Impact of Hydraulic Loading Rate and Season on Water Contaminant Reductions Within Integrated Constructed Wetlands

Yu Dong, Piotr R. Wilinski, Mawuli Dzakpasu, Miklas Scholz*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

Abstract

The impact of hydraulic loading rate (HLR) and seasonal temperature on contaminant removal efficiencies within an integrated constructed wetland (ICW) system of 3.25 ha was assessed. The ICW system was designed to treat domestic wastewater from Glaslough (Ireland). The current loading rate is 800 population equivalents. The system has shown good removal performances (2008 to 2010). Mean concentration removal efficiencies were high: 92% for chemical oxygen demand (COD), 98% for the 5 days at 20A degrees C N-allylthiourea biochemical oxygen demand (BOD), 94% for total suspended solids (TSS), 97% for ammonia-nitrogen (NH3-N), 90% for nitrate-nitrogen (NO3-N), 96% for total nitrogen (TN), and 96% for molybdate reactive phosphate (MRP). The mean mass removal efficiencies were 92% for COD, 98% for BOD, 96% for TSS, 92% for NH3-N, 83% for NO3-N, 90% for TN, and 91% for MRP. Loading rate fluctuations were mainly due to high variation in rainfall (0.4 to 400 m(3) day(-1)) and in evapotranspiration rate (0 to 262 m(3) day(-1)). The influence on the removal efficiencies of the hydraulic loading rate (-0.7 to 15.3 cm day(-1)), which was based on overall water balance, was negligible. This implies that the large footprint of the system provides a high hydraulic retention time (92 days).

Original languageEnglish
Pages (from-to)499-509
Number of pages11
JournalWetlands
Volume31
Issue number3
DOIs
Publication statusPublished - Jun 2011

Keywords

  • NITROGEN REMOVAL
  • SYSTEMS
  • NUTRIENTS
  • CAPACITY
  • DOMESTIC WASTE-WATER
  • FLOW
  • Phosphorus
  • Chemical oxygen demand
  • PHOSPHORUS RETENTION
  • Hydraulic retention time
  • Biochemical oxygen demand
  • Mass balance
  • Nitrogen
  • DAIRY FARM WASTEWATERS
  • MECHANISMS

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