Font Size: a A A

A Study On Integrated Disposal Technology Of Oil Sludge By Thermal Washing And Bio-reactor

Posted on:2021-02-10Degree:MasterType:Thesis
Country:ChinaCandidate:S XuFull Text:PDF
GTID:2381330605964936Subject:Institute of Geochemistry
Abstract/Summary:PDF Full Text Request
Oily sludge is a mixture of mud,sand and water polluted by crude oil and other organic matters,which is produced in oil exploration and development,transportation,refining and oily sewage treatment projects.Oily sludge is a kind of hazardous waste listed in the national list of hazardous wastes.The hydrocarbon contained in oily sludge will cause great harm to the environment.Therefore,it is necessary to turn it into a valuable secondary resource through harmless treatment.In this paper,the oily sludge of Daqing oil field No.3 oil production plant is taken as the research object.Ultrasonic centrifugation and microbial disposal technology are used to treat it innocuously and reduce its oil content,so as to provide technical reference for the treatment and reuse of oily sludge.In this paper,the water content and oil content of experimental oily sludge were analyzed by weight method,ultrasonic extraction and ultraviolet spectrophotometry.After analysis,the water content and oil content of experimental oily sludge were 25.71% and 26.59%respectively.Through the experiment,the cleaning agent,flocculant and demulsifier were screened,among which sodium silicate had better cleaning effect on oily sludge,the residual oil content in the washed sludge was as low as 1.5%,and the compound was as low as 1.5%In the process,the change of sodium silicate has a significant effect on the residual oil rate.At the same time,adding AX-1 and ax-9 in proper proportion can further improve the cleaning effect.When the addition amount of demulsifier XDF is 25mg/L,the dehydration effect is the best,and the dehydration rate has reached 85.0% after 30 minutes of dehydration.After dehydration,the purified oil contains 0.16% water and 1164 mg/L oil;BS flocculant is composed of organic polymer and inorganic polymer,and has the effect of demulsification and flocculation.When it is added to the sewage,the particles and oil in the sewage are easy to flocculate with it.It promotes the suspended solids in the sewage to flocculate into flocs,and different flocs may bridge into larger flocs.Due to its large volume,the bulky flocs can not pass through the surface layer of the filter material and are intercepted during filtration,thus successfully removing the oil substances and suspended solids in the sewage.The dosage should be controlled about 150mg/L;the laboratory experiment shows that the treatment effect is the best when the ultrasonic frequency is 40 k W,the power is 10 k W,the action time is20 min,and the action temperature is 45?.According to the information obtained from the indoor experiment,the field test of heat washing treatment of oily sludge shows that the effect of conditioning and quality separation is relatively good when the mud water ratio is 1:5?1:7.The effect of different centrifugal parameters on the centrifugal action was analyzed.1:7 was the best proportion of water in sludge treatment.The cleaning agent can improve the separation effect of oil sludge,and the test shows that the cleaning effect of sodium silicate solution is better.When the dosage is400-600mg/L,the sludge treatment effect is relatively good.Considering the economic benefits,the best dosage of cleaning agent is 450 mg/L.Compared with the laboratory experiments,the best parameters of the field ultrasonic treatment were determined.The ultrasonic irradiation was 50?,the ultrasonic output power was 12 KW,the ultrasonic action time was 20-25 min,and the dosage of demulsifier was 10mg/L.Flocculant can promote the separation of sludge and water.Considering the temperature,the dosage of flocculant,the speed of centrifuge and other parameters as well as economic benefits,the optimal centrifugal conditions are determined.The temperature is 50?,the speed of centrifuge is 2200r/min,and the dosage of flocculant is 400mg/L.The oil content in the oily sludge at the centrifugal outlet of the field test is basically less than 2%,which conforms to the technical requirements for comprehensive utilization of oil sludge resources and pollution control in onshore oil and gas exploitation.The high-efficiency petroleum hydrocarbon degrading bacteria WJ-1 was screened in the laboratory by using microorganism immobilization technology and solidification technology respectively.Among them,the high-efficiency petroleum hydrocarbon degrading bacteria WJ-1 had the highest TPH degradation rate under the conditions of inoculation amount of13%,shaking table speed of 120r/min,solution p H=7 and degradation temperature of 30?;the high-efficiency petroleum hydrocarbon degrading bacteria wj-4 had the highest TPH degradation rate under the conditions of The TPH degradation rate was the highest under the conditions of 13% inoculum amount,150r/min rotating speed of shaking table,p H=7 of solution and 30? degradation temperature;the TPH degradation rate was the highest under the conditions of 10% inoculum amount,180r/min rotating speed of shaking table,p H=7 of solution and 30 ? degradation temperature of high efficient petroleum hydrocarbon degrading bacteria wj-5;straw and wheat bran were selected as embedding materials to provide sufficient nutrients for soil microorganisms and promote high efficiency The growth of degrading bacteria,the optimization of soil structure,and the improvement of living environment of efficient degrading bacteria.Among them,the moisture retention ability of wheat bran is better than that of straw.Compared with straw,wheat bran is easier to mixevenly with soil particles,which makes wheat bran improve the porosity of soil better.After curing,the compressive strength of pavement brick basically reaches 3Mpa specified in JC/T446-2000 standard of concrete pavement brick.The leachability of the road brick was tested and analyzed,and the leachability reached the integrated wastewater discharge standard(GB8978-1996).Sludge,cement and fly ash with the ratio of 2:1:1 have a good curing effect.After the formation of the junction material,various metal elements and oils are effectively condensed into the sample.The oil-bearing ions and oils in the leaching solution are relatively low,and the road tiles after curing are harmless in the use process.The sample exudate of sludge,cement and fly ash solidified as per 2:1:1 can meet the secondary treatment standard of domestic sewage discharge.The content of toxic and harmful pollutants is very low.The solidified product has no harm in the use process,so it can be used to pave the road.
Keywords/Search Tags:oily sludge, Ultrasonic centrifugation, High efficient degradation bacteria, biological treatment, Curing technology
PDF Full Text Request
Related items