Optimization of Lead (II) Adsorption of Coconut Husk Cocos nucifera and Its Biochar Derivatives
Lead is a highly toxic heavy metal that is mostly absorbed through digestion respiration, and, in rare cases, through skin absorption. Biosorption is adsorbing heavy metals using organic substances such as agricultural waste products. This study used coconut husk, a type of lignocellulosic biomass t...
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| Summary: | Lead is a highly toxic heavy metal that is mostly absorbed through digestion respiration, and, in rare cases, through skin absorption. Biosorption is adsorbing heavy metals using organic substances such as agricultural waste products. This study used coconut husk, a type of lignocellulosic biomass that can be sourced from agricultural crop waste. The study also prepared biochar from coconut husk via thermal activation, pyrolysis, and chemical activation, utilizing KOH as an alkali activator. Box-Behnken Design was conducted to model the Response surface to render various 3D plots to determine the interaction of each parameter. A quadratic regression model was generated to predict the removal efficiency and the optimized parameter solutions for the best removal efficiency. The optimal adsorption conditions were determined by adjusting three different parameters: adsorbent dosage (1.2g/L –12g/L), initial Pb2+ concentration (10mg/L – 30 mg/L), and contact time (30 mins – 195 mins). Langmuir isotherm model best fits experimental data for coconut husk while the Freundlich model was best observed for the biochar derivatives. Our results suggest that raw coconut husk has a high removal efficiency due to its functional groups, which can bind to Pb²⁺ ions. In contrast, the biochars produced a higher adsorption efficiency, yielding a porous structure with a high surface area. Furthermore, KOH activation shows improved adsorption of Pb²⁺ ions due to a developed macropore and mesopore formation and an increased number of functional groups during the activation process |
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