贵州省污水处理厂污泥中重金属形态分布及其潜在生态风险评价

发布时间：2018-03-31 18:16

本文选题：贵州省　切入点：城市污泥　出处：《中国农村水利水电》2016年12期

【摘要】：通过现场调查采样及室内分析,采用ICP-MS和修正的BCR法研究了贵州省污水处理厂污泥中重金属(Mn、Cu、Zn、Pb、Cr、Ni、As和Cd)污染状况及其分布特征,并利用综合污染指数法(Nemerow)和地累积指数法(Igeo)对重金属污染及其潜在生态风险进行综合评价。研究结果表明:贵州省污水厂污泥呈现高有机质、高氮的特点,具有较好的土地利用价值,8种重金属元素平均含量的大小顺序为MnCuZnPbCrNiAsCd,其中Mn和Cu所占比例最高,Cd所占比例最小。相关分析可知,贵州省污水处理厂污泥有机质含量与各重金属含量均呈显著或极显著正相关,由此表明有机质含量是决定贵州省污水处理厂污泥重金属含量的主要因素。贵州省污水处理厂污泥Cu和Cr主要以酸溶可交换态形式存在,Pb和Cd以水溶态形式存在,As和Zn则主要是以可氧化态和可还原态存在,Ni较均匀地分布于不同形态(水溶态T1、酸溶可交换态T2、可还原态T3、可氧化态T4和残渣态T5);其生物活性系数大小依次为NiCuMnCrAsZnCdPb,表明Cu、Ni表现出相对较高的不稳定性和可利用性,而Pb、Cd在污泥中稳定性较好,生物可利用性较低。贵州省污水处理厂污泥Cr、Ni、As单因子污染系数均值均小于1,属于低污染水平;污染系数均值由大到小依次为CdPbCuMnZnCrNiAs。贵州省各城市污水厂污泥中重金属危害指数(Ei)基本表现为:CdPbAsNiMnZnCuCr,其中毒害性最强的是Cd,其他城市各重金属污染处于低污染水平,复合生态危害指数(RI)大小依次为铜仁贵阳兴义遵义凯里六盘水毕节;Cu和Zn地累积指数较低,表现为轻度污染,而其他重金属的地累积指数较高,各城市之间的地累积指数差异较大,从均值来看,Cu、Ni、As和Zn属于轻度污染,Cr和Mn属于中度污染,Pb和Cd属于重度污染。
[Abstract]:Based on field investigation and indoor analysis, ICP-MS and modified BCR method were used to study the pollution and distribution characteristics of heavy metals in sewage treatment plant sludge of Guizhou Province. The pollution of heavy metals and its potential ecological risk were evaluated by the comprehensive pollution index (Nemerow) method and the geoaccumulation index (Igeoo) method. The results showed that the sludge of the wastewater treatment plant in Guizhou Province showed the characteristics of high organic matter and high nitrogen. The order of the average content of 8 heavy metals is MnCuZnPbCrNiAsCd2.The ratio of mn and Cu is the highest and the proportion of CD is the lowest. The content of organic matter in sludge of Guizhou sewage treatment plant was significantly or extremely significantly correlated with the content of heavy metals. The results show that the organic matter content is the main factor to determine the heavy metal content in the sludge of the wastewater treatment plant of Guizhou Province, Cu and Cr mainly exist in the form of acid soluble exchangeable form, Pb and CD exist in the form of water solution. The distribution of Ni in different forms (water soluble T1, acid soluble exchangeable T2, reducible T3, oxidizable T4 and residue T5) is the main reason for the distribution of Ni in different forms (water soluble T1, acid soluble exchangeable T2, oxidable T4 and residue T5N). The results of NiCuMnCrAsZnCdPb show that the Cu Ni exhibits relatively high instability and availability. However, the stability and bioavailability of Pb ~ (2 +) ~ (2 +) CD in sewage treatment sludge of Guizhou Province are lower than 1, and the average pollution coefficient of Cr ~ (2 +) Ni ~ (2 +) as a single factor is less than 1, which belongs to the low pollution level. The average value of pollution coefficient is CdPbCuMnZnCrNiAs. the heavy metal hazard index (Eii) in the sludge of municipal wastewater treatment plants in Guizhou Province is basically: CDPbAsNiMnZnCuCr-CdPbAsNiMnZnCuCr. among them, the most toxic is cadmium, and the pollution of heavy metals in other cities is at a low pollution level. The composite ecological hazard index (RI) was lower in order of accumulation of Cu and Zn in Xiupanshui, Xingyi, Zunyi, Tongren, showing slight pollution, while the accumulation index of other heavy metals was higher than that of other heavy metals, and the accumulation index of Cu and Zn in Liupanshui was higher than that in other heavy metals. There is a great difference in the land accumulation index among different cities. According to the average value, Cu, Ni, as and Zn belong to light pollution, Cr and mn belong to moderate pollution, Pb and CD belong to heavy pollution.
【作者单位】：贵州工程应用技术学院;贵州大学资源与环境工程学院;
【基金】：贵州省科技厅课题“贵州省城市污水处理与防治技术探讨”(GZ20140230) 贵州省高校创新课题“城市重金属防治研究(K052836)”
【分类号】：X703;X826

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