Skip to main content

Marine Sewage Treatment Plant

The basic principle of working of a biological treatment plant is decomposition of the raw sewage. This process is done by aerating the sewage chamber with fresh air. The aerobic bacteria survive on this fresh air and decompose the raw sewage which is dispose off in the sea. Air is a very important criteria in the functioning of the biological sewage plant because if air is not present, it will lead to growth of anaerobic bacteria which produces toxic gases that are hazardous to health. Also after decomposition of the sewage with anaerobic bacteria, a dark black liquid causes discoloration of water which is not accepted for discharging. Thus in a biological sewage treatment plant the main aim is to maintain the flow of fresh air.

Division of processes:The biological sewage plant is divides into three chambers

  1. Aeration Chamber
  2. Settling tank
  3. Chlorination and Collection tank
Aeration Chamber: This chamber is fed with raw sewage which has been grinded to form small particles. The advantage of breaking sewage in small particles is that it increases the area and high number of bacteria can attack simultaneously to decompose the sewage. The sewage is decomposed into carbon dioxide, water and inorganic sewage. The air is forced through diffuser into the air chamber. The pressure of air flow also plays an important role in decomposition of the sewage. If pressure is kept high then the mixture of air and sewage will not take place properly and it will escape.
Without doing any work required for decomposition. It is for this reason, controlled pressure is important inside the sewage treatment plant as this will help in proper mixing and decomposition by the agitation caused by air bubbles. Generally the pressure is kept around 0.3-0.4 bars.

Settling tank: The mixture of liquid and sludge is passed to settling tank from the aeration chamber. In the settling tank the sludge settles at the bottom and clear liquid on the top. The sludge present at the bottom is not allowed to be kept inside the settling tank as this will lead to growth anaerobic bacteria and foul gases will be produced. The sludge formed is recycled with the incoming sludge where it will mixes with the later and assist in the breakage of sewage.

Chlorination and Collection: In this chamber the clear liquid produced from the settling tank is over flown and the liquid is disinfected with the help of chlorine. This is done because of the presence of the e-coil bacteria present in the liquid. To reduce these bacteria to acceptable levels chlorination is done. Moreover to reduce the e-coil, the treated liquid is kept for a period of at least 60 minutes. In some plants disinfection is also done with the help of ultra violet radiation. The collected liquid is discharged to overboard or settling tank depending on the geological position of the ship. If the ship is in restricted or near coastline then the sewage will be discharged into the holding tank, otherwise, the sewage is discharge directly into the sea when high level is reached and is disposed automatically until low level switch activates.

Comments

  1. Your article is so best that I never stop myself to say something about it. You’re amazing Man, I like it water treatment<2/www.pu never comment on blor/about-us->... Keep it up. eitpk.com

    ReplyDelete
    Replies
    1. Hello, after reading this remarkable paragraph i am too glad to share my knowledge here with colleagues.

      Thanks & Regards
      Physiotherapist in Brampton

      Delete
  2. Disease emergency clinics utilize cutting edge innovations for delicate tissue sarcoma tumor extractions including Brachytherapy, and furthermore utilization of LINAC for outside radiation treatment. treatment centers for teens

    ReplyDelete
  3. It is somewhat fantastic, and yet check out the advice at this treat. What is CBD Oil?

    ReplyDelete
  4. I just finished reading the 1212 angel number pregnancy meaning and I am fascinated.

    ReplyDelete

Post a Comment

Popular posts from this blog

Difference Between A, B & C-Class Divisions?

IMO Symbol A Class Division  IMO Symbol B Class Division  SOLAS has tables for structural fire protection requirement of bulkheads and decks. The requirements depend on the spaces in question and are different for passenger ships and cargo ships. The Administration has required a test of a prototype bulkhead or deck in accordance with the Fire Test Procedures Code to ensure that it meets the above requirements for integrity and temperature rise. Types of Divisions: "A" Class "B" Class "C" Class "A" Class: "A" class divisions are those divisions formed by bulkheads and decks which comply with the following criteria: They are constructed of steel or equivalent material They are suitably stiffened They are constructed as to be capable of preventing the passage of smoke and flame to the end of the one-hour standard fire test. they are insulated with approved non-combustible materials such that the average tempera

Load Line & Why it is Important

Merchant ships have a marking on their hull know as the Plimsoll line or the Plimsoll mark, which indicates the limit until which ships can be loaded with enough cargo, internationally, the Plimsoll line on a ship is officially referred to as the international load line. Every type of ship has a different level of floating and the Plimsoll line on a ship generally varies from one vessel to another.  All vessels of 24 meters and more are required to have this Load line marking at the centre position of the length of summer load water line. There are two types of Load line markings:- Standard Load Line marking – This is applicable to all types of vessels. Timber Load Line Markings – This is applicable to vessels carrying timber cargo. These marks shall be punched on the surface of the hull making it visible even if the ship side paint fades out. The marks shall again be painted with white or yellow colour on a dark background/black on a light background.  The comp

Bilge Injection Valve

Bilge Injection is a valve that enables the engine room bilges to be pumped out directly overboard in the event of an emergency such as flooding. The valve is normally fitted to the end of a branch connection with the main sea water suction line. This enables large main seawater cooling pumps to be used as a bilge pump in an emergency. Emergencies like fire and flooding involve the use of seawater. If there is a fire, seawater is the biggest resource of water available in the sea. Similarly, if it involves flooding of the engine room, cargo spaces or any other place on the ship for that matter; you would again require pumping the sea water out of the ship. In both these cases, you require pumps.  There are two valves in close proximity namely main injection valve and bilge injection valve. Both of them have their own independent controls. The diameter of the bilge injection valve is kept nearly 66% of the main valve diameter which draws water directly from the sea through the