#Types of wastewater treatment process how to#

Inside the tablet-based chlorinator, clean water comes directly in contacts with the chlorine tablets, making a chlorine solution. The chlorinator can be of tablet dosing type or chemical injection type. The chlorinator is fitted in the last chamber to treat the final stage water for discharging overboard. It also helps in treating the Biological Oxygen Demand (BOD) and Suspended Solids. The activated carbon is fitted post the settling chamber to remove Chemical Oxygen Demand (COD) by filtering and absorption. The untreated sludge settled in the bottom of the sedimentation tank returns into the Biofilter reactor to break up by microorganism again. The clarification compartment is usually of the hopper type with sloping sides which prevent the sticking and accumulating of sludge and send it to the suction side of the air lift tube.

The mixture will be further separated to high-grade water and sediment after being settled in Sedimentation tank. The treated sewage water from the biofilter reactor will come to the next chamber which is used for settling purpose. The fine bubble by passing through the diffuser will increase the oxygen transmission rate. The biofilter reactor, with the help of fine air bubbles supplied from the blower, will disperse the contaminated substance diffusing and breaking down the organic matter by the aerobic microorganism. The biofilter is also the part of the aeration chamber which treats the sewage passing from the screen filter. It helps in removing the non-sewage adulteration component such as toilet paper, plastic paper, other solids etc, which can clog the complete system if went inside. The screen filter mesh is fitted on the first tank near the entrance of the sewage to the STP. Related Read: 4 Important Terms Related to Sewage Treatment Plant on Ships Component of STP: The Anaerobic bacteria are equally capable of decomposing and breaking down the sludge but during the process, they generate and release harmful gases such as H2S and methane which are toxic and dangerous for aquatic organisms. The most preferred type of sewage treatment plant is that involving aerobic bacteria. It is to note that each sewage treatment system installed onboard has to be certified by classification society and should perform as per their requirement and regulations. Moreover, the discharge generated from this plant is eco-friendly. There are different methods of treating sewage available in the market, but the most common of them is the biological type for it occupies less space for holding tank, unlike those of the other methods. Generally, ships prefer treating sewage before discharging to save themselves from any type of embarrassment.

#Types of wastewater treatment process how to#

Related Read: MARPOL ANNEX 4 Explained: How to Prevent Pollution from Sewage at Sea The details of the sewage discharge regulations can be found in MARPOL Annex IV.

Also, the discharged sewage should not produce any visible floating solids nor should it cause any discoloration of surrounding water. The rules say that the sewage can be discharged into the seawater only after it is treated and the distance of the ship is 4 nautical miles from the nearest land.Д«ut if the sewage is not treated this can be discharged 12 nautical miles away from the nearest land. Sewage on the sea is generally the waste produced from toilets, urinals, and WC scuppers. Though sewage can be discharged into the sea, we cannot discharge it directly overboard as there are some regulations regarding discharging of sewage that needs to be followed. The sewage generated on the ship cannot be stored on the ship for a very long time and it, for this reason, it has to be discharged into the sea. Discarding sewage produced onboard on a ship is one of the few tasks on a ship which should be taken utmost care of if one wants to save him and his shipping company from heavy fine.