A kind of biofiltration device of handling toluene gas
Technical field
The present invention is mainly concerned with the technical field that low-concentration organic exhaust gas is handled, and refers in particular to a kind of biofiltration device of handling toluene gas.
Background technology
VOC (Volatile Organic Compounds, abbreviation VOCs) is meant that saturated vapour pressure is greater than 70Pa at normal temperatures, under the normal pressure boiling point 260 ℃ with interior organic compound, main component is hydro carbons, oxygen hydro carbons, contain halohydrocarbon, nitrogen hydrocarbon and sulphur hydro carbons etc.The volatile organic matter that discharges in industrial production and the waste treatment process in most cases concentration is lower, and common organic value is not high, perhaps complicated component, and most of VOCs have penetrating odors such as stench.People and various animals and plants are had toxicity, carcinogenic, teratogenesis, mutagenic " three cause " effect are arranged, and can also with the NO in the atmosphere
2Reaction generates O
3, make low airborne O
3Content raises, and ecological environment is produced very big influence.Therefore, the harmfulness of volatile organic matter can not be ignored, and rational governance way and control scheme are actively sought in countries in the world.
The mature technology that VOCs administers mainly contains flame combustion method, catalytic burning method, absorption and burns combination method, condensation at low temperature, absorption process etc.Every kind of traditional treatment technology all has advantage separately, but also inevitably existence much be difficult to the shortcoming that overcomes.The flame combustion method expends the energy, and if the too high meeting of ignition temperature cause NO
2Secondary pollution, auxiliary fuel expense height.The catalytic burning method has been used catalyst in CIU, greatly reduce the incineration temperature of VOCs material, thereby reduced the expense of auxiliary fuel, but the one-time investment expense is higher, than high more than 40% with the flame combustion method of scale, and this method mainly is applicable to and contains the higher waste gas of VOCs concentration, and is not obvious to the VOCs treatment effect of low concentration.For absorption method and absorption process, the purpose that absorbent or adsorbent need be regenerated and be recycled to reach is so complex process has increased disposal cost.
Compare with traditional method, microbial method is handled organic exhaust gas and is had that good purification, stable operation, operating cost are low, easy operating and advantages such as management, non-secondary pollution, handle low concentration, big flow, when containing the strong VOCs of microorganism degradability, more can show its superiority, be with a wide range of applications.
The processing that is applied to the low concentration toluene gas that biofilter is successful, but in concrete operation, also have following subject matter: 1) biomembrane, organic loading, nutrients, moisture content etc. distribute uneven; 2) be not suitable for short empty bench grafting usually and touch time degraded high load capacity organic gas; 3) excessive biomembranous accumulating in the medium.
The filler of biofilter mainly contains two types, and a kind of is the nature organic filler, as the mixture of compositions such as peat, compost, leaf, wood chip and soil; A kind of is the inertia synthetic filling, as perlite, granular active carbon and haydite etc.Sometimes also use the filler that combines by two types.In addition, also having with the active carbon is filler, both can also can provide a buffered ability for biofilm development provides a supporting role.The carrier that these type fillers and composition thereof are often bred as growth of microorganism in the mode of piling up in biofilter.
Though the biofilter of traditional employing organic filler can reach higher removal efficient when handling the low concentration toluene gas, but prolongation and the slowly compacting of dump packing in filter along with running time, exist defectives such as nutritional labeling deficiency in the filler, pressure drop increase, therefore still need be optimized selection the filter packing that application performance is more senior and take better arrangement to overcome and to reduce that the filler that runs in traditional bio-trickling operation stops up, humidity is difficult to a lot of problems such as control and nutrient distribution restriction to filler.
Summary of the invention
The problem to be solved in the present invention just is: at the technical problem that prior art exists, the invention provides a kind of simple and compact for structure, remove that toluene is effective, operating cost is low, the cycle of operation is long, the biofiltration device of the processing toluene gas of non-secondary pollution, convenient operating maintenance.
For solving the problems of the technologies described above, the solution that the present invention proposes is: a kind of biofiltration device of handling toluene gas, it is characterized in that: it comprises air distribution system, biofilter, nutrient solution drips system and constant temperature water bath system, the nutrient solution shower nozzle of nutrient solution dropping system is positioned at the top of biofilter, the outlet of air distribution system links to each other by the air inlet of pipeline with the biofilter upper end, the constant temperature water bath system is positioned at the biofilter outside, described biofilter comprises shell body, be provided with the biological filter material layer of one or more layers of monoblock type in the shell body, the biofilter material layer is by the supporting screening plate supporting of every layer of bottom, what the filter medium of described biofilter material layer adopted is uniform monoblock type material, and its porosity is 90%~98%, the aperture is 1~10mm, percent opening is more than 95%, hot strength is greater than 5000Pa, compression strength is greater than 1000Pa, bulk density is 20~600kg/m
3, specific area is 100~1000m
2/ m
3Material, the bottom of biofilter offers exhaust outlet and the drainpipe that is in communication with the outside.
Described constant temperature water bath system comprises water-bath chamber and the water bath with thermostatic control control cabinet that is wrapped in the biofilter lateral wall, offers the water-bath outlet pipe and the water-bath water inlet pipe that link to each other with the water bath with thermostatic control control cabinet on the water-bath chamber.
Described air distribution system comprises air blast, humidifier, stripping device and blender, the pipeline of leading up to of blower export end links to each other with the stripping device, another road of blower export end links to each other with humidifier by pipeline, the port of export of stripping device and humidifier all links to each other with blender, and the port of export of blender links to each other with the air inlet of biofilter upper end.
Described stripping device is arranged in a constant temperature water bath device.
Described nutrient solution dropping system comprises nutrient solution storage tank, nutrient solution supply pump, nutrient solution shower nozzle and timer, and the nutrient solution storage tank links to each other with the nutrient solution shower nozzle with pipeline by the nutrient solution supply pump, and the nutrient solution supply pump links to each other with timer.
Compared with prior art, advantage of the present invention just is: the present invention handles the biofiltration device of toluene gas, utilization is attached to the biofiltration device design science of the microbiological treatment toluene gas on the monoblock type filler, rational in infrastructure, the filler that is adopted has the percent opening height, good permeability, compression strength is high and have flexible forever characteristics, thereby has the following advantages:
1, nutrient solution is evenly distributed, and the gas distribution performance is good: for example adopt the monoblock type polyurethane sponge as filter packing, because the structure of itself, for the microbial growth breeding provides a good environment.Simultaneously, the perforate supporting screening plate of the reticulated cell gap structure of monoblock type polyurethane sponge and its bottom makes gas and nutrient solution distribute more to become evenly, and between packing layer, gas and nutrient solution can access uniform distribution once more;
2, full contact, the mass-transfer efficiency height: for example adopt polyurethane sponge as filter packing, gas, liquid, solid three contact more fully in the reticulated cell gap structure, and mass-transfer efficiency is higher;
3, the time of staying is short, the treatment effeciency height: the time of staying of toluene gas in filter is when being 2~60 seconds, remove efficient and can reach 80~99%, and the raising of clearance can directly be controlled by gas flow, inlet gas concentration, use simply the waste gas that very suitable treatment is large-minded, concentration is low;
4, easy to be filmed, start fast: microorganism tack on the polyurethane sponge filler is good, and aeration is good, is fit to growth of microorganism, and the biomembrane formation time is short, and system starts fast, and can reach the good treatment effect fast;
5, the cycle of operation is long, safeguard simple: because filler individual layer height is low and the reticulated cell gap structure of itself, can effectively control microorganism portion's undue growth within it, stop up, and the filler individual layer is an integral body, can clean or backwash by simple, can effectively control microbial biomass, so the cycle of operation is long, safeguards simple;
6, the packing layer effective depth is low, and the filler utilization is abundant: the interior overall effective depth of filler of filter is 30cm only, and divides three layers of setting, and the each several part filler all can be utilized effectively;
7, the monoblock type filling-material structure is even, and handling property is good: for example employed polyurethane sponge, be all-in-one-piece, and be different from dump packing in traditional biofilter, use all-in-one-piece filler in operations such as cleaning, replacing, just to seem convenient.And use all-in-one-piece polyurethane sponge, and in running, can avoid the compacting of filler, and make the filter overall performance more even, handling property is better;
8, cost is low, and is easy and simple to handle, compact conformation, and floor space is little
Description of drawings
Fig. 1 is a biofilter process flow diagram of the present invention;
Fig. 2 is a biofilter structural representation of the present invention;
Fig. 3 is the section structure schematic diagram of supporting screening plate of the present invention.
Marginal data
1, air blast 2, stripping device
3, humidifier 4, blender
5, biofilter 6, biofilter material layer
7, supporting screening plate 8, water-bath sleeve pipe
9, nutrient solution shower nozzle 10, drainpipe
11, exhaust outlet 12, nutrient solution supply pump
13, nutrient solution storage tank 14, constant temperature water bath device
15, flowmeter 16, valve
17, water-bath water inlet pipe 18, water-bath outlet pipe
19, S is sample tap 20, air inlet
21, timer 22, bain-marie
23, shell body 24, water-bath chamber
The specific embodiment
Below with reference to the drawings and specific embodiments the present invention is described in further details.
As Fig. 1, Fig. 2, shown in Figure 3, the present invention is a kind of biofiltration device of handling toluene gas, it comprises air distribution system, biofilter 5, nutrient solution drips system and constant temperature water bath system, the nutrient solution shower nozzle 9 of nutrient solution dropping system is positioned at the top of biofilter 5, the outlet of air distribution system links to each other by the air inlet 20 of pipeline with biofilter 5 upper ends, the constant temperature water bath system is positioned at biofilter 5 outsides, biofilter 5 comprises shell body 23, be provided with the biological filter material layer 6 of one or more layers of monoblock type in the shell body 23, biofilter material layer 6 is by supporting screening plate 7 supportings of every layer of bottom, supporting screening plate 7 is the poly (methyl methacrylate) plate of even perforate, and each interlayer has the interval of 5cm.Biofilter material layer 6 has the packing layer of microorganism for a kind of inoculation, what the filter medium of biofilter material layer 6 adopted is uniform monoblock type material, its porosity is 90%~98%, the aperture is 1~5mm, percent opening more than 95%, hot strength is 20~600kg/m greater than 5000Pa, compression strength greater than 1000Pa, bulk density
3, specific area is 100~1000m
2/ m
3Material.This material can be polyurethane mesh sponge or porous ceramics etc., and the microorganism that is inoculated in the filler provides for the residual active sludge of municipal sewage plant.The bottom of biofilter 5 offers exhaust outlet 11 and the drainpipe 10 that is in communication with the outside, purified gas is by 11 dischargings of biofilter 5 base bleed mouths, drainpipe 10 drains back to the liquid that flows out in the nutrient solution storage tank 13 of nutrient solution dropping system again, is equiped with the valve 16 of its keying of control on its pipeline.The constant temperature water bath system comprises water-bath chamber 24 and the water bath with thermostatic control control cabinet that is wrapped in biofilter 5 lateral walls, offers the water-bath outlet pipe 18 and the water-bath water inlet pipe 17 that link to each other with the water bath with thermostatic control control cabinet on the water-bath chamber 24.Air distribution system comprises air blast 1, humidifier 3, stripping device 2 and blender 4, the pipeline of leading up to of air blast 1 port of export links to each other with stripping device 2, another road of air blast 1 port of export links to each other with humidifier 3 by pipeline, the port of export of stripping device 2 and humidifier 3 all links to each other with blender 4, the port of export of blender 4 links to each other with the air inlet 20 of biofilter 5 upper ends, all is equiped with flowmeter 15 on each pipeline.The simulation toluene gas that air distribution system will produce is sent into and is carried out the biological cleaning processing in the biofilter 5, generates CO
2, H
2O and synthetic cell.Stripping device 2 is arranged in a constant temperature water bath device 14, to guarantee its temperature constant.Nutrient solution dropping system comprises nutrient solution storage tank 13, nutrient solution supply pump 12, nutrient solution shower nozzle 9 and timer 21, nutrient solution storage tank 13 links to each other with nutrient solution shower nozzle 9 with pipeline by nutrient solution supply pump 12, nutrient solution supply pump 12 links to each other with timer 21 and is controlled by timer 21, quantitatively intermittent entry.To biofilter material layer 6 spraying nutrient solution, make biofilter material layer 6 keep certain humidity by the nutrient solution shower nozzle 9 at biofilter 5 tops, and be that microorganism in the filter supplies with must nutriment.
Simultaneously referring to table 1 as can be known, compare with various filter methods of the prior art, advantage of the present invention is exactly: gas distribution is even, pressure drop is less, bed height is little, volumetric loading is high, treating capacity is big, construction and operating cost is lower, long-term operation performance is stablized.
Table 1
|
Traditional biological is filtered |
Bio-trickling |
The rotary drum biofiltration |
Biological filter media of the present invention |
Bed height (m) |
1~2 |
0.8~1.5 |
0.15~0.40 |
0.10~0.40 |
The initial voidage of bed |
20% |
50% |
>90% |
>90% |
Filler |
Compost, gravel etc. |
Compost, gravel and synthetic material etc. |
Polyurethane foam |
Poromerics |
Filler service life (year) |
1~4 |
2~6 |
>5 |
>5 |
Exhaust gas residence time (s) |
60~300 |
30~120 |
15~60 |
2~60 |
Volumetric loading (m
3/m
3/d)
|
1,000 |
5,000 |
10,000 |
20,000 |
Disposal ability |
Less |
Bigger |
Less |
Greatly |
The liquid and the consumption that replenish |
Water, less |
Nutrient solution, more |
Nutrient solution is many |
Nutrient solution, more |
The controllability of process |
Difficult |
Be easier to |
Easily |
Easily |
Operation stability |
Unstable |
More stable |
Stable |
Stable |
The scope of application |
Narrower |
Extensively |
Extensively |
Wider |
Remove efficient |
Generally |
Higher |
High |
Higher |
The device expenditure of construction |
Low |
Higher |
High |
Lower |
The plant area area |
Greatly |
Less |
Little |
Less |
The device operation and maintenance cost |
Low |
Generally |
Higher |
Lower |
Operation principle: the air-flow that air blast 1 produces is divided into two parts, a part enters stripping device 2 and produces toluene gas, another part mixes in blender 4 fully with the toluene gas that is produced behind humidifier 3, form the simulation toluene gas, its variable concentrations obtains by the required two parts gas flow of gas flowmeter 15 strict controls.The simulation toluene gas is entered by biofilter 5 top air inlets 20, the biological filter course 6 of the monoblock type of flowing through successively downwards, because the perforate supporting screening plate 7 of the reticulated cell gap structure of filter material layer 6 and its bottom makes the distribution on filtrate of gas and nutrient solution more become even, and between packing layer, gas and nutrient solution can access once more and distribute, the simulation toluene gas contacts with biofilter material 6, is attached after the microbial degradation on the filtrate 6, generates CO
2, H
2O and synthetic cell, purified gas is by 11 dischargings of biofilter 5 base bleed mouths.Be installed in the nutrient solution shower nozzle 9 at biofilter 5 tops, link to each other with supply pump 12 with nutrient solution storage tank 13 by pipeline, and by timer 21 control, to biofilter 5 intermittent entry nutrient solution at regular time and quantity, nutrient solution and simulation toluene gas co-flow from the top down in biofilter 5 are discharged by the drainpipe 10 of bottom.Whole system is by constant temperature water bath system held temperature constant.When biomass on the filler too much or system pressure drop when increasing, need simply clean or backwash to filler, with effective control microbial biomass, the normal stable operation of the system that keeps.
The present invention is not limited to above-mentioned giving an example, those skilled in the art, and in essential scope of the present invention, the variation of making, remodeling, interpolation or replacement all should belong to protection scope of the present invention.