化工进展 ›› 2021, Vol. 40 ›› Issue (5): 2882-2892.DOI: 10.16085/j.issn.1000-6613.2020-1258

• 资源与环境化工 • 上一篇    下一篇

固定化生物吸附剂对Cd(Ⅱ)的去除性能及机理

余关龙1,2,3(), 彭海渊1,2, 王世涛1,2, 汪国梁1,2, 陈宏1,3, 杜春艳1,3, 刘媛媛1, 孙士权1,3(), 禹丽娥1,3, 王建武1,3   

  1. 1.长沙理工大学水利工程学院,湖南 长沙 410114
    2.湖南省环境保护河湖污染控制工程技术中心,湖南 长沙 410114
    3.洞庭湖水环境治理与生态修复湖南省重点实验室,湖南 长沙 410114
  • 收稿日期:2020-07-06 出版日期:2021-05-06 发布日期:2021-05-24
  • 通讯作者: 孙士权
  • 作者简介:余关龙(1978—),男,博士,研究方向为水污染控制及水环境修复。E-mail:ygl079@csust.edu.cn
  • 基金资助:
    国家自然科学基金(51308069);湖南省教育厅重点项目(19A032);长沙理工大学助推项目(2019QJCZ026)

Performance and mechanism of immobilized biological adsorbent for Cd() removal

YU Guanlong1,2,3(), PENG Haiyuan1,2, WANG Shitao1,2, WANG Guoliang1,2, CHEN Hong1,3, DU Chunyan1,3, LIU Yuanyuan1, SUN Shiquan1,3(), YU Li’e1,3, WANG Jianwu1,3   

  1. 1.School of Hydraulic Engineering, Changsha University of Science and Technology, Changsha 410114, Hunan, China
    2.Engineering and Technical Center of Hunan Provincial Environmental Protection for River-Lake Dredging Pollution Control, Changsha 410114, Hunan, China
    3.Key Laboratory of Dongting Lake Aquatic Eco-Environmental Control and Restoration of Hunan Province, Changsha 410114, Hunan, China
  • Received:2020-07-06 Online:2021-05-06 Published:2021-05-24
  • Contact: SUN Shiquan

摘要:

从处理含Cd(Ⅱ)废水的人工湿地基质层中提取微生物,经过重金属浓度梯度筛选后,通过聚合酶链式反应(PCR)技术分析发现筛选后的菌群对Cd(Ⅱ)有较好的耐受性和吸附能力,菌种丰度依次为Lactococcus< Stenotrophomonas< Serratia< Pseudomona。将筛选后的微生物用包埋固定化技术制成固定化生物吸附剂,在pH=4~5、吸附时间48h、吸附剂用量(湿重)50g/L、Cd(Ⅱ)初始浓度100mg/L时,对Cd(Ⅱ)的最大去除率可达91%±2%。通过吸附平衡研究发现吸附过程符合准一级动力学模型和Langmuir模型,对Cd(Ⅱ)的最大单分子层吸附量为34.4mg/g。BET分析结果显示,固定化生物吸附剂具有介孔结构且比表面积大,有利于吸附作用的进行;傅里叶变换衰减全反射红外光谱法(FTIR-ATR)分析结果说明固定化生物吸附剂具有丰富的重金属结合点 位,—COOH、—OH、—NH和—CH基团参与了Cd(Ⅱ)的吸附过程。固定化生物吸附剂重复使用3次能保持较好的吸附效果,显示出较高的经济实用性。水环境中常见阳离子对Cd(Ⅱ)竞争吸附影响顺序依次为Na+<K+<Ca2+

关键词: 重金属, 固定化, 吸附剂, 微生物, 生物修复

Abstract:

The microorganisms extracted from the substrate of constructed wetlands for treating Cd(Ⅱ) wastewater were screened through heavy metal concentration gradients. The analysis result of PCR technology showed that the screened bacteria had better tolerance and adsorption capacity for Cd(Ⅱ). The abundance of bacteria was Lactococcus<Stenotrophomonas<Serratia< Pseudomona. The screened bacteria were used to prepare the immobilized biosorbent by embedding and immobilization technology. The maximum removal efficiency of Cd(Ⅱ) could reach 91%±2% when pH, adsorption time, adsorbent dosage (wet weight), and initial concentration of Cd(Ⅱ) were 4—5, 48h, 50g/L, and 100mg/L, respectively. It was found that the adsorption process was in accordance with the quasi-first-order kinetic model and Langmuir model. The maximum adsorption capacity of Cd(Ⅱ) was 34.4mg/g. The BET analysis results showed that the immobilized biosorbent had a mesoporous structure and large specific surface area, which was conducive to the adsorption. The results of FTIR-ATR analysis showed that the immobilized biosorbent had abundant heavy metal binding sites, and —COOH, —OH, —NH, and —CH groups participated in the adsorption process of Cd(Ⅱ). The immobilized biosorbent could be reused for three times and maintain a good adsorption effect, which had a high economical practicability. The order of competitive adsorption of of common cations in water environment with Cd(Ⅱ) was Na+ <K+ <Ca2+.

Key words: heavy metal, immobilization, adsorbent, microorganism, bioremediation

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