| 朱晓丽,李雪,寇志健,王军强,尚小清,陈超.生物炭基硫酸盐还原菌（SRB）对Cr（Ⅵ）的吸附效应及作用机制[J].农业环境科学学报,2021,40(4):866-875. |
| 生物炭基硫酸盐还原菌（SRB）对Cr（Ⅵ）的吸附效应及作用机制 |
| The adsorption effects and mechanisms of biochar immobilized sulfate-reducing bacteria(SRB) on Cr (Ⅵ) |
| 投稿时间：2020-10-05 |
| DOI：10.11654/jaes.2020-1156 |
| 中文关键词: 生物炭基载体 硫酸盐还原菌（SRB） Cr（Ⅵ）污染 吸附动力学 最佳吸附条件 |
| 英文关键词: biochar carrier sulfate-reducing bacteria Cr(Ⅵ) pollution adsorption kinetics optimized conditions |
| 基金项目:国家重点研发计划项目（2019YFD1002404）；陕西省重点研发计划项目（2019NY-200，2020ZDLNY06-06，2020ZDLNY07-10）；西安市科技计划项目（2019-GXYD18.9，20193057YF045NS045） |
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| 中文摘要: |
| 分别在300、500℃和700℃下制备水稻、小麦和玉米秸秆生物炭，对比以不同类型生物炭为载体制备的炭基硫酸盐还原菌（SRB）对Cr（Ⅵ）的吸附效应，筛选出吸附效果最佳的炭基菌剂。采用扫描电镜、傅里叶红外光谱和比表面积测试仪对生物炭进行表征分析，研究了溶液pH、吸附时间、生物炭添加量和Cr（Ⅵ）初始浓度对炭基SRB吸附Cr（Ⅵ）的影响，并结合吸附动力学和等温吸附模型探讨其对Cr（Ⅵ）的吸附过程及作用机制。结果表明：以700℃限氧热解小麦秸秆（XM700）为载体制备的炭基SRB（IBXM700）对Cr（Ⅵ）的吸附效果最佳，其最佳吸附条件为pH=5、生物炭添加量0.6 g·100 mL-1、吸附时间24 h、Cr（Ⅵ）的初始浓度100 mg·L-1；IBXM700对Cr（Ⅵ）的吸附更符合拟一级动力学，以离子交换和表面物理吸附为主，以化学吸附作用为辅，其等温吸附符合Langmuir模型，属于单分子层吸附；SRB能还原SO42-为S2-，或分泌还原酶将Cr（Ⅵ）还原为Cr（Ⅲ），从而达到去除目的。研究表明，IBXM700去除Cr（Ⅵ）的主要机制为吸附作用与还原作用。 |
| 英文摘要: |
| Biochars were produced from rice straw, wheat straw, and corn straw at 300, 500℃, and 700℃, respectively, and the adsorption effects of sulfate-reducing bacteria(SRB) immobilized by different biochars on Cr(Ⅵ) were compared. Subsequently, the SRB immobilized by XM700(produced from rice straw pyrolysis under 700℃) denoted as IBXM700 was chosen as experimental material based on its higher capability for Cr(Ⅵ) removal than that of other materials. The surface morphology and characteristics of IBXM700 were determined with Scanning Electron Microscope(SEM), Fourier Transform Infrared Spectrosopy(FTIR), and BET surface area(BET). Furthermore, the influence parameters related to the adsorption process, including pH, adsorption time, the amount of biochar added, and the initial concentration of Cr(Ⅵ), were investigated. In addition, the adsorption process was described using adsorption kinetics and an isothermal model. The results showed that the optimized conditions were as follows:a pH of 5.0, a biochar amount of 0.6 g·100 mL-1, an adsorption time of 24 h, and an initial Cr(Ⅵ) concentration of 100 mg·L-1. The adsorption process of Cr(Ⅵ) by IBXM700 was properly fitted by pseudo-first-order kinetics and the Langmuir model, which indicated that the adsorption of Cr(Ⅵ) by IBXM700 is based on monolayer adsorption with ion exchange, surface physical adsorption, and chemical adsorption. SRB could reduce SO42- to S2- and secrete reductase for the reduction of Cr(Ⅵ) to Cr(Ⅲ), thus removing Cr(Ⅵ). Therefore, reduction and adsorption might be the main removal mechanisms of Cr (Ⅵ) by IBXM700. |
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