Potentiality of waste human hair towards removal of chromium(VI) from solution: kinetic and equilibrium studies

Abstract

Industrial and agricultural activities discharges huge amount of hazardous pollutants that lead to massive environmental pollution and health hazards. Keratin is a fascinating protein and useful biopolymer, which is usually found in wool, human hair, nails, feathers, etc. The present research deals with the potentiality of human hair towards removal of hexavalent chromium from aqueous solution through batch mode. The adsorbent was characterized by pH ZPC and SEM study. The Cr(VI) adsorption was studied with the help of different process parameters, viz. initial concentration, contact time, adsorbent dose, pH, and temperature. Results revealed that Cr(VI) adsorption by human hair was highly pH sensitive. Maximum Cr(VI) was adsorbed from water at pH 1.0. Study of temperature effect on chromium adsorption confirmed the endothermic behaviour of the process. On the other hand, thermodynamic properties were also calculated and found that physisorption was dominant with activation energy of 0.385 kJ mol −1. Kinetic study revealed that pseudo-second-order model was followed by the adsorption process. Adsorption equilibrium was analysed with Langmuir, Freundlich, and Dubinin-Radushkevich isotherm models. Results showed that the adsorption system followed both Langmuir and Freundlich isotherms with Langmuir adsorption capacity of 9.852 mg g −1 , which was compared with other adsorbents and observed that the performance of the present adsorbent is better than others. Finally, it can be concluded that human hair could be an alternative chief low-cost waste material for decontamination of heavy metals from an aqueous medium.

Effective Amendments on Cadmium, Arsenic, Chromium and Lead Contaminated Paddy Soil for Rice Safety

“…We found that the alkaline environment of the solution and NaOH modified hairs increased the adsorption of metals to soil and keratin fibers. Our findings are similar to [52,[60][61][62].…”

“…Hairs, as keratin-based adsorbents, are reported to reduce the concentration of HMs in both soil and water [7,52,[58][59][60][61][62]. There are two main mechanisms called physiosorption and chemisorption through which keratin material can remove HMs from air and solution.…”

Adsorption of Cr(VI) from aqueous solution on graphene oxide (GO) prepared from graphite: equilibrium, kinetic and thermodynamic studies

“…However, none of the adsorbent shows excellent performance toward significant Cr(VI) removal efficiency as well as adsorption capacity. Very recently, Mondal et al (2019b, c;Mondal and Basu 2019) reported that Cr(VI) can be removed by using mosambi peel, chicken feather and human hair. Therefore, more new materials should be developed so that effective Cr(VI) removal can be achieved.…”

Potentiality of mosambi (Citrus limetta) peel dust toward removal of Cr(VI) from aqueous solution: an optimization study

“…The two main oxidation states of chromium are available in liquid medium; one is Cr(III) and other is Cr(VI). Moreover, out of these two oxidation state, Cr(VI) is thermodynamically more stable and highly mobile than Cr(III) (Mondal and Basu 2019;Ali et al 2016). Although the form of Cr(VI) is different in different pH medium as chromate (Cr 2 O 4 ), hydrochromate (HCrO 4 − ) or dichromate (AL-Othman et al 2012).…”

“…Many low-cost materials have been used by the earlier researchers for removal of Cr(VI) from aqueous solutions such as Aspergillus niger (Mondal et al 2017); banana peel (Ali et al 2016); potato peel (Mutongo et al 2014); human hair (Mondal and Basu 2019); groundnut hull (Owalude and Tella 2016); lychee peel (Rao et al 2012); chicken feather (Mondal et al 2019b), etc; however, none of the adsorbent showed high adsorption capacity. Therefore, a new easily available adsorbent should be developed for the fulfillment of the above objective.…”