Growth and Treatment Performance of Three Macrophytes in a Pilot-Scale Horizontal Subsurface Flow Constructed Wetland for Slaughterhouse Wastewater
Nelson Mbanefo Okoye *
Department of Agriculture and Bioresources Engineering, Nnamdi Azikiwe University, Awka, Nigeria.
Chimaobi Nnaemeka Madubuike
Department of Agricultural Engineering, Federal University of Technology, Owerri, Nigeria.
Ifeanyi Uba Nwuba
Department of Agriculture and Bioresources Engineering, Nnamdi Azikiwe University, Awka, Nigeria.
Louis Chukwuemeka Orakwe
Department of Agriculture and Bioresources Engineering, Nnamdi Azikiwe University, Awka, Nigeria.
*Author to whom correspondence should be addressed.
Abstract
Slaughterhouse wastewater in Nigeria poses a risk to public health due to lack of treatment as the conventional treatment plants have proven non-sustainable. Constructed wetlands (CW) have emerged as an efficient technology for treatment of wastewater in developing countries because of its low cost, ease of operation/maintenance and good performance. The feasibility of using CW to remove pollutants from slaughterhouse wastewater was tested using three macrophytes; Thalia geniculata, Colocasia esculenta and Typha latifolia. The result showed that all macrophytes tolerated of the tested conditions. The BOD, TSS, NH3-N, NO3-N and PO43- of slaughterhouse effluent reduced after treatment in all cells. There was a higher removal of most pollutants in planted than in unplanted cells. The Thalia geniculata cell outperformed the others for TSS and NH3-N, while Typha latifolia cell had a higher removal rate for BOD and PO43-. In conclusion, Thalia geniculata is a more suitable plant to treat slaughterhouse wastewater because of its higher above ground biomass yield.
Keywords: Water quality, slaughterhouse, wastewater treatment, constructed wetlands, horizontal flow, Nigeria