The treatment of wastewater is dependent upon the standards along with the particular requirements associated with the parameters of effluent, or output stream, quality. The treatment process targets the improvement in the quality of wastewater. Wastewater may contain impurities or pollutants which include suspended solids, biodegradable organics, pathogenic bacteria, non-pathogenic bacteria, soluble organic materials, solids, gases, emulsions, toxins, pharmaceuticals and nutrients. Suspended solids are elements that may choke channels and are capable of settling under the action of gravity. Biodegradable organics are materials that can be used as food for microorganisms which use oxygen along with these impurities to gain the energy that is necessary for them to flourish and reproduce. Nutrients include nitrates and phosphates.
The main purpose of treating wastewater is in general to let effluents from human and industrial sources to be discarded with no danger to human wellbeing or undesirable harm to the ambient environment. Usual treatment processes include a mishmash of chemical, physical, and biological methods to eliminate pollutants from wastewater. There are several processes employed for the treatment of wastewater depending on the extent of treatment done. These processes include preliminary, primary, secondary, and tertiary treatment. Pre-treatment is used for the removal of objects that are easily removable. The kinds of impurities that are removed through pre treatment take in oils, fats, sand, rocks, gravel, etc. Primary treatment takes care of the materials which have the capability to float on water. The sludge is allowed to settle in large settling tanks and then the floating impurities are removed. Secondary treatment involves a biological process which accelerates the process and the wastewater passes through a sequence of sieves that decontaminate all of the remaining smaller objects for instance bacteria and algae. A number of different types of filters are employed in the process. The final steps in some cases take in processes like nutrient removal and disinfection.
Waste water treatment is one of the most cost-effective alternatives to conserve our most valuable resource. It is a known fact that the amount of water that is present on earth is diminishing gradually and the chances of preserving water are much increased if treatment processes are employed and least amounts of water are wasted. There are several types of wastewater treatment plants which include Package plant, Activated Sludge plant, and Extended Aeration Activated Sludge plant, Biological Filter, Oxidation Ditch, Aerated Lagoon and Waste Stabilization Pond System.