Liu Renlu, Guan Yong, Chen Liang, Lian Bin
Jiangsu Key Laboratory for Microbes and Functional Genomics, Jiangsu Engineering and Technology Research Center for Microbiology, College of Life Sciences, Nanjing Normal University, Nanjing, China.
National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei, China.
Front Microbiol. 2018 Jan 26;9:41. doi: 10.3389/fmicb.2018.00041. eCollection 2018.
The purpose of this study was to elucidate the characteristics and mechanisms of adsorption and desorption for heavy metals by micro and nano-sized biogenic CaCO induced by , and the pH effect on adsorption was investigated. The results showed that the adsorption characteristics of Cd and Pb are well described by the Langmuir adsorption isothermal equation, and the maximum adsorption amounts for Cd and Pb were 94.340 and 416.667 mg/g, respectively. The maximum removal efficiencies were 97% for Cd, 100% for Pb, and the desorption rate was smaller than 3%. Further experiments revealed that the biogenic CaCO could maintain its high adsorption capability for heavy metals within wide pH ranges (3-8). The FTIR and XRD results showed that, after the biogenic CaCO adsorbed Cd or Pb, it did not produce a new phase, which indicated that biogenic CaCO and heavy metal ions were governed by a physical adsorption process, and the high adsorptive capacity of biogenic CaCO for Cd and Pb were mainly attributed to its large total specific surface area. The findings could improve the state of knowledge about biogenic CaCO formation in the environment and its potential roles in the biogeochemical cycles of heavy metals.
本研究的目的是阐明由[具体物质]诱导的微米级和纳米级生物成因碳酸钙对重金属的吸附和解吸特性及机制，并研究pH值对吸附的影响。结果表明，Cd和Pb的吸附特性可用Langmuir吸附等温方程很好地描述，Cd和Pb的最大吸附量分别为94.340和416.667 mg/g。Cd的最大去除效率为97%，Pb的最大去除效率为100%，解吸率小于3%。进一步的实验表明，生物成因碳酸钙在较宽的pH范围（3-8）内对重金属保持较高的吸附能力。傅里叶变换红外光谱（FTIR）和X射线衍射（XRD）结果表明，生物成因碳酸钙吸附Cd或Pb后未产生新相，这表明生物成因碳酸钙与重金属离子之间的作用是物理吸附过程，生物成因碳酸钙对Cd和Pb的高吸附容量主要归因于其较大的总比表面积。这些发现可以改善我们对环境中生物成因碳酸钙形成及其在重金属生物地球化学循环中潜在作用的认识。
