Bioadsorbents for the removal of salt ions from saline water: a comprehensive review

Abstract

Water quality can be affected due to organic or inorganic salts present in water depending upon different regions. An increase in salts has deteriorated the quality of the water, harming both human health and aquatic life. Various technologies are developed to extract salts, bioadsorption being the most preferred, eco-friendly, and economical method for desalination. To remove salts from aqueous solutions, an array of adsorbents, including natural, low-cost materials, or wastes, called bioadsorbents are studied. The review aims at studying different bioadsorbents used for reducing salinity and the effect of pH, contact time, bioadsorbent dosage, initial concentration, temperature, and size of particulate matter on the removal efficacy of salts from saline water. The pseudo-second-order kinetics and Freundlich isotherm are the governing models that described salinity ions equilibrium and isotherm data. Prospects of the study including the potential for commercialization, scaling up, extensive applications of adsorbents, and their functional utility are discussed.