Removal of decabromodiphenyl ether (BDE-209) using a combined system involving TiO2photocatalysis and wetland plants.
There is a rising concern about the capability of sewage treatment works in treating emerging chemicals, such as polybrominated diphenyl ethers (PBDEs). A combined photocatalysis (TiO2and visible light) and constructed wetland system (planted with Oryza sativa (rice cultivar: Hefengzhan) and Phragmites australis (common reed)) was designed to study PBDEs removal efficiencies. After the pre-treatment in TiO2suspension, the artificially BDE-209 spiked sewage (78.2 and 782nmol/L) was discharged into the sub-surface flow constructed wetland tanks planted with rice and common reed, respectively. The treated sewage, soil, plant roots, shoots, rice grains and hulls were collected and analyzed for PBDEs by GC-MS. The removals of BDE-209 in the combined systems (93.6±2.19% (78.2nmol/L) and 92.1±1.11% (782nmol/L)) were significantly higher than those in the photocatalytic systems (56.3±5.78% (78.2nmol/L) and 54.7±9.47% (782nmol/L)), which could be explained by the enhanced biodegradability of PBDEs in photocatalysis, led to its better dissipation by rice plants. Therefore, this combined system might help to degrade BDE-209 in the wastewater effluent, reducing its potential entry into aquatic food chains.
Consortium on Health, Environment, Education and Research (CHEER), Department of Science and Environmental Studies, The Education University of Hong Kong, Tai Po, Hong Kong, China; Department of Geography, Hong Kong Baptist University, Hong Kong, China.
Ka Lai
KL
Chow
Consortium on Health, Environment, Education and Research (CHEER), Department of Science and Environmental Studies, The Education University of Hong Kong, Tai Po, Hong Kong, China.
Yu Bon
YB
Man
Department of Biology and Chemistry, City University of Hong Kong, Hong Kong, China.
Nora Fung Yee
NFY
Tam
Laboratory for Food Safety and Environmental Technology, Institutes of Biomedicine and Biotechnology, Shenzhen Institutes of Advanced Technology (SIAT), Chinese Academy of Science (CAS), Nanshan District, Shenzhen, PR China.
Yan
Y
Liang
Consortium on Health, Environment, Education and Research (CHEER), Department of Science and Environmental Studies, The Education University of Hong Kong, Tai Po, Hong Kong, China. Electronic address: minghwong@ied.edu.hk.
Ming Hung
MH
Wong
Common reeds; PBDEs in sewage; Paddy rice; Photocatalysis; Removal efficiency