Environmental Advances (Oct 2023)
Kinetics and isotherms of heavy metals removal from laundry greywater by chitosan ceramic beads
Abstract
The rise of laundry facilities in the residential areas has become main concern on the water quality due to untreated laundry greywater discharge directly into the drainage. The use of detergents, softener and other cleaning additives have contributed to the heavy metals concentration in surface water. Hence, the current study investigated the adsorption behavior of chitosan ceramic beads and the removal efficiency of heavy metal ions from laundry greywater, including Pb2+, Zn2+, and Fe2+ ions. The effects of dosage, pH, time, temperature, and initial to Pb2+, Zn2+, and Fe2+ were evaluated for the efficiency of the adsorption process. The efficacy results of adsorbent's dose in Pb2+, Zn2+, and Fe2+ ions removal process with 38.89 mg/g, 29.87 mg/g and 49.55 mg/g respectively. The isotherm model, Freundlich, and Temkin model plot the experimental adsorption data set to infer the maximum adsorption capacity. The adsorption study observed that the removal of Pb2+, Zn2+, and Fe2+ ions from chitosan ceramic beads best fits the Freundlich Isotherm model. Kinetic models pseudo-first order, pseudo-second order, and the Elovich Equation model were used in this study to understand the kinetics of removal of Pb2+, Zn2+, and Fe2+ ions from laundry greywater. Adsorption kinetic study monitored pseudo-first kinetic model for the removal of Pb2+ ions with an R2 value of 0.98 was the best fitted kinetic model while Elovich Equation fitted for the removal of Zn2+ and Fe2+ with an R2 value of 0.92 and 0.96 respectively. The most significant contribution of this work is an understanding of the optimal isotherms and kinetics model that can describe the behavior of Pb2+, Zn2+, and Fe2+ ions adsorption on chitosan ceramic beads. The study provides the details of the chitosan ceramic beads potential to the adsorption of Pb2+, Zn2+, and Fe2+ ions from laundry greywater for safe disposal.
