|Published Online: June 17, 2015||$US5.00|
This paper presents the findings of an investigation on the performance of a mesocosm-scale horizontal subsurface flow constructed wetland (HSSF-CW) system for treating wastewater contaminated by ibuprofen (IBP) with a high loading (100 μg/L). The HSSF-CW system included a planted bed with “Typha angustifolia” and an unplanted bed as a control. The hydraulic retention time was 4 days. Over a period of 310 days after system start-up, the mean removal efficiencies of COD, ammonium nitrogen (NH4+-N), total phosphate (TP), and IBP in the planted bed were found to be 93%, 61%, 63%, and 69%, respectively, compared to those of 90%, 31%, 26%, and 35% in the unplanted bed. No adverse impacts induced by the high load of IBP were observed during the operation of the system. It was found that plants played a positive role in the removal of NH4+-N, TP, and IBP as demonstrated by the plants’ ability to take up pollutants and their support for the development of microorganisms in the rhizosphere. Two hydroxylated metabolites of IBP in the forms of 2-hydroxy ibuprofen (2-OH IBP) and 1-hydroxy ibuprofen (1-OH IBP) were detected in the outflow water from both the planted and unplanted beds. The significant difference between the concentrations of 2-OH IBP in the two beds is strong evidence that microbial degradation of IBP took place mainly through the aerobic biodegradation process. The experimental results of this study clearly demonstrate the positive performance of the mesocosm-scale HSSF-CW for the removal of high-loaded IBP from wastewater and imply the plausible feasibility of this type of constructed wetland in pilot-scale and full-scale application.
|Keywords:||Wastewater, Constructed wetland, Pharmaceutical, Ibuprofen, Metabolite|
The International Journal of Environmental Sustainability, Volume 11, Issue 2, June 2015, pp.27-39. Article: Print (Spiral Bound). Published Online: June 17, 2015 (Article: Electronic (PDF File; 1.171MB)).
Ph.D Student, Division of Environmental and Water Resources Engineering, School of Civil and Environmental Engineering, Nanyang Technological University, Singapore, Singapore
Division of Environmental and Water Resources Engineering, School of Civil and Environmental Engineering, Nanyang Technological University, Singapore, Singapore