At a wastewater treatment plant, grease and sand is removed by using a trap to protect the plant equipment from damage in the following treatment processes. There are various methods to cleansing wastewater, however, the most common is a combination of mechanical and biological treatment. With this method, wastewater is cleansed in steps, with a biological process or aeration of the wastewater in order to conduct nitrification and denitrification processes.
Mechanical wastewater treatment is used to remove any solid matter, and includes the processes of filtration (or separation) and sedimentation. In the biological stage, the impurities which are not picked up by the mechanical process, are treated. This happens in a sludge activation tank. Other processes (as for example: trickling filter and immersion filter) are used in isolated cases.
Sludge is produced as a waste product of the treatment process. Treatment and preparation of sludge entails its own equipment requirements, which can vary significantly depending on the individual plants. The most common way of disposing sludge remains to be through use in agriculture. Other ways of disposing sludge is to deliver it to an external biogas plant, so that it may be used in renewable energy production.
For projects within wastewater treatment, AVK offers a broad selection of gate valves, butterfly valves, check valves, slide- and knife gate valves, air valves, couplings, adaptors, tapping saddles, repair clamps, surface boxes and valve accessories.