Fabrication of engineered biochar for remediation of toxic contaminants in soil matrices and soil valorization

Biochar has emerged as an efficacious green material for remediation of a wide spectrum of environmental pollutants. Biochar has excellent characteristics and can be used to reduce the bioavailability and leachability of emerging pollutants in soil through adsorption and other physico-chemical reactions. This paper systematically reviewed previous researches on application of biochar/engineered biochar for removal of soil contaminants, and underlying adsorption mechanism. Engineered biochar are derivatives of pristine biochar that are modified by various physico-chemical and biological procedures to improve their adsorption capacities for contaminants. This review will promote the possibility to expand the application of biochar for restoration of degraded lands in the industrial area or saline soil, and further increase the useable area. This review shows that application of biochar is a win-win strategy for recycling and utilization of waste biomass and environmental remediation. Application of biochar for remediation of contaminated soils may provide a new solution to the problem of soil pollution. However, these studies were performed mainly in a laboratory or a small scale, hence, further investigations are required to fill the research gaps and to check real-time applicability of engineered biochar on the industrial contaminated sites for its large-scale application.

Remediation of arsenic contaminated water and soil using mechanically (ball milling) activated and pyrite-amended electrolytic manganese slag

With the development of industry, heavy metal (HM) pollution of soil has become an increasingly serious problem. Using passivators made of industrial by-products to immobilize HMs in contaminated soil is a promising in-situ remediation technology. In this study, the electrolytic manganese slag (EMS) was modified into a passivator (named M-EMS) by ball milling, and the effects of M-EMS on adsorption of As(V) in aquatic samples and on immobilization of As(V) and other HMs in soil samples were investigated under different conditions. Results demonstrated that M-EMS had a maximum As(V) adsorption capacity of 65.3 mg/g in the aquatic samples. Adding M-EMS to the soil reduced the leaching of As (from 657.2 to 319.8 μg/L) and other HMs after 30 d of incubation, reduced the bioavailability of As(V) and improved the quality and microbial activity of the soil. The mechanism for M-EMS to immobilize As in the soil are complex reactions, ion exchange reaction with As and electrostatic adsorption. This work provides new ideas of using waste residue matrix composites for sustainable remediation of Arsenic in the aquatic environment and soil.

Advances in Remediation of Contaminated Sites

With the development of the social economy, the population has increased sharply, and the land area involved in people’s production and life is also gradually increasing [...]