The evaluation of in-site remediation feasibility of Cd-contaminated soils with the addition of typical silicate wastes. (October 2020)

• Record Type: Journal Article
• Authors: Yang, Huifen; Zhang, Ge; Fu, Peng; Li, Zhen; Ma, Wenkai
• Is Part Of: Environmental pollution. Volume 265(2020)Part B
• Publication Date: 2020-10
• Subjects: Remediation -- Cd-contaminated soils -- Typical silicate waste -- Amorphous phase; Pollution -- Periodicals; Pollution -- Environmental aspects -- Periodicals; Environmental Pollution -- Periodicals; Pollution -- Périodiques; Pollution -- Aspect de l'environnement -- Périodiques; Pollution -- Effets physiologiques -- Périodiques; Pollution; Pollution -- Environmental aspects; Periodicals; Electronic journals; 363.73
• DOI: 10.1016/j.envpol.2020.114865
• Languages: English
• ISSNs: 0269-7491

Abstract

Abstract: In-site remediation is a relatively promising and socially acceptable technique for heavy metal contaminated soils. But the key task is to select cost-effective and environment-friendly amendents for the consideration of practical application. Based on the property of four typical silicate wastes such as straw ash (SA), coal fly ash (CFA), ferronickel slag (FNS) and blast-furnace slag (BFS), effects of four wastes on available Cd content and Cd chemical speciation in amended soils, and physicochemical properties of the amended soils were carried out in the study. The results showed that four wastes were dominately composed of the amorphous phases with OH − ions readily released. When the weight ratio of silicate wastes to artificial Cd-contaminated soils reached 10%, the available Cd contents decreased from 4.12 mg/kg in untreated soils to 1.94, 1.92, 1.45 and 1.53 mg/kg in amended soils by adding SA, CFA, FNS and BFS respectively, after the soils were amended for 30 days. The residual fraction of Cd (R) was 2.54, 2.48, 2.77 and 2.58 times higher in amended soil than that in untreated soil when SA, CFA, FNS and BFS was added, respentively. The soil pH and CEC were improved. The amended soils by adding SA and FNS were looser than those by adding CFA and BFS, and air permeability of the amended soils by SA was better than that by FNS. Graphical abstract: Image 1 Highlights: Four typical silicate wastes are selected to amend Cd-contaminated soils for the first time. The available Cd content in tested soils can be decreased effectively by any of four wastes. Alkalinity and amorphous phases of four wastes promote generation of residual fraction of Cd. The suitable remediation sites using four silicate wastes as the amendments should be different.