生物学杂志

生物学杂志 ›› 2019, Vol. 36 ›› Issue (5): 96-.doi: 10.3969/j.issn.2095-1736.2019.05.096

• 技术方法 • 上一篇    下一篇

耐镉功能内生菌的筛选及其固定化处理含镉废水

  

  1. 安徽大学 资源与环境工程学院，合肥 230601
  • 出版日期:2019-10-18 发布日期:2019-10-11
  • 通讯作者: 石先阳，博士，教授，研究方向为废水生物处理与资源化，E-mail: shixi381@163.com
  • 作者简介:杨培，硕士，研究方向为废水生物处理与资源化，E-mail:1421770744@qq.com
  • 基金资助:
    国家自然科学基金项目（51278001）

Screening of cadmium resistant endophytic bacteria and immobilized for treating cadmium of wastewater

  1. School of Resources and Environmental Engineering, Anhui University, Hefei 230601, China
  • Online:2019-10-18 Published:2019-10-11

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摘要： 从芦苇根部筛选出一株耐镉内生细菌，经鉴定为Chryseobacterium rhizosphaerae SH-1；Cd2+对该菌株最小抑菌浓度高达450 mg/L，显微观察发现其细胞表面吸附机制参与了 Cd2+的去除过程；FTIR 分析表明菌株表面的O-H、N-H、C-H、N≡C-、-NO2、C=S、P=O、S-O等基团均参与了吸附作用。采用海藻酸钠凝胶包埋法对菌株SH-1进行固定化，考察了吸附时间、pH和Cd2+初始浓度对固定化微生物吸附Cd2+影响，并对其吸附特性进行了动力学研究。结果表明：固定化内生菌SH-1在Cd2+初始浓度为100 mg/L，吸附时间为480 min，溶液pH值为5条件下，对Cd2+的去除率高达93.24%；Langmuir 等温吸附模型能描述其吸附Cd2+的等温吸附特征，最大理论吸附量为187.41 mg/g。另一方面，准二级动力学模型较好地拟合了固定化SH-1吸附Cd2+的动力学过程，理论平衡吸附量为51.02 mg/g。这些结果均证实固定化内生菌SH-1是一种很有潜力的生物吸附剂。

关键词: font-size:medium, ">内生细菌；海藻酸钠；固定化；吸附；镉离子

Abstract: A cadmium-resistant endophytic bacterium was isolated from reed rhizosphere and identified as Chryseobacterium rhizosphaerae SH-1. The minimum inhibitory concentration of Cd2+ was up to 450 mg/L, and microscopic observation showed that the cell surface adsorption mechanism was involved in the removal process of Cd2+. FTIR analysis showed that O-H, N-H, C-H, N≡C-,-NO2, C=S, P=O and S-O were all involved in the adsorption. The strain was immobilized using sodium alginate. The effects of contact time, pH and Cd2+ initial concentrations on Cd2+ adsorption by immobilized beads were investigated and the adsorption properties were also explored through adsorption kinetics. The result showed that the removal efficiency was over 93.24% while the initial Cd2+ concentration of 100 mg/L, contact time of 480 min and pH of 5.0. The isothermal adsorption characteristics of Cd2+ could be described by Langmuir isothermic adsorption model with the maximum theoretical adsorption capacity of 187.41 mg/g. On the other hand, the pseudo-second-order model well fitted the kinetic process of Cd2+ adsorption by immobilized SH-1 and the theoretical equilibrium adsorption capacity was 51.02 mg/g. The results showed that the immobilized endophytic bacterium SH-1 could be a great potential biosorbent.

Key words: endophytic bacterial, sodium alginate, immobilize, adsorption, cadmium ion

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