自然水体生物膜有机组分对Pb(2+)的吸附特性及其影响因素

生物膜在天然水环境和工程处理中起着重要的作用．关于自然水体生物膜对重金属的吸附作用已有很多报道．但多数报道认为，生物膜中的无机物即铁锰氧化物对重金属的吸附起着主要作用，而对于生物膜的重要组成部分——有机组分对重金属吸附影响的研究则很少．     

Protective effect caused by the exopolymer excreted by Pseudoalteromonas antarctica NF3 on liposomes against Triton X-100

The capacity of the glycoprotein (GP) excreted by Pseudoalteromonas antarctica NF₃ to protect phosphatidylcholine (PC) liposomes against the action of Triton X-100 was studied in detail. Increasing amounts of GP assembled with liposomes resulted in a linear increase in the effective surfactant-to-PC molar ratios needed to produce the same alterations in liposomes and in a linear fall in the surfactant partitioning between the bilayer and the aqueous phase. Thus, the higher the proportion of GP assembled with liposomes the lower the surfactant ability to alter the permeability of vesicles and the lower its affinity with these bilayer structures. In addition, increasing GP proportions resulted in a progressive increase in the free surfactant concentration (S _W) for the same surfactant–liposome interaction step. The fact that S _W was always lower than the surfactant critical micelle concentration indicates that the interaction was mainly ruled by the action of surfactant monomers, regardless of the amount of GP assembled. Received: 4 May 1999 Accepted in revised form: 6 July 1999