Sludge is a by-product of sewage treatment with considerable output. Sludge contains water and solid substances, which are mainly the products of suspended matter intercepted, colloidal substances and dissolved substances after treatment. Sludge accumulates pollutants in sewage and contains a large number of bacteria and parasite eggs, so it must be properly treated to prevent secondary pollution. Nowadays, a large number of unstable sludge has become a heavy burden and a great threat to the environment of municipal sewage treatment plants. In the construction project of municipal sewage treatment plants, filter presses should be installed to consider the outlet of sludge and reduce the pollution of sludge to the environment.
The composition of cop sludge mainly depends on the quality of sewage, treatment process and method. The composition of sludge mainly depends on the quality of sewage, treatment process and method. Sludge mainly includes the following kinds: primary sedimentation tank sludge, secondary sedimentation tank sludge, grid slag, sediment sediment and scum, etc. The primary clarifier sludge is mainly composed of organic substances, while the secondary clarifier sludge contains biological and chemical agents. Sludge contains a lot of water. The water content of sludge in sedimentation tank is generally over 95%. Water content can greatly affect the volume of sludge. If the water content is reduced from 99.5% to 95%, the volume of sludge can be reduced to 1/10 of the original.
The special design of the filter chamber makes it possible to automatically close the feed valve after filling the filter chamber with cake, and to pass gas or liquid into the filter chamber, so that the filter cloth expands and deforms, thus achieving the function of secondary pressing of the filter cake and further reducing water content. Further gas is introduced to further reduce the moisture content in the cake. The high-pressure air passes through the filter cake and separates the capillary water and structural water in the filter cake. This is the blowing drying method.
Generally speaking, the reuse of municipal sewage is an important issue in water-scarce areas, Because municipal sewage has been proved to be a reliable water resource, and with the progress of water treatment technology, sewage regeneration technology has been widely used. In this case, the structure of the filter press adopts hydraulic pressure and automatic pressure retaining devices. The filter cake with high solid content can be manufactured by the pressure generated during filtering. The operation process is simple and safe, and the automation process is high, time-saving and labor-saving, and the cost is reduced.