Renewable P-type zeolite for superior absorption of heavy metals: Isotherms, kinetics, and mechanism

Mingyue Chen; Shuying Nong; Yantao Zhao; Muhammad Sohail Riaz; Yi Xiao; Maxim S Molokeev; Fuqiang Huang

doi:10.1016/j.scitotenv.2020.138535

Renewable P-type zeolite for superior absorption of heavy metals: Isotherms, kinetics, and mechanism

Sci Total Environ. 2020 Jul 15:726:138535. doi: 10.1016/j.scitotenv.2020.138535. Epub 2020 Apr 8.

Authors

Mingyue Chen¹, Shuying Nong¹, Yantao Zhao¹, Muhammad Sohail Riaz¹, Yi Xiao¹, Maxim S Molokeev², Fuqiang Huang³

Affiliations

¹ Beijing National Laboratory for Molecular Sciences and State Key Laboratory of Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China.
² Siberian Federal University, Krasnoyarsk 660041, Russia.
³ Beijing National Laboratory for Molecular Sciences and State Key Laboratory of Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China; CAS Key Laboratory of Materials for Energy Conversion and State Key Laboratory of High-Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050, China. Electronic address: huangfq@pku.edu.cn.

PMID: 32304944
DOI: 10.1016/j.scitotenv.2020.138535

Abstract

Zeolite is a characteristic material for removing heavy metals exhibiting by low tolerance quantities. It is particularly desirable although challenging to cultivate an unmodified and reusable zeolite for eradicating heavy metals with great capacity. Herein, we sought out and firstly synthesized the uniform octahedral zeolite Na₆Al₆Si₁₀O₃₂·12H₂O for heavy metal ions trap, proven extraordinarily effective decontamination of M²⁺ (Pb²⁺, Cd²⁺, Cu²⁺, and Zn²⁺). The maximum capacities of Pb²⁺, Cd²⁺, Cu²⁺, and Zn²⁺ were 649, 210, 90 and 88 mg/g, and the distribution coefficients (K_d) was ~10⁸ mL/g for Pb²⁺ which emphasized the superior effectiveness of Na₆Al₆Si₁₀O₃₂·12H₂O contrasted with other zeolites. Rapid adsorption was observed that Pb²⁺ concentration (7.5 ppm) was reduced to 0.6 ppb in 2 min. The removal mechanism was ascribed to the ion exchange and hydroxyl groups thereby affording high adsorption capacity. We also investigated the heavy metal removal of zeolite 13X and 4A for comparison and concluded the determining factor affecting absorption capacity. The removal rate of Pb remained at 97% even after five regeneration recycles. The zeolite was therefore promising for practical water purification and industrialization.

Keywords: Drinkable level; High efficiency; Regeneration; Uptake capacity.