Wastewater treatment

At wastewater treatment plants, the grease and sand are removed by means of a grease and sand trap to save the equipment in the following processes from damage. There are many different technologies for cleaning wastewater but the most common is a combination of mechanical treatment and biological treatment. The wastewater is cleaned in steps ending with a biological process or aeration of the wastewater in order to begin the nitrification and denitrification processes.

Mechanical wastewater treatment is used to remove solid matter in the water. It includes two processes: filtration (or separation) and sedimentation. Filtration is carried out in various phases using various processes. These can remove coarse impurities such as paper or leaves using a rake or rotaring screen. In the primary sedimentation tank, the purification (reduction of organic material) takes place.

In the biological phase of the wastewater treatment process, the main impurities which are suspended in the water and not picked up by the mechanical process, are treated. The biological wastewater treatment process takes place when the wastewater is being treated in the activated sludge tank. Other processes (e.g. trickling filter, immersion filter) are used in separation cases.

Sludge is produced as a waste product in the wastewater treatment process. Sludge treatment generates required equipment and can vary considerably depending on the plant. The most common way of disposing of wastewater sludge is still using it in agriculture. This is why some countries utilize wastewater sludge thermally. In some cases, the wastewater sludge is supplied to an external biogas plant.

For wastewater treatment, AVK offers gate valves, butterfly valves, check valves, knife gate valves, penstocks, air valves, couplings, adaptors, repair clamps, fittings, and accessories.