In recent years, interest in wastewater treatment through constructed wetlands has been significantly increased because of their low cost and energy requirement. In this study, pilot-scale constructed wetland systems were developed to evaluate the efficacy and effectiveness on the treatment of oil-refining and steel-milling wastewater. The constructed wetland used to treat the oil-refining wastewater included one free water surface system (FWS) filled with sandy media and one subsurface flow system filled with gravel media. The plants grown on the wetland were Phragmites communis. The hydraulic retention time for the two systems was approximately 7 and 5 days, respectively. A two-stage subsurface flow constructed wetland system was used to treat steel-milling wastewater. This system, which filled with gravel media were planted with Phragmites communis (the first stage) and Typha orientalis (the second stage). The hydraulic retention time for this system was approximately 7 days.
Experimental results showed that the two constructed wetland systems for the oil-refining wastewater treatment could remove most of the wastewater pollutants. Moreover, the first system (FWS) played a more important role on the wastewater treatment. The efficiency of the first stage of the wetland system, which was used for steel-milling wastewater treatment was not significant due to the inhibition of the plant growth by the wastewater. However, the treatment efficiency was increased at the second stage after planting new plants. Results from the two-stage treatment system indicate that higher treatment efficiencies were observed except for ammonium. Results from this study would be very useful in the design of constructed wetlands for practical application to treat oil-refining and steel-milling wastewaters.
Identifer | oai:union.ndltd.org:NSYSU/oai:NSYSU:etd-0704103-190717 |
Date | 04 July 2003 |
Creators | Hu, Chih-Ching |
Contributors | Lei Yan, none, none |
Publisher | NSYSU |
Source Sets | NSYSU Electronic Thesis and Dissertation Archive |
Language | Cholon |
Detected Language | English |
Type | text |
Format | application/pdf |
Source | http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0704103-190717 |
Rights | unrestricted, Copyright information available at source archive |
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