Inner Mongolia Sewage Treatment Operation Effect Project Operation Status and Experience: Spray paint wastewater treatment: Air flotation-biochemical process is reasonable and practical. Aiming at the characteristics of the company's spray paint wastewater: low water volume, high concentration, complex composition, and poor biodegradability, the air flotation method was used to carry out Pretreatment to achieve solid-liquid separation. Because the company has a certain amount of domestic sewage, and spray paint wastewater has a sufficient amount of comprehensive treatment of domestic sewage, the air flotation-biochemical method is used. The pre-treated spray paint wastewater is treated with domestic wastewater by anaerobic-anoxic-biological contact oxidation treatment. The operation results show that this process is successful, and at the same time, the effect of removing phosphorus and nitrogen can be achieved, and the total treatment efficiency is high. The removal rate of CODcr of spray paint wastewater by air flotation pretreatment reaches 45.7%, which greatly reduces the load of the subsequent biochemical treatment system and provides favorable conditions for the final drainage standard.
Spray paint wastewater treatment: use of air flotation device and selection of chemicals
The air flotation device has a small volume and a small floor area, and the structure of the tank is simple. It can be started and stopped at any time. Inner Mongolia wastewater treatment does not affect the quality of the effluent water and is easy to manage. In the selection of flocculants, because the raw water contains many types of paints and pigments, multiple flocculants are used in combination. According to test data, polyaluminum chloride and caustic soda were selected as flocculants and coagulant aids. Because the paint spraying wastewater is high turbidity water, a small amount of polymer flocculant polyacrylamide is added as a coagulant. The effect is satisfactory, but the drug cost is quite large. Under the premise of ensuring the effluent effect, the use of ferrous sulfate instead of polyaluminum chloride will still meet the standards for wastewater treatment in Inner Mongolia, and the cost of medicines will be greatly reduced. Several coagulants can be added at the same time to obtain better results, mainly because each coagulant has its own chemical base and has a different chemical base, which can act as a bridge in the water body and give full play to their respective advantages. The alum bloom is enlarged and the effect is obvious.
Spray paint wastewater treatment: start-up and operation of biochemical systems
Because this project has a large amount of domestic sewage, the biochemical system is started by using domestic sewage for culturing, and adding production wastewater for domestication at the later stage of culturing. First, the contact oxidation tank was filled with domestic sewage, and after one day of exposure, water was introduced. The water volume was gradually adjusted from small to large, and it was continuously operated for 5-7 days. After observing the good film of the filler, Inner Mongolia wastewater treatment was gradually added to production wastewater The amount of water inflow until the designed amount of production wastewater is reached. During domestication, each time the ratio is changed, it needs to be kept for several days. After the operation is stable, the ratio can be changed again until the end of domestication. The anaerobic and anoxic tanks are also filled with domestic sewage and continuously recirculated according to the reflux ratio of 100%. After 1 week, 10% of production wastewater was injected. After that, increase the amount of production wastewater by 10% every 3 days until the design water volume is reached. After 35 days, a biofilm was observed on the surface of the filler in the anaerobic and anoxic tanks. After another 80 days, the filler film of the entire biochemical system is about 2mm thick, and the effluent quality meets the design requirements.
Spray paint wastewater treatment: the impact of water inlet concentration on the treatment effect: This project has been commissioned since March 2009. Inner Mongolia wastewater treatment paint spray wastewater CODcr concentration range is 1363-15600mg / l, BOD5 concentration range is Fluctuations between times, water quality changes greatly. After passing through the sewage treatment system, the effluent can still reach the discharge standard. It can be seen that the process device can withstand a higher load of pollutants, is impact resistant, and can efficiently treat high-concentration sewage.