Citation: | Rui-ping Liu, You-ning Xu, Hui-chao Rui, El-Wardany RM, Ying Dong, 2021. Migration and speciation transformation mechanisms of mercury in undercurrent zones of the Tongguan gold mining area, Shaanxi Loess Plateau and impact on the environment, China Geology, 4, 311-328. doi: 10.31035/cg2021030 |
In order to study the migration and transformation mechanism of Hg content and occurrence form in subsurface flow zone of gold mining area in Loess Plateau and its influence on water environment, the field in-situ infiltration test and laboratory test were carried out in three typical sections of river-side loess, alluvial and proluvial strata in Tongguan gold mining area of Shaanxi Province, and the following results were obtained: (1) The source of Hg in subsurface flow zone is mainly caused by mineral processing activities; (2) the subsurface flow zone in the study area is in alkaline environment, and the residual state, iron and manganese oxidation state, strong organic state and humic acid state of mercury in loess are equally divided in dry and oxidizing environment; mercury in river alluvial or diluvial strata is mainly concentrated in silt, tailings and clayey silt soil layer, and mercury has certain stability, and the form of mercury in loess is easier to transform than the other two media; (3) under the flooding condition, most of mercury is trapped in the silt layer in the undercurrent zone where the sand and silt layers alternate with each other and the river water and groundwater are disjointed, and the migration capacity of mercury is far less than that of loess layer and alluvial layer with close hydraulic connection; (4) infiltration at the flood level accelerates the migration of pollutants to the ground; (5) the soil in the undercurrent zone is overloaded and has seriously exceeded the standard. Although the groundwater monitoring results are safe this time, relevant enterprises or departments should continue to pay attention to improving the gold extraction process, especially vigorously rectify the small workshops for illegal gold extraction and the substandard discharge of the three wastes, and intensify efforts to solve the geological environmental problems of mines left over from history. At present, the occurrence form of mercury in the undercurrent zone is relatively stable, but the water and soil layers have been polluted. The risk of disjointed groundwater pollution can not be ignored while giving priority to the treatment of loess and river alluvial landform areas with close hydraulic links. The research results will provide a scientific basis for water conservancy departments to groundwater prevention and control in water-deficient areas of the Loess Plateau.
Bardini L, Boano F, Cardenas MB, Revelli R, Ridolfi L. 2012. Nutrient cycling in bedform induced hyporheic zones. Geochimicaet Cosmochimica Acta, 84, 47–61. doi: 10.1016/j.gca.2012.01.025. |
Clements FE. 1905. Research methods in Ecology. Lincoln, NB, University of Nebraska Publishing Company, 334. |
Cui XX. 2012. Research of Migration Law of Poisonous Metal in Soil in Sewage Irrigation Area. Chinese Academy of Geological Sciences, Master’s thesis, 79 (in Chinese with English abstract). |
Feng XB, Dai QQ, Qiu GL, Li GH, He L, Wang DY. 2006. Gold mining related mercury contamination in Tongguan, Shaanxi Province, PR China. Applied Geochemistry, 21(11), 1955–1968. doi: 10.1016/j.apgeochem.2006.08.014. |
Han FX, Banin A, Triplett GB. 2001. Redistribution of heavy metals in arid-zone soils under a wetting-drying soil moisture regime. Soil Science, 166(1), 18–28. doi: 10.1097/00010694-200101000-00005. |
Li Y, Zhang WW, Yuan JH, Huang ML, Zhu L, Ni LX, Wu YH. 2016. Research advances in flow patterns and nitrogen transformation in hyporheic zones. Journal of Hydrology, 44(1), 0001–0007. doi: 10.3876/j.issn.1000-1980.2016.01.001. |
Liu JH, Wang WH, Peng A. 2000. The effect of the property of soil on the distribution of mercury species in soil. Environmental Chemistry, 19(5), 474–478 (in Chinese with English abstract). |
Liu RP, Xu YN, He F, Ke HL, Zhang JH, Chen HQ, Qiao G. 2017. The mercury concentration time and space characterized of Shuangqiao River in the gold mine area. Northwestern Geology, 50(3), 231–238 (in Chinese with English abstract). |
Mantey J, Nyarko K, Owusu-Nimo F, Awua AK, Bempah CK. 2020. Mercury contamination of soil and water media from different illegal artisanal small-scale gold mining operations (galamsey). Heliyon, 6, 1–13. doi: 10.1016/j.heliyon.2020.e04312. |
Marcello MV, Omotayo F. 2020. A review of the failed attempts to curb mercury use at artisanal gold mines and a proposed solution. The Extractive Industries and Society, 7, 1135–1146. doi: 10.1016/j.exis.2020.06.023. |
Ji HB, Zhang Y, Bararunyeretse P, Li HX. 2018. Characterization of microbial communities of soils from gold mine tailings and identification of mercury-resistant strain. Ecotoxicology and Environmental Safety, 165, 182–193. doi: 10.1016/j.ecoenv.2018.09.011. |
Ju L. 2007. Speciation analysis and bioavailability of heavy metals in sediments. Jinan, Shandong University, Master’s thesis, 88 (in Chinese with English abstract). |
Siergieiev D, Widerlund A, Ingri J, Öhlander B. 2014. Flow regulation effects on the hydrogeochemistry of the hyporheic zone in boreal rivers. Science of the Total Environment, 499, 424–436. doi: 10.1016/j.scitotenv.2014.06.112. |
Tang XC, Lin T, Xia PH, Huang XF, Ma L, Yang Y. 2020. Speciation distribution and risk assessment of Hg and As in sediment of Lake Caohai wetlands under different water level gradients, Guizhou Province. Journal of Lake Sciences, 32(1), 100–110 (in Chinese with English abstract). doi: 10.18307/2020.0110. |
Tian Y, Yang WC. 2019. Analysis on migration of heavy metals in groundwater fluctuation zone. Environmental Science and Management, 44(10), 40–45 (in Chinese with English abstract). |
Tian T. 2016. The characteristics study on vertical distribution and adsorption-desorption of water-soluble salts and heavy metals in soil—Different landscape soil Tongguan gold mining area as an example. Xi’an, Chang’an University, Master’s thesis, 83 (in Chinese with English abstract). |
Wang MY, Zhang L, Qin YW, Li FS, Jia J, Cao W, Zheng BH. 2011. Speciation of heavy metals in sediments from Xiang River and analysis of their environmental factors. Acta Scientiae Circumstantiae, 31(11), 2447–2458 (in Chinese with English abstract). |
Wang C, Shan BQ, Tang WZ, Wang X, Shi MW, Jin X. 2017. Heavy metal speciation in the surface sediments of Yang River System (Guanting Reservoir). Acta Scientiae Circumstantiae, 37(9), 3471–3479 (in Chinese with English abstract). |
Wang PA. 2007. Dynamic variation of mercury species in soil in wet-dry rotation environment. Xi’an, Southwest University, Master’s thesis, 54 (in Chinese with English abstract). |
Wang JX, Sun XC, Xing Y, Xia JC, Feng XB. 2019. Immobilization of mercury and arsenic in a mine tailing from a typical Carlin-type gold mining site in southwestern part of China. Journal of Cleaner Production, 240, 231–238. doi: 10.1016/j.jclepro.2019.118171. |
Wu GZ, Zheng XL, Lin GQ, Hao P. 2011. Field experimental study on infiltration in seasonal river channels. Arid Zone Researc, 289(1), 74–79 (in Chinese with English abstract). |
Wu ZR, Liu GJ, Qian JZ, Wei Y, Yue QS. 2019. Experimental study on the vertical migration of Pb from the saturated zone to unsaturated done. Environmental Science and Technology, 42(9), 36–41 (in Chinese with English abstract). |
Wu YJ, Wang S, Zhao YY. 2019. Characteristics of soil heavy metals and prevention of environmental problems in the Duobuza mining area, Tibet. Acta Geologica Sinica, 93(11), 2985–2996 (in Chinese with English abstract). doi: 10.19762/j.cnki.dizhixuebao.2019095. |
Xia JH, Chen YM, Wang WM, Han YL, Liu HY, Hu L. 2013. Dynamic processes and ecological restoration of hyporheic layer in riparian zone. Advances in Water Science, 24(4), 589–597 (in Chinese with English abstract). |
Xiao R, Wang S, Li RH, Wang JJ, Zhang ZQ. 2017. Soil heavy metal contamination and health risks associated with artisanal gold mining in Tongguan, Shaanxi, China. Ecotoxicology and Environmental Safety, 141, 17–24. doi: 10.1016/j.ecoenv.2017.03.002. |
Xie XJ, Johnson TM, Wang YX, Lundstrom CC, Ellis A, Wang XL, Duan MY, Li JX. 2014. Pathways of arsenic from sediments to groundwater in the hyporheic zone: Evidence from an iron isotope study. Journal of Hydrology, 511, 509–517. doi: 10.1016/j.jhydrol.2014.02.006. |
Xu YN, Zhang JH. 2008. Contents of heavy metals in bottom sediments of the Taiyu River in the Tongguan gold mining area, Shaanxi, China, and contamination assessments. Geological Bulletin of China, 27(8), 1263–1671 (in Chinese with English abstract). |
Yang Y. 2015. Research on the model of contaminant migration insoil considering groundwater level fluctuation. Baoding, Hebei Agricultural University, Master’s thesis, 62 (in Chinese with English abstract). |
Yi YL, Li Y, Zhang DG, Liu SS, Zhao MD. 2010. Dynamic process of the form of mercury in the soil under different water conditions. Journal of Shenyang Agricultural University, 41(1), 42–45 (in Chinese with English abstract). |
Yuan XZ, Luo G. 2003. A brief review for ecological studies on hyporheic zone of stream ecosystem. Acta Ecologica Sinica, 23(5), 956–964 (in Chinese with English abstract). |
Yuan ZY. 2012. Study on pollutant migration in soil under fluctuating groundwater table. Baoding, Hebei Agricultural University, Master’s thesis, 71 (in Chinese with English abstract). |
Zhang C, Chen H, Sun RG, Zhang X, Wang DY. 2014. Risk assessment of mercury in soil at different water-1evel altitudes in Drawdown Areas of Three Gorges Reservoir. Journa1 of Soil and Water Conservation, 28(1), 242–246 (in Chinese with English abstract). |
Zhu SH, Zhao YF, Liu P, Bai YF, Liu P, Bai Y. 1987. The study on chemical forms of mercury in soils. Acta Agriculturae Universitatis Pekinensis, 13(1), 59–63 (in Chinese with English abstract). |
Zhu DN, Zou SZ, Zhou CS, Lu HP, Xie H. 2020. Hg, As contents and ecological health risk assessments in soil-crop system under different tillage types. Geology in China, 1‒16. https://kns.cnki.net/kcms/detail/11.1167.P.20200724.1603.006.html. |
Zhang JH, Xu YN, Wu YG. 2019. Health risk assessment of heavy metals in wheat and maize in the Xiaoqinling gold mining area. Acta Geologica Sinica, 93(2), 501–508 (in Chinese with English abstract). doi: 10.19762/j.cnki.dizhixuebao.2019030. |
Experimental locations at the Shuangqiao River.
Vertical distribution of the content of various forms of mercury, total mercury content, water content, and pH in loess geomorphology (Dongshe) in winter. a‒distribution of hydraulic connection between groundwater and the river water and geotechnical properties of the vertical section of the alluvial geomorphology; b‒vertical change characteristics before infiltration; c‒vertical change characteristics after the infiltration at a constant surface water level; d‒vertical change characteristics after the infiltration at a flood level.
Vertical distribution of the content of various forms of mercury, total mercury content, water content, and pH in alluvial geomorphology (Dongshuangqiao) in winter. a‒distribution of hydraulic connection between groundwater and the river water and geotechnical properties of the vertical section of the alluvial geomorphology; b‒vertical change characteristics before infiltration; c‒vertical change characteristics after infiltration at a constant surface water level; d‒vertical change characteristics after infiltration at a flood level.
Vertical distribution of the content of various forms of mercury, total mercury content, water content, and pH in proluvial geomorphology (Yaoshang) in winter. a‒distribution of hydraulic connection between groundwater and river water and geotechnical properties of a vertical section of proluvial stratum; b‒vertical change characteristics before infiltration; c‒vertical change characteristics after infiltration at a constant surface water level; d‒vertical change characteristics after infiltration at a flood level.
Comparison of changes of heavy metal elements in river sediment and tailings.