悬浮泥沙对酚类化合物的吸附特性研究

研究了4种分别取自长江口和杭州湾的悬浮泥沙样品对苯酚、邻氯酚和2,4-二氯酚的吸附特性.结果表明,在12 h内可以达到对酚类化合物的吸附平衡,对苯酚的吸附量小,且不同样品间无显著差别,样品对酚类化合物吸附量随着酚类化合物氯化程度的提高而增大,与样品粒径分布、比表面积、有机物含量有关.在酚类化合物初始浓度＜2.0 mg/L时,样品对酚类化合物的等温吸附可以用Freundlich吸附等温式来表征,计算得到吸附常数Koc分别为622～1 410、3 287～3 707、6 444～8 787.挥发酚国家二级排放标准限定浓度为0.5 mg/L以下,此浓度下水体中悬浮泥沙能够有效吸附挥发酚,但高盐度不利于酚类化合物的吸附.

Sorption of Phenolic Compounds by Suspended Particulates

Sorption properties of phenol, o-chlorophenol, 2, 4-dichlorophenol on four kinds of suspended particles sampled from Changjiang Estuary and Hangzhou Bay were investigated. Experiments show that sorption equilibrium can be achieved in 12h for these phenolic compounds. As the content of chlorine in phenolic ring increases, the sorption amount on the samples enhances. For phenol, sorption amount on the samples are much less than the other two phenolic compounds and no distinct differences are obtained between different samples. The sorption ability of suspended particles has close relation with their particle size distribution, specific surface area and organic content. It is shown that when the initial phenolic concentration is smaller than 2.0 mg/L, Freundlich isotherm is suggested as the most appropriated fitting type. Sorption constants Koc calculated from Freundlich isotherm for these three phenolic compounds are 622-1,410, 3,287-3,707, 6,444-8,787 respectively. As limited by the national discharge standard, volatile phenols discharge concentration can't exceed 0.5 mg/L. Suspended particles can absorb them effectively under this concentration range, but high salinity has a negative effect.