Comparison of single-stage and a two-stage vertical flow constructed wetland systems for different load scenarios

Abstract

Constructed wetlands (CWs) are known to be robust wastewater treatment systems and are therefore very suitable for small villages and single households. When nitrification is required, vertical flow (VF) CWs are widely used. This contribution compares the behaviour and treatment efficiencies of a single-stage VF CW and a two-stage VF CW system under varying operating and loading conditions according to standardized testing procedures for small wastewater treatment plants as described in the European standard EN 12566-3. The single-stage VF CW is designed and operated according to the Austrian design standards with an organic load of 20 g COD m(-2) d(-1) (i.e. 4 m(2) per person equivalent (PE)) The two-stage VF CW system is operated with 40 g COD m(-2) d(-1) (i.e. 2 m(2) per PE). During the 48 week testing period the Austrian threshold effluent concentrations have not been exceeded in either system. The two-stage VF CW system showed to be more robust as compared to the single-stage VF CW especially during highly fluctuating loads at low temperatures.

The State of the Art of Clogging in Vertical Flow Wetlands

“…The two-stage VF wetland system [10,22] is designed by using 2 m 2 per PE. The first stage has a coarser filter media with a grain size of 1-4 mm and an impounded drainage layer (15 cm).…”

Návrhové parametry, provozní zkušenosti a možnosti intenzifikace umělých mokřadů

“…Plocha zemního fi ltru by se měla pohybovat v rozmezí od 3 m 2 /EO do 6 m 2 /EO, v Belgii je v průměru navrhována plocha 3,8 m 2 /EO [7], v Dánsku 3,2 m 2 /EO [8], v Rakousku normy pro navrhování jednostupňových vertikálně protékaných umělých mokřadů uvádějí plochu 4 m 2 /EO, pro dvoustupňové systémy potom plochu 2 m 2 /EO [9], v Německu je požadována minimální plocha > 2,5 m 2 /EO.…”

Removal efficiency of Fe, Zn and Ni from wastewater of academic campus using hybrid constructed wetlands

“…In terms of the complexity of the occurring processes, constructed wetlands create a more diverse environment compared to the conventional treatment technologies. [2][3][4][5] Thus, constructed wetlands are now attracting more attention and are considered promising for being environmentally-friendly and for their cost and efficiency features. [6,7] Over the past few decades, CWs have proved to be functional in treating domestic municipal wastewater, [8] landfill leaches, [9] and industrial sewage water.…”