The role of SSVF and SSHF beds in concentrated wastewater treatment, design recommendation

摘要

The return flows of reject water from sewage sludge dewatering alter the activated sludge process inna conventional WWTP and increase TN concentration in the final effluent from WWTP. The objectivenof the investigation carried out was to consider the application of multistage treatment wetlandn(MTW) for the treatment of reject water from sewage sludge dewatering in a centrifuge (RWC). Thisnpaper aims to present the design and performance of each stage of the treatment as well as thenefficiency of total MTW. The full scale pilot plant for RWC, consisting of two vertical flow beds (SS VF)nworking in series, followed by an horizontal flow bed (SS HF), was built in 2008. The appliednconfiguration ensured a very high removal efficiency of principal pollutant (COD – 76.0% and NH4nþ-Nn– 93.6%). In the investigated facilities, the SS VF beds ensured an effective removal of nitrogenncompounds, especially NH4nþ-N, whereas the decomposition of hardly degradable Org-N and CODntook place in SS HF. This research illustrates that the MTW could be successfully applied for thentreatment of RWC.