【摘要】 用胶质芽孢杆菌作吸附剂,探讨了采用生物吸附-浮选法去除水相中Pb2+的可能性,并对生物吸附机理和吸附剂与捕收剂的作用机理进行了分析。结果表明,用阳离子型捕收剂对胶质芽孢杆菌有较高的去除率,在pH为3~6的范围内,用十二胺浮选吸附了Pb2+的胶质芽孢杆菌,可获得较好的菌细胞和Pb2+的去除效果。在浮选pH=6.25、十二胺用量为0.375 mol/L时,菌细胞和Pb2+的去除率均达到了98%以上。选用Na2CO3作为解吸剂,浓度为1.2 mol/L、pH=4.75时,对吸附Pb2+后的胶质芽孢杆菌的解吸效果可以达到100%。动电位测试和红外光谱分析结果表明,胶质芽孢杆菌的自然等电点为2.39,吸附Pb2+后变为2.83,菌细胞与Pb2+的吸附过程主要与细胞多糖成分有关,吸附过程主要是静电吸引;吸附了Pb2+的菌细胞用十二胺浮选后等电点增至2.94,十二胺对菌细胞的浮选与细胞表面的酰胺基团和缔合—OH有关,吸附过程中有静电力、氢键和范德华力参与。更多还原

【Abstract】 The possibility of using bacillus mucilaginosus as the adsorbent to remove Pb2+ from water by biosorption-flotation process is studied,and the biosorption mechanism and the mechanism of the adsorbent and the collector are analyzed.The results indicate that cationic collector has a high removal rate of bacillus mucilaginosus.A good bacillus cell and Pb2+ removal effect can be achieved by floating Pb2+-loaded bacillus mucilaginosus with dodecyl amine(DA) at a pH value between 3~ 6.When at a pH value of 6.25 and a DA dosage of 0.375 mol/L,the removal rate can be above 98%.When 1.2 mol/L Na2CO3 is used as a desorbent at a pH value of 4.70,the Pb2+ desorption rate from bacillus mucilaginosus can reach 100%.Zeta potential and infrared spectroscopy analysis results show the isoelectric point of bacillus mucilaginosus will change from the original 2.39 to 2.83 when it has adsorbed Pb2+.The adsorption between the bacillus cell and Pb2+ is mainly related to the cell’s amylase component and the adsorption process is mainly of electrostatic attraction type.The isoelectric point of Pb2+-loaded bacillus mucilaginosus increases to 2.94 when it is floated by DA,whose flotation for the bacillus cells is related to the acetylamino group on the cell surface and associating —OH.Electrostatic attraction,hydrogen bonding and Ven De Waals force are involved in the adsorption process.更多还原