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, NH 3 -N, NO 3 -N and PO 4 3of 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 Original Research Article

Wastewater treatment using constructed wetlands is one of the effective and low-cost technologies to improve the quality of slaughterhouse effluent. This study was carried out to investigate the suitability of palm kernel shell as a substrate material for constructed wetlands treating slaughterhouse wastewater. Rhizomes of Thalia Geniculata and Typha Latifolia were grown in four pilot horizontal subsurface flow constructed wetland beds filled with palm kernel shell and grave, and their growth and treatment performance evaluated. The results of the study showed that Thalia Geniculata survives and proliferates in palm kernel shell bed. The mean removal rates of 72.81% (BOD5), 89.87% (TSS), 39.42% (NH4-N), 60.79% (NO3-N) and 42.52% (PO43-) for the palm kernel shell were comparable to the values obtained for the gravel bed. The study proved that palm kernel shell, as a substrate material in constructed wetlands had the potentials to sustain the growth of some macrophytes, as well as the capacity to remove contaminants from wastewater.