Organic Hybrid Hydrogels: A Sustenance Technique in Waste‐Water Treatment

Abstract

Water sustenance is the primary exigency for human survival, besides being significant for food, energy generation, ecology, and socio-economic modernization. The water crisis headed call for wastewater treatment. Owing to positive aspects of Organic Hybrid Hydrogels (OHH) viz. non-toxicity, multiplefunctionalities, biodegradability, biocompatibility, and high sorption capacities; researchers are exploring their usage in waste-water treatment for removal of organic (dyes) and inorganic (heavy metals, radionuclides) contaminants. The boon of OHH application is their ease of separation after the adsorption of pollutants by removing and dewatering them. This review corroborates the complete design of the synthesis of hydrogels, and the adsorption of impurities by them followed by their recovery, required for successful application in the removal of organic and inorganic contaminants from wastewater. It was observed hydrogels employed for the removal of metal ions and dyes follow either Langmuir or Freundlich isotherm or both. The usage of bio-based hydrogels increased the adsorption of contaminants from wastewater. Due to the scarcer exploration of bio/hybrid hydrogels (especially carboxymethyl tamarind kernel gum), this review is expedient for researchers for developing green hydrogels as a water conservation and sustenance technique.

Magnetic, Biocompatible and Biodegradable Carboxymethyl Cellulose‐Based Hydrogel for Cationic Dye Adsorption

“…The adsorption data was fitted to these models, and the model with the highest correlation coefficient (R 2 ) was selected. The Langmuir isotherm model represents the saturated adsorption process and monolayer adsorption, while the Freundlich model generally demonstrates multilayer adsorption and shows that adsorption heat distributions non‐uniformly [53–55] . The mathematical equations of the Langmuir and Freundlich isotherm models in their non‐linear form are as follows: $$$\vcenter{\openup.5em\halign{$\displaystyle{#}$\cr {q}_{e}={{{q}_{m}b{C}_{e}}\over{1+b{C}_{e}}}\hfill\cr}}$$$ $$$\vcenter{\openup.5em\halign{$\displaystyle{#}$\cr {q}_{e}={K}_{F}{C}_{e}^{1/n}\hfill\cr}}$$$ …”

“…The Langmuir isotherm model represents the saturated adsorption process and monolayer adsorption, while the Freundlich model generally demonstrates multilayer adsorption and shows that adsorption heat distributions non-uniformly. [53][54][55] The mathematical equations of the Langmuir and Freundlich isotherm models in their non-linear form are as follows:…”