Membrane bioreactor (MBR) is an innovative and efficient wastewater treatment technology that combines membrane separation technology with traditional biological treatment processes. It utilizes the high-efficiency separation capability of membrane components to significantly enhance sludge-water separation efficiency, thereby increasing the concentration of activated sludge in the aeration tank. The presence of specific bacteria in the sludge greatly improves the biochemical reaction rate, leading to a substantial reduction in residual sludge production. This technology effectively addresses the issues associated with large residual sludge production, large footprint, and low operational efficiency in conventional biological treatment methods.
In general, wastewater treatment consists of the following three stages: primary treatment, biological treatment, and advanced treatment. In the primary treatment stage, mechanical processes such as screening, sedimentation, or flotation are employed to remove large solids, stones, sand, fats, iron ions, manganese ions, and oils from the wastewater. The secondary treatment involves the biological degradation and conversion of pollutants in the wastewater into sludge through microbial action. The tertiary treatment, also known as the advanced treatment, includes the removal of nutrients and disinfection of the wastewater through processes such as chlorination, ultraviolet irradiation, or ozone treatment. It is important to note that not all wastewater treatment processes include all of the above stages, as they may vary depending on the treatment objectives and water quality.
The treatment process for producing purified water depends on the quality of the source water. If the source water is municipal tap water, the general process may include sand filtration, activated carbon filtration, softening (optional), security filtration, reverse osmosis, ultraviolet disinfection, and water production. If the source water is surface water, it may require disinfection and the addition of coagulants before entering the aforementioned process. For well water, an iron and manganese removal filter is typically added after the sand filtration stage. Water is then circulated and purified.
Quartz sand filtration is an effective method for removing suspended solids in water and is an important unit in wastewater treatment, water reuse, and water supply processes. Its function is to further remove already coagulated pollutants in water through the interception, settling, and adsorption effects of the filter media, achieving the goal of producing clean water.