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How much does a set of integrated sewage treatment equipment cost? Generally, such equipment costs tens of thousands of yuan, and in some cases the price is even higher. The cost is primarily determined by the amount of sewage that needs to be treated on site, as this provides the basis for determining the price. Integrated sewage treatment equipment is applied in: Its main treatment method is the biochemical treatment technique of contact oxidation. The design of such integrated domestic sewage treatment equipment takes into account that the water quality parameters for domestic sewage and similar industrial organic sewage are calculated based on those of ordinary domestic sewage, with an inlet BOD5 level of 200 mg/L. Main components: 1. Hydrolysis and acidification tank; 2. Contact oxidation tank; 3. Impurity sedimentation tank; 4. Disinfection treatment; 5. Aerobic sludge digestion tank. 1. Hydrolysis and acidification tank: This process is primarily used for pre-treatment of wastewater before it is processed further. It involves carrying out anaerobic fermentation of the wastewater, thereby improving its biodegradability. This is an important step prior to wastewater treatment, as it can directly affect the efficiency and processing time of subsequent treatment steps, helping to maximize the efficiency of wastewater treatment and reduce costs. 2. Contact oxidation tank The oxidation tank is divided into several grades depending on the degree of pollution in the water to be treated, namely standard type and enhanced type. It is generally determined based on the processing time. For treatment times of no more than four hours, a standard oxidation tank is used; for treatment times between 4 and 6 hours, an enhanced oxidation tank is employed. Primarily, the effluent from the hydrolysis-acidification tank flows by gravity to the contact oxidation tank for biochemical treatment. Most of the organic substances in the raw wastewater are degraded and purified here. Aerobic bacteria, using the filler as a support, feed on the organic substances in the wastewater and break them down into inorganic salts, thereby achieving purification. For aerobic bacteria to survive, there must be sufficient oxygen, that is, enough dissolved oxygen in the wastewater, in order to achieve biochemical treatment. Air for the aerobic tank is supplied by fans. The tank uses a new type of elastic three-dimensional filler, which features a large surface area, a long service life, easy biofilm formation, and corrosion resistance. Rotary mixing aerators are installed at the bottom of the tank, ensuring a high transfer rate of dissolved oxygen; these aerators also have the advantages of being lightweight, not prone to aging, not easily clogged, and having a long service life. The air-to-water ratio in the contact tank is around 12:1. (0.5–5 m3/h; the contact tank is of secondary type) 3. Sedimentation tank: After being treated in the biological contact oxidation tank, the wastewater flows by gravity into the sedimentation tank, where further sedimentation occurs to remove the detached biofilm as well as some organic and inorganic particles. The sedimentation tank operates on the principle of gravity – as the wastewater containing suspended solids flows from bottom to top, gravity causes these substances to settle. An adjustable outlet weir is installed at the upper part of the sedimentation tank to regulate the water level at the outlet; a conical sedimentation area and a sludge gas handling system are provided at the lower part. The air supply is provided by a fan, and the sludge is transported to the aerobic sludge digestion tank via air lift. 4. Disinfection The retention time in the disinfection tank is 30 minutes in accordance with the standard «TJ14-74»; for hospital wastewater, this retention time is increased to 1–1.5 hours. Our company uses chlorine dioxide disinfection systems; the disinfection tanks and these systems are capable of adjusting the amount of chemical added according to the volume of water discharged, so that more chemicals are used when more water is discharged and less chemicals are used when less water is discharged. Other devices can be installed if needed. (If used for industrial wastewater, disinfection tanks and disinfection devices may not be necessary. 5. Aerobic sludge digester: The excess sludge discharged from the sedimentation tank is subjected to aerobic digestion in this tank as a means of stabilizing it, thereby reducing its volume and enhancing its stability. The amount of sludge after aerobic digestion is relatively small; during cleaning, a sewage pump can be used to reach the bottom of the sludge tank through the inspection holes, and the sludge can then be pumped out for disposal (cleaning is carried out once every six months). A supernatant reflux device is installed at the top of the aerobic sludge digester to allow the supernatant to flow over into the hydrolysis-acidification tank