Harmful Impacts of Heavy Metals and Utility of Biosorption Technique for Their Removal from Wastewater: A Review

Abstract

The increasing number of efluents discharged from the source of water (urban, industrial, agricultural etc.), is resulting in a higher concentration of heavy metals in the source. Heavy metals have a density of over 5g/cm3 to the metals. These are toxic, mutagenic, carcinogenic and resistant in watery and non-aquatic environments and impact water and non-water bodies seriously by substituting the basic metals of the same function. The extraction from the wastewater can be done in numerous techniques for example using an ion replacement, membrane filtration, osmosis, etc. This study discusses the adverse effects of heavy metals on the human body, the benefits of biosorption over traditional approaches for removal of heavy metals, the different biosorbents used to extract heavy metals and concerning issues regarding its commercial use, offering a wider viewpoint for the diversity of biosorbents and utilization of biosorption technique. It is evident from the profound literature survey that pH, biosorbent particle size, contact time, initial metal ion concentration, presence of chelating ligands etc. are some factors that affect the rate and extent of biosorption.

Adsorptive removal of Cd (II) ions from wastewater using biosorbent of Tectona grandis leaves: kinetic, equilibrium and thermodynamic studies

“…The correlation coefficient/ regression value (R 2 ) for Freundlich isotherm was 0.988. The value of 1/n came out as 0.631 i.e., between 0 and 1, implying that the biosorption of Cd (II) on TGLB surface was commendatory (Negi et al, 2021).…”

“…ions was fixed at 10 mg/L, which worked as a concentration gradient (Negi et al, 2021). As a result, while Qe dropped with increasing adsorbent dosage, the percentage removal of Cd (II) ions increased (Fig.…”

Removal of Zn, Pb, and Ni heavy metals from aqueous system using efficient modified-banana peel adsorbent

“…The untreated plant wastes such as papaya wood, maize leaf, tea leaf powder, lalang (Imperata cylindrica) leaf powder, rubber (Hevea brasiliensis) leaf powder (Coriandrum sativum), peanut hull pellets, sago waste, saltbush (Atriplex canescens) leaves, tree fern, rice husk ash, neem bark, grape stalk wastes, sugarcane bagasse, etc. are mostly used as an adsorbents for the removal of heavy metals from waste water [10][11][12][13] . The paper reported that hydroxyl, carboxyl, phosphate, amino and thio functional groups on the agricultural biomass surface are responsible for the heavy metals binding.…”