A kind of offshore platform domestic sewage processing method
Technical field
The present invention relates to sanitary sewage disposal, relate in particular to the treatment process of marine oil production vessel, drilling unit, floating type production, storage and offloading device (FPSO) and oceangoing vessel sanitary sewage.
Background technology
Offshore platform sanitary sewage refers to the sewage that contains excrement, urine (being commonly called as Heisui River) that discharge in platform lavatory, the sewage (being commonly called as buck) that the sewage that contains washing composition that the kitchen in platform production facility district, toilet, washing place discharge and consulting room are got rid of.
For protecting the marine environment; country comes into effect " offshore oil exploration and exploitation Pollutant emission concentration limit value " (GB4914-2008) standard on May 1st, 2009; the COD limit value that offshore oil exploration and exploitation is arranged in extra large sanitary sewage has been made regulation, sees the following form.
Sanitary sewage emission concentration limit value unit: mg/L
Offshore platform is processed sanitary sewage at present two kinds of methods.One is biochemical process, utilize the microorganism in active sludge to degrade to the pollutent in sanitary sewage, but offshore platform is due to away from land, in order to save Freshwater resources, platform all uses seawater flushing lavatory, cause saltiness in sewage to increase, microorganism active is declined or inactivation, practical application mesophytization method is unsatisfactory to the treatment effect of sanitary sewage.Another kind is electrolytic process, the sanitary sewage that is mixed with seawater is carried out to electrolysis, and the clorox (NaClO) of generation is strong oxidative disinfectant, can contact with the bacterium of sewage fully, by sterilization, reach the object of removing pollutent, but in actual use, because saltiness in seawater only has 3% left and right, electrolytic process can be wasted a large amount of electric energy, and electrolytic process is that seawater and sanitary sewage are mixed to rear electrolysis, and the organic pollutant in sewage very easily causes electrode damage, reduction of service life.
Summary of the invention
The object of the invention is to overcome the shortcoming of prior art, a kind of power-saving, long service life, offshore platform sewage treatment unit that treatment effect is good are provided.
A kind of offshore platform domestic sewage processing method of the present invention, it comprises the following steps:
(1) send into equalizing tank after kitchen drainage is removed to oil slick by oil trap, in equalizing tank, mix with excrement and urine waste and other drainings, then pump in sterilization pool by sewage output tube;
(2) after the following seawater in 5 meters, sea is softened by softening installation, pump in brine tank, in brine tank, add solid sodium chloride, being mixed with massfraction is greater than after 20% strong brine, pump into electrolyzer by salt water delivery pipe, in electrolyzer, generate the sterilized water that contains clorox, then sterilized water is pumped in sterilization pool;
(3) in sterilization pool, sewage and sterilized water mix, and use agitator rapid stirring, realize the elimination to bacterium in sewage, some groups of iron-carbon galvanic cells are installed in sterilization pool and can produce ferrous ion and carbon granules, in realizing sterilization, pass through throwing out simultaneously, remove the suspended contamination in sewage,, there is electrochemical oxidation decomposition reaction in the organic compound in sewage simultaneously between galvanic cell, changes the more easily organism of degraded into;
(4) sewage after flocculation, sterilization flows in settling tank automatically, and after leaving standstill, supernatant liquid is directly arranged sea after reaching emission standard; Lower floor's mud enters in plate-and-frame filter press, and the dewatered sludge obtaining is transported land back and processed, and after pressing filtering liquid is qualified after testing, directly row sea, if defective, in pressing filtering liquid recycle pump suction sterilization pool, continues to process, until row is extra large again after qualified.
The present invention compared with prior art, has the following advantages:
(1) by electrolysis after seawater salt adding, heighten electrolytic efficiency, in producing the sterilized water higher containing clorox (NaClO), saved electric energy.
(2) sewage directly enters sterilization pool, only high density salt solution is carried out to electrolysis at electrolyzer, has avoided the damage of the organism in sewage to electrode, the work-ing life of having improved electrode.
(3) use iron-carbon galvanic cell, the ferrous ion and the carbon granules that produce, suspended substance in sewage is played to throwing out, and produced simultaneously electrochemical energy has further promoted organic decomposition in sewage, and the advantage such as galvanic cell has that cost is low, long service life, usage space are little.
(4) mud, after pressure filter compacting mummification, is transported land back and is processed, and no longer directly row sea, has further reduced the pollution to ocean.
Brief description of the drawings
Accompanying drawing is the schema of a kind of offshore platform domestic sewage processing method of the present invention.
Embodiment
Below in conjunction with the drawings and specific embodiments, the present invention is described in detail:
A kind of offshore platform domestic sewage processing method of the present invention as shown in drawings, it comprises the following steps: (1) sends into equalizing tank 7 after kitchen drainage is removed to oil slick by oil trap 4, in equalizing tank, mix with excrement and urine waste and other drainings, then pump in sterilization pool by sewage output tube; (2) after the following seawater in 5 meters, sea is softened by softening installation, pump in brine tank 11, in brine tank, add solid sodium chloride, being mixed with massfraction is greater than after 20% strong brine, pump into electrolyzer 14 by salt water delivery pipe, in electrolyzer, generate the sterilized water that contains clorox, then sterilized water is pumped in sterilization pool 17; (3) in sterilization pool, sewage and sterilized water mix, and with agitator 19 rapid stirrings, realize the elimination to bacterium in sewage, some groups of iron-carbon galvanic cells are installed in sterilization pool, can produce ferrous ion and carbon granules simultaneously, in realizing sterilization, can also pass through throwing out, remove the suspended contamination in sewage, simultaneously the organic compound in sewage, between galvanic cell, there is electrochemical oxidation decomposition reaction, change the more easily organism of degraded into; (4) sewage after flocculation, sterilization flows in settling tank automatically, and after leaving standstill, supernatant liquid is directly arranged sea (COD≤300mg/L) after reaching emission standard; Lower floor's mud enters in plate-and-frame filter press 22, and the dewatered sludge obtaining is transported land back and processed, and pressing filtering liquid is qualified rear (COD≤300mg/L) after testing, directly row sea, if defective, in pressing filtering liquid recycle pump suction sterilization pool, continue to process, until row is extra large again after qualified.
As the device of realizing the inventive method, it comprises equalizing tank 7, and there are oil trap 4 and liquidometer 6 in inside, and kitchen drainage 2 is imported in oil trap 4, removes after oil slick, mixes with excrement and urine waste and other drainings 1, pumps in sterilization pool 17 through sewage output tube 13.In equalizing tank 7, offer oil slick and reclaim mouth 5 and emergency overflow mouth 3.
After seawater 9 is softening by softening installation 10, pump in brine tank 11, in brine tank 11, be provided with and throw salt mouth, add solid sodium chloride by throwing salt mouth 8, be mixed with massfraction and be greater than after 20% dense salt solution, brine tank 11 is connected with electrolyzer 14 by salt water delivery pipe 12, electrolyzer 14 is connected by pipeline with sterilization pool 17, dense salt solution pumps into electrolyzer 14, generates the sterilized water that contains clorox (NaClO), then sterilized water is pumped in sterilization pool 17 in electrolyzer 14.Electrolyzer 14 offers hydrogen discharge mouth 15, carries out voltage-regulation by electrolyzer control panel 16.
In sterilization pool 17, sewage and sterilized water mix, and with agitator 19 rapid stirrings, realize the elimination to bacterium in sewage, some groups of iron-carbon galvanic cells 18 are installed simultaneously in sterilization pool 17, can produce ferrous ion and carbon granules, remove the suspended contamination in sewage by throwing out.
Sewage after flocculation, sterilization flows in settling tank 20 automatically, leaves standstill after 45min, and supernatant liquid is through being arranged on the Sewage outlet 21 row seas on settling tank 20 tops; Lower floor's mud is in manually entering plate-and-frame filter press 22, and the dewatered sludge obtaining is transported land back and processed, after pressing filtering liquid detection is qualified, directly arrange sea through pressing filtering liquid discharge outlet 23, if defective, in pressing filtering liquid recycle pump 24 suction sterilization pools 17, continue to process, until row is extra large again after qualified.
Embodiment 1
(1) send into equalizing tank after kitchen drainage is removed to oil slick by oil trap, in equalizing tank, mixes with excrement and urine waste and other drainings, then pass through sewage output tube with 1.5m
3the flow of/h pumps in sterilization pool;
(2) after the following seawater in 5 meters, sea is softened by softening installation, pump in brine tank, in brine tank, add solid sodium chloride, be mixed with massfraction and be greater than after 20% strong brine, by salt water delivery pipe pump with 0.5m
3the flow of/h pumps into electrolyzer, generates the sterilized water that contains clorox, then sterilized water is pumped in sterilization pool in electrolyzer;
(3) in sterilization pool, sewage and sterilized water mix, and use agitator rapid stirring, realize the elimination to bacterium in sewage, some groups of iron-carbon galvanic cells are installed in sterilization pool, can produce ferrous ion and carbon granules simultaneously, in realizing sterilization, can also pass through throwing out, remove the suspended contamination in sewage, simultaneously the organic compound in sewage, between galvanic cell, there is electrochemical oxidation decomposition reaction, change the more easily organism of degraded into;
(4) sewage after flocculation, sterilization flows in settling tank automatically, and after 45min leaves standstill, supernatant liquid is directly arranged sea after reaching emission standard; Lower floor's mud enters in plate-and-frame filter press, and the dewatered sludge obtaining is transported land back and processed, and after pressing filtering liquid is qualified after testing, directly row sea, if defective, in pressing filtering liquid recycle pump suction sterilization pool, continues to process, until row is extra large again after qualified.
Adopt the effect of present method to be: the method is applied in certain offshore production platform, it is (70-125) mg/L that COD arranges extra large numerical value, meet " offshore oil exploration and exploitation Pollutant emission concentration limit value " (GB4914-2008) limit value of middle COD≤300mg/L completely, suspended substance is arranged extra large concentration and is less than 35mg/L, respond well.