The Pre-treatment 
Pre-treatment is the process that removes all of the easily removable large objects. The types of debris that are removed during pre treatment include fats, oils and greases, sand, gravel, rocks, rags and feminine hygiene products and any other larger solids that can easily be filtered out.
Secondary Treatment 
The secondary treatment is where the sewage that is from human waste, food waste, soaps and detergents is broken down and composted using an aerobic biological process which speeds up the process. After it is composted, it goes through a series of filters that clean out all of the other little things such as bacteria and algae. There are several different types of filters including a trickling filter and biological aerated filters. Trickling filters are where the settled sewage liquor is spread onto the surface of a deep bed made of carbonized coal, limestone chips or a specially fabricated plastic media that has high surface areas to support the biofilms that form.
Primary Treatment 
In the first stage of processing, the sewage flows through the primary clarifiers which are large tanks. These tanks are large enough that the sludge can settle and all of the floating material like grease and oils rise to the surface where they can be skimmed off. They are equipped with mechanically driven scrapers that drive the collected sludge into a hopper.
Nutrient Removal and Disinfection 
Wastewater contains high levels of nutrients such as nitrogen and phosphorus which can be very harmful in large doses. Nitrogen is removed by oxidation which converts it to nitrate and then into nitrogen gas which is removed from the water by releasing it into the air. Phosphorus is removed through the use of chemicals such as salts of iron or aluminum.
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Phone: +86 13817134452 &+86 13817145452 &+86 13918724674
Email: qilee@qileegroup.com
Contact person: Xia Miao
Add: Room 412, Xianglu Building, No. 3009, Gudai Road, Minhang District, Shanghai, China

If you are interested in Membrane Water Treatment Systems, please check our website at https://www.qileegroup.com for details.