Remediation of arsenic-contaminated water using agricultural wastes as biosorbents

ABSTRACT

Arsenic (As) contamination of groundwater reservoirs is a global environmental and health issue given to its toxic and carcinogenic nature. Over 170 million people have been affected by As due to the ingestion of As-contaminated groundwater. Conventional methods such as reverse osmosis, ion exchange, and electrodialysis are commonly used for the remediation of As-contaminated water; however, the high cost and sludge production put limitations on their application to remove As from water. This review critically addresses the use of various agricultural waste materials (e.g., sugarcane bagasse, peels of various fruits, wheat straw) as biosorbents, thereby offering an eco-friendly and low-cost solution for the removal of As from contaminated water supplies. The effect of solution chemistry such as solution pH, cations, anions, organic ligands, and various other factors (e.g., temperature, contact time, sorbent dose) on As biosorption, and safe disposal methods for As-loaded biosorbents to reduce secondary As contamination are also discussed.

KEYWORDS:

• Arsenic removal
• biosorption
• drinking water
• iron oxides
• water filter
• industrial solid waste

Funding

The authors are very grateful to the Grand Challenges Canada–Stars in Global Health (GCC Grant No. S5 0433-01) and the Institute of Soil and Environmental Sciences, University of Agriculture Faisalabad, Pakistan, for providing financial support. Dr. Balaji Seshadri's contribution is part of the project funded by the Cooperative Research Centre for Contamination Assessment and Remediation of the Environment (CRC CARE), Australia in collaboration with the postdoctoral fellowship from University of South Australia, Mawson Lakes Campus, Adelaide, South Australia. The postdoctoral fellowship program (PJ010923) with Dr Won-Il Kim at the National Academy of Agricultural Science, Rural Development Administration, Republic of Korea, supported Dr. Kunhikrishnan's contribution.