CN105712559A - Membrane treatment system and technology for desulfurization wastewater - Google Patents

Abstract

The invention belongs to the technical field of treatment of desulfurization wastewater and particularly provides a membrane treatment system and technology for desulfurization wastewater. The treatment system comprises a raw water tank, a pre-sedimentation tank, a first reaction tank, an intermediate water tank, a second reaction tank, a concentration tank, a TMF (tubular micro-filtration membrane) device, a TMF water producing tank, a DTRO (disk tubular reverse osmosis) device, an evaporator and a drying device which are sequentially connected through a pipeline, wherein the TMF device is connected with the concentration tank through a reflux pipeline, and a concentrated water outlet of the DTRO device is connected with an inlet of the evaporator. The membrane treatment system for the desulfurization wastewater is simple in structure, small in occupied area and low in cost, the adopted membrane treatment technology is better in treatment effect of the desulfurization wastewater, heavy metals and suspended solids in the wastewater can be completely removed, the water yield is high, produced water conforms to the discharge standard, and the technology has feasibility and adaptability in zero-discharge treatment of the desulfurization wastewater.

Description

A kind of desulfurization wastewater film processing system and technique

Technical field

The invention belongs to desulfurization wastewater processing technology field, be specifically related to a kind of desulfurization wastewater film processing system and technique.

Background technology

At present, the prevailing technology of flue gas desulphurization is wet desulfurization of flue gas by limestone-gypsum method, its technology maturation, strong adaptability.During wet desulfurizing process desulfurization, in desulfuration absorbing tower, serosity iterative cycles utilizes, in tower, soluble salt serosity constantly concentrates, for guaranteeing chloride equilibrium in desulfurization performance and maintenance system, needs are continuously replenished, update serosity, giving off the waste water containing plurality of heavy metal ion in this process, the waste water of discharge is desulfurization wastewater.

In desulfurization wastewater, species of metal ion includes conventional heavy metal (Cd, Cu, Cr, Ni, Pb, Zn etc.), also some other non-heavy metal ion is included, such as As, Ba, Mo, Fe, Al, Sn, Ra etc., also have the features such as high salinity, float are high simultaneously.The common feature of these pollutant is to add some medicaments to form precipitate.Tradition method for treating desulfurized wastewater adopts chemical precipitation method, this processing method needs to arrange sedimentation tank, consider precipitation water outlet can not remove the ss suspended solid in water quality completely, containing heavy metal float, and also need to quartz filter, ultrafiltration etc. after precipitating, carry out reuse after the water being settled out is carried out advanced treating again, thus cause waste water processing station in order to place substantial amounts of equipment and increase floor space and equipment investment.And, adopt commonsense method to process desulfurization wastewater and be difficult to qualified discharge, process for desulfurization wastewater and propose aobvious particularly important of novel processing method.

Summary of the invention

It is an object of the invention to overcome the defect of above-mentioned prior art, it is provided that a kind of desulfurization wastewater film processing system and technique, good waste water treatment effect, the product water after process reaches qualified discharge standard, adopts film processing system floor space little, and cost is low.

For this, the invention provides a kind of desulfurization wastewater film processing system, produce water tank, DTRO device, vaporizer and drying device including the former pond being sequentially connected with by pipeline, preliminary sedimentation tank, the first reaction tank, intermediate water tank, the second reaction tank, thickener, TMF device, TMF；Described TMF device is connected with thickener by reflux pipe, and the dense water out of described DTRO device is connected with evaporator inlet.

Desulfurization wastewater film processing system provided by the invention, first waste water is carried out preliminarily softened pretreatment, tentatively eliminate the calcium in waste water, magnesium heavy metal ion and float, next adopts TMF (tube type filter membrance) device to carry out cross flow filter process, macromole float is retained by TMF device, reduce waste water hardness, the permeate of TMF device enters in DTRO (high pressure reverse osmosis membrane) device and carries out concentration, remove the COD in waste water, antibacterial, the pollutant such as ammonia nitrogen, and by concentration after dense water deliver to vaporizer be evaporated process, solid crystal thing is dried packing, product water after concentration meets qualified discharge standard.This film processing system, good waste water treatment effect, the ss suspended solid in water quality can be removed completely, containing heavy metal float, produce water and meet qualified discharge standard, area occupied is little, invests little.

Further, described thickener is connected with filter press by pipeline.The mud produced in thickener is carried out dehydration by described filter press, and the mud after dehydration is as general fixed-end forces.

As preferably, the pipeline between described former pond and preliminary sedimentation tank is provided with the first elevator pump, and the pipeline between described first reaction tank and intermediate water tank is provided with the second elevator pump, and the pipeline that described TMF produces between water tank and DTRO device is provided with the 3rd elevator pump.

As preferably, the pipeline between described thickener and TMF device is provided with circulating pump.Under the promotion of circulating pump, flow of inlet water is big, flow velocity is high for TMF device, carrying capacity is strong.

Further, it is respectively equipped with self-poking arrangement in described first reaction tank and the second reaction tank.Waste liquid in first reaction tank and the second reaction tank is sufficiently stirred for by self-poking arrangement, and the homogenizing waste liquid reaction after stirring is more abundant, and treatment effect is better, and rate of deposition is high.

As improvement, described first reaction tank and the second reaction tank are each configured with PH monitor.The degree of accuracy of pH value directly affects water treatment effect, if pH value deviation control scope, heavy metal in waste water precipitation will be caused not exclusively, it is impossible to effectively remove the heavy metal ion in waste water, PH in reaction tank can be monitored by PH monitor in real time, strictly controls pH value.

Present invention also offers a kind of desulfurization wastewater membrane treatment process, comprise the steps:

Step a: be transported in former pond by the desulfurization wastewater collected, when in former pond, liquid level reaches setting height, rises in preliminary sedimentation tank by the first elevator pump by desulfurization wastewater, and in preliminary sedimentation tank, float and big particulate matter in desulfurization wastewater carry out preformed precipitate；

Step b: be transported in the first reaction tank by the preliminary sedimentation liquid on preliminary sedimentation tank top, adds Calx in the first reaction tank and carries out preliminarily softened process, form the precipitate of calcium sulfate, magnesium hydroxide, and magnesium hydroxide carries silicon dioxide and forms co-precipitation simultaneously；The first reactant liquor after preliminarily softened is risen to intermediate water tank by the second elevator pump；

Step c: the first reactant liquor in intermediate water tank is from flowing in the second reaction tank, sodium hydroxide is added in the second reaction tank, the PH of the first reactant liquor is carried out accurate adjustment, PH is controlled between 10-12, magnesium hydroxide is precipitated completely, adding sodium carbonate liquor in the second reaction tank, sodium carbonate liquor reacts formation precipitation of calcium carbonate with the calcium ion of residual in the first reactant liquor simultaneously；

The second reactant liquor obtained after reaction in step d: the second reaction tank enters into thickener, second reactant liquor concentrating and precipitating in thickener, concentrated solution after concentration is sent to TMF device through circulating pump, concentrated solution is carried out cross flow filter by TMF device under the promotion of circulating pump, product water after filtration circulates between TMF device and thickener, product water after circulation carries out PH adjustment through adding hydrochloric acid, discharges after reaching qualified discharge standard, or the product water after circulation enters into TMF and produces water tank；

The TMF product water that step e:TMF produces in water tank rises to DTRO device through the 3rd elevator pump, TMF is produced water and carries out high power concentration by DTRO device, dense water after concentration is sent to vaporizer and is evaporated crystallization treatment, the solid crystal salt obtained is dried packing, and the product water after concentration is recycling after collecting.

Further, the thickener in described step d is connected with filter press by pipeline, and the mud obtained after concentration in thickener is transported to filter press and carries out sludge press filtration process, and the mud after filter pressing being processed carries out follow-up mud solidification disposal of waste.

Further, it is respectively equipped with self-poking arrangement in described first reaction tank and the second reaction tank.

As further improvement, described first reaction tank and the second reaction tank are each configured with PH monitor.

Beneficial effects of the present invention: this desulfurization wastewater film processing system provided by the invention, simple in construction, area occupied are little, cost is low, the membrane treatment process adopted, the effect processing desulfurization wastewater is better, can removing the heavy metal in waste water and float completely, producing water ratio height and product water meet discharge standard, have feasibility and adaptability in desulfurization wastewater zero discharge treatment.

Accompanying drawing explanation

Fig. 1 is the process flow diagram of desulfurization wastewater film processing system provided by the invention.

Description of reference numerals: 1, former pond；2, preliminary sedimentation tank；3, the first reaction tank；4, intermediate water tank；5, the second reaction tank；6, thickener；7, TMF device；8, TMF produces water tank；9, DTRO device；10, vaporizer；11, drying device；12, filter press；13, the first elevator pump；14, the second elevator pump；15, circulating pump；16, reflux pipe；17, the 3rd elevator pump.

Detailed description of the invention

Below in conjunction with the drawings and specific embodiments, it is further elucidated with the present invention.

Embodiment 1:

A kind of desulfurization wastewater film processing system as shown in Figure 1, produces water tank 8, DTRO device 9, vaporizer 10 and drying device 11 including the former pond 1 being sequentially connected with by pipeline, preliminary sedimentation tank the 2, first reaction tank 3, intermediate water tank the 4, second reaction tank 5, thickener 6, TMF device 7, TMF；Described TMF device 7 is connected with thickener 6 by reflux pipe 16, and the dense water out of described DTRO device 9 is connected with vaporizer 10 entrance.Pipeline between described former pond 1 and preliminary sedimentation tank 2 is provided with the first elevator pump 13, and the pipeline between described first reaction tank 3 and intermediate water tank 4 is provided with the second elevator pump 14, and the pipeline that described TMF produces between water tank 8 and DTRO device 9 is provided with the 3rd elevator pump 17.Pipeline between described thickener 6 and TMF device 7 is provided with that circulating pump 15, TMF device 7 flow of inlet water under the promotion of circulating pump 15 is big, flow velocity is high, carrying capacity is strong.Described thickener 6 is connected with filter press 12 by pipeline.The mud produced in thickener 6 is carried out dehydration by described filter press 12, and the mud after dehydration is as general fixed-end forces.

It is respectively equipped with self-poking arrangement in described first reaction tank 3 and the second reaction tank 5.Waste liquid in first reaction tank 3 and the second reaction tank 5 is sufficiently stirred for by self-poking arrangement, and the homogenizing waste liquid reaction after stirring is more abundant, and treatment effect is better, and rate of deposition is high.

It addition, the first reaction tank 3 and the second reaction tank 5 are each configured with PH monitor.The degree of accuracy of pH value directly affects water treatment effect, if pH value deviation control scope, heavy metal in waste water precipitation will be caused not exclusively, it is impossible to effectively remove the heavy metal ion in waste water, PH in reaction tank can be monitored by PH monitor in real time, strictly controls pH value.

The desulfurization wastewater film processing system that the present embodiment provides, first waste water is carried out preliminarily softened process, tentatively eliminate the calcium in waste water, magnesium heavy metal ion and float, secondly TMF device is adopted to carry out cross flow filter process, macromole float is retained by TMF device, reduce waste water hardness, the permeate of TMF device enters into and carries out concentration in DTRO device, remove the COD in waste water, antibacterial, the pollutant such as ammonia nitrogen, and by concentration after dense water deliver to vaporizer be evaporated process, solid crystal thing is dried packing, product water after concentration meets qualified discharge standard.This film processing system, good waste water treatment effect, the ss suspended solid in water quality can be removed completely, containing heavy metal float, produce water and meet qualified discharge standard, area occupied is little, invests little.

Embodiment 2:

On the basis of embodiment 1, we additionally provide a kind of desulfurization wastewater membrane treatment process, are specifically described technical process in conjunction with Fig. 1, comprise the steps:

Step a: the desulfurization wastewater collected is transported in former pond 1, when in former pond 1, liquid level reaches setting height, rising in preliminary sedimentation tank 2 by the first elevator pump 13 by desulfurization wastewater, in preliminary sedimentation tank 2, float and big particulate matter in desulfurization wastewater carry out preformed precipitate；

Step b: be transported in the first reaction tank 3 by the preliminary sedimentation liquid on preliminary sedimentation tank 2 top, adds Calx in the first reaction tank 3 and carries out preliminarily softened process, form the precipitate of calcium sulfate, magnesium hydroxide, and magnesium hydroxide carries silicon dioxide and forms co-precipitation simultaneously；The first reactant liquor after preliminarily softened is risen to intermediate water tank 4 by the second elevator pump 14；It is provided with self-poking arrangement in described first reaction tank 3.By being sufficiently stirred for so that medicament and exhausted water are thoroughly mixed reaction.

Step c: the first reactant liquor in intermediate water tank 4 is from flowing in the second reaction tank 5, sodium hydroxide is added in the second reaction tank 5, the PH of the first reactant liquor is carried out accurate adjustment, it is provided with PH monitor in first reaction tank 3, PH is controlled between 10-12, it is preferable that 11.5, magnesium hydroxide is precipitated completely, adding sodium carbonate liquor in the second reaction tank 5, sodium carbonate liquor reacts formation precipitation of calcium carbonate with the calcium ion of residual in the first reactant liquor simultaneously；It is provided with self-poking arrangement and PH monitor in described second reaction tank 5.By being sufficiently stirred for so that medicament and exhausted water are thoroughly mixed reaction.

The second reactant liquor obtained after reaction in step d: the second reaction tank 5 enters into thickener 6, second reactant liquor is concentrating and precipitating in thickener 6, concentrated solution after concentration is sent to TMF device 7 through circulating pump 15, concentrated solution is carried out cross flow filter by TMF device 7 under the promotion of circulating pump 15, reflux pipe 16 it is provided with between TMF device 7 and thickener 6, product water after filtration circulates between TMF device 7 and thickener 6, product water after circulation carries out PH adjustment through adding hydrochloric acid, discharge after reaching qualified discharge standard, or the product water after circulation enters into TMF and produces water tank 8；Further, thickener 6 is connected with filter press 12 by pipeline, and the mud obtained after concentration in thickener 6 is transported to filter press 12 and carries out sludge press filtration process, and the mud after filter pressing being processed carries out follow-up mud solidification disposal of waste.

TMF device 7 adopts cross-current type tubular filter, instead of traditional sedimentation and clarification process, reach good effluent quality, utilize microporous membrane that the precipitate in waste water is separated, do not need precipitate particle sizes sufficiently large sufficiently large with proportion, so after material is converted into insoluble state from dissolved state, being a kind of more effective separation method.

After stable operation after a while, the former water of TMF device and product water water analysis are as follows,

From indexs such as key hardness it can be seen that TMF device produces the calcium water, magnesium hardness can control within 50mg/L, fully meet subsequent film concentration requirement, furthermore it is possible to supplement basicity by improving the mode of chemical feeding quantity, reduce hardness.

The TMF product water that step e:TMF produces in water tank 8 rises to DTRO device 9 through the 3rd elevator pump 17, TMF is produced water and carries out high power concentration by DTRO device 9, dense water after concentration is sent to vaporizer 10 and is evaporated crystallization treatment, the solid crystal salt obtained is dried packing, and the product water after concentration is recycling after collecting.

DTRO device 9 is provided with single DTRO film (high pressure reverse osmosis membrane), membrane area 9.405m², membrane flux is set in 5-30L/m^2.Between h, corollary equipment has filter, high-pressure pump, booster pump, high pressure putamina.The high pressure reverse osmosis membrane of to be pressure rating the be 120kg selected, high-pressure pump is that frequency conversion is arranged, pressure adjustable.During the minimum 90kg of high-pressure pump pressure, now recording dense water TDS is 98600mg/L, and high-pressure pump maximum pressure is 117kg grade, and now recording the dense the highest TDS of water is 130580mg/L.The water analysis situation of DTRO device is as follows,

Analysis project	The dense water 1 of DTRO	The dense water 2 of DTRO
			Conductance (ms/cm)	114.4	124.4
TDS(mg/L)	111820	130580
			Ca2+(mg/L)	37.81	42.65
Mg2+(mg/L)	6.59	5.12
			Cl-(mg/L)	54118.1	60874.96
SO42-(mg/L)	1124.742	1262.104
			F-(mg/L)	ND	ND
NO3-N(mg/L)	718.98	780.76
			Strontium (mg/L)	0.5	0.5
Sodium (mg/L)	37000	41000
			Potassium (mg/L)	520	600

Stable operation about 1 month, membranous system pressure reduction shows no obvious abnormalities, membranous system less pollution, the product water TDS of DTRO is within 500mg/L, producing water and meet discharge standard, the dense water of DTRO is directly entered subsequent evaporation crystal system, it is possible to arrange two-stage reverse osmosis system and water quality is brought up to higher standard.

Exemplified as above is only illustration to the present invention, is not intended that the restriction to protection scope of the present invention, every belongs within protection scope of the present invention with the same or analogous design of the present invention.

Claims (10)

1. a desulfurization wastewater film processing system, it is characterized in that, produce water tank (8), DTRO device (9), vaporizer (10) and drying device (11) including the former pond (1) being sequentially connected with by pipeline, preliminary sedimentation tank (2), the first reaction tank (3), intermediate water tank (4), the second reaction tank (5), thickener (6), TMF device (7), TMF；Described TMF device (7) is connected with thickener (6) by reflux pipe (16), and the dense water out of described DTRO device (9) is connected with vaporizer (10) entrance.

2. a kind of desulfurization wastewater film processing system as claimed in claim 1, it is characterised in that described thickener (6) is connected with filter press (12) by pipeline.

3. a kind of desulfurization wastewater film processing system as claimed in claim 1, it is characterized in that, pipeline between described former pond (1) and preliminary sedimentation tank (2) is provided with the first elevator pump (13), pipeline between described first reaction tank (3) and intermediate water tank (4) is provided with the second elevator pump (14), and the pipeline that described TMF produces between water tank (8) and DTRO device (9) is provided with the 3rd elevator pump (17).

4. a kind of desulfurization wastewater film processing system as claimed in claim 1, it is characterised in that the pipeline between described thickener (6) and TMF device (7) is provided with circulating pump (15).

5. a kind of desulfurization wastewater film processing system as claimed in claim 1, it is characterised in that be respectively equipped with self-poking arrangement in described first reaction tank (3) and the second reaction tank (5).

6. a kind of desulfurization wastewater film processing system as claimed in claim 1, it is characterised in that described first reaction tank (3) and the second reaction tank (5) are each configured with PH monitor.

7. a desulfurization wastewater membrane treatment process, it is characterised in that comprise the steps:

Step a: the desulfurization wastewater collected is transported in former pond (1), when in former pond (1), liquid level reaches setting height, by the first elevator pump (13), desulfurization wastewater is risen in preliminary sedimentation tank (2), in preliminary sedimentation tank (2), float and big particulate matter in desulfurization wastewater carry out preformed precipitate；

Step b: the preliminary sedimentation liquid on preliminary sedimentation tank (2) top is transported in the first reaction tank (3), in the first reaction tank (3), add Calx carry out preliminarily softened process, forming the precipitate of calcium sulfate, magnesium hydroxide, magnesium hydroxide carries silicon dioxide and forms co-precipitation simultaneously；The first reactant liquor after preliminarily softened is risen to intermediate water tank (4) by the second elevator pump (14)；

Step c: the first reactant liquor in intermediate water tank (4) is from flowing in the second reaction tank (5), sodium hydroxide is added in the second reaction tank (5), the PH of the first reactant liquor is carried out accurate adjustment, PH is controlled between 10-12, magnesium hydroxide is precipitated completely, adding sodium carbonate liquor in the second reaction tank (5), sodium carbonate liquor reacts formation precipitation of calcium carbonate with the calcium ion of residual in the first reactant liquor simultaneously；

The second reactant liquor obtained after reaction in step d: the second reaction tank (5) enters into thickener (6), second reactant liquor is concentrating and precipitating in thickener (6), concentrated solution after concentration is sent to TMF device (7) through circulating pump (15), concentrated solution is carried out cross flow filter by TMF device (7) under the promotion of circulating pump (15), product water after filtration circulates between TMF device (7) and thickener (6), product water after circulation carries out PH adjustment through adding hydrochloric acid, discharge after reaching qualified discharge standard, or the product water after circulation enters into TMF and produces water tank (8)；

The TMF product water that step e:TMF produces in water tank (8) rises to DTRO device (9) through the 3rd elevator pump (17), TMF is produced water and carries out high power concentration by DTRO device (9), dense water after concentration is sent to vaporizer (10) and is evaporated crystallization treatment, the solid crystal salt obtained is dried packing, and the product water after concentration is recycling after collecting.

8. a kind of desulfurization wastewater membrane treatment process as claimed in claim 7, it is characterized in that, thickener (6) in described step d is connected with filter press (12) by pipeline, the mud obtained after concentration in thickener (6) is transported to filter press (12) and carries out sludge press filtration process, and the mud after filter pressing being processed carries out follow-up mud solidification disposal of waste.

9. a kind of desulfurization wastewater membrane treatment process as claimed in claim 7, it is characterised in that be respectively equipped with self-poking arrangement in described first reaction tank (3) and the second reaction tank (5).

10. a kind of desulfurization wastewater membrane treatment process as claimed in claim 7, it is characterised in that described first reaction tank (3) and the second reaction tank (5) are each configured with PH monitor.