Multistage treatment wetland for treatment of reject waters from digested sludge dewatering.
The paper presents the influence of sewage composition on treatment in pilot-scale facility for reject waters (RW) from sewage sludge centrifugation. The facility consisted of mechanical (two tanks with 10 d retention each) and biological parts composed of three subsurface flow reed beds working in batch. Two years of monitoring of the facility proved high efficiency removal of predominant pollutants: chemical oxygen demand (COD) 75-80%, biochemical oxygen demand (BOD) 82.2-95.5% and total nitrogen 78.7-93.9% for low ratio of BOD5/COD in discharged RW. The differences in efficiency removal were correlated with the composition of organics and nitrogen compounds rather than with concentrations. It was assumed that high concentration of colloidal fraction of Org-N and COD in discharged RW led to a decrease in efficiency removal.
Faculty of Civil and Environmental Engineering, Gdańsk University of Technology, 11/12 Narutowicza St, 80-233 Gdańsk, Poland E-mail: mgaj@pg.gda.pl.
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M
Gajewska
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H
Obarska-Pempkowiak
D057919:Biological Oxygen Demand Analysis; D009584:Nitrogen / Q000032:analysis; D012722:Sewage / Q000737:chemistry*; D014865:Waste Disposal, Fluid / Q000379:methods*; D014867:Water / Q000737:chemistry; D014873:Water Pollutants / Q000032:analysis; D053833:Wetlands
D012722:Sewage; D014873:Water Pollutants; D014867:Water; D009584:Nitrogen