Optimization and Thermodynamic Studies of Lead (II) and Cadmium (II) Ions Removal from Water Using Musa acuminate Pseudo-Stem Biochar  

作　　者：Daniel Nimusiima Irene Nalumansi Paul Mukasa Denis Byamugisha Emmanuel Ntambi Daniel Nimusiima;Irene Nalumansi;Paul Mukasa;Denis Byamugisha;Emmanuel Ntambi(Department of Chemistry, Faculty of Science, Mbarara University of Science and Technology, Mbarara, Uganda)

机构地区：[1]Department of Chemistry, Faculty of Science, Mbarara University of Science and Technology, Mbarara, Uganda

出　　处：《Green and Sustainable Chemistry》2023年第4期254-268,共15页绿色与可持续化学（英文）

摘　　要：We recently found out that water from the Ugandan stretch of the Kagera transboundary river (East Africa) is contaminated with lead (Pb²⁺) and cadmium (Cd²⁺) ions at levels that are above permissible limits in drinking water. Because lignocellulosic biomass-based adsorbents have been explored for the remediation of metal ions from water, this study investigated the potential of Musa acuminata pseudo-stem (MAPS) biochar for the remediation of Pb²⁺ and Cd²⁺ ions from water. Batch adsorption experiments were performed to optimize the adsorption conditions while the isotherms were analyzed using Freundlich and Langmuir models. Results showed that the maximum adsorption capacity at equilibrium was 769.23 mg/g and 588.23 mg/g for Pb²⁺ and Cd²⁺ ions, respectively. Langmuir isotherm model provided the best fit for the data, and it was favorable since all r² values (Cd²⁺ = 0.9726 and Pb²⁺ = 0.9592) were close to unity. Gibb’s free energy change was found to be negative for both metals, implying the feasibility of the adsorption process. Correspondingly, the enthalpy change was positive for both metal ions which revealed that the adsorption process was endothermic and it occurred randomly at the solid-liquid interface. These results suggested that biochar from MAPs could be utilized for the removal of Pb²⁺ and Cd²⁺ from polluted water in the Kagera transboundary river to make it suitable for domestic use. Further studies should consider chemical modification of the biochar as well as characterization to examine the chemical nature of the biochar.We recently found out that water from the Ugandan stretch of the Kagera transboundary river (East Africa) is contaminated with lead (Pb²⁺) and cadmium (Cd²⁺) ions at levels that are above permissible limits in drinking water. Because lignocellulosic biomass-based adsorbents have been explored for the remediation of metal ions from water, this study investigated the potential of Musa acuminata pseudo-stem (MAPS) biochar for the remediation of Pb²⁺ and Cd²⁺ ions from water. Batch adsorption experiments were performed to optimize the adsorption conditions while the isotherms were analyzed using Freundlich and Langmuir models. Results showed that the maximum adsorption capacity at equilibrium was 769.23 mg/g and 588.23 mg/g for Pb²⁺ and Cd²⁺ ions, respectively. Langmuir isotherm model provided the best fit for the data, and it was favorable since all r² values (Cd²⁺ = 0.9726 and Pb²⁺ = 0.9592) were close to unity. Gibb’s free energy change was found to be negative for both metals, implying the feasibility of the adsorption process. Correspondingly, the enthalpy change was positive for both metal ions which revealed that the adsorption process was endothermic and it occurred randomly at the solid-liquid interface. These results suggested that biochar from MAPs could be utilized for the removal of Pb²⁺ and Cd²⁺ from polluted water in the Kagera transboundary river to make it suitable for domestic use. Further studies should consider chemical modification of the biochar as well as characterization to examine the chemical nature of the biochar.

关 键 词：ADSORBENT BIOCHAR LIGNOCELLULOSE Heavy Metals Water Treatment 

分 类 号：O64[理学—物理化学]