作　　者： ; ; ;

机构地区： 成都理工大学材料与化学化工学院

出　　处： 《环境污染与防治》 2012年第9期28-32,共5页

摘　　要： 选取成都东郊唯一的火力发电厂周围的稻田土为研究对象,对稻田土中各种形态汞的分布特征进行了调查与研究,探讨稻田土中汞的分布规律,为分析和判断稻田土中汞的迁移和转化行为及该区汞污染土壤的修复提供重要依据。结果表明,处于火力发电厂烟尘排污口下风向的1#、2#、3#、4#采样点土样受到了严重的汞污染,呈现出高含汞特征,总汞平均质量浓度在9～41mg/kg,平均值为24.546mg/kg,远远超出《土壤环境质量标准》(GB 15618—1995)二级标准所规定的限值(0.5mg/kg),而处于排污口上风向的5#、6#、7#、8#土样没有受到明显的汞污染,大部分土样的总汞含量与成都市土壤汞平均含量接近;1#、2#、3#、4#土样中5种形态汞的垂直分布均呈现出随着土壤深度增加而减少的特征;1#、2#、3#、4#土样中的各形态汞平均百分比为有机结合态汞>硝酸溶汞>残渣态汞>铁锰氧化态汞>水溶和可交换态汞,土壤中含有的大部分汞化学性质比较稳定,难以被植物吸收利用,而易被植物吸收利用的水溶和可交换态汞虽然仅占极小一部分,但含量还是高于成都市土壤中水溶和可交换态汞的背景值。 The rice paddy field around the only coal-fired power plants in eastern suburb of Chengdu was select- ed as the research subject to study the distribution characteristic of mercury species in soils. The transportation and transformation of mercury in paddy field soil were analyzed,which would provide the important basis for remediation of mercury-contaminated soil. Results showed that the soil of 1 # , 2 # , 3 # and 4 # sampling sites, which located at down- wind of soot outlet, were seriously polluted by mercury; they presented the obvious high mercury contamination characters with the total mercury concentration ranged 9-41 mg/kg and average value was 24. 546 mg/kg, which was far beyond the secondary standard limited value （0.5 mg/kg） of soil environmental quality standard （GB 15618 1995）. The soils of 5 #, 6 #, 7 # , 8 # sampling sites avoided the mercury pollution by being upwind of soot outlet, the total mercury concentration was close to background value of Chengdu. The content of 5 species mercury in 1 #-4 # sampling sites was decreased with depth increasing, the content of mercury fractions was in order of organic combined mercury 2〉nitric acid dissolved mercury〉residual mercury〉Fe-Mn oxides mereury〉 soluble and exchangeable mercury. Most of the mercury fractions were stable in soil, they could not be absorbed by the plants; the soluble and exchangeable mercury only contributed little part of total mercury in soil, but they still much higher than the background value of Chengdu.

关 键 词： 水稻田 土壤 汞 分布

领　　域： [环境科学与工程]