TREATMENT OF AQUACULTURE EFFLUENT

ABSTRACT

This study was aimed at assessing the performance of hyacinth biochar in the treatment of aquaculture effluent with various objectives including the characterization of aquaculture effluent (cat fish pond waste water) to determine the concentration of solids [total suspended solids (TSS),total dissolved solids (TDS)], nutrients (nitrogen as nitrate and phosphorus as phosphate) and organic matter [chemical oxygen demand (COD)], comparison with relevant effluent standards and evaluation of the performance of biochar in the removal of the pollutants. Batch adsorption studies were carried out while investigating the influence of dosage and contact time on the removal efficiency of biochar and the Pseudo-first and second order kinetic model were used to analyze the results. The aquaculture effluent was found to have levels of COD, TSS, PO4 and NO3 which exceeded the limits in the National Environmental (surface and ground water control) Regulations, 2011 and National Environmental Protection (effluent limits) Regulations [S.I.8 of 1991]. The influence of dosage and contact time on the removal performance of biochar was investigated and maximum removal of pollutants was observed at a dosage of 0.75g/l and contact time of 40minutes, with 93.04% removal of COD, 93.04% removal of PO4, 93.35% removal of NO3, and 95.79% removal of TSS. The kinetic studies showed that the adsorption process was a pseudo-second order reaction with 𝑅 2 value of 0.999.