Waste water is the number one source of problem for many cities as improper disposal of waste water can cause health problems to the public. Treatment plants are set up to take sewage and other liquid wastes and transform these into treated water or water that can be used again. To treat the water, the waste water undergoes five processes to ensure that the water is free from contaminants and can be re-used again by the public.
The first stage of the treatment occurs when the waste water is screened. Solid particles are removed from the liquid particles, and large stainless steel wedge wire filters are used to separate the pollutants from the liquid. The wedge wire filter bars are usually one to three inches away from each other to ensure that they are big enough to catch waste but not small enough to clog. The bars are made of stainless steel material to ensure that these are protected from chemicals or other corrosive substances that might be in the waste water. The filter screens can remove solid waste materials such as plastics, cups, bottles, paper, cotton and other solids.
Once all solid particles are removed, the remaining water may still contain small organic solid matter. The water then undergoes another process where all the solid matter is separated from the liquid. Scrapers are used to remove the solid matter that have settled in the bottom while the rest of the water goes through the second process.
Once water is separated, bacteria are added to the water to start the oxidation process. Mixing these with what’s left in the container tank removes any aerial and other microorganisms in the water. The process typically takes about 2 to 3 hours depending on the treated amount.
After the second treatment, all water will undergo a disinfection process to ensure that other harmful organisms are killed. The wastewater fills up a chemical tank where chlorine and sodium are mixed together to further treat the water. The treated water is then released to public areas or local waterways such as beaches or recreational areas once deemed safe.
Digested and Dewatering of Solid Materials
The solid materials or sludge separated from the liquid particles will undergo a separate process where the solid waste is mixed with anaerobic bacteria to stabilize it and separate it further to gas, water and other materials.
After the treatment process, the remaining sludge undergoes a dewatering which removes the rest of the liquids to water and the solid into bio-solid matter. The liquid and solid materials are placed in centrifugal baskets or filters which separate them with the water going back for treatment and the solid being made into bio-solid matter.