摘要
离子型稀土是我国重要的战略资源,其开采过程中产生的残留氨氮污染是亟待解决的环境问题.为了揭示稀土浸矿崩塌堆积体地表产流和残留氨氮迁移特征,从而为离子型稀土矿区氨氮污染治理提供科学依据,在我国赣南稀土矿区典型浸矿崩塌堆积体建设3个自然坡面径流小区,在此基础上开展降雨径流监测,分析崩塌堆积体地表产流和氨氮迁移特征.结果表明:矿区崩塌堆积体径流系数变化范围为0.01~0.30,地表径流深和径流系数可用降雨特征因子的线性函数拟合,且复合降雨因子的拟合精度优于单因子,其中以降雨量×最大10 min雨强的拟合效果最优(最大R^(2)=0.97);监测得到的地表径流平均氨氮浓度在1.58~5.99 mg/L之间,高于《地表水环境质量标准》(GB 3838—2002)Ⅴ类水环境标准;径流氨氮浓度与降雨量、降雨历时均呈负相关,与其他降雨因子均呈正相关,其中最大30 min雨强线性方程对氨氮浓度的拟合精度最优(最大R^(2)=0.83).研究显示,研究区稀土浸矿崩塌堆积体地表径流存在氨氮污染风险,而崩壁是残留氨氮由浸矿山体向地表迁移的关键部位,基于最大30 min雨强指标构建的拟合方程可用于地表径流氨氮预测.以上研究结果有助于我国赣南离子型稀土矿区残留氨氮污染风险评估和水土环境治理措施优化.
Ionic rare earths are important strategic resources in China,and the-southern Jiangxi Province accounts for 2/3 of the total reserves in the country.However,the ammonia nitrogen pollution problem which generated during the rare earth mining process needs to be solved.This study was conducted to reveal the surface runoff production and residual ammonia migration characteristics of rare earth leaching collapsed debris deposits,and provide a scientific basis for the ammonia of ammonia nitrogen pollution in ionic rare earth mining areas.Three natural slope runoff plots were constructed based on typical ore leaching collapsed debris deposits in southern Jiangxi Province.Rainfall runoff monitoring was carried out to analyze the surface runoff production and ammonia nitrogen migration characteristics of the collapsed debris deposits.The results show that the runoff coefficient of the collapsed debris deposits in the mining area varies from 0.01 to 0.3,the surface runoff depth and runoff coefficient can be characterized by the linear function of rainfall characteristic factor,and the fitting accuracy of the composite rainfall factor is better than that of the single factor.The rainfall×maximum10-min rainfall intensity is the best method for predicting the runoff production on the collapsed slope(maximum R^(2)=0.97).The average concentration of ammonia nitrogen in surface runoff is between 1.58 mg/L and 5.99 mg/L,which is higher than the Surface Water Environmental Quality Standard(GB 3838-2002)for ClassⅤwater.Runoff ammonia concentration is negatively correlated with rainfall and rainfall duration,and positively correlated with other rainfall factors.The linear equation of maximum 30-min rainfall intensity has the best fitting accuracy for ammonia concentration(maximum R^(2)=0.83).There is a risk of ammonia pollution in the surface runoff of the collapsed debris deposits of rare earth leaching ore in the study area,and the collapsed wall is the key part of residual ammonia nitrogen migration from the leaching mountain
作者
张雅妮
李瑞
李宇
陈果
曹龙熹
ZHANG Yani;LI Rui;LI Yu;CHEN Guo;CAO Longxi(College of Ecology Environment,Chengdu University of Technology,Chengdu 610059,China;Institute of Soil Science,Chinese Academy of Sciences,Nanjing 210008,China)
出处
《环境科学研究》
CAS
CSCD
北大核心
2023年第3期590-598,共9页
Research of Environmental Sciences
基金
国家重点研发计划项目(No.2018YFC1801801)。
关键词
离子型稀土
原地浸矿
崩塌堆积体
地表径流
氨氮迁移
ionic rare earth
in-situ leaching
collapsed debris deposits
surface runoff
ammonia nitrogen migration
