Abstract
This study attempted to investigate the adsorptive potential of blended bamboo (Oxytenanthera abyssinica) sawdust/rice husk (BSD/RH) at a ratio of 1:1 carbonized at 400 °C for the sorption of cadmium ions from synthetic solutions in batch mode. The Box-Behnken Design in response surface methodology (RSM) was used to achieve the best removal efficiency and adsorption capacity of the biochar. With a p-value of 0.0001, the initial Cd2+ concentration and adsorbent dose were discovered to be the most significant parameters controlling the adsorption capacity and removal efficiency of Cd2+ from the solution. At a pH of 8.95, ionic strength of 0.020 mol/L KNO3, a contact time of 15 min, an initial concentration of 200 mg/L, and an adsorbent dose of 0.5 g, the optimum Cd2+ removal and adsorption capacity of 99.97% and 358.65 mg/g, respectively, were obtained. The optimized conditions were later used to determine the removal efficiency and adsorption capacity of pristine biochars of rice husk and bamboo sawdust, which were found to be 79.8% and 83.7%, respectively. This finding indicates the potential for using biosorbent derived from blended feedstock materials to remove heavy metals such as cadmium.
NOVELTY STATEMENT
Many studies investigated the pollutant removal potential of agricultural wastes as single feedstock adsorbent materials. The novel aspect of this study is that it examines their potentials on Cd2+ removal by combining two feedstocks (bamboo saw dust and rice husk) while optimizing the common influencing factors. Furthermore, a comparative analytical study was carried out between the blended feedstock biochar and their respective pristine ones. According to the findings, using blended biochar instead of pristine biochar results in a significant increase in Cd removal efficiency.
Authors contributions
M.M.K did the conceptualization, methodology, formal analysis, visualization, writing, and first draft preparation, and all writers contributed equally to the concept development. Review and editing, as well as critical revision and supervision, were done by Y.C. and B.T. The final version of the manuscript for publication has been read, approved, and signed by all authors.
Disclosure statement
The authors declare that they have no known competing financial interests or personal ties that would have influenced the work presented in this study.