In the collection as well as management of the sewage that goes to the sewage treatment plants, there are rules and standards set by the local as well as federal government. Sewage can be gathered and treated by the local sewage treatment plants. The local sewage treatment plants make use of the biofilters, septic tanks or anaerobic treatment systems. In the event that these facilities are not available, it’s taken by sewers to the main sewage treatment plants operated by the municipal government in the area. Every single city has structured and properly designed pipe infrastructures for this specific purpose.
If you wonder where the domestic wastewater goes and fit for reuse then sewage treatment plants is definitely the answer. The sewage treatment plants isolate the contaminants from the wastewater to treat it and make it clean. Domestic wastewater consists of liquid wastes which flow out from the bathroom, toilet, laundry station, kitchens and others. The domestic wastewater is actually divided into 2 groups: the greywater and the blackwater. The greywater are liquid wastes from washing dishes and clothes and taking a shower. The blackwater consists of fecal matter and urine.
Domestic wastewater treatment is primarily concerned on the blackwater. The blackwater is the medium for growth of pathogenic bacteria which when not treated and disposed wrongly can cause diseases and is also damaging to the environment. The treatment of blackwater is extremely a necessity before it can be released to the bodies of water such as rivers, lakes, and streams. Blackwater is likewise termed as sewage. The domestic wastewater management in the treatment plants are grouped in three stages: primary, secondary and tertiary.
The main objective at the primary stage is to separate the solid wastes from the liquid waste materials. This is important because treatment for the solid wastes differ from the treatment of the liquid waste materials. In the separation process sedimentation is utilized. The sewage is stored in the large sedimentation tanks. These sedimentation tanks are big enough so that the lighter solids like oil fats, and grease will float on top and the sludge or heavier solids will stay at the base. The floating solids are going to be skimmed off. In the secondary phase, the removal of dissolved biological elements is done. This is done by the natural water-borne microorganisms. The solid wastes gathered undergo special treatment to be fitted for reuse or discharge. The secondary treatment systems are categorized as: activated sludge, fixed film system and suspended growth system.
In the tertiary stage in the sewage treatment plants, the goal is to enhance the quality of water that undergone the secondary stage. The liquid is treated with chemical and physical agents to eliminate the contaminants or all undesirables mass. In the filtration procedure, sand is utilized to block the flow of substances dissolved in water. The toxins that are not filtered out by the sand will get absorbed by the adsorbents like the activated charcoal to separate from water. The charcoal assists in removing the residual toxins. At this point, the elimination of nitrogen and phosphorous also occurs by biological oxidation to nitrification followed by de-nitrification. The liquid is cleaned before it’s discharge to the natural environment or reused for different purposes.