Effect of Feeding Strategies on Pharmaceutical Removal by Subsurface Flow Constructed Wetlands
- Dong Qing Zhang *a,
- Richard M. Gersbergb,
- Tao Huaa,
- Junfei Zhua,
- Anh Tuan Nguyena,
- Wing-Keung Lawa,
- Wun Jern Ngc and
- Soon Keat Tand
- a DHI-NTU Centre, Nanyang Environment & Water Research Institute, Nanyang Technological Univ., 50 Nanyang Ave., Singapore 639798
b Graduate School of Public Health, San Diego State Univ., Hardy Tower 119, 5500 Campanile, San Diego CA 92182-4162
c Nanyang Environment & Water Research Institute
d Maritime Research Centre, School of Civil and Environmental Engineering, Nanyang Technological Univ., 50 Nanyang Ave., Singapore 639798.Assigned to Associate Editor Kuldip Kumar
This study presents findings on an assessment of the effect of continuous and batch feeding strategies on the removal of selected pharmaceuticals from synthetic wastewater. Six mesocosm-scale constructed wetlands, including three horizontal subsurface flow constructed wetlands and three sand filters, were set up at the campus of Nanyang Technological University, Singapore. The findings showed that ibuprofen and diclofenac removal in the wetlands was significantly (p < 0.05) enhanced in the batch versus continuous mode. In contrast, naproxen and carbamazepine showed no significant differences (p > 0.05) in elimination under either feeding strategy. Our results also clearly showed that the presence of plants exerts a stimulatory effect on pharmaceutical removal for ibuprofen, diclofenac, and naproxen in batch and continuous mode. Estimation of the quantitative role of this stimulatory effect on pharmaceutical elimination of batch operation as compared with the effect of the presence of the higher plant alone showed that batch operation may account for 40 to 87% of the contribution conferred by the aquatic plant. The findings of this study imply that where maximal removal of pharmaceutical compounds is desired, periodic draining and filling might be the preferred operational strategy for full-scale, subsurface flow constructed wetlands.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
Copyright © 2012. . Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.