细菌-矿物复合吸附剂对重金属离子的吸附与解吸作用  

Adsorption and desorption of heavy metal ions by bacteria-contained mineral composite adsorbents

作　　者：邹春艳[1] 连宾[2] 臧淑艳[2] 吴丰昌[3] 

机构地区：[1]贵州大学喀斯特环境与地质灾害防治教育部重点实验室,贵阳550003 [2]中国科学院地球化学研究所环境地球化学国家重点实验室,贵阳550002 [3]中国环境科学研究院国家环境保护湖泊污染控制重点实验室,北京100012

出　　处：《安全与环境学报》2011年第2期43-46,共4页Journal of Safety and Environment

基　　金：国家自然科学基金重点项目(40632011);国家自然科学基金项目(40803037);中国科学院知识创新工程项目(kzex2-yw-135-2)

摘　　要：将胶质芽孢杆菌(Bacillus mucilaginosus)K02菌株在无氮培养基中培养得到细菌吸附剂,将K02分别接种到含有硅藻土或沸石粉的培养基中培养,得到细菌-硅藻土复合吸附剂和细菌-沸石复合吸附剂,研究三者对几种重金属离子的吸附和解吸作用。结果表明,细菌与矿物的复合吸附剂效果更好,解吸率也更高,其中细菌-沸石复合吸附剂效果最好。比较对CH^(2+)、Zn^(2+)、Cd^(2+)、Cr^(3+)、Pb^(2+)的吸附作用,该吸附剂对Pb^(2+)选择性最好,吸附率达97%,且吸附后可以自动聚集成团沉降,相比细菌和矿粉单独使用,沉降时间明显加快。用浓度均为0.1 mol/L的草酸、草酸铵、乙二胺四乙酸二钠(EDTA-2Na)、硝酸钠4种溶液作解吸剂,分别对上述3种吸附剂体系进行解吸。EDTA-2Na对3种吸附条件下的Pb2解吸效果最好,最高达到90%。在应用细菌吸附剂和细菌-硅藻土吸附剂条件下,EDTA-2Na解吸效果从大到小为pb^(2+)、Cu^(2+)、Cr^(3+),其他解吸剂均对Cu^(2+)效果最好;草酸的解吸率从大到小依次为Cu^(2+)、Cr^(3+)、Cd^(2+)、Zn^(2+)、Pb^(2+)。而在采用细菌沸石吸附剂条件下,不同解吸剂对不同重金属解吸效果完全不同。用EDTA-2Na做解吸剂,5种离子的解吸率都明显高于其他组,草酸对Cr^(3+)解吸率最高。研究表明,对重金属离子废水吸附和解吸效果较好的组合为细菌-沸石吸附剂和EDTA-2Na。The aim of this paper is to explore the function of adsorption and desorption for heavy metal ions by the three adsorbents and the four de-adsorbents （oxalic acid, ammonium oxalate, EDTA-2Na and sodium nitrate）. The above-said bio-adsorbents can be obtained from the culture of Bacillus mucilaginosus K02 growing in the nitrogen-free medium whereas the bio-diatomite and bio-zeolite composite adsorbent were formed by the K02 strain cultured in nitrogen-free medium with 1 g/100 mL diatomite or zeolite particles （all mineral particles had been sieved through 200 mesh screen）. The results of our testing and measurements show that the adsorption effect of the adsorptive bacteria and mineral composites were better than the simple bacteria-adsorption, and the desorption rates were also higher than the simple bacteria-adsorption. Comparing the adsorption efficiencies of Cu^2＋ , Zn^2＋ , Cd^2＋ , Cr^3＋ , Pb^2＋ , we have found that the composite adsorbents are better suitable for removing Pb^2＋ from the water. The bacteria-zeolite composite adsorbent displayed the best adsorption power among the three adsorbents, whose adsorption rate of Pb^2＋ tends to reach 97%. In addition, we have also found that it can be automatically gathered into aggregate settlement after the adsorption. In comparison with bacteria or mineral alone, the setting time has significantly been accelerated. Oxalic acid, ammonium oxalate, EDTA-2Na and sodium nitrate （all the concentration were 0.1 mol/L） can be used in the desorption experiments. The results of our experiments show that the desorption efficiency of EDTA 2Na to Pb^2＋ at the three sorption conditions turns to be the strongest. The highest efficiency can be 90%. At the conditions with the application of bacterial adsorbent and bacteria-diatomite composite adsorbent, the varied de-sorption effects order to heavy metals by using EDTA-2Na can be expressed as Pb^2＋〉 Cu^2＋〉Cr^3＋ with the other two de-adsorbents displaying highest desorption efficiency to Cu^2＋

关 键 词：环境工程学 胶质芽孢杆菌 重金属 吸附 解吸 沸石 硅藻土 

分 类 号：X703.1[环境科学与工程—环境工程]