固定香菇(Lentinus edodes)菌柄废弃物吸附Cd和Pb后的解吸试验研究  

Desorption of Pb^(2+) and Cd^(2+). from the immobilized Lentinus edodes by HCl

作　　者：何海江[1,2] 张丹[1] 曾雪丹[1,2] 李伟[1] 李恩霞[1] 

机构地区：[1]中国科学院水利部成都山地灾害与环境研究所 山地环境演变与调控重点实验室,成都610041 [2]中国科学院研究生院,北京100083

出　　处：《安全与环境学报》2011年第5期26-31,共6页Journal of Safety and Environment

基　　金：国家自然科学基金项目(40871111);四川省科技支撑项目(07FC-001-006)

摘　　要：利用6种不同的解吸剂对吸附了Pb^(2+)和Cd^(2+)的固定香菇小球进行解吸。结果表明,HCl溶液做解吸剂最佳,可以分别在90 min和60 min内将大量的Pb^(2+)和Cd^(2+)从聚乙烯醇-海藻酸钠(PVA-SA)固定香菇小球上解吸出来。利用模拟二级动力学方程描述HCl溶液对PVA-SA固定香菇小球上Pb^(2+)和Cd^(2+)的解吸过程,决定系数R^2分别为0.996 9和0.998 9。Cd^(2+)的解吸率在HCl浓度为0.1 mol·L^(-1)时达到平衡,解吸率为80%;Pb^(2+)的解吸率在HCl浓度为1.0 mol·L^(-1)时达到最大,为99.01%。微观形态研究表明,未吸附重金属的PVA-SA固定香菇小球表面粗糙多孔,小球通过物理性吸附或形成无机沉淀将重金属沉积在细胞壁上后,表面变得密实。经HCl解吸后的PVA-SA固定香菇小球表面粗糙度和孔隙度都恢复到吸附前的状态。PVA-SA固定香菇小球对Pb^(2+)和Cd^(2+)进行吸附后,利用HCl进行解吸,再吸附,如此3次循环使用后,其吸附率略有降低,但仍可达到85.24%和69.07%。Aiming to improve the industrial and mine sewage treat- ment by using immobilized Lentinus edodes, a kind of cheap biosorbent, this paper is focused on the study of the desorption process of Pb2＋ and Cd2＋ by immobilized Lentinus edodes, so as to find a method for recycling heavy metals. In proceeding with our study, we have first of all investigated such important parameters, as the sort of desorbent, equilibrium time and the concentration of the desorbent. The experimental results from our research indicate that among the six desorbents（H2SO4, HNO3, HCl, Na2CO3, NaHCO3, NH4Cl）, HCl and HNO3 could desorb more Pb2 ＋ and Cd2 ＋ from the immobilized Lentinus edodes than the other four, with the effect of HCl being bet- ter for the desorption behavior. Desorbing Pb2＋ and Cd2 ＋ with HCl, the equilibrium time was 90 min and 60 rain respectively. With the pseudo-second-order model well fitted for Pb2＋and Cd2＋ desorption data, and the correlation coefficient--0.996 9 and 0.998 9, respec- tively, the desorption ratio of Pb2＋ tends to reach its maximum limit of 99.01% when the concentration of HCI is 1 mol·L-1, while that of Cd2＋ reaches its maximum limit of 80.81% at the concentration of HC1 being 0.1 mol· L- 1. According to the scanning electronic micro- scope and the energy spectrum observation, the surface of polyvinyl alcohol-Na-alginate （PVA- SA） immobilized Lentinus edodes beads is rough and porous before the absorption. By the physical adsorption or/and forming inorganic sediment, heavy metals were adsorbed on the cell walls of immobilized beads after adsorption. In addition, the Pb2 ＋ and Cd2 ＋ crystal was found on PVA - SA immobilized Lentinus edodes after absorption. And the surface of PVA - SA immobilized beads would become close-grained. But after deserption with HCI, the surface of the beads would return to be rough and porous again. Then the recycled beads could be used for absorbing heavy metals a- gain. Thus Pb2 ＋ and Cd2＋ biosorption ratios for PVA - SA immobi- lized L

关 键 词：微生物学 固定香菇 PB2+ Cd2+ 解吸 扫描电镜 能谱 

分 类 号：X703[环境科学与工程—环境工程]