The first system is an artificial rapid percolation sewage treatment system. Its principle is to use a medium with good permeability performance (mainly natural river sand of a certain grade and based on the rapid percolation system). Incorporating active mineral fillers), using the alternating dry and wet operation mode, the sewage will produce comprehensive physical, chemical and biological reactions when passing through the rapid seepage tank, so that pollutants can be removed. Since constructed wetlands have strict requirements for incoming water quality, poor incoming water will lead to very serious hypoxia and blockage in the constructed wetland, and the constructed wetland occupies a very large area.
Artificial rapid percolation is used for pre-treatment. The hydraulic load of the core rapid percolation tank is about 1.5m?/(㎡·d). It uses an extremely cost-saving way to reduce COD, BOD and ammonia nitrogen in the sewage. , TP, SS for rapid removal. In particular, SS pollutants that cause wetland clogging can be treated to extremely low levels (<10 mg/L) through artificial rapid seepage.
The artificial rapid seepage process flow is simple:
Sewage raw water→grill→primary sedimentation tank→artificial rapid seepage tank→drainage into subsequent constructed wetland
This project The water is drawn from the Second Drainage Ditch of the Phoenix River, which is mainly high-concentration domestic sewage with extremely high levels of SS and ammonia nitrogen and organic nitrogen. After artificial rapid seepage treatment, sewage COD can be reduced from the original 400-550mg/L to 30-60mg/L, and SS can be reduced from 300-400mg/L to less than 10mg/L. For ammonia nitrogen, it can be treated from 30-40 to less than 5mg/L. Although the total phosphorus efficiency is low, it still has a removal efficiency of 50-70%. Artificial rapid seepage is relatively provincial and land-saving. The 20,000 tons/day sewage treatment facility in this project occupies no more than 20,000 square meters. It accounts for 20% of the total land used for the entire Fenghuang River Ergou sewage treatment project. Using 20% ??of the land to solve 90% of the pollution load will be more conducive to the stable operation of the subsequent in-depth treatment of the artificial wetland and meet the landscape water demand of the subsequent artificial wetland park.