摘要
为探究"稀土王国"江西省赣南地区离子型稀土矿对周边水体环境的影响,以离子型稀土矿分布密集区定南县濂江月子河流域和龙迳河龙头流域为研究对象,综合分析研究区特征污染物ρ(NH^+4-N)空间分布特征,采用相关性分析和主成分分析揭示其主要污染来源及影响因素.结果表明:①离子型稀土矿停产整顿半年后,濂江月子河流域和龙迳河龙头流域ρ(NH^+4-N)超过1. 00和2. 00 mg/L的采样点分别达72%和68%;p H范围为2. 95~7. 66,平均值分别为6. 23和5. 53,水体总体上偏酸性;ρ(TN)、ρ(NH^+4-N)、EC与ρ(NO^-3-N)变异系数较大,均介于0. 80~1. 50之间.②相关性分析结果显示,ρ(NH^+4-N)与ρ(TN)、EC均呈极显著正相关(P<0. 01);ρ(NH^+4-N)与pH呈显著负相关(P<0. 05).③流经稀土尾矿区的水体中ρ(NH^+4-N)随距离增加呈现明显的空间梯度分布特征,即距稀土矿区边界200 m处水体中ρ(NH^+4-N)最高(12. 20~200. 00 mg/L),其次为1. 15 km内(3. 69~11. 80 mg/L)及3. 5 km以上水体(0. 80~1. 51 mg/L),矿区周边未受到采矿活动影响的水体中ρ(NH^+4-N)最低(0. 03~0. 15 mg/L).④PCA结果表明,2条河流的主要环境影响因子为ρ(TN)、ρ(NH^+4-N)、p H和EC,主要受到周边稀土矿山尾矿的强烈影响.研究显示,离子型稀土矿原位浸矿开采停产半年后,重点小流域水体中ρ(NH^+4-N)高概率超标的现状仍然存在,受稀土开采活动影响较大.建议进一步开展重点小流域NH^+4-N剩余"库容"精算和矿山周边地表水定期监测.
Southern Jiangxi is called the‘rare earth kingdom’because of its due rich ion-absorbed rare earth ores.Dingnan County is one of the most densely distributed areas in southern Jiangxi.This study took two watersheds of Dingnan(i.e.the Yuezi River in Lianjiang River Basin and Longtou River in Longjing River Basin)as the objects to explore the influence of rare earth tailings on the river water quality.The spatial pattern,major sources of the specific pollutant(ρ(NH^+4-N))in the two river basins and its influencing factors were explored and analyzed with correlation analysis and principal component analysis(PCA).The results showed that after the mining activities stopped for six months,the proportion of the sample sites with ammonia concentration exceeded 1.00 and 2.00 mg/L was 72%and 68%in the two basins,respectively.In general,the river water was acidic with the p H value ranging from 2.95 to 7.66,and the average p H value was 6.23 in Yuezi River and 5.53 in Longtou River,respectively.The variation coefficient ofρ(TN),ρ(NH^+4-N),ρ(NO3--N)and conductivity(EC)were 0.80 to 1.50.The significant positive correlation was detected betweenρ(NH^+4-N)andρ(TN)or(P<0.01),andρ(NH^+4-N)was negatively core related with p H(P<0.05).The spatial gradient phenomenon ofρ(NH^+4-N)in the water-bodies was found with the increase of distance along the flowing direction away from the tailings of the rare earth mine.The concentration of ammonia in the water column was detected as the highest away from rare earth mining area 200 m with theρ(NH^+4-N)ranging from 12.20 mg/L to 200.00 mg/L,and followed by 1.15 km with theρ(NH^+4-N)ranging from 3.69 mg/L to 11.80 mg/L and≥3.5 km with theρ(NH^+4-N)ranging from 0.80 mg/L to 1.51 mg/L.Ammonia concentration was the lowest in the river areas above the mining areas with no mining interference andρ(NH^+4-N)was from 0.03 mg/L to 0.15 mg/L.According to the results of PCA,the main environmental impact factors wereρ(TN),ρ(NH^+4-N),p H and EC in the two rivers,which were strongly influenced by the existence of the rare earth tailings.It’s suggested that high probability of NH^+4-N exceeding the standard still existed in the small branch watershed after the mining activities with the in-situ leaching process stopped for half a year.Measurement of the remaining NH^+4-N‘reservoir capacity’and regular monitoring of surface water around the tailings in the small branch watershed need to be carried out in the future.
作者
师艳丽
张萌
姚娜
曾萍
冯兵
陈明
李发东
张依章
SHI Yanli;ZHANG Meng;YAO Na;ZENG Ping;FENG Bing;CHEN Ming;LI Fadong;ZHANG Yizhang(Jiangxi Provincial Research Institute of Environmental Protection,Nanchang 330039,China;Jiangxi Key Laboratory of Mining&Metallurgy Environmental Pollution Control,Jiangxi University of Science and Technology,Ganzhou 341000,China;Chinese Research Academy of Environmental Sciences,Beijing 100012,China;Institute of Geographic Sciences and Natural Resources Research,CAS,Beijing 100101,China)
出处
《环境科学研究》
EI
CAS
CSCD
北大核心
2020年第1期94-103,共10页
Research of Environmental Sciences
基金
江西省重点科技计划项目(No.20171ACG70019)
江西省科技计划项目(No.20133BBG70001,20141BBG70012)~~
关键词
离子型稀土尾矿
赣南
水污染
NH^+4-N
分布特征
ion-absorbed rare earth tailings
southern Jiangxi
water pollution
ammonia
distribution patterns