Physicochemical analysis and heavy metals remediation of pharmaceutical industry effluent using bentonite clay modified by h2so4 and hcl

Abstract

Environmental pollution by industrial effluent has become a vital issue partly because of the detection of heavy metals in them, which need to be mitigated. Adsorbents were produced from Bentonite clay using 2 M H2SO4 and 2 M HCl as modifying agents in ratio 1:2 by wet impregnation method. Physicochemical properties of the pharmaceutical effluents such as pH, temperature, turbidity, conductivity, Chemical Oxygen Demand (COD), Biological Oxygen Demand (BOD), and heavy metals were determined. High concentrations of Fe(III) and Zn(II)were observed in the effluents when compared with standards. The optimal value of pH for Fe(III) and Zn(II) was 8, and a dose of 0.05 g was found to be the optimal value for all the adsorption system. The adsorption was best fit to Langmuir isotherm and the pseudo-second-order kinetic model. The results obtained in this study showed that the produced adsorbents could be used to supplement the commercial adsorbents in the specific application. Furthermore, the acid modification was helped to increase the sorption capacity of the clay to the heavy metals studied with H2SO4 being the better modification agent.