title: Efficiency of subsurface flow constructed wetland with trickling filter.
abstract: Effective wastewater purification in subsurface flow constructed wetlands must include adequate pretreatment and ensure a sufficient amount of dissolved oxygen. In a pilot-scale operation, a subsurface flow constructed wetland (CW) consisted of a primary settlement tank, a trickling filter for pretreatment and two serially assembled basins. The trickling filter was added to ensure sufficient aeration, increase purification of the wastewater and shorten the wastewater purification time. The estimated nominal flow was 0.7 m3/d. The experiments were conducted using the wastewater from the municipal sewage canal of the city of Zagreb, with utilization of three different flows: 0.72 (A), 1.44 (B) and 2.88 (C) m3/d. The efficiency of the purification process was monitored over a period of three years (TSS, BOD5, COD, NH4-N, NO2-N, PO4-P, dissolved oxygen, temperature and pH). The experimental results showed an increase in the removal efficiency with a doubling of the nominal flow from 0.7 to 1.44 m3/d, which could be related to the implementation of the trickling filter where high removal rates were achieved.
authors.affiliation: University of Zagreb, Faculty of Geotechnical Engineering, Hallerova aleja 7, 42000 Varazdin, Croatia.
authors.forename: Aleksandra Anic
authors.initials: AA
authors.lastname: Vucinic
authors.forename: Jasna
authors.initials: J
authors.lastname: Hrenovic
authors.forename: Predrag
authors.initials: P
authors.lastname: Tepes
mesh_terms: D057919:Biological Oxygen Demand Analysis; D005374:Filtration; D017672:Nitrogen Compounds / Q000032:analysis; D010100:Oxygen / Q000032:analysis; D010710:Phosphates / Q000032:analysis; D010865:Pilot Projects; D018505:Waste Management; D053833:Wetlands
chemical_list: D017672:Nitrogen Compounds; D010710:Phosphates; D010100:Oxygen