Heavy Metals Removal from Synthetic Wastewater Through Layered Double Hydroxide (LDH)(Mg-Al)-Hydrochar

An experiment was conducted to explore the potential use of Coconut Shell HydroChar (CSHC) using batch adsorption. CSHC-LDH (Mg-Al) is mixed with layered double hydroxide (LDH) to remove Ni (II), Cd (II), and Zn (II) from a ternary-metal solution (with a mixing ratio of ۰.۵:۰.۳:۰.۲). We investigated the effects of initial concentrations, pH, adsorbent dosages, and contact time through adsorption kinetic and isotherm studies. The optimal conditions that give higher removal percentages were: pH of ۶ and ۴, adsorbent dose ۱ and ۰.۷ mg, initial metals concentration ۲۵۰ mg/L, and the equilibrium time of ۹۰ min for CSHC and CSHC/MgAl-LDH, respectively. The CSHC and CSHC/MgAl-LDH composite revealed a strong sorption ability to Cd (II), Ni (II), and Zn(II) in aqueous solutions with the Langmuir maximum adsorption capacity of ۱۸۸.۶۷, ۲۰۴.۰۸, and ۲۲۲.۲۲ mg/g and ۳۱۲.۵, ۳۴۴.۸۲, and ۳۵۷.۱۴ mg/g, respectively. The adsorption kinetic study revealed that the adsorption process followed second-order kinetics. The batch experiment results showed that the CSHC and CSHC-Mg-Al LDH were effective in the simultaneous removal of Ni (II), Cd (II), and Zn (II) to a significant extent. The CSHC-Mg-Al LDH composite has demonstrated considerable promise in removing heavy metals from wastewater. It offers the benefits of easy synthesis and exceptional adsorption capability.

کلیدواژه ها:

kinetic and isotherm studies ، coconut shells hydrochar ، heavy metals ، layered double hydroxide (Mg-Al) ، Ni(II) ، Cd(II) ، and Zn(II) adsorption