ABSTRACT
The problem of water Scarcity, water pollution and cost of accessing water for domestic needs have become growing concerns to the ever increasing global population. Waterwaterremediation has long been accepted as a viable option to mitigate water scarcity. This research examines the potentials of an environmentally friendly technique of using local but modified tropical plant materials in remediation of greywater for re-use. Column adsorption experiment was conducted using synthesized and characterized Biochar and Activated Carbon made from Shea tree (Vitellariaparadoxa), African Mahogany tree (KhayaSenegalenses) and the Fig tree (FicusSycomous) as filter media in constructed filter columns made from polyvinyl chloride pipes. Greywater Samples from Ahmadu Bello University Zaria's student hostel were passed through these filters at a hydraulic loading rate of 0.033m3/m2/day for a period of 21 days. The parameters assessed in this experiment were Electrical Conductivity (EC), Biological and Chemical Oxygen Demand (BOD and COD), Ammonium Nitrogen (NH4-N), Nitrate Nitrogen (NO3-N), Total Nitrogen (Tot-N), available Phosphate (PO4-P), Total Phosphorus (Tot-P) and pH. The results obtained showed high treatment efficiencies for both Activated Carbon and Biochar on all tested parameters except for NH4-N in which AC had a low efficiency of 49% at one instance. Activated Carbon had (85 - 95%) in remediating organic matter, (61 -81%) in remediating EC, (39 - 89%) in remediating NH4-N, (93 - 100%) for NO3-N, 92 - 99% for Total Phosphorus. Biochar showed 88 - 92% efficiency in remediating Total Phosphorus, 91 - 99% for NO3-N, 68 - 89% for NH4-N, 85 - 90% for EC and 76 - 90% for organic matter removal. The factors of time, particle size, activation status and parent material used in the filters were used to determine the efficiency of the filters and the results showed that time, parent material used, and activated status of the filters had significant effect on the performance of the filters while differences in particle sizes had little effect on the performance. It could be concluded therefore that biochar compared favourably with activated carbon in the remediation of greywater, which is more complex to synthesize and cost more to produce. In addition, because of the ease of production and availability of raw materials in the tropics, biochar can be used to remediate greywater and replace Activated Carbon in some water treatment systems.