DDTs在海河干流市区段沉积物/水间迁移行为研究

于2007年8月~2008年3月对海河干流表层水和沉积物中滴滴涕(DDTs)污染状况进行了采样调查.结果表明,海河干流水体DDTs含量为6.88~78.82 ng/L(均值28.54 ng/L),表层沉积物中DDTs含量为5.82~45.5 ng/g(均值21.55 ng/g),表层水和表层沉积物中DDTs主要成分分别为p,p-′DDT和p,p-′DDE.利用稳态非平衡逸度模型计算了p,p-′DDT在海河干流沉积物/水间迁移和分布,模型结果用现场实测浓度进行验证,计算值与实测值吻合很好.模型参数灵敏度分析进一步表明,生物降解速率常数、污染物在悬浮颗粒物/水间分配系数以及水体颗粒物沉降通量是影响p,p-′DDT在沉积物/水间迁移过程的主要因素.

DDTs Transport Between Sediment and Water in the Mainstream of Haihe River in the Urban Area

DDTs concentrations in surface water and sediment were measured from August 2007 to March 2008 in the mainstream of Haihe River. The results showed that DDTs concentrations ranged from 6.88-78.82 ng/L (mean 28.54 ng/L) in surface water, 5.82-45.5 ng/g (mean 21.55 ng/g) in sediment. The dominant DDTs form in surface water and sediment was found to be p, p'-DDT and p,p'-DDE,respectively. A steady state fugacity model (sediment-water exchange model) was established and successfully applied to the field data for p,p'-DDT in Haihe River. The parameter sensitivity analysis showed that sediment-water exchange of p, p'-DVT was mainly influenced by biodegradation rate constant, suspended particle-water partition coefficient and particle settling flux.