Cadmium Removal From Aqueous Solutions Facilitated by Biochar Derived From Active Sewage Sludge

Biochar was previously confined to agriculture applications, but its utilization has since expanded across various sectors. In this case, sludge acquired from a sewage treatment facility was employed in the production of biochar. The study investigates the adsorption of cadmium in aqueous solution by both untreated biochar and biochar treated with H3PO4, examining the influence of adsorbent dosage, contact time, pH, and initial concentration. Phosphorus compounds present on the biochar surface activate it, enhancing cadmium removal compared to untreated biochar. The experimental results showed that the optimal dosage (1000 mg/l) and adsorption rate were significantly affected by pH. The Langmuir isotherm is more in accordance with the results of the experiment than other models, an indication that the majority of the adsorption is accomplished through monolayer chemical adsorption. The study determined that biochar derived from surplus sludge can be further utilized to serve as an economical adsorbent for the removal of Cadmium from wastewater.