从土壤铁锰结核及其附近土壤中分离、培养并筛选到3株锰氧化细菌:芽孢杆菌(Bacillus sp.)WH4和GY16,假单胞菌(Pseudomonas sp.)WHS26,应用这3个菌株大量合成了生物氧化锰.在此基础上,比较研究了这3个菌株催化合成的生物氧化锰与一种化学合成锰氧化物矿物(S-MnOx:Synthesized Mn oxide)对重金属Cu^2+、Zn^2+、Cd^2+的吸附特征.结果表明,3种生物氧化锰对重金属的吸附具有明显优势,其对Cu^2+、Zn^2+、Cd^2+的最大吸附量约为S-MnOx的10-100倍;各种氧化锰对Cu^2+、Zn^2+、Cd^2+的吸附过程均符合Langmuir等温吸附模型,且是一个快速吸附的过程;3种锰氧化物对Cu^2+、Zn^2+、Cd^2+3种重金属的最大吸附量与其比表面积呈正相关,吸附过程受pH影响,最适的pH范围为3-6.
Microbially mediated manganese (Mn) oxidation is a key process in the biogeochemical cycling of Mn, and is responsible for the formation of Mn oxide minerals. Biogenic Mn oxides are highly reactive, have a huge surface area and a nanocrystalline structure. In this study, three strains of bacteria with high Mn-oxidizing activity were isolated from iron-manganese nodules and their surrounding soil and identified as Bacillus sp. WH4, GY16, and Pseudomonas sp. WHS26. Biogenic Mn oxides produced by these three bacteria and one chemically synthesized in the laboratory, were investigated to determine their adsorption characteristics for the heavy metal ions Cu^2 + , Zn^2 + , and Cd^2 + . The adsorption capacities of the biogenic Mn oxides for heavy metals were 10 - 100 times greater than that of the synthesized Mn oxide. Adsorption equilibriums were established quickly in 3 hours. The greatest adsorption capacity of biogenic Mn oxides for heavy metals was positively correlated with their surface area. The adsorptive process was strongly affected by pH and the optimal pH for the adsorption by the three biogenic Mn oxides ranged from 3 to 6.