Operation mode of the activated sludge treatment system.

The last edit to this post was made by wamj6566 on 2015-10-1 at 21:28. Process flow: The main biochemical unit of this treatment station utilizes the SBR wastewater treatment technology designed by Fujian Thumb Company. After the wastewater is adjusted in terms of quality and volume and undergoes pretreatment, it is pumped into the main biochemical unit. There, it undergoes biochemical treatment before being discharged in compliance with standards. The excess sludge is then concentrated and dewatered, and sent outside the site from time to time； Water quality, quantity regulation and storage, as well as pretreatment: The wastewater for this project, along with process wastewater, is supplied directly to the regulation tank via pressure pipes mounted on support structures ； The gravity-fed wastewater, which has gathered through the underground pipeline network of the plant (sewage and domestic wastewater drainage pipes), passes through the sewage grid ； After removing large-sized debris, the wastewater is directed into the sewage tank; from there, it is pumped up to the homogenization and adjustment tank. Domestic wastewater as well as the main production wastewater undergo quality and volume adjustments and homogenization in this tank, thereby minimizing the variability of the wastewater. The wastewater to be treated then flows from the adjustment tank to the SBR reaction tank 2 by gravity ； Biological treatment 3 ； Principle of biochemical treatment: Biochemical treatment employs the activated sludge method, which utilizes microorganisms to break down organic matter, thereby achieving the purification of wastewater. As mentioned earlier, in addition to C-source organic matter, the wastewater from this project contains 180 mg/l of NH3-N, resulting in a low C/N ratio (≤1.68), which is much higher than the amount of NH3-N required for microbial metabolic processes. Therefore, in addition to removing organic pollutants, wastewater treatment processes must also pay special attention to the effective removal of NH3-N. The proper application of nitrification-denitrification biological treatment techniques (with timely supplementation of carbon sources) is necessary to ensure that the treated wastewater meets regulatory standards before being discharged. This sewage treatment plant is equipped with three SBR reactors for intermittent multi-cycle reactions. This process creates aerobic, anoxic, and anaerobic environments by repeatedly carrying out operations such as aeration, stirring, sedimentation, and discharge (removal of water and sludge) within a single tank, and utilizes aerobic, facultative anaerobic, and anaerobic microorganisms to carry out the biochemical treatment process for decomposing organic matter (BOD) and removing ammonia nitrogen (NH3-N). This process technology is designed based on the traditional principles and techniques of nitration-denitrification biological nitrogen removal, while also taking into account the potential application of new biological nitrogen removal methods such as short-cut nitration-denitrification, anaerobic ammonium oxidation, and simultaneous nitration-denitrification, in order to further reduce energy consumption and the need for C-source supplementation. The water purified through biochemical reactions is discharged into the intermediate tank via a decanter in the supernatant discharge device; it is then pressurized by a pump and passed through a fibrous ball filter before being sent to the sewage tank in the rainwater pumping station. The excess sludge generated during the reaction process is pumped out by a sludge extraction pump and sent to a sludge thickening tank, where it is then dewatered using a filter press before being transported away. 4 ； Process characteristics: As mentioned earlier, the wastewater in this project contains not only C-source organic compounds but also high levels of NH3-N pollutants; as a result, its C/N ratio is low (≤1.68), which is much higher than the amount of NH3-N required for microbial metabolic processes. Therefore, in addition to removing organic pollutants, the wastewater treatment process also places special emphasis on the effective removal of NH3-N. The biochemical unit utilizes SBR process technology, featuring three SBR reactors that carry out intermittent multi-cycle reactions. Through repeated operations of aeration, mixing, sedimentation, and discharge (of water and sludge) within each reactor, aerobic, anoxic, and anaerobic environments are created. Aerobic, facultative anaerobic, and anaerobic microorganisms are then used to carry out the biochemical processes of decomposing organic matter (BOD) and removing ammonia nitrogen (NH3-N). This process technology is designed based on the traditional nitration-denitrification biological denitration principles and techniques to ensure that the treatment plant meets regulatory discharge standards. This process also takes into account the potential application of new biological nitrogen removal technologies such as short-term nitrification-denitrification, anaerobic ammonium oxidation, and simultaneous nitrification-denitrification, in order to further reduce energy consumption and the need for C-source supplementation, thereby saving operating costs.