Permeable reactive barrier of waste sludge from wine processing utilized to block a metallic mixture plume in a simulated aquifer

Abstract

Heavy metal contamination in underground water commonly occurs in industrial areas in Taiwan. Wine-processing waste sludge (WPWS) can adsorb and remove several toxic metals from aqueous solutions. In this study, WPWS particles were used to construct a permeable reactive barrier (PRB) for the remediation of a contaminant plume comprising HCrO4−, Cu2+, Zn2+, Ni2+, Cd2+, and AsO43− in a simulated aquifer. This PRB effectively prevented the dispersals of Cu2+, Zn2+, and HCrO4−, and their concentrations in the pore water behind the barrier declined below the control standard levels. However, the PRB failed to prevent the diffusion of Ni2+, Cd2+, and AsO43−, and their concentrations were occasionally higher than the control standard levels. However, 18% to 45% of As, 84% to 93% of Cd, and 16% to 77% of Ni were removed by the barrier. Ni ions showed less adsorption on the fine sand layer because of the layer's ineffectiveness in multiple competitive adsorptions. Therefore, the ions infiltrated the barrier at a high concentration, which increased the loading for the barrier blocking. The blocking efficiency was related to the degree of adsorption of heavy metals in the sand layer and the results of their competitive adsorption.

Reaction medium for permeable reactive barrier remediation of groundwater polluted by heavy metals

“…In recent years, solid waste have been used in the reaction medium, which plays a role in reducing the hazard of heavy metals in groundwater, as well as the cost of solid waste treatment and PRB operation. Solid waste such as waste sludge (Chien et al, 2021), fly ash (Yang et al, 2020), and recycled concrete (Indraratna et al, 2010) etc., has become a popular research object for the development of new reaction media. Solid waste in line with the concept of sustainable development is selected as the medium material.…”