Influence of vegetation type and temperature on the performance of constructed wetlands for nutrient removal

• Published in: Water science and technology 2018-02, Vol.77 (3), p.829-837
• Main Authors: Zhu, Hui, Zhou, Qing-Wei, Yan, Bai-Xing, Liang, Yin-Xiu, Yu, Xiang-Fei, Gerchman, Yoram, Cheng, Xian-Wei
• Format: Article
• Language: English
• Subjects: Aquatic plants; Artificial wetlands; Canna indica; Efficiency; Engineering; Flowers & plants; Low temperature; Lythrum salicaria; Metabolism; Mineral nutrients; Monoculture; Monoculture (aquaculture); Nitrates; Nitrogen; Nutrient removal; Nutrients; Phosphorus; Pollution; Polyculture; Polyculture (aquaculture); Removal; Rhizosphere; Soil; Soil temperature; Studies; Temperature effects; Urease; Vegetation; Vegetation type; Water treatment; Wetlands
• ISSN: 0273-1223; 1996-9732
• DOI: 10.2166/wst.2017.556

In this study, the influence of vegetation type and environmental temperature on performance of constructed wetlands (CWs) was investigated. Results of vegetation types indicated that the removal of most nutrients in polyculture was greater than those in monoculture and unplanted control. The greatest removal percentages of NH -N, total nitrogen (TN) and total phosphorus (TP) in polyculture were 98.7%, 98.5%, and 92.6%, respectively. In experiments of different temperatures, the removal percentages of NH -N, NO -N, TN and TP in all CWs tended to decrease with the decline of temperature. Especially, a sharp decline in the removal percentages of NO -N (decreased by above 13.8%) and TN (decreased by above 7.9%) of all CWs was observed at low temperature (average temperature of 8.9 °C). Overall, the performance of CWs was obviously influenced by temperature, and the polyculture still showed best performance in the removal of nitrogen when the average temperature dropped to 19.8 °C. Additionally, the variations of urease activities in rhizosphere soil tended to decrease with the decreasing temperature. Overall, a substantial enhancement for nitrogen and TP removal in polyculture (Canna indica + Lythrum salicaria) was observed. In conclusion, CW cultivated with polyculture was a good strategy for enhancing nutrient removal when temperature was above 19.8 °C.