Optimization of Petroleum Refinery Wastewater Treatment by Vertical Flow Constructed Wetlands Under Tropical Conditions: Plant Species Selection and Polishing by a Horizontal Flow Constructed Wetland

• Published in: Water, air, and soil pollution air, and soil pollution, 2018-04, Vol.229 (4), p.1-17, Article 137
• Main Authors: Mustapha, Hassana Ibrahim, van Bruggen, J. J. A., Lens, P. N. L.
• Format: Article
• Language: English
• Subjects: Ammonium; Ammonium compounds; Aquatic plants; Artificial wetlands; Atmospheric Protection/Air Quality Control/Air Pollution; Biochemical oxygen demand; Chemical oxygen demand; Climate Change/Climate Change Impacts; Climatic conditions; Constructed wetlands; Contaminants; Earth and Environmental Science; Efficiency; Effluent quality; Effluent treatment; Effluents; Environment; Environmental monitoring; Flowers & plants; Freshwater plants; Heavy construction; Hydrogeology; Nitrates; Petroleum; Petroleum industry wastewaters; Petroleum refineries; Petroleum refining; Phosphates; Plant species; Pollutant removal; Pollution load; Refineries; Refinery wastes; Removal; Sewage treatment; Soil Science & Conservation; Species; Suspended particulate matter; Total oxygen demand; Total suspended solids; Tropical climate; Turbidity; Vertical flow; Vertical mixing; Wastewater; Wastewater treatment; Water Quality/Water Pollution; Wetlands
• ISSN: 0049-6979; 1573-2932
• DOI: 10.1007/s11270-018-3776-3

Typha latifolia -planted vertical subsurface flow constructed wetlands (VSSF CWs) can be used to treat petroleum refinery wastewater. This study evaluated if the removal efficiency of VSSF CWs can be improved by changing the plant species or coupling horizontal subsurface flow constructed wetlands (HSSF CWs) to the VSSF CW systems. The VSSF CWs had a removal efficiency of 76% for biological oxygen demand (BOD 5 ), 73% for chemical oxygen demand (COD), 70% for ammonium-N (NH 4 + -N), 68% for nitrate-N (NO 3 − -N), 49% for phosphate (PO 4 3− -P), 68% for total suspended solids (TSS), and 89% for turbidity. The HSSF CWs planted with T. latifolia further reduced the contaminant load of the VSSF CW-treated effluent, giving an additional removal efficiency of 74, 65, 43, 65, 58, 50, and 75% for, respectively, BOD 5 , COD, NH 4 + -N, NO 3 − -N, PO 4 3− -P, TSS, and turbidity. The combined hybrid CW showed, therefore, an improved effluent quality with overall removal efficiencies of, respectively, 94% for BOD 5 , 88% for COD, 84% for NH 4 + -N, 89% for NO 3 − -N, 78% for PO 4 3− -P, 85% for TSS, and 97% for turbidity. T. latifolia strived well in the VSSF and HSSF CWs, which may have contributed to the high NH 4 + -N, NO 3 − -N, and PO 4 3− -P removal efficiencies. T. latifolia -planted VSSF CWs showed a higher contaminant removal efficiency compared to the unplanted VSSF CW. T . latifolia is thus a suitable plant species for treatment of secondary refinery wastewater. Also a T. latifolia -planted hybrid CW is a viable alternative for the treatment of secondary refinery wastewater under the prevailing climatic conditions in Nigeria.