Reclamation of Pesticides Contaminated Soil and Water Using Biochar: A Review on Adsorption Potential of Biochar

Abstract

The application of agrochemicals into the environmental matrix has sluggishly degraded the quality of their original form. Pesticide consumption in the agricultural sector has been used for the quantity production of crops however, now considered as a culprit for the quality crops. Lands that once provided ample crops of good quality are now facing a case of severe damage impacting their crop quality. The prime need is to reclaim these contaminated matrices. For the same, an eco-friendly approach should be adopted. One such approach is the application of biochar for pesticide sorption. Biochar is a carbon-rich, stabilized product acquired when biomass undergoes pyrolysis at 200-650˚C. It is known for sequestration ability and mitigation of environmental contaminants. Its properties (surface area, pore size, ash contents, and functional groups) determine the potential for sorption. Biochar when modified is most effective for the sorption mechanism. For instance, rice straw biochar when treated with phosphoric acid (T-RSBC) showed stronger adsorption capacity for sorption in waste water effluent. Corn straw when doped with phosphorus functional groups was highly effective for adsorption of triazine pesticide from water. Other biochar that could remove pesticides are corn cob and corn starch. Activated coconut shell biochar showed the highest adsorption capacity for diazinon removal from water than other modified coconut shell biochar. Plant biochar (pine needle, oak wood, corn stover) having a high content of lignin have better properties such as large surface areas (112-642 m g ) and macropores (0.06- 1.90 cm g ) that increase the sorption capacity of pesticides in soils than animal and cellulose-based biochar. This review paper aims to evaluate the role of biochar in the sorption of pesticides from soil and water.