Assessment of Sawdust Activated Carbon (sac) in the Treatment of Aquaculture Effluent

The rapid growth in the aquaculture industry, while crucial for food security, generates polluted wastewater posing environmental and health risks. Simultaneously, sawmill waste like sawdust creates disposal challenges. The study is aimed at assessing of sawdust activated carbon (SAC) in removing these pollutants and improving water quality of the aquaculture effluent. The sawdust was prewashed and oven dried, then carbonized at 450°C in a furnace and impregnated with potassium hydroxide, KOH as the activation reagent. The produced SAC was characterized for pH, moisture content, ash content, carbon yield, surface area, pore volume and surface morphology. The surface morphology of the SAC was determined using Scanning Electron Microscope (SEM). The SAC was further characterized using BET surface area at 77K. The aquaculture effluent was assessed for pH, COD, BOD, TDS, TSS, phosphates, nitrates and nitrites. An optimization study was conducted using batch treatment of different dosages of the SAC. The surface morphology of the sawdust activated carbon (SAC) showed a very porous media and the resulting surface area was 815.22 m2g-1. The optimum treatment dosage was found to be 5g/l at 80minutes which gave an overall 90.48% reduction of COD, 90.40% reduction of BOD, 84.32% removal of TDS, 100% removal of TSS, 73.12% removal of phosphates, 72.88% removal of nitrate and 72.73% removal of nitrites. The treated sample satisfied the requirements when compared to the international World Health Organization (WHO) and National Environmental Standards and Regulations Enforcement Agency (NESREA)standards. After the assessment, it was found that among other uses of sawdust, it is a good precursor for the production of activated carbon for the treatment of polluted aquaculture effluent prior to its disposal into the environment.