微生物诱导碳酸盐沉积介导的Cd^(2+)固定  

Immobilization of Cd^(2+) by microbial induced carbonate precipitation

作　　者：朱广森 汪文军 吴峥 司友斌[1] ZHU Guang-sen;WANG Wen-jun;WU Zheng;SI You-bin(Anhui Province Key Laboratory of Farmland Ecological Conservation and Pollution Prevention,School of Resources and Environment,Anhui Agricultural University,Hefei 230036,China)

机构地区：[1]安徽农业大学资源与环境学院,农田生态保育与污染防控重点实验室,安徽合肥230036

出　　处：《中国环境科学》2021年第12期5912-5920,共9页China Environmental Science

基　　金：国家重点研发计划(2019YFC1805203);国家自然科学基金资助项目(42077123);安徽高校协同创新项目(GXXT-2021-061)。

摘　　要：实验室条件下,研究了碳酸盐矿化菌施氏假单胞菌(Pseudomonas stutzeri)、枯草芽孢杆菌(Bacillus subtilis)和巴氏芽孢杆菌(Bacillus pasteurii)的生长对Cd^(2+)的耐受性和固定效果,以及羟基磷灰石对3种菌固定Cd^(2+)的影响,通过扫描电镜(SEM)、X射线能谱(EDS)、傅里叶红外光谱(FTIR)和X射线衍射(XRD)对碳酸盐矿化菌的诱导矿化产物进行了表征.结果表明,3种菌生长过程中B.pasteurii的脲酶活性最强,是P.stutzeri和B.subtilis脲酶活性的10倍左右,且P.stutzeri,B.subtilis,B.pasteurii产CO^(2-)_(3)的最高浓度分别为588.19,661.72,1735.18mg/L,培养体系中pH值均呈现升高的趋势,最高pH值分别为8.23,9.06,9.52;Cd^(2+)浓度在0~10mg/L范围内对P.stutzeri的生长影响较小,而当Cd^(2+)浓度高于1mg/L时则会抑制B.subtilis和B.pasteurii的生长.初始Cd^(2+)浓度为0.5mg/L时,培养120h,P.stutzeri,B.subtilis和B.pasteurii对Cd^(2+)的固定去除率分别为96.37%,99.40%,97.57%;加入羟基磷灰石能够提高碳酸盐矿化菌对Cd^(2+)的去除率.SEM和EDS结果显示,P.stutzeri和B.subtilis诱导形成的矿化产物多聚集在菌体周围或附着在菌体表面,呈球状或网状结构,表面疏松多孔,B.pasteurii的矿化产物附着在菌体表面,结构致密,呈不规则的球状;FTIR分析表明矿化产物中存在CO^(2-)_(3),结合XRD结果,证实3种菌诱导沉淀矿化产物主要是CaCO_(3),而Cd^(2+)与Ca^(2+)会以同晶置换的方式形成CdCO_(3)晶体,B.pasteurii在诱导矿化的过程中可将Cd^(2+)以Ca_(0.67)Cd_(0.33)CO_(3)共沉淀的方式固定.Under laboratory culture conditions,three carbonate mineralization bacteria,Pseudomonas stutzeri,Bacillus subtilis and Bacillus pasteurii were used to study the growth specialities,the resistance and removal of Cd^(2+)by the bacteria,and the effect of hydroxyapatite on Cd^(2+)immobilization.The scanning electron microscope(SEM),energy dispersive spectrum(EDS),fourier transform infrared spectroscopy(FTIR)and X-ray diffraction(XRD)were employed to characterize the biomineralization products.The results showed that the urease activity of B.pasteurii was about 10 times than those of P.stutzeri and B.subtilis.The CO^(2-)_(3)was produced and the pH of culture media had an increasing during the growth of the three bacteria.The highest CO^(2-)_(3)concentrations were 588.19,661.72,1735.18mg/L,while the highest pH value could reach 8.23,9.06 and 9.52 for P.stutzeri,B.subtilis and B.pasteurii,respectively.The growth of P.stutzeri was not affected within the Cd^(2+)concentration of 0~10mg/L,while the growth of B.subtilis and B.pasteurii were inhibited in the Cd^(2+)concentration beyond 1mg/L.With the initial Cd^(2+)concentration of 0.5mg/L and biomineralization for 120h,the removal rates of Cd^(2+)by P.stutzeri,B.subtilis and B.pasteurii were 96.37%,99.40%and 97.57%,respectively.The addition of hydroxyapatite could enhance the immobilization of Cd^(2+)by the bacteria to a certain extent.SEM and EDS analysis showed that the mineralized products induced by P.stutzeri and B.subtilis were mostly clustered around or attached to the surface of the bacteria,with spherical,reticulated structure and porous surface,while the mineralized products by B.pasteurii were attached to the surface of the bacteria,with compact structure and irregular spherical structure.FTIR analysis suggested that there was CO^(2-)_(3)in the mineralized products.XRD identified,the mineralized products CaCO_(3) induced by the three bacteria.The CdCO_(3) crystal were forms by isomorphic substitution of Ca^(2+)with Cd^(2+).As an alternative,Ca_(0.67)Cd_(0.33)CO_(

关 键 词：微生物矿化 Cd^(2+) 羟基磷灰石 碳酸盐沉淀 

分 类 号：X172[环境科学与工程—环境科学]