A Petrochemical Company of China Petroleum Corporation has an annual capacity of processing crude oil of 4 million t. The refinery sewage and domestic sewage produced in the whole production process are discharged into the sewage treatment plant through their respective pipe networks, and then produced by sewage. water and domestic sewage treatment devices are discharged after treatment respectively. Among them, all kinds of sludge produced by production sewage and domestic sewage treatment device are dehydrated by the same sludge system. Crude oil contains a small amount of sulfur, nitrogen, oxygen and other elements, which are converted into harmful compounds and dissolved into water during the refining process, causing waste water. In addition, because chemical agents (such as acid and alkali) and catalysts are needed in the petroleum refining process, various waste residues are produced.
Sludge produced in oil refining, chemical engineering and domestic sewage treatment plants mainly includes: Grid slag, sediment of sand sink, sediment of primary sedimentation tank, sediment of oil separation tank, sediment of flotation tank, biological sludge and scum, etc, the sludge should be pretreated before sludge dewatering, and the efficient conditioner suitable for the electric load on the surface of sludge particles should be selected to destroy the particle structure of sludge and reduce the affinity of water to improve its dehydration, then the petrochemical filter press device is used to replace the secondary sedimentation tank in the traditional process, which can conduct solid-liquid separation efficiently and obtain stable reclaimed water directly used. It can also maintain a high concentration of microbial quantity in the biological pool, with less excess sludge in the process, which can remove ammonia nitrogen very effectively. The suspended solids and turbidity in the effluent are close to zero, and bacteria and viruses in the effluent are greatly removed, low energy consumption and small floor space.
In this way, after layers of filtration, the oil content and organic matter in the waste water are greatly reduced, and the water discharged finally can be recycled.