A treatment method for domestic sewage on an offshore platform

Abstract

The invention discloses an offshore platform domestic sewage treatment method which comprises the following steps: (1) kitchen drainage is subjected to floating oil removal by an oil separator, sent into a regulating tank, mixed with excrement sewage and other drainages in the regulating tank, and pumped into a disinfection tank through a sewage output tube; (2) seawater is softened by a softening plant and pumped into a brine tank, sodium chloride solid is added into the brine tank to prepare concentrated brine, the concentrated brine is pumped into an electrolysis tank to generate a disinfectant fluid containing sodium hypochlorite, and the disinfectant fluid is pumped into the disinfection tank; (3) the sewage and disinfectant fluid are mixed in the disinfection tank and quickly stirred with a stirrer to eliminate bacteria in the sewage; and (4) the sewage subjected to flocculation and disinfection automatically flows into a precipitation tank and is subjected to standing, and then directly discharged to the sea after the supernate satisfies the discharge standard. The seawater is electrolyzed after adding salt, thereby enhancing the electrolysis efficiency. The method prevents organic matters in the sewage from damaging the electrodes, and prolongs the service life of the electrodes.

Description

technical field [0001] The invention relates to treatment of domestic sewage, in particular to a treatment method for domestic sewage of offshore oil production platforms, drilling platforms, floating production storage and offloading devices (FPSO) and ocean-going ships. Background technique [0002] Offshore platform domestic sewage refers to sewage containing feces and urine (commonly known as black water) discharged from platform toilets, sewage containing detergent discharged from kitchens, toilets and laundry rooms in the production facility area of ​​the platform, and sewage discharged from medical offices (commonly known as gray water) ). [0003] In order to protect the marine environment, the country began to implement the "Offshore Oil Exploration and Development Pollutant Discharge Concentration Limits" (GB4914-2008) standard on May 1, 2009, and made a limit value for COD in domestic sewage discharged from offshore oil exploration and development. regulations, s...

AI Technical Summary

Problems solved by technology

One is the biochemical method, which uses microorganisms in activated sludge to degrade pollutants in domestic sewage. However, because offshore platforms are far away from land, in order to save fresh water resources, platforms use seawater to flush toilets, resulting in increased salt content in sewage. The activity of microorganisms is reduced or inactivated, and the effect of biochemical methods on domestic sewage treatment is not ideal in practical applications

The other is the electrolysis method, which electrolyzes the domestic sewage mixed with seawater, and the sodium hypochlorite (NaClO) produced is a strong oxidizing disinfectant, which can fully contact with the bacteria in the sewage, and achieve the purpose of removing pollutants through disinfection, but the actual In use, because the salt content in seawater is only about 3%, the electrolysis method will waste a lot of electric energy, and the electrolysis method is to mix seawater and domestic sewage and then electrolyze. The organic pollutants in the sewage can easily cause electrode damage and shorten the service life.

Images