The first and foremost question which one asks is, What is the need of having a sewage treatment plant if the waste is biodegradable?” And, the question is definitely not wrong but the issue is that not all of the sewage constituents are biodegradable and not all are taking the same time to break down. Additionally, untreated sewage consists of solid particles that take a lot of time to crumble. It is the main cause that the sewage treatment plant is widely used. Here, you will focus on the fact of STP on Ships Explained in detail.
Water raw sewage requires oxygen for natural break down and this sewage absorbs excessive oxygen when disposed to the sea and hence, reduces the essential amount of oxygen required by the fishes as well as marine plants. Available bacteria in the sewage generate hydrogen sulfide gas that available in the sewage creates hydrogen sulfide gas that generates smells like acrid. Human waste has E.Coli bacteria that are found in the intestine. The E.Coli bacteria amount in a water sample shows that the sewage content of that sample.
There are two types of Sewage Treatment Plant on Ship
- Biological Sewage Treatment Plant
- Chemical Sewage Treatment Plant
Chemical Sewage Treatment Plant
A chemical treatment plant includes a huge storage tank that gathers, treats, and stores the sewage to discharge it to the shore or a sea receiving facility. The sewage is first gathered in a tank and the liquid content is reduced. It can be done by flushing water from the washbasins as well as bathroom drains into the sea. The liquid from any sources is chemically treated to overcome the bad smell and color and after that, it is re-used as the flushing water in the toilets. The chemicals which are utilized are used to help in the solid constituents breaking process and also in the sterilization.
A mechanical communitor instrument is widely used to help in breaking the solid particles into the smaller ones. The liquid sewage stays at the top and the solid particles settle down, which is then, discharged to a sullage tank. The liquid sewage is chemically treated and is widely used for toilet flushing purposes. The sewage from the tank is discharged to the shore gathering facilities. It is very essential to supply the suitable chemical dosage quantity to prevent corrosion and odor that might cause due to the high level of alkalinity.
Biological Sewage Treatment Plant
This sewage treatment plant uses bacteria to simplify the breaking down the procedure for the solid constituents. It creates an oxygen rick atmosphere which aerobic bacteria uses to disintegrate and to multiply the sewage waste to convert into sludge. The treated sewage after that generated and can be disposed of to any water. The procedure which takes place inside the plant is called the aeration procedure.
The entire plant is divided into three compartments name,
- Settling compartment
- Aeration compartment
- Chlorine treatment compartment
Sewage firstly enters the sewage treatment plant via the aeration compartment. Aerobic bacteria digest the sewage waste and lessen it to the small particles. A continuous supply of atmospheric oxygen is offered to enhance the digestion rate of the entire procedure. The disintegrated solid waste is that transmitted to the settling compartment where the solid constituents settle down easily under the gravity effect.
Liquid at the top is after that passed to the chlorine treatment compartment and in this compartment, the liquid is treated with chlorine as well as other chemicals to destroy the alive bacteria that are present in the water. When finished the water is that discharged into the sea and the procedure of the chlorination is enabled with the chlorine tablets. The sludge in Sewage Treatment Plant which actually settles down in the compartment is stored after removing in the storage tank to discharge it to shore further facilitates or decontrolled areas.