铜-苯并[a]芘复合污染体系中铜的微生物吸附特性

Biosorption Characteristics of Copper(Ⅱ) from Copper-Benzo[a]pyrene Co-existed Solution

研究了铜-苯并[a]芘(BaP)复合污染体系中,嗜麦芽窄食单胞菌对铜的微生物吸附特性。实验结果表明,该菌可以选择性地吸附Cu2+,并把NO3-还原为NO2-,pH、投菌量、处理时间和铜浓度等因素及BaP均会对铜的生物吸附产生显著的影响,BaP和这4个因素的相互作用对铜的生物吸附也达到了显著的水平。投菌量会对铜吸附过程中F-、Cl-、NO2-、NO3-、PO34-和SO24-等离子的释放产生显著的影响,BaP则会显著的影响F-、NO2-、NO3-和PO34-的浓度水平。当BaP的浓度为0、0.1、1.0、10.0 mg.L-1时,2.5 g.L-1菌体对pH为6.0、浓度为2 mg.L-1的铜溶液的吸附率分别高达97.1%、93.8%、94.0%和93.3%。BaP和铜在2 h内均没有造成菌体表面形态的明显变化;处理10 mg.L-1 Cu2+及其与BaP的复合污染2 d后,菌体表面会产生突起结构。

The biosorption characteristics of Cu2＋ by Stenotrophomonas maltophilia have been studied in a benzo[a]pyrene（BaP）-Cu2＋ com-bined pollution system.The results showed that S.maltophilia could adsorb Cu2＋ selectively and reduce NO3-to NO2-.BaP,initial pH,biosor-bent dosage,contact time and Cu2＋ concentration were the significant factors for Cu2＋ removal.The interactions between BaP concentration and these parameters also showed statistical significance.Moreover,the releases of F-,Cl-,NO2-,NO3-,PO34-and SO24-by different dosages of S.maltophilia were distinct,while the concentrations of BaP significantly affected the release of F-,NO2-,NO3-and PO34-.In the presence of 0,0.1,1 mg.L-1 and 10 mg.L-1 BaP,the maximum removal ratios of 2 mg.L-1 Cu2＋ at pH 6.0 were 97.1%,93.8%,94.0% and 93.3% respectively,when the biosorbent dosage was 2.5 g.L-1.Morphological characteristics illuminated that co-existed BaP and Cu2＋ did not present obviously toxic effects against S.maltophilia within 2 h.However,the cells were surrounded by granules after treated 10 mg.L-1 Cu2＋ and BaP for 2 d.