Biochar as heavy metal sequestration agent in various soils

The use of chemical fertilizers in modern agriculture as well as increasing urbanization, mining and metal processing has led to the contamination of soil and water with heavy metals such as Pb, Cd, Zn, Cu, Cr and As. The detrimental effects of these elements on human health is a worldwide concern and triggers interest in the remediation of contaminated soils. Several strategies have been proposed over the years to manipulate their bioavailability using a range of soil amendments by some techniques such as isolation, immobilization, toxicity and/or mobility reduction of heavy metals. Biochar, pyrolyzed solid biomass residues, has received great attention. Agreed and conflicting results, identify gaps and recommend research needs have been reviewed. The main mechanisms of heavy metals sorption by biochars also investigated. The results showed that biochars are highly suitable for the amendment of contaminated soils. However, the high rate application of biochar and the expenses of effective biochar production are the most limiting factors for application of biochars. The effects of feedstock types, the application rate of biochars and the metal species have led to conflicting results of studies of biochar application on heavy metals sorption

Keywords:

heavy metals , contamination , remediation , biochar