PARTICLE SIZE AND OCCURRENCE CHARACTERISTICS OF ARSENIC IN RIVER SEDIMENTS OF ARSENIC-BEARING MINE AREAS
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摘要: 矿区河流沉积物是重金属污染物的迁移载体。研究了某含砷矿区河段沉积物砷含量分布、赋存形态及粒径对沉积物中砷水力传输的影响机制。结果表明:矿区河流沉积物中砷污染问题突出;沉积物颗粒大小不仅影响砷在沉积物组分中的分配与赋存形态,还会影响水环境中砷的传输。在矿区上游和中上游河段,沉积物均以粗砂、中砂组分为主,上游河段沉积物中砷含量为18.53 mg/kg,主要来源于原生矿物,以结晶水合铁铝氧化物结合态和残渣态等稳定形式存在。中上游河段沉积物中砷含量达到3492 mg/kg,主要来源于采矿活动导致矿石中砷的氧化溶出和部分原生矿物,粗砂、中砂组分(73.90%)中砷以弱结晶水合铁铝氧化物结合态和残渣态为主,分别占总砷含量的83.71%和83.82%,细砂、极细砂、粉砂中砷主要以专性吸附态和弱结晶水合铁铝氧化物结合态存在,分别占总砷含量的58.72%、58.51%和73.10%。在距离矿区2,4 km处的中游、下游河段沉积物砷含量仍有371,247 mg/kg,以细砂、极细砂、粉砂为主,其中专性吸附态和弱结晶水合铁铝氧化物结合态砷是主要形态;沉积物<0.25 mm(细砂、极细砂、粉砂)组分中砷含量是粗砂组分的1.5倍,<0.25 mm细颗粒沉积物对砷的水力传输起主导作用。因此,应加强废弃含砷矿区河流生态治理和水土保持,防止细泥沙入水;同时,加强下游河段沉积物生态疏浚和修复治理,防止沉积物中砷的再释放。Abstract: River sediments are the transporters of pollutants. In this study, the effects of sediments particle size on hydraulic transport, content distribution, and speciation of arsenic in arsenic-bearing mine river were studied. The results showed that arsenic pollution was prominent in river sediments of the mine area; particle size affected not only the distribution and speciation of arsenic in various sediment particle size fractions but also their transport in water environment. The sediments were mainly composed of coarse sand and medium sand in the upstream and middle and upper reaches. In the upstream reaches, arsenic content in the sediments was 18.53 mg/kg, which mainly came from the primary minerals and existed in stable forms, such as well-crystallized hydrous Fe and Al oxides and residual. The content of arsenic reached 3492 mg/kg in the middle and upper reaches, which mainly came from oxide dissolution of arsenic-bearing ore and some original mineral. The amorphous and poorly-crystalline hydrous oxides of Fe and Al and residual were the main existing forms in coarse sand and medium sand components(73.90%), accounting for 83.71%, 83.82% of the total arsenic content, respectively. In fine sand, very fine sand and silty sand, the specific adsorption and amorphous and poorly-crystalline hydrous Fe and Al oxides were the main constituents, accounting for 58.72%, 58.51% and 73.10% respectively. The arsenic contents were still 371, 247 mg/kg in the sediments from middle and lower reaches of 2 km and 4 km away from the mine. The sediments existed mainly in fine sand, extremely fine sand and silt-sand, and predominant forms of arsenic were the specific adsorption and amorphous and poorly-crystalline hydrous Fe and Al oxides. Arsenic in the component less than 0.25 mm(fine sand, very fine sand, silted sand) was 1.5 times of that of the coarse sand component, and fine grain sediments played a leading role in the hydraulic transmission of arsenic. Therefore, the ecological control and soil and water conservation in the upper and middle reaches and the ecological dredging and rehabilitation of sediments in the downstream reach should be strengthened.
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Key words:
- river sediment in mine area /
- fine particle /
- arsenic /
- speciation /
- distribution characteristics
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[1] BAEYENS W,MIRLEAN N,BUNDSCHUH J,et al.Arsenic enrichment in sediments and beaches of Brazilian coastal waters:a review[J].Science of the Total Environment,2019,681(1):143-154. [2] 蹇丽,黄泽春,刘永轩,等.采矿业污染河流底泥及河漫滩沉积物的粒径组成与砷形态分布特征[J].环境科学学报,2010,30(9):1862-1870. [3] LIU J J,XU Y Z,CHENG Y X,et al.Occurrence and risk assessment of heavy metals in sediments of the Xiangjiang River,China[J].Environmental Science and Pollution Research,2017,24(3):2711-2723. [4] ZHUANG Q F,LI G,LIU Z Y.Distribution,source and pollution level of heavy metals in river sediments from South China[J].Catena,2018,170:386-396. [5] 王辉,赵悦铭,刘春跃,等.辽河干流沉积物重金属污染特征及潜在生态风险评价[J].环境工程,2019,37(11):65-69. [6] 邓瑜衡,赵军.沉积物中重金属的迁移转化影响机制研究[J].环境工程,2017,35(4):184-189. [7] BOUZEKRI S,HACHIMI M,TOUACH N,et al.The study of metal (As,Cd,Pb,Zn and Cu) contamination in superficial stream sedimentsaround of Zaida mine (High Moulouya-Morocco)[J].Journal of African Earth Sciences,2019,154:49-58. [8] 张远,石陶然,于涛.滇池典型湖区沉积物粒径与重金属分布特征[J].环境科学研究,2013,26(4):370-379. [9] 王胜强,孙津生,丁辉.海河沉积物重金属污染及潜在生态风险评价[J].环境工程,2005,23(2):62-64. [10] INZUNZA J,RUIZ C,NEVÁREZ M,et al.Biomonitoring of Cd,Cr,Hg and Pb in the Baluarte River basin associated to a mining area (NW Mexico)[J].2011,409(18):3527-3536. [11] 米玉婷,蔡永兵,于靖,等.金矿区河流沉积物中砷形态及释放动力学[J].环境科学与技术,2016,39(3):6-11. [12] WENZEL W W,KIRCHBAUMER N,PROHASKA T,et al.Arsenic fractionation in soils using an improved sequential extraction procedure[J].Analytica Chimica Acta,2001,436(2):309-323. [13] YU T,ZHANG Y,ZHANG Y.Distribution and bioavailability of heavy metals in different particle-size fractions of sediments in Taihu Lake,China[J].Chemical Speciation and Bioavailability,2012,24(4):205-215. [14] CHRISTOPHER E,JAMIESON H,PALMER M,et al.Controls governing the spatial distribution of sediment arsenic concentrations and solid-phase speciation in a lake impacted by legacy mining pollution[J].The Science of the Total Environment,2019,654:563-575. [15] GUO T,LI L G,ZHAI W W,et al.Distribution of arsenic and its biotransformation genes in sediments from the East China Sea[J].Environmental Pollution,2019,253:949-958. [16] GALLOWAY J,SWINDLES G,JAMIESON H,et al.Organic matter control on the distribution of arsenic in lake sediments impacted by-65 years of gold ore processing in subarctic Canada[J].Science of the Total Environment,2018,622/623:1668-1679. [17] HERREWEGHE S V,SWENNEN R,VANDECASTEELE C,et al.Solid phase speciation of arsenic by sequential extraction in standard reference materials and industrially contaminated soil samples[J].Environmental Pollution,2003,122(3):323-342. [18] LIU J J,DIAO Z H,XU X R,et al.In situ arsenic speciation and the release kinetics in coastal sediments:a case study in Daya Bay,South China Sea[J].Science of the Total Environment,2019,650:2221-2230. [19] LUCIC M,JURINA I,SCANCAR J,et al.Sedimentological and geochemical characterization of river suspended particulate matter (SPM) sampled by time-integrated mass flux sampler (TIMS) in the Sava River (Croatia)[J].Journal of Soils and Sediments,2019,19(2):989-1004. [20] LIANG J,LIU J,XU G,et al.Distribution and transport of heavy metals in surface sediments of the Zhejiang nearshore area,East China Sea:sedimentary environmental effects[J].Marine Pollution Bulletin,2019,146:542-551. [21] TANSEL B,RAFIUDDIN S.Heavy metal content in relation to particle size and organic content of surficial sediments in Miami River and transport potential[J].International Journal of Sediment Research,2016,31:324-329. [22] GROOT A,GOEIJ J,ZEGERS C.Contents and behaviour of mercury as compared with other heavy metals in sediments from rivers Rhine and Ems[J].Geol Mijnbouw,1971,50:393-398. [23] ACKERMANN F,BERGMANN M,SCHLEICHERT G.Monitoring of heavy metals in coastal and estuarine sediments-a question of grain-size:<20 μm versus<60 μm[J]. Environmental Technology Letters,1983,4:317-328. [24] LI S Y,YANG C L,PENG C H,et al.Effects of elevated sulfate concentration on the mobility of arsenic in the sediment-water interface[J].Ecotoxicology and Environmental Safety,2018,154:311-320. [25] DUAN Y H,GAN Y Q,WANG Y X,et al.Arsenic speciation in aquifer sediment under varying groundwater regime and redox conditions at Jianghan Plain of Central China[J].Science of the Total Environment,2017,607/608:992-1000. [26] ORDIALES E,COVELLI S,RICO J,et al.Occurrence and speciation of arsenic and mercury in estuarine sediments affected by mining activities (Asturias,northern Spain)[J]. Chemosphere,2018,198:281-289. [27] SELIM A,JEAN J S,YANG H J,et al. Occurrence of arsenic in core sediments and groundwater in the Chapai-Nawabganj District,northwestern Bangladesh[J].Water Research,2010,44:2021-2037.
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