Facile modification of natural absorbents for removal of as iii from water

Abstract

Natural resources are regarded as the precious gift from nature to mankind. Among the natural resources, water is considered as the most vital and precious gift from nature to mankind. However, water is being more contaminated day by day due to release of industrial effluents into the water bodies without any pretreatment process, due to which the water bodies contain a range of pollutants above the permissible limit. Water pollution due to heavy metals is one of the major concerns and needs ubiquitous attention since they are highly toxic and endangers both biotic and abiotic environments. Innovative, competent, and cost-effective techniques are required for management of water contaminated with hazardous metals that may enter the food chain and their accretion in living species is causing various diseases. In the present work, pristine Phyllanthus Emblica seed coat (PPE), derivatized Phyllanthus Emblica seed coat (DPE), Prunus Armeniaca seed coat (PASC) powder and its modified form (MPASC) and pristine Punica Granatum carpellary membrane (PPC) have been utilized as adsorbents for remediation of trivalent arsenic ions (As(III)) from aqueous system. All the materials were characterized by suitable techniques. Batch adsorption studies were conducted to identify the effect of initial As(III) ion concentration, time of contact, temperature, pH, and adsorbent dose on remediation of As(III) ion using pristine and modified form of the adsorbents. Langmuir/Freundlich/Temkin was the different isotherm models applied to assess the equilibrium data. Adsorption kinetics was also studied by applying different kinetic models. Optimization studies using response surface methodology were also conducted to assess the removal efficiency of adsorbents in different conditions by optimizing the adsorption variables. The experiments were designed for pristine and modified adsorbents using Design Expert® software and responses were observed from randomized runs. To check out the reusability of each adsorbent, regeneration studies have