从分子质量的变化分析有机物对GAC吸附内分泌干扰物(BPA)的影响

从分子质量分布的角度研究了水中有机物对颗粒活性炭(GAC)吸附双酚A(BPA)容量及吸附速率的影响.结果表明,相对于以去离子水为本底的BPA溶液来说,GAC吸附以滤后水、臭氧后出水和原水为本底的BPA溶液的Langmuir模型的最大吸附容量q_m值分别下降了29.95%、43.56%和44.44%,而其拟二级动力学模型的k₂值分别下降了43.05%、49.75%和56.38%.相对分子质量3 000以上,尤其是10 000以上的有机物堵塞GAC的二级微孔;3 000以下,尤其是1 000以下的有机物与BPA分子之间存在直接的竞争吸附,是导致GAC对BPA的吸附容量以及吸附速率下降的主要原因.

Impact of organic matter in water on the adsorption of EDCs (BPA) onto granular activated carbon (GAC) from the view of Molecular Weight Distribution

Impact of organic material with different molecular weight( MW) on the adsorption performance of endocrine disrupting chemicals(EDCs)--bisphenol A (BPA) in water on granular activated carbon (GAC) were investigated. Compared to the adsorption capacity in deionized water, the qm values of Langmuir of BPA-raw water, BPA-filtered water and BPA-effluents after ozonation solution decrease 29.95 % ,43.56% and 44.44% respectively, and the k2 values of pseudo second order decrease 43.05 %, 49.75% and 56.38% respectively. On the hand, the secondary micropores may be blocked up by the organic matter with MW higher than 3 000, especially higher than 10 000, on the other hand, the direct sites competitive adsorption may be exists between the BPA molecule and the organic matter with MW lower than 3000, especially lower than 1000. Both of process may be resulted in reduction of the adsorption capacity, k2 value of adsorption kinetics of BPA onto GAC.