Includes Appendix and Reference

The study investigated the effectiveness of sugarcane waste biochar as a sustainable material for purifying greywater to address environmental pollution and enhance water recycling. Biochar was produced by heating sugarcane waste at 500°C, with half of it activated using potassium hydroxide to enhance adsorption. X-ray fluorescence, X-ray diffraction and Fourier transform infrared spectroscopy were used to characterize the biochar structure. The structure showed the presence of amorphous carbon with C-H, C-O and COOH functional groups. Greywater samples obtained from the kitchen, bathroom and carwash were purified by filtering 100 mL of samples through 10 g of biochar for 5 minutes. The activated and inactivated biochar achieved 92-96%and80-87% removal efficiency of lead (II) ions, respectively. Chromium(VI) ions removal ranged from 84-92% and 82-86% with activated and inactivated biochar, respectively. Activated biochar removed 76-77% of oil and grease compared to 51-57%forinactivated biochar. Both biochar increased the pH levels, with activated biochar causinga more rise by 63-73%. Total suspended solids removal efficiencies were 21-34%and40-54% in inactivated and activated biochar, respectively. Slight decrease in sodium dodecyl sulphate detergent, electrical conductivity and total dissolved solids was observed for both biochar. There was a significant difference between the purification efficiency of inactivated and activated biochar shown by the |t| statistic values, which were above t4 critical value of 2.78 (P = 0.05). Based on the study findings, activated sugarcane biochar was reliable for greywater treatment, especially the removal of heavy metal pollutants, oil and grease. The study recommends further pilot-scale applications and field testing to validate its long-term performance and integration into decentralized wastewater management systems.