Synergistic effect of novel Co-modified micro/nano geopolymers in a photo-PDS system

Xiaohuan Yang; Zehua Ji; Kemeng Wang; Yuansheng Pei

doi:10.1016/j.chemosphere.2022.136211

Synergistic effect of novel Co-modified micro/nano geopolymers in a photo-PDS system

Chemosphere. 2022 Dec;308(Pt 1):136211. doi: 10.1016/j.chemosphere.2022.136211. Epub 2022 Aug 26.

Authors

Xiaohuan Yang¹, Zehua Ji², Kemeng Wang¹, Yuansheng Pei³

Affiliations

¹ State Key Laboratory of Water Environment Simulation, Ministry of Education, School of Environment, Beijing Normal University, Beijing, 100875, China; The Key Laboratory of Water and Sediment Sciences, Ministry of Education, School of Environment, Beijing Normal University, Beijing, 100875, China.
² Center for Water and Ecology, State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing, 100084, China.
³ State Key Laboratory of Water Environment Simulation, Ministry of Education, School of Environment, Beijing Normal University, Beijing, 100875, China; The Key Laboratory of Water and Sediment Sciences, Ministry of Education, School of Environment, Beijing Normal University, Beijing, 100875, China. Electronic address: yspei@bnu.edu.cn.

PMID: 36037946
DOI: 10.1016/j.chemosphere.2022.136211

Abstract

Persulfate activation is an efficient advanced oxidation process for water treatment. However, many catalyst materials make their preparation methods and raw materials very complicated and expensive while pursuing high-efficiency catalytic effects. In this research, a novel Co-modified micro/nano geopolymer (Co-MNG) material was prepared from solid waste using a mechanochemical method. The whole preparation process of Co-MNG is simple and time-saving, and most of its raw materials are solid waste. In addition, it has few adverse effects on the environment during preparation and use and has a good effect on PDS activation. Under dark conditions, 1 mg L^-1 of unloaded Co metal MNG material could degrade 20 mg L^-1 Rhodamine B solution by 79% in 60 min with 15 mM PDS, but the application of visible light could not enhance its effect. However, after adding 4 wt% of different Co-containing compounds, the prepared Co-MNG materials could improve their degradation effect under the same conditions, and it is more obvious under the condition of applying visible light. Among them, MNG-Co(NO₃)₂ could completely degrade RhB within 40 min under the application of visible light. ESR (electron spin resonance) tests showed that the MNG-Co(NO₃)₂ material could generate a variety of active radicals in a photo-PDS system, such as h⁺, ·OH, ·O₂^- and SO₄^-. Mechanistic research experiments showed that both visible light and Co-MNG materials can activate PDS to a certain extent, but when both exist at the same time, the material could effectively couple visible light and Co activation of PDS in a photo-PDS activation system to achieve synergistic degradation of pollutants in water.

Keywords: Advanced oxidation; Geopolymer; Micro/nano materials; Persulfate activation; Solid waste utilization.

MeSH terms

Catalysis
Environmental Pollutants*
Solid Waste
Water Pollutants, Chemical* / analysis
Water Purification*

Substances

Environmental Pollutants
Solid Waste
Water Pollutants, Chemical