Embodiment
For enabling above-mentioned purpose of the present utility model, feature and advantage become apparent more, are described in detail embodiment of the present utility model below in conjunction with accompanying drawing.Set forth a lot of detail in the following description so that fully understand the utility model.But the utility model can be much different from alternate manner described here to implement, those skilled in the art can when doing similar improvement without prejudice to when the utility model intension, and therefore the utility model is by the restriction of following public concrete enforcement.
The method for municipal sewage treatment of one embodiment comprises the steps:
S110: municipal effluent is removed the gred, except silt, obtains the first pre-treatment municipal effluent.
Remove larger suspended substance and floating matter in municipal effluent, prevent subsequent processing device from blocking.By municipal effluent is removed Slag treatment, remove larger suspended substance and floating matter in municipal effluent, prevent subsequent processing device from blocking.
Such as, by municipal effluent respectively by middle grid, fine fack, larger suspended substance and floating matter in interception municipal effluent.And for example, the grizzly bar gap of middle grid is 20mm, and the grizzly bar gap of fine fack is 8mm, municipal effluent enters middle grid, the flow velocity of fine fack is 0.8m/s, like this, effectively can remove the macrobead suspended substance in municipal effluent and floating matter, prevent subsequent processing device from blocking.
In order to the contact area of grid in increasing and fine fack and municipal effluent, such as, the setting angle of middle grid and horizontal plane is 75 °, the setting angle of fine fack and horizontal plane is 75 °, the speed of sanitary sewage by middle grid and fine fack can be accelerated like this, accelerate the processing speed of municipal effluent, thus improve the processing efficiency of municipal effluent.
By removing the silt in municipal effluent, reducing the impact that silt sets subsequent disposal, also can reduce the turbidity of municipal effluent simultaneously, alleviating the burden of subsequent treatment process.
Such as, municipal effluent is passed into settling pit, based on gravity or centrifugal force separate, the municipal effluent flow rate control being about to enter settling pit is sunk at the inorganic particle that relative density can only be made large, as, 0.1m/s ~ 0.3m/s, organic suspension particle is then taken away with current, thus sand, inorganic particle that cinder isodensity is larger can be removed from sewage, in order to avoid the normal operation of these impurity effect subsequent treatment process.
And for example, municipal effluent is passed into rotational flow grit chamber, rotational flow grit chamber produces waterpower eddy current by the stirring of machinery, makes silt, haydite and separating organic matters to reach object of removing sand.
And for example, the foreign material produced in step S110, haydite, sand grains etc., regularly can be transported to rubbish factory landfill disposal, reduces environmental pollution.
S120: by the first pre-treatment municipal effluent by anaerobic treatment, obtain the second pre-treatment municipal effluent and the first pre-treatment bed mud.
Be appreciated that COD (Chemical Oxygen Demand), i.e. chemical oxygen demand (COD) is under certain conditions, when adopting certain strong oxidizer process water sample, and the oxidant content consumed.It is the index representing that in water, reducing substances is how many.Reducing substances in water has various organism, nitrite, sulfide, ferrous salt etc., but importantly organism.Therefore, chemical oxygen demand (COD) is again often as weighing the how many index of Organic substance in water matter content.Chemical oxygen demand (COD) is larger, illustrates that water body is more serious by organic pollution.
BOD (Biochemical Oxygen Demand), and biochemical oxygen demand (BOD) or biochemical oxygen demand (referring generally to biochemical oxygen requirement on the five), represent a comprehensively instruction of the aerobic pollution matter content such as Organic substance in water.Biochemical oxygen demand (BOD) refers under defined terms, the dissolved oxygen of the Biochemical processes consumption of some oxidizable species, particularly decomposing organic matter in microbial decomposition water.Refer to that water sample is full of in completely airtight dissolved oxygen bottle under normal circumstances, cultivate 5d the dark places of 20 DEG C, measure the mass concentration of dissolved oxygen in water sample before and after cultivating respectively, by the difference of the mass concentration of dissolved oxygen before and after cultivation, calculate the dissolved oxygen content that often liter of sample consumes, represent with BOD5 form.Its value higher explanation organic pollutants matter is more, pollutes also more serious.
First pre-treatment municipal effluent is being carried out in the process of anaerobic treatment, based on the complicated organism in the first pre-treatment municipal effluent under the effect of anaerobion and facultative microbe, complicated organic substance decomposing becomes the materials such as methane, carbonic acid gas, water, hydrogen sulfide and ammonia, thus COD and BOD of municipal effluent can be significantly reduced, greatly facilitate the reaction efficiency of follow-up aerobic treatment, simultaneously, due to the effect of the factors such as anoxic, free ammonia and temperature in anaerobic treatment process, the pathogenic bacteria of municipal effluent, virus and parasitic ovum etc. can be killed.
In order to ensure that anaerobion breeds better, such as, the temperature in anaerobic process being controlled at 5 DEG C ~ 60 DEG C, preferably, temperature being controlled at 20 DEG C ~ 40 DEG C.And for example, the pH value of the first pre-treatment municipal effluent in anaerobic process is controlled 6.8 ~ 7.8, preferably, the pH of the first pre-treatment municipal effluent is controlled 7.2 ~ 7.6, thus anaerobion is bred better, improve organic degradation speed in the first pre-treatment municipal effluent.
Due in anaerobic treatment process, organic reduction have passed through hydrolysis, acidifying, product acid and methane phase four-stage, like this for some long-chains and band phenyl ring etc. be difficult to by aerobic bacteria the organism of degrading by Hydrolysis Acidification resolve into small-molecule substance or chain rupture utilize by anaerobion, improve the biological degradability of municipal effluent.
Such as, flow lifting type anaerobic filter can be adopted to carry out anaerobic treatment, top, filter tank and sealed bottom; filler is filled in filter tank; as, sandstone, haydite or baton round etc.; microorganic adhesion is at filling surface; when municipal effluent is upwards by packing layer, under the effect of the anaerobe film of filling surface, the organism in municipal effluent is degraded; and producing biogas, biogas is discharged from top, filter tank.Because filler is that attached growth of microorganisms provides larger surface-area, thus can improve organic degradation speed, and filler can also play a role in filtering, and retains the suspended substance in sewage.
S130: by the second pre-treatment municipal effluent by oxidation ditch, obtain the 3rd pre-treatment municipal effluent and the second pre-treatment bed mud.
By the second pre-treatment municipal effluent is entered oxidation ditch, in oxidation ditch, the mixed solution of municipal effluent and active sludge is under the effect of additionaling power, ceaselessly circulate, utilize in oxidation ditch the biological denitrification system constructing anaerobism-anoxic-aerobic, organonitrogen in second pre-treatment municipal effluent is converted into nitrate nitrogen under the effect of nitrifier, and at anaerobism section, nitrate nitrogen is converted into again nitrogen and discharges by denitrifying bacteria; Organophosphorus in second pre-treatment municipal effluent is absorbed by polyP bacteria, discharges phosphoric acid salt, reduce further COD and BOD of municipal effluent.
In order to be more conducive to microbial growth in oxidation ditch, such as, municipal effluent is regulated to enter the water yield of oxidation ditch, make load in oxidation ditch at 0.05 ~ 0.12kg BOD/ (MLSSd), and for example, control the temperature of municipal effluent between 20 DEG C ~ 30 DEG C, and for example, keep the dissolved oxygen of oxidation ditch at 2mg/L ~ 3mg/L, and for example, control ph is 6.2 ~ 8.6, and for example, carbon containing nutrition is added in oxidation ditch, make the ratio of BOD:N:P at 130 ~ 100:5:1, like this, microbial growth in oxidation ditch can be beneficial to, improve the denitrogenation dephosphorizing speed of organism in oxidation ditch.
And for example, the second pre-treatment municipal effluent is 12h ~ 14h in the residence time of oxidation ditch, makes the organism of the second pre-treatment municipal effluent degradable in oxidation ditch.
The nutritive elements such as carbon, nitrogen, phosphorus are rich in due in the second bed mud of obtaining through oxidation ditch, such as, the second bed mud produced in oxidation ditch is partly refluxed to anaerobic pond, as the nutrition of microorganism in anaerobic pond, the interpolation of anaerobic treatment Middle nutrition thing can be reduced, reduce processing cost.
S140: the 3rd pre-treatment municipal effluent is carried out precipitation process, obtains the 4th pre-treatment municipal effluent and the 3rd pre-treatment bed mud.
Be appreciated that, after oxidation ditch, amount of activated mud can be brought in 3rd pre-treatment municipal effluent, in order to remove the active sludge in the second pre-treatment municipal effluent, such as, the 3rd pre-treatment municipal effluent is left standstill, active sludge is deposited completely, and for example, leave standstill after adding flocculation agent in the 3rd pre-treatment municipal effluent.
In order to make the active sludge in the 3rd pre-treatment municipal effluent farthest deposit, such as, time of repose is 2h ~ 4h.
S150: carry out disinfection the 4th pre-treatment municipal effluent germicidal treatment, discharges.
In order to remove the pathogenic microbes in the 4th pre-treatment municipal effluent, such as, dioxide peroxide disinfection is added toward the 4th pre-treatment municipal effluent.
And for example, municipal effluent is passed into sterilization pool, inhale at pump and drop into sterilizing agent, through the intense mixing of water pump, sterilizing agent fully contacts with municipal effluent, sterilizing agent is fully contacted with bacterium, reaches sterilisation purpose.And for example, sterilizing agent is dioxide peroxide and chlorine gas mixture.
Because the chlorine residue during municipal effluent is after cholorination can cause disadvantageous effect to water body environment and aquatic organism, and for example, in the 3rd pre-treatment municipal effluent after sterilization, add S-WAT, the available chlorine in removing municipal effluent.
S160: the first pre-treatment bed mud, the second pre-treatment bed mud and the 3rd pre-treatment bed mud are carried out thickening process, obtains the 4th pre-treatment bed mud.
Be appreciated that the water content of the first pre-treatment bed mud, the second pre-treatment bed mud and the 3rd pre-treatment bed mud is higher, volume is comparatively large, and conveying, process or disposal are all inconvenient.As, the water content of the second pre-treatment bed mud produced by oxidation ditch can reach more than 99%, has highly variable.In order to reduce the water content of the first pre-treatment bed mud, the second pre-treatment bed mud and the 3rd pre-treatment bed mud, reducing volume, reducing subsequent disposal burden, such as, gravity concentration being carried out to the first pre-treatment bed mud, the second pre-treatment bed mud and the 3rd pre-treatment bed mud.And for example, centrifugal concentrating is carried out to the first pre-treatment bed mud, the second pre-treatment bed mud and the 3rd pre-treatment bed mud.And for example, floatation thickening is carried out to the first pre-treatment bed mud, the second pre-treatment bed mud and the 3rd pre-treatment bed mud.
In order to reduce the water ratio of the first pre-treatment bed mud, the second pre-treatment bed mud and the 3rd pre-treatment bed mud further, such as, process is dehydrated to the first pre-treatment bed mud, the second pre-treatment bed mud and the 3rd pre-treatment bed mud.And for example, the first pre-treatment bed mud, the second pre-treatment bed mud and the 3rd pre-treatment bed mud are carried out mechanical dehydration process.
S170: the 4th pre-treatment bed mud is carried out heavy metal and sloughs process, after drying and crushing, obtains agricultural bed mud.
In order to slough the heavy metal in the 4th pre-treatment bed mud, such as, in the 4th pre-treatment bed mud, adding citric acid, after stirring, leaving standstill, after solid-liquid separation, obtaining agricultural bed mud by after lower sediment drying.Utilize citric acid heavy metal to have stronger complex ability, the heavy metal in the 4th pre-treatment bed mud is dissolved in citric acid, thus sloughs the heavy metal in the 4th pre-treatment bed mud.
In order to farthest slough the heavy metal in the 4th pretreating sludge, such as, in the 4th pre-treatment bed mud, add citric acid, after stirring 24h, leave standstill process again, and for example, after the 4th pre-treatment bed mud is carried out ultrasonic grinding, the particle diameter of the 4th pretreating sludge is made to reach 0.1cm ~ 0.3cm, after adding citric acid stirring 24h again, leave standstill process, like this, the heavy metal rate of sloughing in mud can be made to reach more than 90%.
Such as, in the present embodiment, the concentration of citric acid is 0.2mol/L, and the solid-to-liquid ratio of citric acid and the 4th pre-treatment bed mud is 20:1, like this, both can ensure that higher metal ion sloughed rate, also can reduce the usage quantity of citric acid simultaneously, reduces reagent cost.
And for example, soda-lime can also be added in the lower sediment after solid-liquid separation, like this, the pH of lower sediment can be regulated to neutral, and meanwhile, soda-lime also can slough the part free-water in lower sediment, kill the microorganism such as the roundworm egg in lower sediment, class coliform, obtain agricultural bed mud.
The above-mentioned method for municipal sewage treatment, by removing the gred to municipal effluent, remove silt, anaerobic treatment, oxidation ditch process, after disinfection process, effectively can reduce COD and BOD of municipal effluent, make it reach emission standard, simultaneously, by utilizing citric acid to slough heavy metal in mud, decreasing secondary environmental pollution, improve resource utilization; Meanwhile, this method also has the advantages such as operational path is short, and cost is lower, convenient operation.
Such as, in order to introduce the above-mentioned method for municipal sewage treatment further, the utility model also provides a kind of equipment for municipal sewage treatment.
As shown in Figure 1, it is the structural representation of the equipment 10 of the equipment for municipal sewage treatment of an embodiment.
Refer to Fig. 1, for the equipment of municipal sewage treatment, comprise sewage manifold trunk 100, except slag bath 200, settling pit 300, anaerobic pond 400, oxidation ditch 500, second pond 600, disinfecting tank 700, mud collecting pond 800, concentration basin 900, abstraction pool 900a, drying and crushing machine 900b.
Refer to Fig. 1, except the exit end of slag bath 200 with sewage manifold trunk is communicated with.By passing into except slag bath 200 by the municipal effluent in sewage manifold trunk 100, larger suspended substance and floating matter in removing municipal effluent, prevent subsequent processing device from blocking.
Such as, be provided with middle grid and fine fack except in slag bath 200, by municipal effluent respectively by middle grid, fine fack, larger suspended substance and floating matter in interception municipal effluent.And for example, the grizzly bar gap of middle grid is 20mm, and the grizzly bar gap of fine fack is 8mm, municipal effluent enters middle grid, the flow velocity of fine fack is 0.8m/s, like this, effectively can remove the macrobead suspended substance in municipal effluent and floating matter, prevent subsequent processing device from blocking.
In order to the contact area of grid in increasing and fine fack and municipal effluent, such as, the setting angle of middle grid and horizontal plane is 75 °, the setting angle of fine fack and horizontal plane is 75 °, the speed of sanitary sewage by middle grid and fine fack can be accelerated like this, accelerate the processing speed of municipal effluent, thus improve the processing efficiency of municipal effluent.
Refer to Fig. 1, settling pit 300 is communicated with except slag bath 200.Municipal effluent in slag bath 200 is passed in settling pit 300, the silt in municipal effluent can be removed, reduce the impact that silt sets subsequent disposal, also can reduce the turbidity of municipal effluent simultaneously, alleviate the burden of subsequent treatment process.
Such as, municipal effluent is passed into settling pit 300, based on gravity or centrifugal force separate, the municipal effluent flow rate control being about to enter settling pit 300 is sunk at the inorganic particle that relative density can only be made large, as, 0.1m/s ~ 0.3m/s, organic suspension particle is then taken away with current, thus sand, inorganic particle that cinder isodensity is larger can be removed from municipal effluent, in order to avoid the normal operation of these impurity effect subsequent treatment process.
And for example, settling pit 300 is rotational flow grit chamber, and municipal effluent is passed into rotational flow grit chamber, and rotational flow grit chamber produces waterpower eddy current by the stirring of machinery, makes silt, haydite and separating organic matters to reach object of removing sand.
Refer to Fig. 1, anaerobic pond 400 is communicated with settling pit 300, is passed into by the supernatant liquid in settling pit 300 in anaerobic pond 400, and the organism in municipal effluent can be made to degrade, and reduces COD and BOD of municipal effluent.
Municipal effluent is being carried out in the process of anaerobic treatment, based on the complicated organism in the first pre-treatment municipal effluent under the effect of anaerobion and facultative microbe, complicated organic substance decomposing becomes the materials such as methane, carbonic acid gas, water, hydrogen sulfide and ammonia, thus COD and BOD of municipal effluent can be significantly reduced, greatly facilitate the reaction efficiency of follow-up aerobic treatment, simultaneously, due to the effect of the factors such as anoxic, free ammonia and temperature in anaerobic pond 400, the pathogenic bacteria of municipal effluent, virus and parasitic ovum etc. can be killed.
In order to ensure that anaerobion breeds better, such as, the temperature in anaerobic process being controlled at 5 DEG C ~ 60 DEG C, preferably, temperature being controlled at 20 DEG C ~ 40 DEG C.And for example, the pH value of the first pre-treatment municipal effluent in anaerobic process is controlled 6.8 ~ 7.8, preferably, the pH of municipal effluent in anaerobic pond 400 is controlled 7.2 ~ 7.6, thus anaerobion is bred better, organic degradation speed in municipal effluent in raising anaerobic pond 400.
Due in anaerobic treatment process, organic reduction have passed through hydrolysis, acidifying, product acid and methane phase four-stage, like this for some long-chains and band phenyl ring etc. be difficult to by aerobic bacteria the organism of degrading by Hydrolysis Acidification resolve into small-molecule substance or chain rupture utilize by anaerobion, improve the biological degradability of municipal effluent.
Such as, anaerobic pond 400 is flow lifting type anaerobic filter, and settling pit 300 is communicated with the bottom of anaerobic pond 400.Top, filter tank and sealed bottom, fill filler in filter tank, microorganic adhesion is at filling surface, when municipal effluent is upwards by packing layer, under the effect of the anaerobe film of filling surface, the organism in municipal effluent is degraded, and producing biogas, biogas is discharged from top, filter tank.Because filler is that attached growth of microorganisms provides larger surface-area, thus can improve organic degradation speed, and filler can also play a role in filtering, and retains the suspended substance in sewage.
Refer to Fig. 1, oxidation ditch 500 is communicated with anaerobic pond 400, by passing in oxidation ditch 500 by the municipal effluent in anaerobic pond 400, can reduce COD and BOD of municipal effluent further.
By the municipal effluent in anaerobic pond 400 is entered oxidation ditch 500, in oxidation ditch 500, the mixed solution of municipal effluent and active sludge is under the effect of additionaling power, ceaselessly circulate, utilize in oxidation ditch the biological denitrification system constructing anaerobism-anoxic-aerobic, organonitrogen in municipal effluent is converted into nitrate nitrogen under the effect of nitrifier, and at anaerobism section, nitrate nitrogen is converted into again nitrogen and discharges by denitrifying bacteria; Meanwhile, the organophosphorus in municipal effluent is absorbed by polyP bacteria, discharges phosphoric acid salt, reduce further COD and BOD of municipal effluent.
In order to be more conducive to microbial growth in oxidation ditch 500, such as, municipal effluent is regulated to enter the water yield of oxidation ditch, make load in oxidation ditch at 0.05 ~ 0.12kg BOD/ (MLSSd), and for example, control the temperature of municipal effluent between 20 DEG C ~ 30 DEG C, and for example, keep the dissolved oxygen of oxidation ditch at 2mg/L ~ 3mg/L, and for example, control ph is 6.2 ~ 8.6, and for example, carbon containing nutrition is added in oxidation ditch, make the ratio of BOD:N:P at 130 ~ 100:5:1, like this, microbial growth in oxidation ditch can be beneficial to, improve the denitrogenation dephosphorizing speed of organism in oxidation ditch.
Such as, oxidation ditch 500 is Carrousel oxidation ditch, and technique is simple, and be easy to control, and BOD degradation rate can reach 95% ~ 98%, COD degradation rate can reach 90% ~ 95%.
Refer to Fig. 1, second pond 600 is communicated with oxidation ditch 500, passes into second pond 600 by by the municipal effluent in oxidation ditch 500, makes it reach mud-water separation effect.
Be appreciated that after oxidation ditch 500, in municipal effluent, amount of activated mud can be brought into, in order to remove the active sludge in municipal effluent, such as, the second pre-treatment municipal effluent is left standstill, active sludge is deposited completely, and for example, leaves standstill add flocculation agent in the second pretreating sewage after.
Refer to Fig. 1, disinfecting tank 700 is communicated with second pond 600, the supernatant liquid in second pond 600 is passed into disinfecting tank 700 and to carry out disinfection germicidal treatment, make it reach emission standard, discharges.
Such as, municipal effluent is passed into disinfecting tank 700, inhale at pump and drop into sterilizing agent, through the intense mixing of water pump, sterilizing agent fully contacts with municipal effluent, available chlorine is fully contacted with bacterium, reaches sterilisation purpose.
Because the chlorine residue during municipal effluent is after cholorination can cause disadvantageous effect to water body environment and aquatic organism, and for example, in the municipal effluent after sterilization, add S-WAT, the available chlorine in removing municipal effluent.
And for example, in the middle of second pond 600 and disinfecting tank 700, be provided with magnetic flow meter, control the flooding quantity entering disinfecting tank 800, and then control the amount of sterilizing agent.
Refer to Fig. 1, sewage sludge storage pond 800 is communicated with anaerobic pond 400, oxidation ditch 500 and second pond 600 respectively, the mud bottom anaerobic pond 400, oxidation ditch 500 and second pond 600 is passed into sewage sludge storage pond 800, carries out subsequent disposal after being collected by mud.
Refer to Fig. 1, concentration basin 900 is communicated with sewage sludge storage pond 800, inputs in concentration basin 900, carry out thickening to bed mud by the bed mud in sewage sludge storage pond 800 by sludge pump, reduces the volume of bed mud, alleviates the burden of subsequent technique.
Such as, concentration basin 900 is floatation thickening pond, is provided with chain-type mud scraper and degassed pond in floatation thickening pond, and like this, the concentrated speed of bed mud is faster, and the bed mud solid content obtained is higher.
And for example, in concentration basin, be also provided with mechanical dehydration machine, the bed mud after concentrated is carried out processed further.
Refer to Fig. 1, abstraction pool 900a is communicated with concentration basin 900, is inputed in abstraction pool 900a by the bed mud after concentration basin 900 is concentrated, sloughs the heavy metal in bed mud, bed mud chemurgy is utilized.
Add citric acid toward abstraction pool 900a, utilize citric acid heavy metal to have stronger complex ability, the heavy metal in bed mud is dissolved in citric acid, thus reach the object of the heavy metal sloughed in bed mud.
The conveniently interpolation of citric acid, such as, is provided with dosing mouth in abstraction pool 900a, facilitates the interpolation of citric acid.
In order to make bed mud fully mix with citric acid, such as, in abstraction pool 900a, being provided with whipping device, like this, bed mud can being made fully to contact with citric acid, the heavy metal in bed mud is dissolved in citric acid.
And for example, larger contact area is had in order to make bed mud and citric acid, ultrasonic grinder is provided with in the middle of abstraction pool 900a and concentration basin 900, bed mud after thickening is broken through excusing from death ripple, form the particle between 0.3cm ~ 0.8cm, like this, bed mud and citric acid can be made to have larger contact area, heavy metal is dissolved completely in citric acid.
Refer to Fig. 1, drying and crushing machine 900b is communicated with abstraction pool 900a, is passed into by the bed mud in abstraction pool 900a in drying and crushing machine 900b, after carrying out drying and crushing, obtains agricultural bed mud.
The above-mentioned equipment 10 for municipal sewage treatment, by arranging except slag bath, settling pit, anaerobic pond, oxidation ditch, disappear disinfecting tank, effectively can reduce COD and BOD of municipal effluent, it is made to reach emission standard, meanwhile, by utilizing abstraction pool to slough heavy metal in mud, the bed mud chemurgy produced is utilized, decrease secondary environmental pollution, improve resource utilization; Meanwhile, this method also has the advantages such as operational path is short, and cost is lower, convenient operation.
The above embodiment only have expressed several embodiment of the present utility model, and it describes comparatively concrete and detailed, but therefore can not be interpreted as the restriction to the utility model the scope of the claims.It should be pointed out that for the person of ordinary skill of the art, without departing from the concept of the premise utility, can also make some distortion and improvement, these all belong to protection domain of the present utility model.Therefore, the protection domain of the utility model patent should be as the criterion with claims.