Vertical-flow constructed wetlands treating domestic wastewater contaminated by hydrocarbons

Al-Isawi, R; Sani, A; Almuktar, S; Scholz, M

Abstract

The aim was to compare the impact of different design (aggregate size) and operational (contact time, empty time and chemical oxygen demand (COD) loading) variables on the long-term and seasonal performance of vertical-flow constructed wetland filters operated in tidal flow mode before and after a one-off spill of diesel. Ten different vertical-flow wetland systems were planted with Phragmites australis (Cav.) Trin. ex Steud. (common reed). Approximately 130 g of diesel fuel was poured into four wetland filters. Before the spill, compliance with secondary wastewater treatment standards was achieved by all wetlands regarding ammonia-nitrogen (NH4-N), nitrate-nitrogen (NO3-N) and suspended solids (SS), and non-compliance concerning biochemical oxygen demand and ortho-phosphate-phosphorus (PO4-P). Higher COD inflow concentrations had a significantly positive impact on the treatment performance for COD, PO4-P and SS. The wetland with the largest aggregate size had the lowest mean NO3-N outflow concentration. However, the results were similar regardless of aggregate size and resting time for most variables. Clear seasonal outflow concentration trends were recorded for COD, NH4-N and NO3-N. No filter clogging was observed. The removal efficiencies dropped for those filters impacted by the diesel spill. The wetlands system shows a good performance regarding total petroleum hydrocarbon removal.

Citation

Al-Isawi, R., Sani, A., Almuktar, S., & Scholz, M. (2015). Vertical-flow constructed wetlands treating domestic wastewater contaminated by hydrocarbons. Water Science and Technology, 71(6), 938-946. https://doi.org/10.2166/wst.2015.054

• Journal Article Type: Article
• Acceptance Date: Jan 23, 2015
• Online Publication Date: Feb 5, 2015
• Publication Date: Mar 1, 2015
• Deposit Date: Mar 17, 2015
• Journal: Water Science and Technology
• Print ISSN: 0273-1223
• Publisher: IWA Publishing
• Peer Reviewed: Peer Reviewed
• Volume: 71
• Issue: 6
• Pages: 938-946
• DOI: https://doi.org/10.2166/wst.2015.054
• Publisher URL: http://dx.doi.org/10.2166/wst.2015.054
• Related Public URLs: http://www.iwaponline.com/wst/default.htm
• Additional Information: Funders : Funder not known