title: Effect of artificial aeration, temperature, and structure on nutrient removal in constructed floating islands.
abstract: To study the optimal performance characteristics and maximize the removal efficiency of contaminants by the constructed floating islands (CFIs), four kinds of parallel pilot-scale CFIs with different structures were set up outdoors to treat eutrophic water for approximately 6 months. The contribution of artificial aeration to nutrient removal on the basis of gas-water ratios was investigated, and the influences of the structure and temperature were evaluated simultaneously. It was noted that the nutrient removal rate of the multi-medium CFI was greater than those of others. In the four kinds of units, aeration could significantly increase the nutrient removal efficiency, and a gas-water ratio of 10 was adequate for the relatively high removal of nutrients. Using the aforementioned gas-water ratio of 10 and a hydraulic residence time (HRT) of 2 days, the mean removal efficiencies of the multi-medium CFI for NH3-N and total phosphorus were 71.7% and 63.6%, respectively-approximately twice as great as those in the non-aerated system. Furthermore, temperature was an important factor for nutrient removal in the multi-medium CFI. With the water temperature of >13 degrees C and the HRT of 2.5 days, the mean removal efficiencies for NH3-N and total phosphorus were 87.6% and 83.5%, respectively, whereas the removal efficiency decreased significantly when the temperature was lower than 13 degrees C.
authors.affiliation: College of Environmental Science and Engineering, Guilin University of Technology, Guilin, Guangxi, China.
authors.forename: Wang
authors.initials: W
authors.lastname: Dunqiu
authors.forename: Bai
authors.initials: B
authors.lastname: Shaoyuan
authors.forename: Wang
authors.initials: W
authors.lastname: Mingyu
authors.forename: Xie
authors.initials: X
authors.lastname: Qinglin
authors.forename: Zhu
authors.initials: Z
authors.lastname: Yinian
authors.forename: Zhang
authors.initials: Z
authors.lastname: Hua
mesh_terms: D005068:Eutrophication; D009584:Nitrogen / Q000302:isolation & purification; D010758:Phosphorus / Q000302:isolation & purification; D013696:Temperature; D014873:Water Pollutants / Q000302:isolation & purification*; D018508:Water Purification / Q000379:methods*
chemical_list: D014873:Water Pollutants; D010758:Phosphorus; D009584:Nitrogen