Supercritical Water Oxidation of the sewage sludge from Ryaverket Wastewater Treatment Plant

Supercritival Water Oxidation (SCWO) is an innovative, modern and effective destruction process for treatment of organic-rich sewage sludge. In the SCWO sludge treatment system, dilute aqueous organic waste is combined with on oxidizant above the critical point of water, 22,1 Mpa and 374,2.C. For most organic wastes, these conditions are sufficient to achieve more than 99,99% destruction and removal efficiencies and better in 30-60 seconds of reaction time. There are no harmful gaseous emissions to the environment (e.g., Nox and SO) from the SCWO process. Trace amounts of N[2]O are produced; however, they can be thermally or catalytically destroyed. Inorganic compounds leaving the SCWO process are oxidized to their highest valencies, which gives an opportunity for their recovery. Aqua Reci is a process in which SCWO is used to decompose the organic material, followed by a chemical process to recover valuable components from the inorganic residual ash such as phosphates and precipitation chemicals.