不同超滤膜去除三卤甲烷前体物比较

摘要

比较不同孔径超滤膜截留混凝沉淀出水和砂滤出水的三卤甲烷(THMs)前体物效果.水样经0.45 μm膜过滤后加氯消毒,光谱扫描分析溶解性有机碳(DOC)分子比例和THMs前体物化学结构变化,采用气相色谱-质谱法测定THMs生成潜能.结果表明:200 nm、100 nm、30 nm和10 nm超滤膜对混凝沉淀出水THMs前体物平均去除率分别为10.92％、11.18％、34.27％和53.38％,而对砂滤池出水THMs前体物平均去除率分别为7.80％、13.28％、22.31％和48.68％.光谱扫描表明羰基、烯烃、炔烃、不饱和烃、共轭烯烃以及苯及其衍生物结构普遍存在于DOC化学结构中,THMs前体物来源于它们的贡献.DOC中大分子的THMs生成潜能和活性强,小分子的生成THMs潜能和活性弱.%The efficiencies of ultrafiltration (UF) membranes with different pore size in removal of trihalomethanes (TMHs) precursors from coagulation-sedimentation tank's effluent and sand filter's effluent were compared.The water samples were filteredthrough 0.45μm membrane filters and chlorinated.The changes of the dissolved organic carbon (DOC) portion and the chemical structure of THMs precursors were analyzed by spectral scanning(200～400 nm).TMHs formation potential was quantified using gas chromatography-mass spectrometry.The results showed that the average removal efficiencies of THMs precursors from coagulation-sedimentation effluent were 10.92％,11.18％,34.27％ and 53.38％ for UF membranes with pore size of 200 nm,100 nm,30 nm and 10 nm,respectively;while the values were 7.80％,13.28％,22.31％ and 48.68％from sand filtration effluent.Spectral scanning indicated that carbonyl,olefins,alkynes,unsaturated hydrocarbons,conjugated olefins,and benzene and its derivatives were structurally present in the DOC.THMs precursors derived from carbonyl,olefins,alkynes,unsaturated hydrocarbons,conjugated olefins and benzene and its derivatives.Macromolecules had higher THMs formation potential and activity than small molecules.