BIOREMEDIATION AND RECYCLING OF TREATED WASTEWATER IN AN AQUAPONICS SYSTEM

Abstract

This study highlighted bioremediation of aquaponics wastewater and its re-use by providing a breeding compartment for the fish, plant and bacteria. The aquaponics wastewater from the fish, bio-remediated water from the bio-filter and water from the plant pots that recycled back to the fish tanks were characterized. An aquaponics setup was made to have three fish tanks and nine plant pots with three different bed media of gravel, periwinkle and palm kernel shell to hold the plant without soil.  As the fishes grew, nitrite and nitrate concentrations significantly increased from 0.00 to 10.66 mg/L and from 0.00 to 30.13 mg/L respectively. The plants show a significant increase to a maximum height growth of 22.86 cm for periwinkle, 20.24 cm for gravel, and 30.48 cm for palm kernel shells bed in each of the beds. However, the palm kernel shells bed yielded the best plant growth measured up to 30.48 cm height. Atomic absorption spectrophotometer (AAS) analysis shows that plants used up essential nutrients like zinc, iron, and potassium from the bio-remediated water after the ninth week. For kinetic study, Line Weaver-Burke plot of reciprocals of the data was plotted to examine the possibility of the reaction fitting into the Michaelis-Menten model. V_max was obtained to be 19.12 % which indicates the minimum concentration of substrate at which there will be maximum oxidation. K_s obtained to be 0.97 indicates the substrate concentration at which half the bacteria's active sites are occupied by a substrate. This confirmed that the reaction in the system follows the first order reaction so the behavior of the system’s reaction can be predicted over a desired time interval; Microbial nitrification shows Michaelis-Menten kinetics.