SMALL WASTEWATER TREATMENT PLANTS IN FLANDERS (BELGIUM) : STANDARD APPROACH AND EXPERIENCES WITH CONSTRUCTED REED BEDS

A pilot scale constructed two-stage reed bed is used to optimise the concept of the reed beds. The concept consists of a primary clarifier, two parallel vertical flow reed beds followed by a sub-surface flow reed bed. The removal efficiencies for organic pollutants, phosphorus, nitrogen, and pathogens were evaluated. Seasonnal variations of performances were also investigated. Clogging problems were noticed and appeared to be related with presettlement, feed interval and geotextile.