title: Purification of landscape water by using an innovative application of subsurface flow constructed wetland.
abstract: This study attempted to purify eutrophic landscape water under a low pollutant concentration and high hydraulic volume loading using an embedded subsurface flow (SSF) constructed wetland (CW). Three species of aquatic plants (i.e., Cyperus alternifolius subsp. flabelliformis, Canna indica, and Hydrocotyle verticillata) were found to be conducive to the requirements of purifying the low-polluted water. Field results of nearly 2 years of experiments showed that SSF CW purified the eutrophic water and maintained the landscape water in a visibly clear condition. In an environment approaching the SSF CW background concentration, pollutant removal processes were divided into modulation and optimum performance periods. Average concentrations of biochemical oxygen demand (BOD), ammonium-nitrogen (NH4 (+)-N), and total phosphorous (TP) in the optimum performance period were 0.69-1.00, 0.35-1.42, and 0.19-0.23 mg/L, respectively. Almost 500 days of BOD and NH4 (+)-N removals were necessary to perform optimally. A shorter period, 350 days, was required for TP optimum removal. This feature of two stage removals was not found in chlorophyll-a (Chl-a) and suspended solids (SS), whose averages were 11.86-17.98 and 13.30 μg/L, respectively. Filter cleaning and water replacement were unnecessary, while only water recharging was needed to compensate for the water lost by evapotranspiration. The field SSF CW has maintained its performance level for over 7 years.
authors: Department of Environmental Resources Management, Chia Nan University of Pharmacy and Science, Tainan, 71710, Taiwan. mjmchyan@mail.cnu.edu.tw.
authors: Jih Ming
authors: JM
authors: Chyan
authors: Department of Environmental Science and Engineering, Chia Nan University of Pharmacy and Science, Tainan, 71710, Taiwan.
authors: Chien Chang
authors: CC
authors: Lu
authors: Department of Marine Environment & Engineering, National Sun Yat-Sen University, Kaohsiung, 80424, Taiwan.
authors: Ruei Feng
authors: RF
authors: Shiu
authors: Archie Eustaquio Research Laboratory, Universidad de Zamboanga, Zamboanga City, 7000, Philippines.
authors: Luzvisminda M
authors: LM
authors: Bellotindos
mesh_terms: D001673:Biodegradation, Environmental; D028041:Centella / Q000378:metabolism*; D029786:Cyperus / Q000378:metabolism*; D004777:Environment; D052918:Environmental Restoration and Remediation / Q000379:methods*; D009584:Nitrogen / Q000378:metabolism; D010758:Phosphorus / Q000378:metabolism; D014874:Water Pollutants, Chemical / Q000378:metabolism*; D053833:Wetlands; D019862:Zingiberales / Q000378:metabolism*
chemical_list: D014874:Water Pollutants, Chemical; D010758:Phosphorus; D009584:Nitrogen
keywords: Ammonium–nitrogen; Biochemical oxygen demand; Chlorophyll-a; Embedded subsurface flow constructed wetlands; Suspended solids; Total phosphorus