Development of Biofiltration Wastewater Stabilization Pond For Agricultural Purposes

ABSTRACT 

A biofiltration wastewater treatment pond was developed and the performance evaluation undertaken at the Department of Agricultural and Bioresources Engineering, University of Nigeria, Nsukka, southeast, Nigeria. The biofiltration wastewater treatment system is made of three compartments comprising a wastewater storage unit, wastewater treatment unit and treated wastewater compartment. The compartments are of the same size with the following dimensions 0.61m x0.61m x 0.5m having a volume of 0.1861m3 . Wastewater collected from the University of Nigeria, Nsukka waste stabilization pond and African catfish were used as test samples. The experimental study was divided into two parts, the laboratory analyses of wastewater before and after the treatment and the use of treated wastewater to rear African catfish. Water hyacinth sourced from the bank of Niger River, Lokoja Kogi State, Nigeria was used as the biofilter. The results of the experimental studies showed that the water quality was good for agricultural applications especially for fish farming. The laboratory analyses using the sampled wastewater showed that the concentration of ammonia( NH3) was reduced from 1.2 mg/l to 0.80mg/l; while Nitrate (NO3) reduced from 2.5mg/l to 2.1 mg/l; Chlorine (Cl) reduced from 99mg/l to 90mg/l; (pH) from 6.8 to 6.7 when Copper (Cu) was reduced from 0.011mg/l reduced to 0.00mg/l concentrations. Further biological test using African catfish showed that at the end of the experimental set up the average weight gain of the catfish reared in the biofilter treated wastewater was 3.4kg when the feed consumed was 0.17kg while the control was 3.2kg average weight gain and 0.37kg feed consumed respectively in 45 days. It is concluded that water hyacinth could be a good tool in the treatment of wastewater and the purification for useful applications such as for fish and animal rearing. Further research studies is hereby recommended to ascertain other purposeful applications.