Work

Persulfate gel sustaining-release materials and nano zero-valent iron for in situ remediation of high- and low-permeability systems

Year: 2024

Type: article

Abstract: The research on in-situ remediation of heterogeneous aquifers using sustain-release material is scarce. In this study, the persulfate gel sustaining-release material (PGSR) was fabricated, and pollutants dynamic change, remediation efficiency and impact mechanism of nano zero-valent iron (NZVI) activated PGSR on high- and low-permeability systems contaminated with toluene and naphthalene were explored by tank experiments. The results demonstrated that PGSR possesses superior remediation efficiency compared to conventional persulfate solutions, and the pollutants’ removal efficiency attains the maximum when the molar ratio of Na 2 S 2 O 8 in PGSR to NZVI is 2/2. The long-term release of PGSR significantly extends the reaction time between persulfate and NZVI, which is conducive to addressing the tailing issue in the low-permeability zone (LPZ). The influence of process parameters on the remediation efficiency is important. Excessive activators or oxidants exert an influence on sulfate ions, thereby impeding pollutant degradation. Additional, injecting a small amount of PGSR will be diluted due to groundwater flow and unable to form a persistent reaction zone, while injecting a large amount of PGSR will block the pores, causing groundwater to flow around the reaction zone and influencing pollutant removal. Research offers technical support for in-situ remediation of contaminated sites with complex hydrogeological conditions. • PGSR performs better than persulfate solution in removing TOL and NAP. • PGSR is conducive to addressing the long-term tailing of pollutants in LPZ. • The molar ratio of NZVI to PGSR strongly influenced pollutant remediation efficiency. • The aquifers heterogeneity and oxidant injection jointly affect pollutants transport.

Source: Environmental Technology & Innovation

DOI: 10.1016/j.eti.2024.103978

Authors: Zhongran Wu, Shengyu Wu, Yao Hou, Hongjian Cao, Chao Cai

Institutions: Chinese Academy of Sciences, Institute of Urban Environment, University of Chinese Academy of Sciences, Fujian Agriculture and Forestry University

Language: English

Topic: Environmental remediation with nanomaterials

Subfield: Biomedical Engineering

Field: Engineering

Domain: Physical Sciences

SDGs: Clean water and sanitation, Responsible consumption and production

Open Access status: gold

Estimated APC paid: $2,440