Abstract
This article examines the practical utilization of biochar obtained from Turbinaria ornata biomass in batch and packed bed column modes for remediation of zinc from synthetic and electroplating industrial wastewaters. The zinc uptake by Turbinaria ornata-derived biochar (TODB) was high at pH 4.5 according to the batch pH edge experimental trials performed using the aqueous zinc solution. The maximum uptake of 1.78 mmol/g was determined through batch isotherm trials. The isotherm data were successfully described using the Toth and Redlich-Peterson models, whereas pseudo-first-order model better predicted Zn-TODB kinetics data. The elution of zinc from zinc-loaded TODB was more successful with 0.01 M HCl as elutant with potential reuse of TODB for three subsequent cycles. The industrial wastewater employed in the present research was quantified to comprise of 1.34 mmol/L zinc ions with large quantity of dissolved solids (838 mg/L) and surplus co-ions. Due to this excessive presence of competing ions, zinc uptake by TODB from industrial wastewater was strongly inhibited. Continuous-flow sorption experiments were performed in TODB-loaded packed column at 5 mL/min. The results indicated that TODB column portrayed sorptional capacities of 1.21 and 1.13 mmol zinc/g for synthetic solutions and industrial wastewaters, respectively. Column regeneration trials for three adsorption-elution cycles were successful which confirms that application of TODB for clean-up of real zinc effluent was effective and practical.