【作者】 康江丽；

【导师】 迟杰；

【作者基本信息】 天津大学 ， 环境科学， 2006， 硕士

【摘要】 有机污染物在水体悬浮颗粒物(SPM)上的吸附/解吸行为会影响它们在自然环境中的迁移、转化、归宿和生物生态效应。这种行为会受到有机污染物本身的物理化学性质、吸附剂的组成和结构、环境条件及共存有机物等多种因素的影响。目前,对吸附机理及影响因素的认识的局限性,使得有机污染物的迁移转化和归宿模型在实际水环境中的预测存在较大的误差。本文选用优先控制污染物PAEs作为目标化合物,研究了邻苯二甲酸二正丁酯(DBP)、邻苯二甲酸异辛酯(DEHP)两种PAEs在三种SPM(包括沉积颗粒物、铜绿微囊藻颗粒和普通小球藻颗粒)上的吸附/解吸行为以及迟滞效应;研究了环境因素对吸附过程的影响,并进行了现场采样分析。论文主要取得了以下成果:(1)这两种化合物在SPM上的吸附过程进行的很快,很短时间内即可达到吸附平衡,沉积颗粒物约为2h,藻颗粒约为0.5h。(2)三种SPM对DEHP的吸附能力明显大于DBP;不同SPM对同一种化合物的吸附能力差异较大,Koc值由大到小的顺序为沉积颗粒物>普通小球藻>铜绿微囊藻,说明沉积颗粒物中的腐殖质对DBP和DEHP的吸附能力显著大于藻体中的有机质;普通小球藻的吸附能力明显大于铜绿微囊藻,这是由于脂肪在藻体吸附中起着重要作用。(3)在实验浓度范围内,SPM对DBP和DEHP的吸附和解吸等温线具有较好的线性关系,解吸过程存在明显的迟滞现象,而且沉积颗粒物比藻颗粒物具有明显的迟滞效应,DBP比DEHP具有较大程度的迟滞效应。(4)腐殖酸浓度、温度、pH值及盐度增大,DBP和DEHP在SPM上的吸附量增加,而随着SPM浓度的增加,DBP和DEHP在SPM上的吸附量降低。(5)渤海、海河以及湖泊水相和沉积相采样分析结果表明,三种水体均存在PAEs类化合物DBP和DEHP的污染,且在沉积物中有一定程度的富集。这类污染物在海河水体和湖泊水体中沉积物-水间分配接近平衡,而污染物在渤海水体中远未达平衡,是污染物的汇。更多还原

【Abstract】 Behaviors of sorption and desorption of organic pollutants on suspended particulate matter (SPM) play an important role in their transport, transformation and bioavailability in natural environment, and are influenced by factors such as physical-chemical properties of organic pollutants, composition of sorbent, evironmental condition and coexistent organic compounds. Presently, knowledge of mechanism of sorption and desorption is limited, which results in significant errors in environmental prediction of fate of organic compounds in aqueous environment.Behaviors of sorption, desorption and hysteresis of dibutyl phthalate (DBP) and Di-(2-ethyl)hexyl phthalate (DEHP) on three kinds of SPM, including suspended sediment particulate, Chlorella vulgari and Microcystis aeruginosa, were studied. Effects of environmental factors on sorption of DBP and DEHP were investigated. Field sampling was also proceeded.Experimental results are as follows:(ⅰ) Sorption equilibrium of DBP and DEHP on the SPM was reached quickly, 2 h for suspended sediment and 0.5 h for phytoplankton.(ⅱ) Sorption ability of DEHP on SPM was significantly higher than that of DBP. Sorption ability between the SPM for DBP or DEHP differed greatly. Sorption ability of DBP and DEHP in humic materials was higher that that in algal organic matter. Fat was approved to have played an important role in the process of sorption.(ⅲ) All kinds of SPM were found to exhibit significant sorption-desorption hystersis phenomenin, and the extent of hystersis for suspended particulate was obviously larger than phytoplankton, and the extent of hystersis for DBP was larger than DEHP.(ⅳ) The sorption amounts of DBP and DEHP increased with the increase of humic acid concentration, temperature, pH and salinity, while decreased with increasing SPM concentration.(ⅴ) Field investigations in Bohai estuary, Haihe river and a small lake showed that DBP and DEHP were found in all the samples of water and sediment, and enriched in sediment. Distribution of DBP and DEHP between water and sediment was nearly reached equilibrium in Haihe river and the small lake, and far away from equilibrium in Bohai estuary. Sediment was the sink of DBP and DEHP.更多还原