TREATMENT ALTERNATIVES FOR WASTEWATER EFFLUENTS FROM A MEDIUM SCALE PHARMACEUTICAL INDUSTRY

Abstract

This research work examined the application and capacity of using constructed wetlands, as alternative
secondary treatment system on industrial wastewater from a medium scale pharmaceutical company. Four parallel pilotscale sub-surface flow constructed wetland systems with dimensions: 1800 mm (L); 900 mm (W); 900 mm (D) each, were
installed at the Department of Civil Engineering, LAUTECH Ogbomoso, Nigeria for conducting the proposed
phytoremediation study. Four different emergent wetland plant species including Wild Sorghum (Sorghum arudinaceum),
White Lotus (Nymphaea lotus), Yerba De Jicotea (Ludwigia erecta), and Ginger-leaf morning-glory (Ipomoea asarifolia)
were used. The averaged influent contains approximately 160 FTU turbidity, 140 mg/l total hardness, 3.1 mg/l Iron, 8.9 mg/l
Nickel, 12 mg/l Zinc, 5465 mg/l oil and grease, 0.4 mg/l chemical oxygen demand (COD), 0.26 mg/l biochemical oxygen
demand (BOD), and 0.27 mg/l ammonium. The wetland cells were fed with wastewater collected from a pharmaceutical
industry nearby the University campus and treated effluents were collected for analyses at 7- day interval for a retention
period of 28 days. The results obtained showed that phytoremediation reduced over sixty percent (64.1%) turbidity, 71.4 %
total hardness, 42 % chloride, about 34 % sulphate. Nitrate and phosphate were removed by 38.8 % and 57.8 % respectively.
Metal contents reduction in treated wastewaters such as 61.5 % aluminum, about fifty percent (49.4 %) Iron, 38.2 % Nickel,
49.8 % Zinc, were recorded. Yerba De Jicotea (Ludwigia erecta) reduced BOD and COD by 65.4 % and 65 % respectively,
while Ginger-leaf morning-glory (Ipomoea asarifolia) removed 8.3 % of oil and grease as the highest removal efficiency.
Averagely, wild Sorghum (Sorghum arudinaceum) possessed the optimal phyto-remedial efficiency of the four emergent
wetland plants. Treated effluents proved the efficacy of constructed wetland, using locally available macrophytes as an
effective secondary treatment technology for pharmaceutical wastewater. The treated effluents meets the current industrial
wastewater discharge standards in Nigeria.