摘要
为评价广西阳朔县思的河流域矿区的重金属污染情况,将流域水文模型ArcSWAT与地下水模型(groundwater modeling system,GMS)中MT3DMS溶质运移模块相结合,定量分析污染物锌和镉的迁移过程,为进一步的治理措施提供参考依据。结果表明:采用ArcSWAT和GMS可以更准确地确定垂向入渗量,从而准确进行地下水数值模拟。在没有防治措施的情况下,矿井废水对地下水环境造成较大的污染威胁:尾砂矿矿洞出水口水样中锌和镉的含量分别为18.62 mg/L和0.096 mg/L,是流域重金属污染的源头。模拟期20 a内,锌和镉的污染晕分别在16 d和44 d之后到达河流,前端最远距离污染晕中心分别为2303.75 m和1887.04 m,两端最长处为3159.57 m和2478.57 m,最宽处分别为1533.54 m和1128.36 m。锌和镉进入流域的质量分别为3512.44 g和18.15 g,流出流域的质量为1640.49 g和8.47 g,残留在流域的比例分别为53.28%和53.33%。根据已有研究结果表明,龙葵对镉具有较强的富集能力,在植物体中的最高富集量为1084.4 mg/kg,并对锌具有较强的耐性,富集量也超过1000 mg/kg。因此,设置一个模拟情景对尾矿库生态修复工程进行评价。以尾矿积水塘中锌含量0.284 mg/L和镉含量0.002 mg/L为替代污染源强,模拟期内,锌沿河谷方向的迁移速度由94.38 m/a降低至80.78 m/a,最大污染晕面积由3.80×10^(6)m^(2)缩小至2.50×10^(6)m^(2);镉的迁移速度由86.09 m/a降低至69.13 m/a,最大污染晕面积由1.67×10^(6)m^(2)缩小至1.29×10^(6)m^(2),说明生态修复工程取得较好效果,建议继续投入建设。根据模拟预测结果,建议在矿洞出水口修建防渗帷幕等防治措施,划分污染防治区,并加强地下水水质监测,同时制定地下水风险事故应急预案,避免污染进一步加剧。
In order to evaluate heavy metal contamination in Sidi River Basin mining area of Yangshuo County,Guangxi,the watershed hydrological model by ArcSWAT and the solute transport model by MT3DMS in groundwater modeling system(GMS)were combined to quantitatively analyze the migration of zinc and cadmium.The results suggest that utilizing ArcSWAT and GMS can more accurately determine the vertical infiltration amount and accurately groundwater numerical simulation.Without prevention and control measures,mine wastewater poses a significant pollution threat to groundwater environment.It is found that the content of zinc and cadmium in water sample of tailing cave outlet is 18.62 mg/L and 0.096 mg/L respectively,which is the source of heavy metal contamination in entire basin.Within simulated period of 20 years,the contaminated halo of zinc and cadmium reaches the river after about 16 d and 44 d respectively,and the farthest front end of halo is 2303.75 m and 1887.04 m away from the center.The longest part at both ends is 3159.57 m and 2478.57 m,and the widest part is 1533.54 m and 1128.36 m.The mass of zinc and cadmium entered basin is 3512.44 g and 18.15 g,and flowed out is 1640.49 g and 8.47 g,remaining proportion are 53.28%and 53.33%separately in basin.There are existing research results show that Solanum nigrum L.is hyperaccumulator for cadmium that the highest accumulation in plant is 1084.4 mg/kg and strong tolerance to zinc with enrichment exceeding 1000 mg/kg.Therefore,a simulated circumstance is set up to evaluate the ecological restoration of tailings reservoir.The content of zinc is 0.284 mg/L and cadmium is 0.002 mg/L in tailings pond which is taken as alternative contaminated source.The migration speed of zinc along river valley reduces from 94.38 m/a to 80.78 m/a,and cadmium reduced from 86.09 m/a to 69.13 m/a during simulated period.The maximum halo of zinc reduced from 3.80×10^(6)m^(2)to 2.50×10^(6)m^(2)and of cadmium from 1.67×10^(6)m^(2)to 1.29×10^(6)m^(2).It indicated that the ecological restoration
作者
周正涛
刘明龙
夏源
ZHOU Zheng-tao;LIU Ming-long;XIA Yuan(College of Environmental Science and Engineering,Guilin University of Technology,Guilin 541006,China)
出处
《科学技术与工程》
北大核心
2024年第13期5662-5673,共12页
Science Technology and Engineering
基金
国家自然科学基金(41967028)
广西科技计划(2020GXNSFBA297050)。
