Summary of the invention
Based on the existing in prior technology problem, the embodiment of the invention provides a kind of system and method for handling sludge containing heavy metal, can solve existingly, can't satisfy the requirement of landfill after the processing, can cause secondary pollution problem environment to containing the sludge treatment cost height of heavy metal.
The objective of the invention is to be achieved through the following technical solutions:
The embodiment of the invention provides a kind of system that sludge containing heavy metal is handled, and comprising:
Sludge conveyor, mixing reactor, moisture eliminator, mud extraction handling machinery, medicament storage tank, medicament volume pump and emission-control equipment;
Described sludge conveyor is connected with mixing reactor, moisture eliminator and mud extraction handling machinery successively;
The medicament storage tank that is used to store the heavy metal complexing agent storage is connected with the dosing mouth of mixing reactor through the medicament volume pump, can pass through described dosing mouth described heavy metal complexing agent of even sprinkling in mixing reactor;
Described emission-control equipment is connected with the venting port of described moisture eliminator.
The embodiment of the invention also provides a kind of method of handling sludge containing heavy metal, comprising:
Sludge containing heavy metal is delivered in the mixing reactor, behind the heavy metal complexing agent uniform mixing that adds in the mixing reactor, make heavy metal ion and heavy metal complexing agent in the mud fully carry out complex reaction, the heavy metal ion in the mud is solidified in the organic complex that forms;
Mud after the complex reaction is transported to carries out drying and other treatment in the moisture eliminator, reduce the moisture of mud and change the proterties of mud, make the mud of exporting after the drying and other treatment satisfy the requirement of landfill by drying and other treatment.
By technique scheme as can be seen, by with sludge conveyor, mixing reactor, moisture eliminator, the medicament volume pump, the mud extraction handling machinery, medicament storage tank and emission-control equipment organically combine and form the system that can handle sludge containing heavy metal, make sludge containing heavy metal in the mixing reactor of this system, carry out complex reaction with the heavy metal complexing agent thorough mixing, heavy metal ion in the mud is solidified in the polymer organic complex that complex reaction forms, and the mud after utilizing moisture eliminator to complex reaction is handled, reduce sludge moisture content and change sludge character, make that heavy metal content reaches the landfill requirement in the mud, and its water content and proterties have all satisfied the requirement of landfill, have realized the innoxious of sludge from wastewater treatment plant, stabilization, minimizing is handled; This system architecture is simple, equipment is few, flexible operation, and processing cost is low, can be widely used in sewage treatment plant dewater sludge and remove the various heavy metals that contain.
Embodiment
The embodiment of the invention provides a kind of system and method for handling sludge containing heavy metal, and this system is made of sludge conveyor, mixing reactor, moisture eliminator, mud extraction handling machinery, medicament storage tank, medicament volume pump, high-pressure atomization nozzle and emission-control equipment; This system utilizes the heavy metal in the mud that contains heavy metal of mixing reactor in having realized heavy metal complexing agent and having entered mixing reactor to carry out complex reaction after full and uniform the mixing, and utilize moisture eliminator to realize the reduction of moisture percentage in sewage sludge, the change of proterties to the mud after the complex reaction, handle back mud all satisfies landfill on heavy metal content, water content and proterties requirement thereby make; This system architecture is simple, equipment is few, flexible operation, and the mud after the processing can satisfy the requirement of landfill, has realized that innoxious, the stabilization of mud, minimizing handle; Can be widely used in sludge from wastewater treatment plant and remove each heavy metal species.
For ease of understanding, the invention will be further described below in conjunction with the drawings and specific embodiments.
Embodiment one
Present embodiment provides a kind of system that handles sludge containing heavy metal, and the dewatered sludge that can handle the city domestic sewage treatment plant that contains heavy metal is handled, and makes the mud after the processing satisfy the landfill requirement, and as shown in Figure 1, this system comprises:
Sludge conveyor 1, mixing reactor 2, moisture eliminator 3, mud extraction handling machinery 4, medicament storage tank 8, medicament volume pump 5, high-pressure atomization device 6 and emission-control equipment 7;
Wherein, sludge conveyor 1 is connected with mixing reactor 2, moisture eliminator 3 and mud extraction handling machinery 4 successively;
Medicament storage tank 8 is connected with the dosing mouth 23 of mixing reactor 2 through medicament volume pump 5, medicament storage tank 8 adopts corrosion resistant plastics pot or stainless cylinder of steel, be used to store heavy metal complexing agent, be provided with whipping appts (whipping appts is not shown) in the medicament storage tank 8, can prevent that by whipping appts the heavy metal complex soup in the medicament storage tank 8 from precipitating or crystallization; Medicament volume pump 5 is connected with the dosing mouth 23 of mixing reactor 2 through high-pressure atomization device 6, the mouth spray of high-pressure atomization device 6 is connected with the dosing mouth 23 of mixing reactor 2, and medicament volume pump 5 is connected by the fluid inlet of pipeline with high-pressure atomization device 6, and medicament volume pump 5 can adopt Hydraulic Diaphragm Metering Pump; The high-pressure atomization device can adopt high-pressure atomization nozzle that stainless steel corrosion-resistant, carrying capacity makes, its medicament spray volume is generally 50~100L/h, operating pressure is 0.1~0.2MPa, by high-pressure atomization device 6, medicament volume pump 5 can evenly be injected to the mode of the heavy metal complexing agent in the medicament storage tank 8 with high-pressure atomization in the mixing reactor 2, thereby in the short period of time, effectively guarantee the mix uniformly effect of handled a large amount of mud in heavy metal complexing agent and the mixing reactor 2, guaranteed the effect of complex reaction;
Emission-control equipment 7 is connected with the venting port of moisture eliminator 3, is used for discharging the waste gas that 3 pairs of sludge drying treating processess of moisture eliminator are discharged, and makes the waste gas qualified discharge after the processing, and moisture eliminator 3 can adopt the rotary kiln type moisture eliminator; Emission-control equipment can adopt the leaching tower.
Sludge conveyor in the said system can adopt does not have the axle spiral conveyer, this nothing axle spiral conveyer is provided with weight sensor, can monitor the mud weight of advancing that sludge conveyor is transported to the mud in the mixing reactor by weight sensor, and the output terminal of weight sensor is electrically connected with the control end of medicament volume pump, thereby decide the weight of the heavy metal complex that medicament volume pump 5 adds to mixing reactor by the numerical value that advances mud weight that weight sensor records, be input to mud weight in the mixing reactor 2 by this according to sludge conveyor 1, control medicament volume pump 5 is to the mode of the weight of the heavy metal complexing agent of mixing reactor 2 addings, guarantee the complex reaction effect, also guaranteed heavy metal complexing agent with the mud of handling in mixing reactor, keep suitable ratio, make that utilizing this system to connect constantly with automated manner sludge containing heavy metal handles, and has improved processing efficiency.
Mixing reactor in the said system adopts continous way mixing reactor corrosion-resistant and that the carrying capacity material is made, and the continous way mixing reactor can adopt any in ploughshare continuous mixing device or the two oar formula continuous mixing device; Side at mixing reactor is provided with mud inlet, and opposite side is provided with mud mouth, and dosing mouth is arranged on the mixing reactor front end, is convenient to the adding of heavy metal complexing agent.
When said system is handled sludge containing heavy metal, mainly be to make the sludge containing heavy metal that is transported in the mixing reactor, carry out complex reaction with the heavy metal complexing agent in joining mixing reactor after mixing, heavy metal ion is converted into stable, harmless state, reduce the toxicity of heavy metal, form stable complex compound, heavy metal ion is solidified in the polymer organic complex that forms the most at last, has realized the deactivation function of heavy metal; After mud after the passivation has carried out drying and other treatment in moisture eliminator, reduce water ratio and change proterties, thereby the mud that makes output is in the requirement of all satisfying the mud landfill aspect heavy metal content, water content and the proterties.
Below in conjunction with to containing the treating processes that heavily belongs to mud, said system is described further:
Certain municipal sewage treatment scale is the sewage work of 50,000 ton per days, because entering of the trade effluent of upstream leather-making enterprises, make that its water ratio is to contain the total Cr ion of higher toxic heavy metal in 80% the dewatered sludge, concrete numerical value is the dried mud of 6.1g/kg, in " urban wastewater treatment firm sludge disposal--mix the landfill shale " (CJT 249-2007) standard less than the requirement of the dried mud of 1g/kg.Now utilize this system that this water factory's dewatered sludge is handled, make it reach the requirement of landfill.
Adopt the system of the embodiment of the invention shown in Figure 1, wherein, heavy metal complexing agent is stored in the soup storage tank 8 of plastics, and the volume of soup storage tank 8 is 1m
3 Medicament volume pump 5 adopts Hydraulic Diaphragm Metering Pump; High-pressure atomization device 6 adopts stainless chemical industry conical hollow finer atomization nozzle, advantages such as corrosion-resistant, difficult obstruction that this high-pressure atomization device 6 has, cleaning convenience, long service life; The soup spray volume of this high-pressure atomization device 6 is about 50~100L/h, operating pressure 0.1~0.2MPa; Medicament volume pump 5 and high-pressure atomization device 6 can evenly be sprayed into heavy metal complexing agent in the mixing reactor and react; Establish whipping appts in the medicament storage tank 8, prevent heavy metal complexing agent precipitation or crystallization;
The heavy metal complexing agent that is adopted in the medicament storage tank is the macromolecule organic that is generated by polyamines and dithiocarbonic anhydride reaction, is in a liquid state; Can with the total Cr ion of poisonous and hazardous heavy metal generation complex reaction in the sewage treatment plant dewater sludge of water ratio 80%, and then form stable complex compound, the total Cr of heavy metal ion solidifies in the polymer organic complex the most at last; Its dosage is the wet mud (water ratio 80%) of 12.5L/t;
During processing, adopt sludge conveyor 1 that mud is conveyed in the mixing reactor 2, sludge conveyor 1 adopts the no axle spiral conveyer of band weighing device, can send in the mixing reactor 2 dewatered sludge is continual, carry the weight of mud to export in real time by weighing device, because the output terminal of weighing device is associated with the control end of medicament volume pump 5, can carry the weight control medicament volume pump 5 of mud to add the weight of heavy metal complexing agents according to sludge conveyor 1, make the working order of the numerical value decision medicament volume pump 5 of weighing of sludge conveyor 1; The major function of mixing reactor 2 provides heavy metal complexing agent and mixes with heavy metal in the mud and the place of reacting, the ploughshare continuous mixing device that can adopt rotating speed to regulate, mud and the heavy metal complexing agent hybrid reaction time in mixing reactor is 5min;
Reacted mud enters in the moisture eliminator 3, and the major function of moisture eliminator 3 is that mud is carried out drying and other treatment, and moisture percentage in sewage sludge is reduced to below 60% from 75~85%, can carry out the standard of landfill to satisfy mud extraction; Moisture eliminator 3 can adopt the rotary kiln type moisture eliminator, adds unslaked lime as stablizer in the mud that moisture eliminator is handled, carry out thermopositive reaction and then lower the water ratio of mud, the consumption of lime by processing mud weight 15~25%; The residence time of mud in moisture eliminator 3 is not less than 30min, the mud extraction of moisture eliminator in pelletized form, what particle diameter 20mm was following accounts for 80%, water ratio is less than 60%; Moisture eliminator 3 can discharge waste gas in the drying and other treatment process, ability qualified discharge after need handling by emission-control equipment 7, and emission-control equipment 7 can adopt leaching turriform formula;
The proterties of handling back mud through said system is as follows: water ratio 54%; Mud extraction granulating, the average 12mm of particle diameter; The total Cr ion of mud extraction (detection method-" sludge from wastewater treatment plant detection method " (CJ/T211-2005)) content is the 0.76g/kg dewatered sludge; Therefrom as can be seen, by this system handles, total chrome content in the mud can be reduced to the 0.76g/kg dewatered sludge from the 6.1g/kg dewatered sludge, curing efficiency is about 87.5%, guarantee that mud extraction can satisfy the standard of mud mixing landfill, alleviated of the harm of the total chromium of heavy metal greatly environment.
Embodiment two
Present embodiment provides a kind of method of handling sludge containing heavy metal, the dewatered sludge that can handle the city domestic sewage treatment plant that contains heavy metal is handled, make the mud after the processing satisfy the landfill requirement, the system that can adopt the foregoing description one to provide realizes this method, idiographic flow comprises as shown in Figure 2:
With sludge conveyor sludge containing heavy metal is transported in the mixing reactor, heavy metal complexing agent evenly is sprayed onto in the mixing reactor in the handled mud in the high-pressure fog mode through the high-pressure atomization device by the medicament volume pump, make both even thorough mixing, heavy metal ion in the mud and heavy metal complexing agent carry out complex reaction, and the heavy metal ion in the mud is solidified in the organic complex that complex reaction forms; The heavy metal complexing agent that adds in the mixing reactor can adopt liquid macromolecule organic, can with poisonous and hazardous heavy metal ion generation complex reaction in the mud of water ratio 75~85%, its branched monomer can form stable list of coordination units (even if carry out concentrated acid alkali clear up to make cooperated stable heavy metal ion to dissociate out) with heavy metal ion, and then form stable complex compound, heavy metal ion is solidified in the polymer organic complex the most at last, and the time of complex reaction generally is not less than 5 minutes;
In the reality, used heavy metal complexing agent can be selected according to the difference of contained heavy metal in the mud, as long as this heavy metal complexing agent can form the organic complex that solidifies contained heavy metal ion with contained heavy metal generation complex reaction in the mud, is that monomer synthetic heavy metal complexing agent can have complexing effect preferably to cupric ion and the nickel ion (in the electroplating wastewater) that contains in the mud as quadrol; As to mix polyamines be that monomer synthesizing heavy metal complexing agent can have complexing effect preferably to the chromium in the mud (leather-making waste water); Heavy metal complexing agent can constitute monomeric proportioning of this heavy metal complexing agent and reaction conditions acquisition by adjusting;
The consumption of heavy metal complexing agent can be selected with reference to the sludge containing heavy metal gross weight that is transported in the mixing reactor, the dosage of general heavy metal complexing agent adds (wherein in the wet mud that contains heavy metal by 5~100L/t, the L/t of unit of heavy metal complexing agent dosage represents the heavy metal complexing agent that wet mud per ton adds 5~100 liters), with the present embodiment is example, handle in the mud heavy metal chromium with heavy metal complexing agent dosage change curve as shown in Figure 3.
Mud after the complex reaction is conveyed into carries out drying and other treatment in the moisture eliminator; reduce the moisture of mud and change the proterties of mud by drying and other treatment; moisture percentage in sewage sludge is reduced to below 60% from 75~85%; mud extraction granulating, particle diameter average out to 12~20mm, the mud of the output after the moisture eliminator drying and other treatment satisfies the requirement of landfill.
In the aforesaid method, the mud after the complex reaction is conveyed into carries out drying and other treatment in the moisture eliminator and specifically can adopt:
Add lime as stablizer in moisture eliminator, the add-on of lime is to be transported to 15~25% of the interior mud gross weight of moisture eliminator; The drying time of mud in moisture eliminator is not less than 30 minutes;
Perhaps, adopt the direct mummification of hot steam.
Also can adopt both blended drying and other treatment technology,
In sum, heavy metal complexing agent by complex reaction will can take place with the heavy metal in the handled mud in the embodiment of the invention sprays in the sludge containing heavy metal in the mixing reactor by high-pressure atomization, carry out complex reaction behind the thorough mixing, be converted into the heavy metal in the mud stable, behind the harmless state, again with mud by carrying out drying and other treatment in the moisture eliminator, make mud extraction satisfy the requirement of sanitary landfill, realized innoxious to the sludge from wastewater treatment plant that contains heavy metal, stabilization, minimizing is handled, be specially adapted to based on municipal wastewater, the dewatered sludge of the municipal sanitary sewage disposal factory that the trade effluent that has simultaneously part to contain heavy metal again enters is handled, and makes mud after the processing satisfy the requirement of mud hygienic safety landfill.
The above; only for the preferable embodiment of the present invention, but protection scope of the present invention is not limited thereto, and anyly is familiar with those skilled in the art in the technical scope that the present invention discloses; the variation that can expect easily or replacement all should be encompassed within protection scope of the present invention.Therefore, protection scope of the present invention should be as the criterion with the protection domain of claims.