Assessment of Water Lettuce and Duckweed in Phytoremediation of Slaughter Effluent

Background and Objective: In Nigeria, it is alarming that all the abattoirs have no wastewater treatment. Huge effluents are being directly discharged on a daily basis to the environment without being checked and controlled creating serious pollution risks to living organisms in the environment. The objective of this study was to characterize the selected abattoir effluent pollutants and also to evaluate the performance of water lettuce and duckweed in removing pollutants from abattoir effluent. Materials and Methods: Phytoremediation of slaughter-contaminated river water in Trans Amadi slaughterhouse, Port Harcourt, Rivers State was carried out using hydroponically cultivated water lettuce and duckweed. The physicochemical parameters investigated were physicochemical parameters: Temperature, pH, electrical conductivity (EC), total dissolved oxygen (TDS), total suspended solid (TSS), dissolved oxygen (DO), biochemical oxygen demand (BOD), chemical oxygen demand (COD), turbidity, nitrate (NO^-3), ammonia (NH₄⁺N) and phosphate (PO₄) were conducted according to the standard methods. Results: The percentage increase in pH varied between 13.4 and 29.7% for water lettuce and 12.6 and 32.2% for duckweed. The percentage increase in EC varied between 6.4 and 87.1% for water lettuce and 5.4 and 86% for duckweed. The percentage increase in TDS varied between 15.4 and 82% for water lettuce and 14.6 and 79% for duckweed. The observed differences between the mean values of TDS, TSS, BOD, COD, DO and turbidity values were statistically significant (p<0.05) for both plants. Conclusion: It can be concluded that discharging abattoir water without prior treatment could lead to serious environmental problems for human beings, aquatic lives and Eco diversity since all pollution indices are far above the tolerance limit.