CN1686851A - Method for treating sewage containing crude oil - Google Patents

Abstract

The present invention relates to a new method for treating oil-field sewage. Said invention is characterized by that it uses the iron in sewage as oxidation catalyst and coagulating agent, uses hydrogen peroxide as pre-oxidant and uses active silicic acid series as coagulant aids so as to implement said method.

Description

Method for treating sewage containing crude oil

One, technical field: the novel method that the present invention relates to a kind of disposing polluted water in oil.

Two, background technology: existing disposing polluted water in oil, though there is different technical process at each disposing polluted water in oil station according to own characteristic, but generally speaking, all be that physics combines with chemical process, promptly except filtering and wait some mechanical-physical methods with big jar (pond) gravitational settling, swash plate separation, (meticulous), generally also will be in conjunction with chemical process, promptly add water purification agent (inorganic coagulant is used with organic floculant) (or flotation or gravitational settling separate) purifying treatment earlier, add the sterilant kill bacteria again, add inhibiter and Scale inhibitors at last and carry out anticorrosion, scale inhibition.Because oilfield sewage contains a large amount of oil, iron content, sulfur-bearing etc. are unfavorable for the factor of water conditioning simultaneously, all need handle and every processing generally all is single-item handling, the method that comes and see is isolated in this processing every unfavorable factor, treatment scheme and processing costs have not only been increased, but also to consider synergistic effect between various different medicaments, strengthen the factor that influence is handled, thereby increased intractability.Therefore the actual needs from handling should keep each unfavorable factor is handled in the water continuity and consistence, should make full use of their change unfavorable factors and be favorable factor, could dispose of sewage effectively, reduces intractability and expense.

Three, summary of the invention: the objective of the invention is the problems referred to above at the prior art existence, the novel method that provides a kind of wastewater containing oil to handle, this method technology is favorable factor by the factor that becomes the unfavorable sewage disposal in the water, can reduce treatment scheme and medicament dosage effectively, reduce the water treatment expense, simultaneously can avoid medicament and water yield shakiness to bring variation water quality, improve the water treatment effect.

Technical scheme of the present invention is that having proposed with the iron in the water is oxide catalyst and coagulating agent, is the preoxidation agent with the hydrogen peroxide, is the treatment process and the method for coagulant aids with active silicic acid series at oilfield sewage oil-containing, iron content, characteristics that salinity is high.At first make full use of the catalysis and the coagulation of the iron in the water, adopt the preoxidation technique principle, before sewage disposal, utilize the hydrogen peroxide of efficient pollution-free to carry out pre-oxidation treatment.Utilize the redox system of iron and hydrogen peroxide formation on the one hand, organic substance in the sewage is decomposed, because these water miscible organism both can be the nutritive substances of bacterial growth, also may be the colloid that protects that is unfavorable for coagulating sedimentation, carry out germicidal treatment simultaneously.On the other hand, ferrous iron in the water and sulphur are corrosivess, behind hydrogen peroxide oxidation, sulphur has become harmless ion, after ferrous iron becomes ferric iron, be a kind of ion of high electric charge, have very strong charge neutrality effect and coagulation, the purifying treatment that helps the later stage, variable like this adverse factors is favourable factor.So just reached the purpose of sulphur removal and deironing and Pre-coagulation.Then, at the high characteristics of oilfield sewage calcic magnesium, adopt active silicic acid coagulant aid with low cost, utilize ferric iron in itself and the water to be formed with the ferric-polysilicate flocculation agent of very strong flocculating effect, form the very strong material of oily adsorptivity with calcium, the absorption of magnesium chelating in itself and the water, thereby reach oil removing, enhanced flocculation, scale inhibition, and the sewage disposal purpose of further deironing.By above-mentioned treating processes, utilize conventional existing oil field sewage treating equipment, oilfield sewage can reach the water quality requirement of oil field reinjection water, has greatly reduced water treatment process and expense.

The present invention compared with prior art has following advantage and effect: (1) concentrates in together sulphur removal, deironing and sterilization, has saved their single-item handling flow process.(2) deironing and purification, deironing and sterilization, oil removing and scale inhibition are organically combined, realized the purpose of the treatment of wastes with processes of wastes against one another, also realized the continuity of polyenergic effect of potion and water treatment simultaneously.(3) simplify the handling procedure of oilfield sewage, reduced cost of water treatment.

Four, description of drawings: do not have.

Five, embodiment: sewage treatment process method of the present invention is divided two processes, and the first step is determined the consumption of preoxidation agent hydrogen peroxide according to oilfield sewage iron content and sulphur content, and general consumption is all more than 5mg/l.Utilize ram pump in the continuous oily(waste)water that adds after joint station is received oil of aqueous hydrogen peroxide solution, and under intense stirring condition, mix with sewage.At short notice, finish the modification and the sterilization process of sulphur, iron ion between medicament and sewage.Second step through the pretreated water of hydrogen peroxide, with the coagulant aids of activated silica acids, mixed under vigorous stirring, required the time that mixes between them longer as much as possible, and this is main relevant with the character of activated silica acids coagulant aids.Treatment effect can be more better like this.Get final product through conventional treatment scheme gravitational settling, swash plate separation, filtration then.Water after the processing is iron content, sulphur, oil, oxygen hardly, and the filter membrane coefficient is greater than 32, and erosion rate is reduced to 0.0408mm/a from the 0.6607mm/a of sewage, and scaling rate is reduced to 0.0041l/d from the 0.23l/d of sewage, can reach the requirement of oil field reinjection water fully.

Claims (2)

1, a kind of method for treating sewage containing crude oil is characterized in that: with the iron in the water is oxide catalyst and coagulating agent, is the preoxidation agent with the hydrogen peroxide, is the treatment process of coagulant aids with active silicic acid series.

2, method for treating sewage containing crude oil according to claim 1, it is characterized in that: the catalysis and the coagulation that at first make full use of the iron in the water, adopt the preoxidation technique principle, before sewage disposal, utilize the hydrogen peroxide of efficient pollution-free to carry out pre-oxidation treatment, adopt active silicic acid coagulant aid then,, form the very strong material of oily adsorptivity with calcium, the absorption of magnesium chelating in the water with the ferric iron generation ferric-polysilicate flocculation agent in the water.