence sludge dewaterability and methane productivity. In this study, the roles played by different EPS fractions in methane production of sludge were investigated. Results demonstrated that combined acid-alkali microwave pretreatment dissolved the intracellular organic matters and changed the distribution of EPS, and furthermore enhanced methanogenesis. The optimal conditions were observed to be pH=10, 500 W microwave and 120 s, and then the concentration of soluble chemical oxygen demand (SCOD) in S-EPS reached 11460 mg/L, increased by 84.5% compared with the control. The accumulative methane production approached 89.08 mL/g-VS, whose increase rate was 59.9%. At pH=10, 12, the contribution of S-EPS to methane production accounted for 16.6% and 30.4%, respectively, much higher than LB-EPS and TB-EPS. During the anaerobic digestion process, the contribution of S-EPS rapidly increased in the first four days and then slightly and constantly decreased in the following days. Therefore, acid-alkali pretreatment combined with microwave accelerated the methane production of sludge by enhancing the release of polysaccharide and protein from sludge flocs into S-EPS fraction.
2020, 38(12): 26-31.
doi: 10.13205/j.hjgc.202012005
Abstract:
In this work, a nano MnO2 microsphere with high large specific surface area has been successfully prepared by a facile hydrothermal process. Then it was used to replace Fe2+ in Fenton reagent. Methylene blue (MB) was degraded by electro-like Fenton reaction. The experimental results showed that when the initial concentration of methylene blue solution was 30 mg/L, the optimal degradation condition was voltage of 5.3 V, 80 mg/L MnO2, H2O2 solution content of 20.4 g/L, pH of 4. Then the degradation rate of MB reached 94.08% within 40 min.The changes of MnO2 before and after the reaction were discussed and the reaction mechanism was proposed.This study could provide theoretical basis and guidance for electro-Fenton technology in practical application.
In this work, a nano MnO2 microsphere with high large specific surface area has been successfully prepared by a facile hydrothermal process. Then it was used to replace Fe2+ in Fenton reagent. Methylene blue (MB) was degraded by electro-like Fenton reaction. The experimental results showed that when the initial concentration of methylene blue solution was 30 mg/L, the optimal degradation condition was voltage of 5.3 V, 80 mg/L MnO2, H2O2 solution content of 20.4 g/L, pH of 4. Then the degradation rate of MB reached 94.08% within 40 min.The changes of MnO2 before and after the reaction were discussed and the reaction mechanism was proposed.This study could provide theoretical basis and guidance for electro-Fenton technology in practical application.
2020, 38(12): 32-37,44.
doi: 10.13205/j.hjgc.202012006
Abstract:
The long-and short-term effects of temperature change on partial nitrification granules was investigated. The results showed that nitrite accumulation efficiency and ammonium removal loading rates of the granular reactor were stably maintained at above 95% and 0.18~0.25 kg/(m3·L), when treating the influent of (35.8±5.2) mg/L with hydraulic retention time of 2.0 h at 7~17 ℃. The low DO/NH4+-N ratio (<0.25) caused the efficient nitrite oxidizing bacteria (NOB) repression in the granular reactor. Though the lowering temperature caused the decrease of specific ammonia oxidation rates (SAOR) of partial nitrification granules from (237±14) g/(g·d) (at 17 ℃) to (93±11) g/(g·d) (at 8 ℃), the active AOB ratio (the ratio between actual SAOR and maximal SAOR of granules) increased from 48% to 85%. Batch tests results indicated that the temperature coefficient (θ) and activation energy (Ea) of the ammonia oxidizing bacteria (AOB) living in the granules was around 1.042~1.063, 29.7~41.9 kJ/mol respectively from 7.1 ℃ to 28 ℃, which were lower than that reported in flocculent sludge systems. These results suggested that the AOB living in the granules were less influenced by low temperatures than that living in the flocs. The research could provide practical support for the development of high-rate nitritation technology for municipal wastewater treatment with granular sludge.
The long-and short-term effects of temperature change on partial nitrification granules was investigated. The results showed that nitrite accumulation efficiency and ammonium removal loading rates of the granular reactor were stably maintained at above 95% and 0.18~0.25 kg/(m3·L), when treating the influent of (35.8±5.2) mg/L with hydraulic retention time of 2.0 h at 7~17 ℃. The low DO/NH4+-N ratio (<0.25) caused the efficient nitrite oxidizing bacteria (NOB) repression in the granular reactor. Though the lowering temperature caused the decrease of specific ammonia oxidation rates (SAOR) of partial nitrification granules from (237±14) g/(g·d) (at 17 ℃) to (93±11) g/(g·d) (at 8 ℃), the active AOB ratio (the ratio between actual SAOR and maximal SAOR of granules) increased from 48% to 85%. Batch tests results indicated that the temperature coefficient (θ) and activation energy (Ea) of the ammonia oxidizing bacteria (AOB) living in the granules was around 1.042~1.063, 29.7~41.9 kJ/mol respectively from 7.1 ℃ to 28 ℃, which were lower than that reported in flocculent sludge systems. These results suggested that the AOB living in the granules were less influenced by low temperatures than that living in the flocs. The research could provide practical support for the development of high-rate nitritation technology for municipal wastewater treatment with granular sludge.
2020, 38(12): 38-44.
doi: 10.13205/j.hjgc.202012007
Abstract:
The study selected 160 inlet and outlet water treatment facilities in rural areas under Jiaxing City as the research object, and analyzed the spatial and temporal distribution characteristics of rural domestic sewage pollutants and the status of treatment facilities in order to improve the efficiency of treatment facilities. The results showed that the nitrogen and phosphorus pollution in rural domestic sewage in Jiaxing was more serious than organic pollution. The annual average values of ρ(COD), ρ(TP), ρ(TN) and ρ(NH4+-N) were 142.23, 4.02, 44.19 and 27.74 mg/L, respectively. And there was a large optimization space for the treatment effect of each sewage treatment facility. The annual removal rates of COD, TP, TN and NH4+-N were 50.5%, 29.7%, 36.8% and 51.7%, respectively. The spatial distribution of rural domestic sewage gradually decreased from west to east and from north to south. And the temporal distribution was in the sequence of winter > spring > autumn > summer. Correlation analysis showed that there was a significant positive correlation between COD, TP, TN and NH4+-N (P<0.01), and the correlation coefficient was between 0.688±0.946. The annual carbon-nitrogen ratio and NH4+-N/TN ratio of the influent water in the facility are 3.21 and 68.9%, respectively. The traditional single A2/O treatment process was proved not ideal for the treatment of low-carbon source wastewater. and the treatment effect of sewage treatment facilities can be further enhanced by combining process design, standardizing operation management, and strengthening post-monitoring work in the future.
The study selected 160 inlet and outlet water treatment facilities in rural areas under Jiaxing City as the research object, and analyzed the spatial and temporal distribution characteristics of rural domestic sewage pollutants and the status of treatment facilities in order to improve the efficiency of treatment facilities. The results showed that the nitrogen and phosphorus pollution in rural domestic sewage in Jiaxing was more serious than organic pollution. The annual average values of ρ(COD), ρ(TP), ρ(TN) and ρ(NH4+-N) were 142.23, 4.02, 44.19 and 27.74 mg/L, respectively. And there was a large optimization space for the treatment effect of each sewage treatment facility. The annual removal rates of COD, TP, TN and NH4+-N were 50.5%, 29.7%, 36.8% and 51.7%, respectively. The spatial distribution of rural domestic sewage gradually decreased from west to east and from north to south. And the temporal distribution was in the sequence of winter > spring > autumn > summer. Correlation analysis showed that there was a significant positive correlation between COD, TP, TN and NH4+-N (P<0.01), and the correlation coefficient was between 0.688±0.946. The annual carbon-nitrogen ratio and NH4+-N/TN ratio of the influent water in the facility are 3.21 and 68.9%, respectively. The traditional single A2/O treatment process was proved not ideal for the treatment of low-carbon source wastewater. and the treatment effect of sewage treatment facilities can be further enhanced by combining process design, standardizing operation management, and strengthening post-monitoring work in the future.
2020, 38(12): 49-53,111.
doi: 10.13205/j.hjgc.202012009
Abstract:
In order to explore the effect of the emerging pollutants brominated flame retardant (BFR) on the biological nitrogen and phosphorus removal (BNPR), an anaerobic/aerobic/anoxic sequencing batch reactor was established to study the effect of different concentrations of polybrominated diphenyl ether (PBDEs) on the BNPR. The results showed that the effect of PBDEs on BNPR was concentration dependent. Low concentration PBDEs had no significant effect on BNPR and sludge characteristics, but more than 0.1 mg/L PBDEs inhibited BNPR significantly. When the concentration of PBDEs was 2.0 mg/L, the removal efficiency of chemical oxygen demand (COD), ammonia nitrogen and ortho-phosphate (OP) were 73.2%~75.6%, 85.2% and 72.1%~73.6%, respectively, which were significantly lower than those of the blank group. In addition, PBDEs reduced the total suspended solids (TSS) and volatile suspended solids (VSS) in the sludge, and increased the sludge volume index (SVI) and extracellular polymer content. PBDEs inhibited nitrification, denitrification, anaerobic phosphorus release and aerobic phosphorus uptake.
In order to explore the effect of the emerging pollutants brominated flame retardant (BFR) on the biological nitrogen and phosphorus removal (BNPR), an anaerobic/aerobic/anoxic sequencing batch reactor was established to study the effect of different concentrations of polybrominated diphenyl ether (PBDEs) on the BNPR. The results showed that the effect of PBDEs on BNPR was concentration dependent. Low concentration PBDEs had no significant effect on BNPR and sludge characteristics, but more than 0.1 mg/L PBDEs inhibited BNPR significantly. When the concentration of PBDEs was 2.0 mg/L, the removal efficiency of chemical oxygen demand (COD), ammonia nitrogen and ortho-phosphate (OP) were 73.2%~75.6%, 85.2% and 72.1%~73.6%, respectively, which were significantly lower than those of the blank group. In addition, PBDEs reduced the total suspended solids (TSS) and volatile suspended solids (VSS) in the sludge, and increased the sludge volume index (SVI) and extracellular polymer content. PBDEs inhibited nitrification, denitrification, anaerobic phosphorus release and aerobic phosphorus uptake.
2020, 38(12): 54-58,77.
doi: 10.13205/j.hjgc.202012010
Abstract:
In order to improve quantitative reduction of the landfill leachate membrane concentrate, the nanofiltration membrane concentrate was treated by lime coagulation-submerged evaporation, and the change rule of water quality was obtained. The results showed that in the lime-coagulation treatment alone, the softening effect of membrane concentration was best when the dosage of lime was 2 g/L; with the increase of lime dosage, the pH of the membrane concentrate, and the removal rate of COD, NH3-N, and metal ions (Fe3+, Mg2+, Al3+, K+ and Na+) increased. In lime coagulation-immersion evaporation synergistic treatment, when the dosage of lime was 2 g/L and the concentration ratio was 10, compared to coagulation alone, the softening effect of evaporation residue liquid was further improved, with hardness removal rate increased from 29.1% to 65.9%, COD removal rate increased from 24.1% to 41.2%, NH3-N removal rate increased from 39% to 81.4%, and K+ and Na+ concentration increased from 4300,5860 mg/L to 36210, 48300 mg/L, respectively. That provided conducive condition for the latter resource utilization. COD concentration in the condensate decreased from 26.3 mg/L to 16.3 mg/L, and NH3-N decreased from 2.0 mg/L to 1.4 mg/L, complying with the relevant requirements of the Control Standard for Domestic Waste Landfill (GB 16889—2008).
In order to improve quantitative reduction of the landfill leachate membrane concentrate, the nanofiltration membrane concentrate was treated by lime coagulation-submerged evaporation, and the change rule of water quality was obtained. The results showed that in the lime-coagulation treatment alone, the softening effect of membrane concentration was best when the dosage of lime was 2 g/L; with the increase of lime dosage, the pH of the membrane concentrate, and the removal rate of COD, NH3-N, and metal ions (Fe3+, Mg2+, Al3+, K+ and Na+) increased. In lime coagulation-immersion evaporation synergistic treatment, when the dosage of lime was 2 g/L and the concentration ratio was 10, compared to coagulation alone, the softening effect of evaporation residue liquid was further improved, with hardness removal rate increased from 29.1% to 65.9%, COD removal rate increased from 24.1% to 41.2%, NH3-N removal rate increased from 39% to 81.4%, and K+ and Na+ concentration increased from 4300,5860 mg/L to 36210, 48300 mg/L, respectively. That provided conducive condition for the latter resource utilization. COD concentration in the condensate decreased from 26.3 mg/L to 16.3 mg/L, and NH3-N decreased from 2.0 mg/L to 1.4 mg/L, complying with the relevant requirements of the Control Standard for Domestic Waste Landfill (GB 16889—2008).
2020, 38(12): 59-63,5.
doi: 10.13205/j.hjgc.202012011
Abstract:
Based on the analysis of the monitoring data of Luoshijiang River, Mijuhe River, and Yong’anjiang River, and the northern lake area of Erhai Lake from 2016 to 2018, this paper explored the pollution characteristics of the rivers entering the northern Erhai Lake and its impact on the northern lake area. The results showed that: 1) TN, TP, COD, and ammonia nitrogen in the monitoring section of North Three Rivers fluctuated between wate quality ranks Ⅱ and Ⅲ. The change in pollutant content during the year showed typical agricultural non-point source pollution characteristics, and was affected by the industrial type in the river basin. 2) During the study period, the primary pollutant in the river was TN, the secondary pollutant was COD in the dry season, and TP in the rainy season. The load into the lake in the rainy season was higher than that in the dry season, and the pollution load on Mijuhe River was greater than that of Luoshijiang River and Yong’anjiang River. The pollution load on North Three Rivers into the lake accounted for 50.1% TN and 59.7% TP of the allowable load in Erhai Lake respectively; 3) The input of phosphorus from rivers entering the lake was an important source of phosphorus in the northern Erhai Lake. The correlation between pollutant concentrations in the northern lake area and the pollution load of nitrogen and phosphorus into the lake was stronger than that in the next month, so the response was delayed. Selecting eco-friendly planting models and controlling the load of nitrogen and phosphorus into the lake from the North Three Rivers was beneficial to protect the water environment.
Based on the analysis of the monitoring data of Luoshijiang River, Mijuhe River, and Yong’anjiang River, and the northern lake area of Erhai Lake from 2016 to 2018, this paper explored the pollution characteristics of the rivers entering the northern Erhai Lake and its impact on the northern lake area. The results showed that: 1) TN, TP, COD, and ammonia nitrogen in the monitoring section of North Three Rivers fluctuated between wate quality ranks Ⅱ and Ⅲ. The change in pollutant content during the year showed typical agricultural non-point source pollution characteristics, and was affected by the industrial type in the river basin. 2) During the study period, the primary pollutant in the river was TN, the secondary pollutant was COD in the dry season, and TP in the rainy season. The load into the lake in the rainy season was higher than that in the dry season, and the pollution load on Mijuhe River was greater than that of Luoshijiang River and Yong’anjiang River. The pollution load on North Three Rivers into the lake accounted for 50.1% TN and 59.7% TP of the allowable load in Erhai Lake respectively; 3) The input of phosphorus from rivers entering the lake was an important source of phosphorus in the northern Erhai Lake. The correlation between pollutant concentrations in the northern lake area and the pollution load of nitrogen and phosphorus into the lake was stronger than that in the next month, so the response was delayed. Selecting eco-friendly planting models and controlling the load of nitrogen and phosphorus into the lake from the North Three Rivers was beneficial to protect the water environment.
2020, 38(12): 64-69,123.
doi: 10.13205/j.hjgc.202012012
Abstract:
CaO2 has been widely used in the in-situ treatment of black-odor rivers sediment. However, most studies focused on the AVS (acidic volatile sulfide) removal effect from the sediment by CaO2, and those focused on other pollution indicators were rare. Through a pilot experiment, the effect of in situ treatment of AVS and organics in black-odor river sediment by CaO2 was investigated. Meanwhile, the color, ORP, pH, heavy metal content and morphology of the sediment were detected. The results showed that in situ treatment of black-odor river sediment pollutants by CaO2 had ideal performance, with the removal rate of AVS reaching 98% above and the content of TOC decreasing by about 0.4%. At the same time, the color of the sediment changed from black to earthen yellow, the ORP increased from -150 mV to about 100 mV, and the pH changed from neutral to alkaline (about pH=11). The addition of CaO2 had no effect on the change of heavy metal content in the sediment, but the heavy metals with relatively stable forms were converted into unstable forms.
CaO2 has been widely used in the in-situ treatment of black-odor rivers sediment. However, most studies focused on the AVS (acidic volatile sulfide) removal effect from the sediment by CaO2, and those focused on other pollution indicators were rare. Through a pilot experiment, the effect of in situ treatment of AVS and organics in black-odor river sediment by CaO2 was investigated. Meanwhile, the color, ORP, pH, heavy metal content and morphology of the sediment were detected. The results showed that in situ treatment of black-odor river sediment pollutants by CaO2 had ideal performance, with the removal rate of AVS reaching 98% above and the content of TOC decreasing by about 0.4%. At the same time, the color of the sediment changed from black to earthen yellow, the ORP increased from -150 mV to about 100 mV, and the pH changed from neutral to alkaline (about pH=11). The addition of CaO2 had no effect on the change of heavy metal content in the sediment, but the heavy metals with relatively stable forms were converted into unstable forms.
2020, 38(12): 70-77.
doi: 10.13205/j.hjgc.202012013
Abstract:
The environmental risks caused by heavy metals have become increasingly serious, and the research on adsorption of heavy metals by sewage sludge-based biochar has attracted more and more attention. Based on current global research status, the adsorption mechanism of sewage sludge-based biochar prepared under different conditions for different heavy metals such as cadmium (Cd), lead (Pb), chromium (Cr), and arsenic (As) were concluded. The adsorption of sludge biochar on most heavy metals in water met the multiple effects of physical and chemical adsorption, and its adsorption performance can be effectively enhanced by increasing effective surface groups and adsorption sites. At the same time, various factors affecting adsorption efficiency were summarized in detail in paper, and the regeneration of sewage sludge-based biochar was explored, and the future research directions of sludge biochar for removing heavy metals in water were prospected.
The environmental risks caused by heavy metals have become increasingly serious, and the research on adsorption of heavy metals by sewage sludge-based biochar has attracted more and more attention. Based on current global research status, the adsorption mechanism of sewage sludge-based biochar prepared under different conditions for different heavy metals such as cadmium (Cd), lead (Pb), chromium (Cr), and arsenic (As) were concluded. The adsorption of sludge biochar on most heavy metals in water met the multiple effects of physical and chemical adsorption, and its adsorption performance can be effectively enhanced by increasing effective surface groups and adsorption sites. At the same time, various factors affecting adsorption efficiency were summarized in detail in paper, and the regeneration of sewage sludge-based biochar was explored, and the future research directions of sludge biochar for removing heavy metals in water were prospected.
2020, 38(12): 78-85.
doi: 10.13205/j.hjgc.202012014
Abstract:
The division of water control-unit for watershed is the basis to implement diverse water eco-environmental management. Combining a series of criteria, including characteristics of small watershed, corresponding water quality, aquatic biodiversity etc, a water body control-unit division approach was proposed. Fuzzy analytic hierarchy process (FAHP) was employed to rank the management priority for each control unit, and thus revealed the nexus between the quality of water ecological environment and the potential pollution source. By taking Nanhe river as a typical case, three control sections and twenty-one water control-units were divided. There were six extremely high control-units and four extremely low control-units identified, which laid a foundation to lead multi-scale and precise management for small watershed.
The division of water control-unit for watershed is the basis to implement diverse water eco-environmental management. Combining a series of criteria, including characteristics of small watershed, corresponding water quality, aquatic biodiversity etc, a water body control-unit division approach was proposed. Fuzzy analytic hierarchy process (FAHP) was employed to rank the management priority for each control unit, and thus revealed the nexus between the quality of water ecological environment and the potential pollution source. By taking Nanhe river as a typical case, three control sections and twenty-one water control-units were divided. There were six extremely high control-units and four extremely low control-units identified, which laid a foundation to lead multi-scale and precise management for small watershed.
2020, 38(12): 86-91.
doi: 10.13205/j.hjgc.202012015
Abstract:
As the most advanced technological method for recovering total acid from stainless steel mixed acid waste, spraying and roasting can not only recover free acid and compound acid, but also recover metal oxide. In this process, the flow field and temperature field distribution chaos in the roaster will intensify metal oxide powder wall-hanging, and eventually lead to that the waste acid can not be fully reacted and corrode the roastor. In this study, simulation software Fluent was used to simulate the distribution of the flow field and temperature field in the roastor under different conditions such as air-fuel ratio and initial velocity of the post combustion gas, so as to obtain the optimal flow field and temperature field, eliminate the wall-hanging phenomenon of metal oxide powder to the maximum extent, and ensure the stable operation of the equipment for a long time. The results showed that the optimal flow field and temperature field distribution could be simulated when the gas medium was coal gas, the initial flow velocity of the post combustion gas was 20 m/s, and the air-fuel ratio was 1.7∶1. The actual measurement of the temperature gradient in the roaster under this optimal condition was basically consistent with the simulation results, which further verified the correctness of the model establishment. Under the condition of changing the gas medium to natural gas, the optimal flow field and temperature field distribution could also be simulated when the initial velocity of the post combustion gas was 20 m/s and the air-fuel ratio was 13∶1. The model could be used to guide the development, design and operation management of acid regeneration process in the future.
As the most advanced technological method for recovering total acid from stainless steel mixed acid waste, spraying and roasting can not only recover free acid and compound acid, but also recover metal oxide. In this process, the flow field and temperature field distribution chaos in the roaster will intensify metal oxide powder wall-hanging, and eventually lead to that the waste acid can not be fully reacted and corrode the roastor. In this study, simulation software Fluent was used to simulate the distribution of the flow field and temperature field in the roastor under different conditions such as air-fuel ratio and initial velocity of the post combustion gas, so as to obtain the optimal flow field and temperature field, eliminate the wall-hanging phenomenon of metal oxide powder to the maximum extent, and ensure the stable operation of the equipment for a long time. The results showed that the optimal flow field and temperature field distribution could be simulated when the gas medium was coal gas, the initial flow velocity of the post combustion gas was 20 m/s, and the air-fuel ratio was 1.7∶1. The actual measurement of the temperature gradient in the roaster under this optimal condition was basically consistent with the simulation results, which further verified the correctness of the model establishment. Under the condition of changing the gas medium to natural gas, the optimal flow field and temperature field distribution could also be simulated when the initial velocity of the post combustion gas was 20 m/s and the air-fuel ratio was 13∶1. The model could be used to guide the development, design and operation management of acid regeneration process in the future.
2020, 38(12): 92-96.
doi: 10.13205/j.hjgc.202012016
Abstract:
In this paper, a standard foam board tied with water hyacinth was set as the target, and the performance of the floating plant radar, including measurement target recognition, detection rang, distance, area and speed, was systematically studied using the radar detection technology. The results showed that floating plant radar could distinguish water hyacinth from water and wall. When the range of radial detection ranged from 37 to 114.5 m, the average ranging errors of different radial distances were within 0.6%. In small-area scan mode with radar sector-scan velocity at 3°/s, the average measurement error of area at long distance was 26.99% higher than that at close distance. At the same distance, the average area measurement error of radar sector-scan velocity at 12°/s was 12.13% lower than that at 3°/s. Meanwhile, the mean square error of radar velocity measurement for water hyacinth was less than 8% within the range of 0.1 m/s to 1.0 m/s.
In this paper, a standard foam board tied with water hyacinth was set as the target, and the performance of the floating plant radar, including measurement target recognition, detection rang, distance, area and speed, was systematically studied using the radar detection technology. The results showed that floating plant radar could distinguish water hyacinth from water and wall. When the range of radial detection ranged from 37 to 114.5 m, the average ranging errors of different radial distances were within 0.6%. In small-area scan mode with radar sector-scan velocity at 3°/s, the average measurement error of area at long distance was 26.99% higher than that at close distance. At the same distance, the average area measurement error of radar sector-scan velocity at 12°/s was 12.13% lower than that at 3°/s. Meanwhile, the mean square error of radar velocity measurement for water hyacinth was less than 8% within the range of 0.1 m/s to 1.0 m/s.
2020, 38(12): 97-102,91.
doi: 10.13205/j.hjgc.202012017
Abstract:
Fine particles from coal combustion have a serious impact on human health and atmospheric environment. Chemical agglomeration technology could help the agglomeration of fine particles to form large aggregation which were captured easily by conventional precipitator. The constituents of chemical agglomeration agents affected greatly the removal efficiency of fine particles. A multi-components chemical agglomeration agent including surfactant, polymer flocculant and inorganic salt was atomized and ejected into the agglomeration chamber to increase the agglomeration of fine particles. The experimental data showed that the two-component agglomeration agent containing inorganic salt and surfactant or flocculant could increase the removal of fine particles. The maximum efficiency in Tween-80 mixture was 44.1%. The increment of the concentration of agglomeration agents could benefit for the removal of particles, especially for positively charges surfactant or flocculant. However, high concentration of flocculant resulted in high viscosity of solution, consequently forming large spray droplet and decreasing the number of droplet, which could not favor the agglomeration process. For the surfactants, high concentration could result in their remains in emission due to the small molecule structure. The concentration of agglomeration agent should be controlled detailed. The removal efficiency of fine particles could be further improved as the inorganic salt, especially when ammonium chloride was added. And high concentration of slat favored this process. The optimum pH value at which the removal was maximum was in weak acid range. The adhesive force among particles increased by 3.5 times when three-component chemical agents were used to remove particles. Therefore, the mass of fine particles reduced by 45%~49%, and the median diameter increased from 3.5 μm to 7.5~8.6 μm.
Fine particles from coal combustion have a serious impact on human health and atmospheric environment. Chemical agglomeration technology could help the agglomeration of fine particles to form large aggregation which were captured easily by conventional precipitator. The constituents of chemical agglomeration agents affected greatly the removal efficiency of fine particles. A multi-components chemical agglomeration agent including surfactant, polymer flocculant and inorganic salt was atomized and ejected into the agglomeration chamber to increase the agglomeration of fine particles. The experimental data showed that the two-component agglomeration agent containing inorganic salt and surfactant or flocculant could increase the removal of fine particles. The maximum efficiency in Tween-80 mixture was 44.1%. The increment of the concentration of agglomeration agents could benefit for the removal of particles, especially for positively charges surfactant or flocculant. However, high concentration of flocculant resulted in high viscosity of solution, consequently forming large spray droplet and decreasing the number of droplet, which could not favor the agglomeration process. For the surfactants, high concentration could result in their remains in emission due to the small molecule structure. The concentration of agglomeration agent should be controlled detailed. The removal efficiency of fine particles could be further improved as the inorganic salt, especially when ammonium chloride was added. And high concentration of slat favored this process. The optimum pH value at which the removal was maximum was in weak acid range. The adhesive force among particles increased by 3.5 times when three-component chemical agents were used to remove particles. Therefore, the mass of fine particles reduced by 45%~49%, and the median diameter increased from 3.5 μm to 7.5~8.6 μm.
2020, 38(12): 103-111.
doi: 10.13205/j.hjgc.202012018
Abstract:
PM2.5 and PM10 pollutions have become important environmental problems which have attracted great attention in the world. Monitoring PM2.5 and PM10 pollutions is of great significance to human health, animal and plant growth, atmospheric environment assessment, etc. Based on the atmospheric PM2.5 and PM10 monitoring data of 17 cities in Shandong during 2013—2018, the paper studied spatial and temporal variation characteristics of PM2.5 and PM10 pollution in Shandong and analyzed the influence of meteorological factors, human factors and policy factors on them, using the temporal-spatial analysis method and the Spearman correlation analysis method. The results showed that: compared with 2013, the pollution extent of PM2.5 and PM10 in Shandong was significantly reduced in 2018, with an annual mean concentration dropped of 48.72% and 37.72% respectively; the presentation of the monthly PM2.5 mean concentration variation in the studied six years was similar to the "U" shape change rule, and the monthly PM10 mean concentration was similar to the "V" shape change rule; the overall pollution conditions of PM2.5 and PM10 showed a spatial trend of gradual reduction from the northwest inland to the eastern coastal area; the concentrations of PM2.5 and PM10 were significantly affected by the meteorological factors of temperature and precipitation, as well as the human factors of road density, urban green coverage, SO2 and NOx emissions, etc. Besides, meteorological and human factors had a greater impact on PM2.5 concentration than PM10 concentration.
PM2.5 and PM10 pollutions have become important environmental problems which have attracted great attention in the world. Monitoring PM2.5 and PM10 pollutions is of great significance to human health, animal and plant growth, atmospheric environment assessment, etc. Based on the atmospheric PM2.5 and PM10 monitoring data of 17 cities in Shandong during 2013—2018, the paper studied spatial and temporal variation characteristics of PM2.5 and PM10 pollution in Shandong and analyzed the influence of meteorological factors, human factors and policy factors on them, using the temporal-spatial analysis method and the Spearman correlation analysis method. The results showed that: compared with 2013, the pollution extent of PM2.5 and PM10 in Shandong was significantly reduced in 2018, with an annual mean concentration dropped of 48.72% and 37.72% respectively; the presentation of the monthly PM2.5 mean concentration variation in the studied six years was similar to the "U" shape change rule, and the monthly PM10 mean concentration was similar to the "V" shape change rule; the overall pollution conditions of PM2.5 and PM10 showed a spatial trend of gradual reduction from the northwest inland to the eastern coastal area; the concentrations of PM2.5 and PM10 were significantly affected by the meteorological factors of temperature and precipitation, as well as the human factors of road density, urban green coverage, SO2 and NOx emissions, etc. Besides, meteorological and human factors had a greater impact on PM2.5 concentration than PM10 concentration.
2020, 38(12): 112-117,162.
doi: 10.13205/j.hjgc.202012019
Abstract:
Based on the analysis and research of the diffusion process of the flue gas in the coke oven head, this paper presented dust collecting hood with a grid mesh suction surface and a side suction structure to control the flue gas and analyzed through the method of computer simulation. The results showed that the suction form of the grid structure increased the effective suction area, optimized the distribution of the suction volume, and solved the problems of small effective suction section and unreasonable air volume distribution of the traditional dust collection hood. The suction structure at the front end of the dust collection hood could form a side suction effect for the smoke moving along the smoke guide plate to both sides, and that realized the collection of the smoke, and solved the problem of smoke discharged to both sides after impacting the smoke guide plate. The new dust collection hood structure could still effectively control the flue gas when the air volume of the fan was reduced by 30%, thus improving the dust collection efficiency.
Based on the analysis and research of the diffusion process of the flue gas in the coke oven head, this paper presented dust collecting hood with a grid mesh suction surface and a side suction structure to control the flue gas and analyzed through the method of computer simulation. The results showed that the suction form of the grid structure increased the effective suction area, optimized the distribution of the suction volume, and solved the problems of small effective suction section and unreasonable air volume distribution of the traditional dust collection hood. The suction structure at the front end of the dust collection hood could form a side suction effect for the smoke moving along the smoke guide plate to both sides, and that realized the collection of the smoke, and solved the problem of smoke discharged to both sides after impacting the smoke guide plate. The new dust collection hood structure could still effectively control the flue gas when the air volume of the fan was reduced by 30%, thus improving the dust collection efficiency.
2020, 38(12): 118-123.
doi: 10.13205/j.hjgc.202012020
Abstract:
Natural trend of improving and upgrading civil heating, and the necessity and urgency of optimizing source and heating mode in north China county town were expounded in this paper. According to the current situation of garbage disposal and civil heating within north China county area, the matching relationship between the amount of garbage generation and civil heating demand was studied. The optimal heating mode (central heating mode within a typical county town based on combined heat and power generation by garbage incineration) was obtained and presented in this paper in order to provide a kind of clean, environmental, economic, efficient, recyclable, safe and reliable civil heating mode in line with the concept of sustainable development (energy resource, heating source and heating system) for upgrading people’s life quality in most north China county towns sustainably.
Natural trend of improving and upgrading civil heating, and the necessity and urgency of optimizing source and heating mode in north China county town were expounded in this paper. According to the current situation of garbage disposal and civil heating within north China county area, the matching relationship between the amount of garbage generation and civil heating demand was studied. The optimal heating mode (central heating mode within a typical county town based on combined heat and power generation by garbage incineration) was obtained and presented in this paper in order to provide a kind of clean, environmental, economic, efficient, recyclable, safe and reliable civil heating mode in line with the concept of sustainable development (energy resource, heating source and heating system) for upgrading people’s life quality in most north China county towns sustainably.
2020, 38(12): 124-129.
doi: 10.13205/j.hjgc.202012021
Abstract:
Waste to Energy (WtE) technology has been rapidly applied in China, with the incineration amount of municipal solid waste (MSW) reaching 102 million tons in 2018, accounting for 45% of the total harmless amount. The MSW disposal pattern of "mainly incinerated, lastly landfill" will soon be formed in China, and it will also continue to develop from "energy recovery" to "resource recovery". WtE industry has not only increased in the scale, but also has undergone profound changes in incineration technology, flue gas clean systems and market competition. China’s WtE industry still has many technical shortage and development bottlenecks, and faces new challenges and opportunities for sustainable development. WtE enterprises and all the participants involved WtE industries should explore the application and profit model of WtE in small and medium-sized cities (<500, 000 population), respond to the needs of landfill mining and incineration disposal, quickly develop the harmless disposal and resource utilization of fly ash; improve technology and management through increasing efficiency of power generation, reducing ratio of power consumption by the plant itself, strengthen the concept of "Good Neighborhood"; actively deploy the international market, attach the interaction with scientific research institutes in universities, and promote technological innovation and technology application.
Waste to Energy (WtE) technology has been rapidly applied in China, with the incineration amount of municipal solid waste (MSW) reaching 102 million tons in 2018, accounting for 45% of the total harmless amount. The MSW disposal pattern of "mainly incinerated, lastly landfill" will soon be formed in China, and it will also continue to develop from "energy recovery" to "resource recovery". WtE industry has not only increased in the scale, but also has undergone profound changes in incineration technology, flue gas clean systems and market competition. China’s WtE industry still has many technical shortage and development bottlenecks, and faces new challenges and opportunities for sustainable development. WtE enterprises and all the participants involved WtE industries should explore the application and profit model of WtE in small and medium-sized cities (<500, 000 population), respond to the needs of landfill mining and incineration disposal, quickly develop the harmless disposal and resource utilization of fly ash; improve technology and management through increasing efficiency of power generation, reducing ratio of power consumption by the plant itself, strengthen the concept of "Good Neighborhood"; actively deploy the international market, attach the interaction with scientific research institutes in universities, and promote technological innovation and technology application.
2020, 38(12): 130-137.
doi: 10.13205/j.hjgc.202012022
Abstract:
Construction waste disposal has problems such as narrow disposal area and low disposal rate, and the lack of efficient disposal facilities network. Considering the coordination of fixed disposal facilities and mobile disposal facilities, this paper firstly analyzed the main evaluation indexes of site selection of two types of disposal facilities from the perspective of the importance of complex network nodes, and proposed the feasible site selection of fixed and mobile disposal facilities by using grey correlation analysis method. Then a mixed integer programming model with minimum regional total cost and social negative effect was established to obtain the site selection of mobile disposal facilities in this period. At last, dynamic site selection and service scope of mobile disposal facilities were calculated according to the data of the following periods. Taking Jiangbei New District of Nanjing as an example, the construction waste disposal facility network was established to verify the validity of this model.
Construction waste disposal has problems such as narrow disposal area and low disposal rate, and the lack of efficient disposal facilities network. Considering the coordination of fixed disposal facilities and mobile disposal facilities, this paper firstly analyzed the main evaluation indexes of site selection of two types of disposal facilities from the perspective of the importance of complex network nodes, and proposed the feasible site selection of fixed and mobile disposal facilities by using grey correlation analysis method. Then a mixed integer programming model with minimum regional total cost and social negative effect was established to obtain the site selection of mobile disposal facilities in this period. At last, dynamic site selection and service scope of mobile disposal facilities were calculated according to the data of the following periods. Taking Jiangbei New District of Nanjing as an example, the construction waste disposal facility network was established to verify the validity of this model.
2020, 38(12): 143-148.
doi: 10.13205/j.hjgc.202012024
Abstract:
A large amount of food waste was produced with high content of organic matter and rich nutrient elements. Resource utilization after proper treatment is one of the potential methods for food waste disposal. Efficient utilization of the biomass energy in food waste could be realized by anaerobic digestion, thus it was the main technology for resource utilization and harmless treatment of food waste. The improvement of anaerobic digestion efficiency to gain clean energy and integrated utilization of digestion products was a research hotspot worldwide. The research progress of treatment and resource utilization of food waste was reviewed in this article, including the basic characteristics of food waste and the mechanism of anaerobic digestion, the problems in each stage of anaerobic digestion of food waste, and the advantages and disadvantages of strategies and research progress. The development direction of anaerobic digestion and products utilization was also proposed.
A large amount of food waste was produced with high content of organic matter and rich nutrient elements. Resource utilization after proper treatment is one of the potential methods for food waste disposal. Efficient utilization of the biomass energy in food waste could be realized by anaerobic digestion, thus it was the main technology for resource utilization and harmless treatment of food waste. The improvement of anaerobic digestion efficiency to gain clean energy and integrated utilization of digestion products was a research hotspot worldwide. The research progress of treatment and resource utilization of food waste was reviewed in this article, including the basic characteristics of food waste and the mechanism of anaerobic digestion, the problems in each stage of anaerobic digestion of food waste, and the advantages and disadvantages of strategies and research progress. The development direction of anaerobic digestion and products utilization was also proposed.
2020, 38(12): 157-162.
doi: 10.13205/j.hjgc.202012026
Abstract:
To study the stabilization of heavy metals in soils of lead-zinc mining area, the contaminated soil of a lead-zinc mining area in Miyi County, Panzhihua, Sichuan Province was collected. First, biochar made from three different sources were used to conduct static experimental research on acid extractable lead, zinc, cadmium, copper and wate-soluble zinc. Then biochar made from animal manure was selected to add into the contaminated soil for 35 d incubation experiments. The results showed that biochar made from animal manure were effective for the stabilization of heavy metals in contaminated soil of lead-zine mining area. The removal rates of lead, zinc, cadmium, copper extracted from weak acid were 13.16%, 15.68%, 96.33% and 65.39%, respectively. The removal rates of soluble Zn stabilized by the three sources of biochar were all gained over 90%. In the incubation experiments, the acid extractable lead in the contaminated soil was decreased by 97.36%, and the wate-soluble zinc was also decreased significantly. Therefore, the application of animal manure biochar could reduce the migration capacity of heavy metals in polluted soils in mining areas, which provided a scientific basis for the prevention and treatment of heavy metals pollution in lead-zinc mining areas.
To study the stabilization of heavy metals in soils of lead-zinc mining area, the contaminated soil of a lead-zinc mining area in Miyi County, Panzhihua, Sichuan Province was collected. First, biochar made from three different sources were used to conduct static experimental research on acid extractable lead, zinc, cadmium, copper and wate-soluble zinc. Then biochar made from animal manure was selected to add into the contaminated soil for 35 d incubation experiments. The results showed that biochar made from animal manure were effective for the stabilization of heavy metals in contaminated soil of lead-zine mining area. The removal rates of lead, zinc, cadmium, copper extracted from weak acid were 13.16%, 15.68%, 96.33% and 65.39%, respectively. The removal rates of soluble Zn stabilized by the three sources of biochar were all gained over 90%. In the incubation experiments, the acid extractable lead in the contaminated soil was decreased by 97.36%, and the wate-soluble zinc was also decreased significantly. Therefore, the application of animal manure biochar could reduce the migration capacity of heavy metals in polluted soils in mining areas, which provided a scientific basis for the prevention and treatment of heavy metals pollution in lead-zinc mining areas.
2020, 38(12): 163-167,172.
doi: 10.13205/j.hjgc.202012027
Abstract:
A rational soil sampling approach is critical to accurately characterizing potentially contaminated sites. Rapid element screening was applied to a case study for a chromium-contaminated site in Hunan Province. The results were processed by four spatial interpolation methods, including inverse distance weighted (IDW), ordinary kriging (OK), local polynomial interpolation (LPI), and radial basis function (RBF) methods, aiming to compare their accuracy and feasibility on predicting contaminated area. Then, the redundancy analysis was leveraged to determine the number of samples collected for laboratory evaluation. Finally, the results of spatial interpolation between field rapid screening and laboratory analysis were compared. The findings were as follows: 1) the results of predicted contaminated area evaluated by four spatial interpolation methods were significantly different, the accuracy decreased in the qequence of IDW > RBF > OK > LPI; 2) the number of sampling locations needed for laboratory analysis decreased from 245 to 113; and 3) the rapid screening technology was effective in evaluating contamination distribution for chromium-contaminated sites.
A rational soil sampling approach is critical to accurately characterizing potentially contaminated sites. Rapid element screening was applied to a case study for a chromium-contaminated site in Hunan Province. The results were processed by four spatial interpolation methods, including inverse distance weighted (IDW), ordinary kriging (OK), local polynomial interpolation (LPI), and radial basis function (RBF) methods, aiming to compare their accuracy and feasibility on predicting contaminated area. Then, the redundancy analysis was leveraged to determine the number of samples collected for laboratory evaluation. Finally, the results of spatial interpolation between field rapid screening and laboratory analysis were compared. The findings were as follows: 1) the results of predicted contaminated area evaluated by four spatial interpolation methods were significantly different, the accuracy decreased in the qequence of IDW > RBF > OK > LPI; 2) the number of sampling locations needed for laboratory analysis decreased from 245 to 113; and 3) the rapid screening technology was effective in evaluating contamination distribution for chromium-contaminated sites.
2020, 38(12): 168-172.
doi: 10.13205/j.hjgc.202012028
Abstract:
In the past few years, the pollution of soil and groundwater by petroleum pollutants became increasingly serious.The fluctuation of groundwater level caused by natural and man-made factors will cause the secondary migration of pollutants and expand the pollution scale.Therefore,the remediation of petroleum pollutants in water-table fluctuation zone have to be settled urgently. In this study, picking diesel as a representative of petroleum pollutants, the migration and transformation of diesel in water-table zone was simulated in a two-dimension sand box. The main purpose of this study were to research the change of diesel lens position, diesel-water-gas saturation in a two-dimension sand box in difference water level variation mode, and to analyze the effect of water-table fluctuation on the transport behavior of petroleum pollutants in unsaturated zone of groundwater. The results showed that when the water level fluctuated downward, the oil phase could drive the water to migrate downward, and the lens position moved downward. During the migration process, part of the oil phase was adsorbed by the medium to form a residual phase, resulting in an increase in the pollution range of the residual phase diesel; when the water level fluctuated upward, the water could drive the oil phase to move upward, and the lens body position moved upward. During the migration, part of the oil phase dissolves, which led to an increase in the pollution range of the dissolved phase diesel.This research could provide theoretical support for the remediation of actual contaminated sites.
In the past few years, the pollution of soil and groundwater by petroleum pollutants became increasingly serious.The fluctuation of groundwater level caused by natural and man-made factors will cause the secondary migration of pollutants and expand the pollution scale.Therefore,the remediation of petroleum pollutants in water-table fluctuation zone have to be settled urgently. In this study, picking diesel as a representative of petroleum pollutants, the migration and transformation of diesel in water-table zone was simulated in a two-dimension sand box. The main purpose of this study were to research the change of diesel lens position, diesel-water-gas saturation in a two-dimension sand box in difference water level variation mode, and to analyze the effect of water-table fluctuation on the transport behavior of petroleum pollutants in unsaturated zone of groundwater. The results showed that when the water level fluctuated downward, the oil phase could drive the water to migrate downward, and the lens position moved downward. During the migration process, part of the oil phase was adsorbed by the medium to form a residual phase, resulting in an increase in the pollution range of the residual phase diesel; when the water level fluctuated upward, the water could drive the oil phase to move upward, and the lens body position moved upward. During the migration, part of the oil phase dissolves, which led to an increase in the pollution range of the dissolved phase diesel.This research could provide theoretical support for the remediation of actual contaminated sites.
2020, 38(12): 173-176,137.
doi: 10.13205/j.hjgc.202012029
Abstract:
Intelligent manufacturing is the key for China’s steel industry to keep up with the world’s development trend and realize transformation and upgrading. It is the deep integration and innovation integration of manufacturing technology, information technology and artificial intelligence technology, as well as the transformation of production organization and business model. This paper discussed the applications and key technologies of intelligence in the iron and steel industry by studying the development status of intelligence, and explored the key difficulties and development prospects of intelligent manufacturing in the iron and steel industry by studying the status in Zhanjiang Plant of Baosteel Corp. and other iron and steel enterprises in China.
Intelligent manufacturing is the key for China’s steel industry to keep up with the world’s development trend and realize transformation and upgrading. It is the deep integration and innovation integration of manufacturing technology, information technology and artificial intelligence technology, as well as the transformation of production organization and business model. This paper discussed the applications and key technologies of intelligence in the iron and steel industry by studying the development status of intelligence, and explored the key difficulties and development prospects of intelligent manufacturing in the iron and steel industry by studying the status in Zhanjiang Plant of Baosteel Corp. and other iron and steel enterprises in China.
