Process Flow Of Wastewater Treatment Equipment

A typical process flow (e.g., for domestic sewage) may include: domestic sewage → screen chamber → equalization tank → anaerobic tank → aerobic tank (MBR) → disinfection → compliant discharge/reuse .
The A/O process consists of an anaerobic stage (A) and an aerobic stage (O); the anaerobic stage is primarily used for nitrogen and phosphorus removal, while the aerobic stage removes organic matter. This process is characterized by its simplicity, low investment costs, and high total nitrogen removal rate, though further improving nitrogen removal efficiency is challenging.
The A2O process is an enhanced version of the A/O process that incorporates an anoxic stage, creating an anaerobic-anoxic-aerobic treatment sequence. Capable of simultaneously and efficiently removing nitrogen, phosphorus, and COD from domestic sewage, it is currently one of the mainstream biochemical treatment methods.
The MBR (Membrane Bioreactor) process combines biological treatment with membrane separation technology. Due to the separation effect of the membrane, the effluent is clear with extremely low suspended solids and turbidity; it also effectively removes bacteria and viruses, typically allowing the effluent to meet high standards for water reuse.
The CASS (Cyclic Activated Sludge System) process is based on the SBR (Sequencing Batch Reactor) method but adds a biological selector, enabling continuous influent flow and intermittent effluent discharge. This process offers advantages such as reduced investment costs (by approximately 20%–30%), land savings (over 30%), and lower operating expenses.