• Journal of Inorganic Materials
  • Vol. 36, Issue 10, 1083 (2021)
XIAO Yao1, WU Zhongjie2, CUI Mei3, SU Rongxin3、4, XIE Lianke2, and HUANG Renliang4、*
Author Affiliations
  • 11. School of Environmental Science and Engineering, Tianjin University, Tianjin 300072, China
  • 22. Shandong Electric Power Research Institute of Chinese Power Company, Jinan 250002, China
  • 33. School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China
  • 44. School of Marine Science and Technology, Tianjin University, Tianjin 300072, China
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    Abstract

    Heavy metals can seriously endanger human health and the ecological environment due to their toxicity, persistence, and bioaccumulative nature. In this study, an alkali-modified biochar-bentonite composite (CaO-Bent-CB) was prepared by alkali modification of corncob residues and bentonite mixture by calcium chloride and calcination at high temperature under anaerobic conditions. The CaO-Bent-CB composite has a specific surface area of ​​441.1 m2/g, which is significantly higher than CB (132.7 m2/g) and CaO-CB (177.2 m2/g). Meanwhile, the adsorption perfermance of CaO-Bent-CB to lead ions in water was evaluated. The results showed that the removal efficiency reached 98% after 6 h-adsorption, and the adsorption capacity was 109.6 mg/g when the concentration of lead ion was 120 mg/L, the weight ratio of bentonite to corncob residues was 1:5, and the dosage was 1 g/L. The adsorption capacity of CaO-Bent-CB was higher than that of CB (13.4 mg/g), bentonite (72.9 mg/g) and CaO-CB (86.9 mg/g). Moreover, the lead ion contaminated soil was stabilized by CaO-Bent-CB. When the concentration of lead ion in soil is 2200 mg/kg, and the loading of CaO-Bent-CB is 8% of soil, the concentration of lead ions in acid leachate (H2SO4-HNO3, pH=3.2, 12 h-soaking) is 4.5 mg/L, which is lower than the standard value of hazardous waste identification (5 mg/L). The results show that CaO-Bent-CB has a great potential in the water treatment and heavy metals removal in soil.

    近年来, 随着工业的快速发展与长期的人为活动, 含重金属离子工业废水的不达标排放对水体和土壤造成了严重污染[1], 导致镉大米、血铅超标、水体砷超标等事件频发。重金属具有持久存留、难以降解、生物积累的特性[2], 严重危害人体健康和生态安全[3]。其中, 铅离子(Pb2+)污染受到广泛关注[4]。例如, 过量的铅会降低土壤质量和肥力, 进而影响植物的生长和农作物的产量[5]; Chen等[6]研究显示斑马鱼的胚胎暴露于低剂量的铅环境, 斑马鱼的行为和学习能力会受到影响。此外, 铅中毒会导致成年人出现脑损伤、精神障碍、高血压以及肾脏问题[7], 并且影响儿童智力和身体发育, 造成注意力和学习能力下降[8]

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    Yao XIAO, Zhongjie WU, Mei CUI, Rongxin SU, Lianke XIE, Renliang HUANG. Co-modification of Biochar and Bentonite for Adsorption and Stabilization of Pb2+ ions [J]. Journal of Inorganic Materials, 2021, 36(10): 1083
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    Category: RESEARCH ARTICLE
    Received: Dec. 30, 2020
    Accepted: --
    Published Online: Nov. 26, 2021
    The Author Email: HUANG Renliang (tjuhrl@tju.edu.cn)