Biosorption of Cadmium by Waste Shell Dust of Fresh Water Mussel Lamellidens marginalis: Implications for Metal Bioremediation

Abstract

The ability of the shell dust of freshwater mussel Lamellidens marginalis (MSD) to remove cadmium from the aquatic system was evaluated. The results indicate that MSD, a waste biomaterial, bears the potential to remove cadmium from contaminated water with a biosorption capacity of 18.18 mg g −1 at pH 6. At equilibrium, the adsorption data fitted to Langmuir (r 2 = 0.992) significantly more than the Freundlich equation (r 2 = 0.66). Regression analysis suggests that the biosorption kinetics followed the pseudo-second-order model (r 2 = 0.999) better than the Lagergren model (r 2 = 0.879). The possible mechanism of biosorption appeared to be ion exchanges with Fe, Al, Si, In, Co, and Ca ions together with binding of different functional groups such as −OH, −CO, −CC, and −C−C, as revealed through FTIR and EDX analyses. Although low in comparison to cadmium, the MSD-adsorbed zinc (q max = 10.64 mg g −1 ) and lead (q max = 8.06 mg g −1 ) varied in amounts, depending upon the initial metal ion concentration and biomass of the adsorbent. These observations substantiate MSD as a low cost and environment friendly biosorbent for heavy metal ion bioremediation.

An insight into the structure, composition and hardness of a biological material: the shell of freshwater mussels

“…Following collection and identication, the esh of the mussels were removed and the shells were washed under running water and then sun dried. 53,54 Further, the esh remnant, if any, attached to the shells were removed carefully, prior to the use in the experiments. In order to carry out the characterization of the shells, 23 shells of C bensoni and 18 shells of L. marginalis were randomly picked from the collections.…”

“…49 Alternatively, the compost bivalve shells can be used, which are more effective than the freshly derived oyster shells. 50 The shells of the mussels and snails are cost effective biosorbent that can be used for the purpose of metal and dye removal, 36,51,52 directly as akes or granules 53,54 or through the formation of hydroxyapatite. 55 The shells of the bivalves are also considered suitable as llers and for the use as a substitute to mortar.…”

“…64 An appraisal of the material features remains pre-requisite to promote the utility of the shells of these mussels that are generated as wastes following exploitation for food 65 and pearl. 66,67 Although, the shell dust of L. marginalis have shown the potential for bioremediation of heavy metals, 54 the ultrastructural details are yet to be deciphered to suggest their use in other purposes. In the present instance, the shell physical characteristics, chemical composition and the nanomechanical properties were also explored to substantiate the freshwater mussel shells as biological material 68 with prospective application in varied elds as a waste bioresource.…”

Sorption of cadmium (II) ion from aqueous solution onto sweet potato (Ipomoea batatas L.) peel adsorbent: Characterisation, kinetic and isotherm studies

“…The pollution of aquatic ecosystems with heavy metal ions such as cadmium is one of the major outlets of metal ion toxicity affecting humans because a large number of number of aquatic resources are used by man for different activities therefore raising the possibility of potential health risk from the contamination of this resource (Hossain et al, 2015). For example wastewater discharges from industrial activities has been reported as one of the main outlets of aquatic pollution from heavy metals.…”

“…These beneficial uses of cadmium in industrial processes have led to increased cadmium transport within the proximity of man's environment. However, poor environmental practices has led to their introduction into the food web at magnified levels resulting in cadmium interfering with the physiological, behavioural and biochemical processes in man (Prapagdee et al, 2014;6 Bernard, 2008;Johri et al, 2010;Hossain et al, 2015). The significance of this problem has led to the inclusion of cadmium as one of the priority pollutants that should be eliminated from drinking water and discharged effluents by the United States Environmental Protection Agency (USEPA) and the World Health Organisation (WHO).…”