Studies on biosorption of Cr(VI) on a green resin: dry cow dung powder and tracer technique

Abstract

The present investigation entails the application of dry cow dung powder (DCP) as an indigenous, inexpensive and eco-friendly material for the removal of Cr(VI) from aqueous medium. Batch biosorption experiments were conducted employing 51 Cr(VI) as a tracer and the effect of various process parameters such as optimum pH, temperature, amount of resin, time of equilibration, agitation speed, concentration of metal ions and interfering effect of different salts etc. were studied. The kinetic studies were carried out employing various models but the best fitting was given by Lagergren Pseudo-second order model with high correlation coefficient R 2 value of 0.997 and adsorption capacity of 10.20 mg/g. The thermodynamic parameters for biosorption were evaluated as ΔG • = −2.837 kJ/mol, ΔH • = −4.757 kJ/mol and ΔS • = 16.64 J/mol K, which indicated spontaneous and exothermic process with high affinity of DCP for Cr(VI). Many naturally available materials are used for the biosorption of heavy metal pollutants, where most of them are physically or chemically modified. In this research work, DCP has been utilized without any pre or post chemical treatment. Thus it manifests the principle of green chemistry and proves to be an eco-friendly resin.

Biosorptive profile of synthetic and natural humiresin for the remediation of metallic water pollutants

“…The rate constant of all the elements indicates rapid kinetics and it signifies practical importance as this kind of system require a smaller reactor volume ensuring efficiency and economy of the process [25]. The different adsorption capacity explains heterogeneous nature of DCP and preferential binding of various functional groups at different pH depending on speciation of particular metal ions in aqueous medium.…”

Experimental Study on Removal of Chromium by using Cow Dung as Low Cost Adsorbents

“…Various methods of treatments such as chemical precipitation, electrodialysis, membrane process, liquid extraction and ion exchange have been employed for the removal of this heavy metal [10]. For the removal of heavy metal from the aqueous milieu, various methods such as chemical precipitation, electrodialysis, membrane process, liquid extraction and ion exchange have been employed [11]. Biogas is a commonly used bio-fuel around the globe and is generated through an environmental friendly process of anaerobic digestion or the fermentation of biodegradable matters such as biomass, manure, sewage, municipal waste, rubbish dumps, septic tank, green waste and energy crops with a stable product for agricultural purposes without any detrimental effect on the environment [12].…”