Biosorption and Characterization Studies of Blepharispermum hirtum Biosorbent for the Removal of Zinc

Abstract

The effectiveness of low-cost biosorbent Blepharispermum hirtum for the removal of Zn(II) ions from aqueous solution was examined. To assess the impact of solution pH and temperature on biosorption capability, batch biosorption tests were conducted. The optimum conditions for biosorption were discovered at pH 6.0, 0.5 g/L of biomass, and 15 min of equilibrium duration. The biosorption data was well represented by Langmuir model with correlation coefficient of 0.9981 followed by Freundlich, Temkin and Dubinin--Radushkevich isotherms with the correlation coefficients of 0.9834, 0.9812 and 0.8790 respectively at a solution temperature of 303 K. According to the Langmuir isotherm model, the maximal adsorption capacities (q_max) for Zn(II) was 27.66 mg/g. The Fourier-transform infrared spectrometer (FTIR), X-ray diffraction (XRD) and scanning electron microscope (SEM) were used to carry out the characterization studies of biosorbent Blepharispermum hirtum. Discrete aggregates developed on the surface of the biosorbent because of interaction with metal ions. Either electrostatic attraction or a complexation mechanism held the metal ions to the biosorbents’ active sites.