Biochar as a low-cost adsorbent for heavy metal removal: A review

Abstract

Conversation of agricultural residues to from biochar can be used as for as the treatment of aqueous solution an alternative remediation of heavy metals from the environment used as low-cost adsorbent. Ground water, originated from natural and anthropogenic source each contaminated by heavy metals. Removal of heavy metals from aqueous solutions which is examined by a number of studies using biochar as a sorbent. Generally development of commercial biochar purposes, reliable data on production of biochar technologies is required. For this purpose, peer-reviewed scientific articles on carbonization technologies (pyrolysis, gasi?cation, ?ash carbonization and hydrothermal carbonization,) have been analyzed. Different mechanisms such as ion exchange, electrostatic interactions, complexation, membrane filtration, physical sorption, and precipitation have been effective for removal of heavy metals. Mathematical sorption models can be used as the efficiency of biochar for removing heavy metals, and also promote in water treatment through the application of biochar technology in water treatment. Biochar used as a low-cost adsorbent to heavy metal removal from aqueous solution is promising and an emerging waste water treatment technology. When the biochar were impregnated with chemicals, the effect was a little increased. An About under the optimum conditions.99% Cd, Pb and Zn were removed from aqueous solution using biochar.