title: Insight into the risk of replenishing urban landscape ponds with reclaimed wastewater.
abstract: Increasing use of reclaimed wastewater (RW) for replenishing urban landscape ponds has aroused public concern about the water quality. Three ponds replenished with RW in three cities in China were chosen to investigate 22 indexes of water quality in five categories. This was achieved by comparing three pairs of ponds in the three different cities, where one pond in each pair was replenished with RW and the other with surface water (SW). The nutrients condition, heavy metal concentration and ecotoxicity did not differ significantly between RW- and SW-replenished ponds. By contrast, significant differences were observed in algal growth and pathogen risk. RW ponds presented a Cyanophyta-Chlorophyta-Bacillariophyta type with high algal diversity while SW ponds presented a Cyanophyta type with low diversity. Regrowth of bacterial pathogens and especially survival of viral pathogens in RW, was the main driver behind the higher risk for RW ponds compared with SW ones. The duration of RW replenishment was proved to have a marked impact on the algal growth and pathogen risk. With continued RW replenishment, non-dominant algal species subjected to decrease while dominant species were enhanced resulting in the biomass increasing but diversity declining, and the risk posed by viral pathogens might become greater.
authors.affiliation: Key Lab of Northwest Water Resources, Environment and Ecology, Ministry of Education, Xi'an University of Architecture and Technology, Xi'an 710055, PR China; Department of Civil and Environmental Engineering, Graduate School of Engineering, Tohoku University, 6-6-06 Aza-Aoba, Aramaki, Aoba-ku, Sendai, Miyagi 980-8579, Japan. Electronic address: chenrong@xauat.edu.cn.
authors.forename: Rong
authors.initials: R
authors.lastname: Chen
authors.affiliation: Key Lab of Northwest Water Resources, Environment and Ecology, Ministry of Education, Xi'an University of Architecture and Technology, Xi'an 710055, PR China.
authors.forename: Dong
authors.initials: D
authors.lastname: Ao
authors.affiliation: Department of Civil and Environmental Engineering, Graduate School of Engineering, Tohoku University, 6-6-06 Aza-Aoba, Aramaki, Aoba-ku, Sendai, Miyagi 980-8579, Japan.
authors.forename: Jiayuan
authors.initials: J
authors.lastname: Ji
authors.affiliation: Key Lab of Northwest Water Resources, Environment and Ecology, Ministry of Education, Xi'an University of Architecture and Technology, Xi'an 710055, PR China. Electronic address: xcwang@xauat.edu.cn.
authors.forename: Xiaochang C
authors.initials: XC
authors.lastname: Wang
authors.affiliation: Department of Civil and Environmental Engineering, Graduate School of Engineering, Tohoku University, 6-6-06 Aza-Aoba, Aramaki, Aoba-ku, Sendai, Miyagi 980-8579, Japan.
authors.forename: Yu-You
authors.initials: YY
authors.lastname: Li
authors.affiliation: Key Lab of Northwest Water Resources, Environment and Ecology, Ministry of Education, Xi'an University of Architecture and Technology, Xi'an 710055, PR China.
authors.forename: Yue
authors.initials: Y
authors.lastname: Huang
authors.affiliation: Key Lab of Northwest Water Resources, Environment and Ecology, Ministry of Education, Xi'an University of Architecture and Technology, Xi'an 710055, PR China.
authors.forename: Tao
authors.initials: T
authors.lastname: Xue
authors.affiliation: Key Lab of Northwest Water Resources, Environment and Ecology, Ministry of Education, Xi'an University of Architecture and Technology, Xi'an 710055, PR China.
authors.forename: Hongbing
authors.initials: H
authors.lastname: Guo
authors.affiliation: Key Lab of Northwest Water Resources, Environment and Ecology, Ministry of Education, Xi'an University of Architecture and Technology, Xi'an 710055, PR China.
authors.forename: Nan
authors.initials: N
authors.lastname: Wang
authors.affiliation: Key Lab of Northwest Water Resources, Environment and Ecology, Ministry of Education, Xi'an University of Architecture and Technology, Xi'an 710055, PR China.
authors.forename: Lu
authors.initials: L
authors.lastname: Zhang
mesh_terms: D002681:China; D000460:Chlorophyta / Q000254:growth & development; D000458:Cyanobacteria / Q000254:growth & development; D017377:Diatoms / Q000254:growth & development; D061005:Ponds / Q000032:analysis*; D014507:Urbanization; D014865:Waste Disposal, Fluid / Q000379:methods*; D062065:Wastewater / Q000737:chemistry* / Q000382:microbiology; D060753:Water Quality
chemical_list: D062065:Wastewater
keywords: Algal growth; Landscape pond; Pathogen risk; Reclaimed water; Replenishment