Horizontal sub-surface flow constructed wetland with pulsing water level

• Published in: Water science and technology Vol. 48; no. 5; pp. 143 - 148
• Main Authors: VYMAZAL, J, MASA, M
• Format: Conference Proceeding Journal Article
• Language: English
• Published: London IWA 01-01-2003; IWA Publishing
• Subjects: Ammonia - analysis; Applied sciences; Artificial wetlands; Biological and medical sciences; Biological treatment of waters; Biotechnology; Ecosystem; Environment and pollution; Exact sciences and technology; Facility Design and Construction; Fundamental and applied biological sciences. Psychology; General purification processes; History, 20th Century; Industrial applications and implications. Economical aspects; Municipal wastewater; Outflow; Oxygen - analysis; Pollution; Surface flow; Waste Disposal, Fluid - methods; Wastewater; Wastewaters; Water discharge; Water levels; Water Movements; Water Purification - methods; Water treatment and pollution; Wetlands; Czech Rep
• ISBN: 9781843394501; 1843394502
• ISSN: 0273-1223; 1996-9732
• DOI: 10.2166/wst.2003.0304

A constructed wetland with horizontal sub-surface flow at Dolni Mesto (Czech Republic) was put into operation in 1999 and treats municipal wastewater from 522 PE. The total area of vegetated beds of 2,646 m2 is divided into two parallel sections of equal size, each with two beds in series. Between two periods of water discharge there is no outflow from the bed. During the period of September 1999-September 2000 one bed was operated with a pulsing water level while the other one was not pulsing, i.e., was operated as regular sub-surface flow in order to evaluate the effect of pulsing on treatment efficiency, especially on removal of NH4-N. Between September 1999 and February 2000 the pulse was 8 cm, for the rest of the experimental period the pulse was 15 cm. The results indicate a positive effect of pulsing on removal of BOD5 (annual average of 53%), COD (30%) and NH4-N (27%) as compared to non-pulsing beds. For SS, a decrease in removal effect by 30% was observed. This is probably due to the higher outflow velocity of discharged water from pulsing beds which can flush out settled particles. The results also indicate that a pulsing level of 15 cm was more efficient than 8 cm.