Optimum usage of biochar derived from agricultural biomass in removing organic pollutant present in pharmaceutical wastewater

The wastewater from pharmaceutical industries contains high concentrations of organic matter, toxic chemicals, and salts, which must be effectively treated before disposal. In this work, the low-cost adsorbents and biochar consortium derived from coir fiber, Moringa oleifera seeds, and groundnut shells were utilized to remove organic contaminants such as BOD from pharmaceutical effluent using a column adsorption study having an initial concentration of 443.6 mg/L. The raw adsorbent consortium was prepared by mixing the powdered components in a 1:1:1 ratio. Each element was then individually pyrolyzed at different temperatures to obtain biochar at a 1:1:1 ratio. The removal efficiency for BOD using the raw consortium was 50.6 % at an optimal dosage of 60 g, pH 7, temperature 25°C, and contact time 120 min, while the biochar consortium achieved 72.1 % removal efficiency at an optimal dosage of 35 g, pH 7, temperature 25°C, and contact time 90 min. The applicability of the Langmuir and Freundlich isotherm models for BOD removal efficiency was tested. Langmuir isotherm plots indicate that the adsorption process is favorable and best fitted for the biochar consortium. From kinetic models, the biochar consortium R² value is 0.9397 (Pseudo first-order) and 0.9642 (Pseudo second-order kinetics). R² of 0.9642 indicates a better fit, with only 3.58 % of the variation unexplained. It is observed that biochar has a higher removal efficiency towards BOD-causing organic pollutants compared to the raw adsorbent consortium.