Adsorptive Removal of Hazardous Cadmium(II) Ions from Synthetic Wastewater using Acid-Treated Algal Biomass Vaucheria sp

The purpose of this investigation was to examine the ability of acid-treated Vaucheria sp., to remove hazardous cadmium(II) ions from synthetic wastewater. The impact of variables such as solution pH, adsorbent dosage, initial metal ion concentration, alga-Cd(II) contact duration and temperature were examined via batch experiments. Using Langmuir, Freundlich and Temkin adsorption models, the equilibrium isotherm constants were calculated. The equilibrium data were found to be more compatible with the Langmuir model. At pH 5, 0.6 g of algal dosage, an equilibrium time of 70 min and a temperature of 318 K, the maximal adsorption capacity achieved by Vaucheria sp. biomass for Cd(II) was 92.59 mg/g. Adsorption kinetics were analyzed using both the pseudo-first-order and pseudo-second-order models, with the latter model demonstrating to be more suitable for the adsorption process by comparing R2 values. The process was determined to be endothermic (ΔHº > 1) and spontaneous (ΔGº < 1) by analyzing the thermodynamic parameters. The biomass was pre-treated to a variety of chemicals in order to improve metal sorption capacity and it emerged that acid pretreatments significantly boosted the metal sorption capacity. Overall, the findings suggest that acid-treated Vaucheria sp. might be a cost-effective and beneficial adsorbent biomass for removing Cd(II) metal ions from synthetic wastewater.