漂白废水中有机氯在湿地土壤中的环境行为

在实验室模拟条件下,研究了漂白废水中有机氯在土壤中的吸附平衡规律和土柱中的迁移特性,同时分析了某造纸废水长期灌溉湿地土壤的可提取有机氯分布特征.结果表明,可吸附有机氯在土壤中的吸附规律符合Freundlich等温式,且在未受灌溉土壤和已灌溉2a土壤中的吸附常数分别为7.341 0和4.950 1,非线性程度常数分别为0.502 4和0.610 8;经漂白废水淋溶的土柱渗滤液中有较多的可吸附有机氯(AOCl)检出,废水中的有机氯被土壤大量的吸附,且在表层中含量最高.经过造纸废水灌溉1、2和3a后的土壤表层可提取有机氯(EOCl)的平均含量分别为4.48、10.35和10.07μg/g,与土壤背景值相比有明显的提高.

Environmental Behavior in Wetland Soil of Organic Chlorine from Pulp Bleaching Wastewater

The adsorption equilibrium and leaching characteristics of organic chlorine on soils were studied by mean of soil column method using bleaching water in laboratory condition. Soil samples were also collected from the wetland that irrigated with pulp wastewater from one to three years, and analyzed for the distributing characteristics of organic chlorine in soils. The results showed that measured equilibrium isotherms for absorbable organic chlorine (AOCl) in the soils were of Freundlich type with the adsorption constant 7.3410 in the soils without irrigated and 4.9501 irrigated for 2 years. The nonlinear constants were 0.5024 and 0.6108, respectively. The AOCl was detected in the leachate, it was found that most of the AOCl was adsorbed by the soils, especially topsoil. The average contents of extractable organic chlorine (EOCl) were 4.48 microg/g, 10.35 microg/g and 10.07 microg/g in the topsoil irrigated for la, 2a and 3a respectively, which had increased distinctly compared with the background value.