1. Project overview
Food industry wastewater, the rest are unknown.
2. Design principles
- According to the actual situation of the sewage treatment station receiving sewage water quality and quantity, the treatment structure form and design parameters are selected to ensure that the sewage treatment system has greater flexibility and adjustment room in operation to adapt to changes in water quality and quantity.
- The treatment system adopts a type that has been proven by engineering practice to be effective, obvious technical and economic benefits, strong adaptability, simple management, and stable effect to fully ensure that the effluent after treatment meets the standard discharge.
- Sewage and sludge treatment equipment uses new materials, low energy consumption, high efficiency, easy maintenance, and products with good performance and price ratio.
- Control and management According to the requirements of the treatment process, consider self-control as much as possible, reduce the labor intensity of operation and operation, make the sewage treatment station run reliably and maintain convenient, and improve the operation and management level of the sewage treatment station.
- Make full use of existing conditions, save land and reduce project investment according to local conditions.
- In the plane layout and engineering design, combine the existing site, and strive to make the layout compact, concise, neat and beautiful.
3. Sewage situation analysis
The sewage is mainly food industry sewage. The sewage treatment implements a three-shift system, and the pollutants to be removed in the sewage are mainly organic matter. Due to the relatively dispersed time of sewage inflow and the large range of changes in water quality and quantity, the sewage treatment process is required to have the ability to withstand impact loads and reliable operation stability.
4. Selection of technological process
Because the sewage water quality is food industry sewage, and the organic content is relatively high. In view of the pollution characteristics of the sewage and the operation and management requirements of the sewage, this plan adopts the mature process A/O method for treatment.
5. Process description
Sewage treatment process: sewage treatment, sewage treatment equipment
The sewage treatment system is composed of a regulating tank, an anoxic tank, an aerobic tank (contact oxidation tank), and a secondary settling tank. Sewage from the production workshop flows into the regulating tank. The entrance of the regulating tank is equipped with a mechanical grid to intercept large granular and fibrous impurities. The slag intercepted by the mechanical grid automatically enters the glove box and is regularly removed and transported by the sanitation department. In the regulating tank, the sewage is fully mixed, the water volume is adjusted and the organic matter is initially degraded, and then the sewage is fed into the anoxic tank through the sewage pump, and the return mixture is fully mixed with the raw sewage in the anoxic tank. Through the action of facultative microorganisms, the Nitrate nitrogen and nitrate nitrogen are converted into nitrogen to complete denitrification and denitrification. The effluent from the anoxic tank flows into the contact oxidation tank. The contact oxidation tank is a biological treatment device based on the biofilm method and combined with the activated sludge method. The oxygen source is provided by the blower, so that the organic matter in the sewage is fully contacted with the biofilm in the tank, and the microorganisms are adsorbed and degraded. The water quality is purified. , The effluent from the second settling tank meets the first-level standard of the “Integrated Wastewater Discharge Standard” and is discharged into the nearby river.
The sludge in the secondary settling tank is regularly pumped to the aerobic tank by the sludge return pump. The remaining sludge is small. The sludge is cleaned every two months or so, and it is removed by the sanitation pumping truck and transported for disposal.
The oxygen required by the biochemical system is supplied by a blower, and the aeration system uses a blower + microporous aerator. Taking into account the high noise of the blower, the fan room is specially set up as a soundproof and silencing type.
6. Process characteristics description
- Sewage treatment facilities have greater flexibility and room for adjustment to adapt to changes in water quality and quantity, and at the same time set up emergency accidents to exceed the discharge pipe for emergency and special circumstances;
- By adopting advanced and mature A/O biochemical treatment process, the removal rate of pollutants is improved, and it has the characteristics of low power consumption and low investment to ensure that the effluent meets the discharge standard.
- Through reasonable selection of design parameters such as the surface load of the secondary settling tank, the effective water depth and the inclination of the mud bucket, the solid-liquid separation effect can be improved.
- The entire processing system is simple in management and reliable in operation
7. Brief introduction of A/O treatment process
The core of a set of sewage treatment system is the biochemical treatment system. This design adopts the A/O treatment process as the biochemical treatment system.
8. Reasons for choosing A/O process
The organic content in sewage is relatively high, but the biodegradability of food wastewater is better. At present, the widely used methods mainly include A2/O method, oxidation ditch method, SBR method, aerated biological filter method, bioreactor, etc., which not only have the function of creating organic pollutants, but also have the ability to remove nitrogen and phosphorus Request processing, the technology is quite mature.
9. A/O process characteristics
A/O method has the advantages of advanced and practical technology, mature and reliable, good running effect, etc., which can meet various strict effluent water quality requirements. The A/O process has the following characteristics:
- Strong impact resistance and good process stability;
- low investment, low operating cost;
- It has the function of denitrification and dephosphorization.
- Less mechanical equipment is required, and daily maintenance is simple;
- It occupies a small area and has no adverse effects on the surrounding environment.