| dc.description.abstract | Despite being the backbone of the Ugandan economy, Agriculture is still one of the least developed sectors in the country, efforts to develop this sector include the appropriate use and disposal of agricultural wastes by farmers to prevent their underutilization Rice is one of the three major grain commodities grown in the country with an annual tonnage of over 170,000 tones translating to over 30,000 tons of rice husk with only 17% is put to good use and the rest subjected to on-site burning and land dumping.. Biochar produced from pyrolysis of agricultural waste such as rice husks is a stable carbon rich compounds which has various beneficial applications like soil conditioning, remediation, carbon sequestration and water treatment This study set out to investigate the performance of rice husk-based bio char in waste water filtration and also compare this performance to the traditional sand filters. Waste water treatment is a worldwide issue due to increment in both urbanization and industrialization. The rice husk biochar was pyrolyzed at temperatures between 300 -500oC giving a gravimetric yield of 50% then Physically and chemically characterized through proximate analysis as these properties have a direct influence on waste water filtration. To study the efficiency of rice husk biochar in comparison to sand filters, samples of waste water were collected from the industrial area in Banda, Nakawa division, Kampala, Uganda. Treatments consisting of different biochar particle sizes (2mm,0.5mm and 25µmm) were taken to determine the best particle size for waste filtration. Other treatments of equal column length (30mm), equal mass (20 g) of biochar and sand were taken to compare their filtration capabilities. Sample wastewater was analyzed (pre and post) for different contaminants (PH, Temperature, Total Dissolved Solids, Electrical Conductivity, Total Hardness and Chloride) after being filtered through biochar and sand filters. Significant decrease in concentration of contaminants was observed. In biochar values of contaminants decreased from (TDS-530 ppm, EC -731µs/cm, T.H-105 mg/l and Cl -245.7 mg/l) in wastewater to (335.3ppm, 433.0µs/cm,116.7mg/l, 164.7mg/l, respectively) for particle size of 2mm to (353.3ppm, 521.0 µs/cm, 98.0mg/l, 130.2mg/l) for particle size of 0.5mm and to (377.3ppm, 554.7 µs/cm, 86.7mg/l, 130.2mg/l) for particle size of 250µmm making the smallest particle size the most efficient In the comparative study with sand filters, the char and sand reduced the contaminants with average efficiencies of 0.15 0.13, respectively in terms of the equal column length and efficiencies of 0.2-RHBC and 0.1-sand in terms of the equal mass. It can be concluded from results that efficiency of biochar in treating wastewater is much better as compared to sand as the reduction in contaminants values is significant in case of afore mentioned therefore rice husk biochar can be used as a sorbent for wastewater filtration in place of sand. Furthermore, given the gravimetric yield of the rice husks, there is a significant reduction in rice husk waste volume meanwhile providing an alternative approach to use of agricultural waste to provide a useful commodity to society | en_US |
