Resource process for synchronously removing VOCs, sulfides and ammonia sulfur in waste gas by chemical coupling and biology
阅读说明：本技术 一种化学耦合生物同步去除废气中VOCs、硫化物和氨并硫资源化工艺 (Resource process for synchronously removing VOCs, sulfides and ammonia sulfur in waste gas by chemical coupling and biology ) 是由 王晓伟 张婷婷 于 2018-06-27 设计创作，主要内容包括：本发明公开了一种化学耦合生物同步去除废气中VOCs、硫化物和氨并硫资源化工艺,属于废气治理领域。首先将废气通入含有微碱性溶液的吸收塔中,吸收硫化氢、氨和部分可溶解性VOCs,排出经脱出大部分硫化氢、氨和部分可溶解性VOCs的气体,将吸收液通入微氧生物反应器中,利用硫氧化、氨氧化、硫自养反硝化,短程反硝化耦合工艺(硫氧化细菌、氨氧化细菌、反硝化细菌、硫自养反硝化细菌)将硫化氢和氨分别转化成单质硫和氮气；然后气体进入另一个生物反应器将气体中剩余的硫化氢、氨和VOCs去除。该工艺合理,去除污染物不受浓度限制,碱性吸收液可循环使用,不再添加碱液,不用添加碳源；不产生二次污染；利用硫氧化、氨氧化、硫自养反硝化,短程反硝化耦合工艺(硫氧化细菌、氨氧化细菌、反硝化细菌、硫自养反硝化细菌),可减少反硝化过程所需的电子供体,节约运行费用；同时将污染转化为可利用的单质硫资源化回收,实现了废弃物资源化,是一种理想的同步去除废气中VOCs、硫化物和氨工艺。(The invention discloses a resource process for synchronously removing VOCs, sulfides and ammonia sulfur in waste gas by chemical coupling and biology, belonging to the field of waste gas treatment. Firstly, introducing waste gas into an absorption tower containing a slightly alkaline solution, absorbing hydrogen sulfide, ammonia and partially soluble VOCs, discharging gas from which most of the hydrogen sulfide, the ammonia and the partially soluble VOCs are removed, introducing an absorption liquid into a micro-aerobic bioreactor, and converting the hydrogen sulfide and the ammonia into elemental sulfur and nitrogen respectively by using sulfur oxidation, ammonia oxidation, sulfur autotrophic denitrification and short-range denitrification coupling processes (sulfur oxidizing bacteria, ammonia oxidizing bacteria, denitrifying bacteria and sulfur autotrophic denitrification bacteria); the gas then enters another bioreactor to remove the remaining hydrogen sulfide, ammonia and VOCs from the gas. The process is reasonable, the removal of pollutants is not limited by concentration, the alkaline absorption solution can be recycled, alkali liquor is not added, and a carbon source is not added; no secondary pollution is generated; by utilizing a sulfur oxidation, ammonia oxidation, sulfur autotrophic denitrification and short-range denitrification coupling process (sulfur oxidizing bacteria, ammonia oxidizing bacteria, denitrifying bacteria and sulfur autotrophic denitrifying bacteria), the electron donor required in the denitrification process can be reduced, and the operation cost is saved; meanwhile, the pollution is converted into available elemental sulfur resource recovery, the waste resource is realized, and the process is an ideal process for synchronously removing VOCs, sulfides and ammonia in the waste gas.)
1. A chemical coupling biological synchronous removing VOCs, sulfide and ammonia sulfur resource technology in waste gas is characterized by comprising the following steps:
(1) absorbing hydrogen sulfide, ammonia and partially soluble VOCs in the waste gas by using an absorption tower, and absorbing the hydrogen sulfide, the ammonia and the partially soluble VOCs in the waste gas by using an absorption liquid containing a slightly alkaline solution in the absorption tower to generate Na2S，(NH4)2S、NH3·H2O and organic matters, etc.;
(2) absorbing Na contained in the absorbing tower2S，(NH4)2S、NH3·H2Pumping the absorbing liquid of O and organic matter into a microbial oxygen bioreactor, and pumping the sulfide (S) by the combined action of sulfur oxidizing bacteria, ammonia oxidizing bacteria, denitrifying bacteria and sulfur autotrophic denitrifying bacteria2-) Is oxidized to elemental sulfur (S)0) Meanwhile, organic matters and ammonia are converted into carbon dioxide and nitrogen to be discharged, and the generated carbonate and organic matters are absorbed to provide a carbon source for the growth of microorganisms;
(3) the gas absorbed by the spray tower enters a biological filter reactor, residual hydrogen sulfide, ammonia and VOCs in the waste gas are adsorbed by using a filler containing functional microorganisms in the biological filter, and pollutants are adsorbed and dissolved in a liquid-phase aqueous solution; the pollutants adsorbed and dissolved in the liquid phase further diffuse to the biological membrane and are captured and absorbed by the microorganisms therein; the pollutants entering the microbial cells are utilized by the microbes as nutrient substances to be oxidized and decomposed into CO2、H2Harmless products such as O, mineral substances and the like remove hydrogen sulfide, ammonia and VOCs;
(4) treating the mixed liquid containing elemental sulfur generated by the bioreactor by a sulfur recovery system to obtain sulfur with higher content for recycling, and returning the alkaline solution generated after sulfur separation to the absorption tower for recycling;
the pH value of the micro-aerobic activated sludge reactor is controlled to be 5.5-10.5, and the temperature is controlled to be 25-45oC, the retention time is controlled to be 2-45 h, the dissolved oxygen is controlled to be 0.05-0.5 mg/L, and C: N: P =200:5: 1; the pH value in the biological filter reactor is controlled to be 5.5-10.5, and the temperature is controlled to be 15-65oC, the retention time is controlled to be 0.5-4.5 s, and C: N: P =200:5: 1.
2. The resource process for synchronously removing VOCs, sulfides and amino-sulfur in waste gas by chemical coupling and biological process as claimed in claim 1, wherein the alkaline absorption liquid utilized in the absorption tower is preferably a mixture of water-soluble alkalis and salts to form a buffer solution, mainly alkalis or salts of group IA or IIA elements, preferably NaOH, CaOH, KOH, NaHCO3、Na2CO3At least one of which is mixed with the alkaline solution produced by the sulfur recovery system.
3. The resource process for synchronously removing VOCs, sulfides, ammonia and sulfur in waste gas by chemical coupling and biology according to claim 1 or 2, characterized in that the sulfur recovery system comprises a sedimentation tank, a sulfur sludge drying system and a sulfur sludge purification system.
4. The resource process for synchronously removing VOCs, sulfides, ammonia and sulfur in waste gas by chemical coupling and biology according to claim 2, characterized in that the absorption tower can adopt a multilayer packed tower or a spray tower; the bioreactor adopts micro-aerobic condition and adopts an activated sludge reactor; the biological filter reactor filler is a mixture of pine bark, peanut shells, withered leaves, sawdust and volcanic rocks; the sulfur recovery system comprises a sedimentation tank and a solid-liquid separation device.
5. The resource process for synchronously removing VOCs, sulfides, ammonia and sulfur in waste gas by chemical coupling and biology according to claims 1, 2 and 4, characterized in that carbon sources used by microorganisms in the micro-aerobic bioreactor are carbonate generated by carbon dioxide absorption in biogas and organic substances generated by soluble VOCs, nitrogen sources are ammonia salts generated by ammonia absorption, and phosphorus sources are dihydrogen phosphate or dihydrogen phosphate; the carbon source used by the microorganism in the biological filter reactor is VOCs in the biogas to generate organic matters, the nitrogen source is ammonia to absorb ammonia to generate ammonia salt, and the phosphorus source is dihydric phosphate or dibasic phosphate.
Technical Field
The invention belongs to the technical field of waste gas treatment, and relates to a recycling process for synchronously removing VOCs, sulfides and ammonia sulfur in waste gas by chemical coupling and biology.
Background
The pollution problems of VOCs and malodorous gas are increasingly prominent and become one of the main sources of PM2.5, the direct emission of waste gas harms the health of human bodies, serious environmental pollution is generated, the ecological balance is damaged, and the prevention and control of VOCs are not slow. VOCs and malodorous substances originate from the aspects of life and industrial production, and mainly contain sulfur-containing compounds (sulfides, thioethers, thiols, etc.), (ammonia gas, amines, indoles, etc.), oxygen-containing organic substances (organic acids, alcohols, ketones, acids, esters, etc.), hydrocarbon compounds (aromatic hydrocarbons, alkanes, alkenes, etc.), halogens and their derivatives (hydrogen halides, chlorine gas, etc.).
The common treatment methods include adsorption, absorption, combustion, condensation, biological, and membrane separation. The biological method has the advantages of low operation cost, convenient maintenance and management, no secondary pollution and the like, and becomes an environment-friendly and clean method for treating malodorous pollutants in the future. The biological method is mainly divided into a biological filtration method, a biological washing method and a biological trickling filtration method. Biofiltration is a gas pollution control technology that is effective in treating malodorous and volatile organic waste gases, and has been widely used for over 40 years in the united states and europe, mainly for treating malodorous gases generated from municipal sewage treatment facilities, oil refineries, composting facilities, and other malodorous-generating processes. The biological filter tower is a device form of the technology, soil, peat or other fillers are filled in the device, and gas containing biodegradable volatile organic compounds and other toxic or malodorous substances passes through the fillers and is degraded by microorganisms in the fillers. When the method is used independently, the humidity is not easy to control in the operation process, the filler layer is easy to compact and block, the filter material needs to be replaced or regenerated frequently, and the automatic control capability is poor; and because of the accumulation of the oxidation product sulfate, the growth activity of the nitrifying bacteria is influenced, thereby influencing the removal of ammonia; when vulcanizedHydrogen (H)2S) and ammonia (NH)3) When the mixture simultaneously enters the biological filter tower, the mixture is oxidized into SO by sulfur oxidizing bacteria4 2-And NH is3Is coated with SO4 2-Neutralization is (NH)4)2SO4Due to (NH)4)2SO4The accumulated matters can inhibit the activity of microorganisms and influence the removal of pollutants.
Therefore, the development of an economic and environment-friendly technology for synchronously removing VOCs, sulfides and ammonia in the waste gas is particularly urgent. As a new method for synchronously removing VOCs, sulfides and ammonia in waste gas, a chemical coupling biological synchronous VOCs, sulfides and ammonia in waste gas and sulfur recycling technology is gradually paid attention to by the advantages of simple equipment, easy control, convenient maintenance, low construction cost, no waste discharge in the purification process, no secondary pollution and the like.
The invention discloses a process system and a method patent (CN 200810064858.9) for synchronously removing carbon, nitrogen and sulfur in wastewater, which are invented by Wang Aijie, the Harbin industry university, and the like, organic matters, sulfate and ammonia nitrogen in the wastewater are respectively converted into carbon dioxide, elemental sulfur and nitrogen, and H generated by metabolism in gas phase is converted into H2S and NH3The sulfur is converted into elemental sulfur and nitrogen, but the high-concentration sulfide has certain toxic effect on microorganisms in an anaerobic environment, so that the overall operation efficiency of the denitrification desulfurization technology is reduced; the toxicity inhibition caused by high sulfide concentration is difficult to ensure the high-load operation of the denitrification desulfurization process.
Robertson and Kuenen (Archives of Microbiology, 1984, 139(4): 351- & 354. Applied and Environmental Microbiology, 1988, 54(11): 2812- & 2818.) in the laboratory, the denitrification phenomenon occurred in the presence of oxygen was observed, and aerobic denitrifying bacteria were first separated from the effluent of the denitrification and desulfurization systemThiosphaera pantotropha、Pseudmonas sp.AndAlcaligenesfaecalisand the like. Other common aerobic denitrifying bacteriaPseudomonas nautical、ThaueraMechernichensis， Alcaligenes sp.、MicrovirgulaaerodenitrificansAnd the like. Some aerobic denitrifying bacteria are heterotrophic nitrifying bacteriaThus, the ammonia can be directly converted into nitrogen and finally the gaseous product can escape, and the simultaneous completion of the nitrification and denitrification in the same reactor is possible.
An energy-saving method for biological desulfurization of marsh gas (CN 201010591471.6) invented by Hanhongjun, Haerbin Industrial university, comprises adding thiobacillus denitrificans and nitrobacteria during biological desulfurization, and metabolizing in gas phase to generate H2S and NH3The sulfur and nitrogen are converted, the thiobacillus denitrificans and the nitrobacteria are a symbiotic system, air (oxygen) is not required to be added in the reaction, and the microorganisms in the system can be completely self-sufficient by utilizing the oxygen and the ammonia in the methane, so that the operation cost is saved.
An integrated biological deodorization treatment device and a treatment process patent (CN 201710547678.5) invented by forest Mesemet et al in 2017 adopt integrated high coupling of biological aeration washing and filtering functions, organically combine various processes into a whole after optimizing and improving the processes of biological aeration, biological washing, biological filtering and the like, a biological washing system and a liquid aeration tank system can effectively reduce the decomposition burden of a biological filtering system, when the concentrations of sulfide, ammonia and VOCs are 253.33 mg/L, 145.46 mg/L and 68.96 mg/L, the removal rates respectively reach 99.94%, 100% and 96.3%, but most of sulfide is converted into sulfate, and further treatment is needed subsequently.
An internal circulation biological fluidized bed system patent (CN 201710036398.8) applied in 2017 by Matjinying et al for treating malodorous gas proposes that VOCs and malodorous gas are removed through microbial mass transfer and degradation processes in a reactor; in addition, the removal of VOCs by biological desulfurization and deamination is mentioned in Chinese patent application Nos. CN201611055479.4, CN201610738690.X, CN201610154267.5 and CNCN 201610392966.3.
The invention adopts the chemical biological coupling to remove VOCs, hydrogen sulfide and ammonia synchronously, firstly, the waste gas is led into an absorption tower containing slightly alkaline solution to absorb hydrogen sulfide, ammonia and partial soluble VOCs, the gas from which most of hydrogen sulfide, ammonia and partial soluble VOCs are removed is discharged, the absorption liquid is led into a micro-aerobic bioreactor, and the hydrogen sulfide and ammonia are respectively converted into elemental sulfur and nitrogen by sulfur oxidation, ammonia oxidation, sulfur autotrophic denitrification and short-range denitrification coupling process (sulfur oxidizing bacteria, ammonia oxidizing bacteria, denitrifying bacteria and sulfur autotrophic denitrification bacteria); the gas then enters another bioreactor to remove the remaining hydrogen sulfide, ammonia and VOCs from the gas.
（3）
The method adopts the chemical biological coupling method, and has the advantages that the pollutant removal is not limited by concentration, the alkaline absorption liquid can be recycled, alkali liquor is not added, and a carbon source is not added; no secondary pollution is generated; by utilizing a sulfur oxidation, ammonia oxidation, sulfur autotrophic denitrification and short-range denitrification coupling process (sulfur oxidizing bacteria, ammonia oxidizing bacteria, denitrifying bacteria and sulfur autotrophic denitrifying bacteria), the electron donor required in the denitrification process can be reduced, and the operation cost is saved; meanwhile, the pollution is converted into available elemental sulfur resource recovery, and the waste resource is realized.
Disclosure of Invention
The invention adopts the chemical biological coupling method and has the advantages that: the removal of pollutants is not limited by concentration, the alkaline absorption liquid can be recycled, alkali liquor is not added, and a carbon source is not added; no secondary pollution is generated; by utilizing the sulfur autotrophic denitrification and short-cut nitrification denitrification processes, the electron donor required in the denitrification process can be reduced, and the operation cost is saved; and simultaneously converting the pollution into elemental sulfur resource recovery.
The technical scheme of the invention is as follows:
(1) absorbing hydrogen sulfide, ammonia and partially soluble VOCs in the waste gas by using an absorption tower, and absorbing the hydrogen sulfide, the ammonia and the partially soluble VOCs in the waste gas by using an absorption liquid containing a slightly alkaline solution in the absorption tower to generate Na2S，(NH4)2S、NH3·H2O and organic matters, etc.;
(2) absorbing Na contained in the absorbing tower2S，(NH4)2S、NH3·H2Pumping the absorbing liquid of O and organic matter into a microbial oxygen bioreactor, and pumping the sulfide (S) by the combined action of sulfur oxidizing bacteria, ammonia oxidizing bacteria, denitrifying bacteria and sulfur autotrophic denitrifying bacteria2-) Is oxidized to elemental sulfur (S)0) Meanwhile, organic matters and ammonia are converted into carbon dioxide and nitrogen to be discharged, and the generated carbonate and organic matters are absorbed to provide a carbon source for the growth of microorganisms;
(3) the gas absorbed by the spray tower enters a biological filter reactor, residual hydrogen sulfide, ammonia and VOCs in the waste gas are adsorbed by using a filler containing functional microorganisms in the biological filter, and pollutants are adsorbed and dissolved in a liquid-phase aqueous solution; the pollutants adsorbed and dissolved in the liquid phase further diffuse to the biological membrane and are captured and absorbed by the microorganisms therein; the pollutants entering the microbial cells are utilized by the microbes as nutrient substances to be oxidized and decomposed into CO2、H2Harmless products such as O, mineral substances and the like remove hydrogen sulfide, ammonia and VOCs;
(4) the mixed liquid containing the elemental sulfur generated by the bioreactor is treated by a sulfur recovery system to obtain sulfur with higher content for recycling, and the alkaline solution generated after the sulfur is separated is returned to the absorption tower for recycling.
A chemical coupling biological synchronous removing VOCs, sulfide and ammonia sulfur resource technology is characterized in that the technology comprises a chemical coupling biological synchronous removing step, a chemical coupling biological synchronous removing step and a chemical coupling biological synchronous removing step.
(1) The desulfurization and deammoniation absorption tower can adopt a multi-layer packed tower or a spray tower; the bioreactor adopts micro-aerobic condition and adopts an activated sludge reactor; the biological filter reactor filler is a mixture of pine bark, peanut shells, withered leaves, sawdust and volcanic rocks; the sulfur recovery system comprises a sedimentation tank and a solid-liquid separation device. The alkali liquor of the absorption liquid in the absorption process of the invention is preferably a mixture of water-soluble alkalis and salts to form a buffer solution, mainly alkalis or salts of group IA or IIA elements, preferably NaOH, CaOH, KOH, NaHCO3、Na2CO3At least one of which is mixed with the alkaline solution produced by the sulfur recovery system.
(2) The pH value of the micro-aerobic activated sludge reactor is controlled to be 5.5-10.5, and the temperature is controlled to be 25-45oC, the retention time is controlled to be 2-45 h, the dissolved oxygen is controlled to be 0.05-0.5 mg/L, and C: N: P =200:5: 1. The carbon source used by the microorganism in the micro-aerobic bioreactor is carbonate generated by carbon dioxide absorption in biogas and soluble VOCs (volatile organic chemicals) generated organic matters, the nitrogen source is ammonia salt generated by ammonia absorption, and the phosphorus source is dihydrogen phosphate or dihydrogen phosphate.
(3) The pH value in the biological filter reactor is controlled to be 5.5-10.5, and the temperature is controlled to be 15-65oC, the retention time is controlled to be 0.5-4.5 s, and C: N: P =200:5: 1. The carbon source used by the microorganism in the biological filter reactor is VOCs in the biogas to generate organic matters, the nitrogen source is ammonia to absorb ammonia to generate ammonia salt, and the phosphorus source is dihydric phosphate or dibasic phosphate.
(4) The microorganisms in the micro-aerobic bioreactor remove ammonia through the processes of nitrification, denitrification, short-cut nitrification and denitrification and sulfur autotrophic denitrification, and the generated nitrogen is discharged into the air without pollution, so that the organic carbon source is reduced, and the cost is reduced.
(5) The microorganisms in the micro-aerobic bioreactor remove hydrogen sulfide through sulfur oxidation and sulfur autotrophic denitrification processes to generate available elemental sulfur resource recovery and recycle wastes.
(6) The microorganisms in the biofilter reactor disclosed by the invention remove VOCs, hydrogen sulfide and ammonia through the combined action process of sulfur oxidizing bacteria, ammonia oxidizing bacteria, denitrifying bacteria and sulfur autotrophic denitrifying bacteria to generate harmless carbon dioxide, water and mineral substances.
(7) The sulfur recovery system comprises a sedimentation tank, a sulfur sludge drying system and a sulfur sludge purification system.
The invention has the advantages that:
(1) the method combines a chemical method and a biological method together, can synchronously remove VOCs, hydrogen sulfide and ammonia in waste gas, and is characterized in that on the basis of the microbial desulfurization, sulfide and ammonia are respectively converted into elemental sulfur and N by utilizing the combined action of sulfur oxidizing bacteria, ammonia oxidizing bacteria, denitrifying bacteria and sulfur autotrophic denitrifying bacteria in a microbial reactor2(ii) a Then removing the residual hydrogen sulfide, ammonia and VOCs by using an aeration biological filter, and realizing sulfur resource recovery in the process of realizing synchronous waste gas desulfurization and denitrification;
(2) the method has the advantages of reasonable process, low energy consumption, low investment and operation cost and no secondary pollution.
Drawings
The attached figure is a recycling process flow chart of synchronously removing VOCs, sulfide and ammonia in waste gas by chemical coupling and biology. In the figure: 1, an exhaust gas inlet; 2, a booster fan; 3, an absorption tower; 4, an absorption liquid circulating pump; 5, a bioreactor; 6, stirring an oxygenation device; 7, a nitrogen outlet; 8, a solid waste separation device; 9 a sulfur recovery system; 10 an exhaust gas outlet; 11 a micro-alkali solution preparation system; 12 micro-alkali liquor feeding pumps, 13 biological filter tanks, 14 temperature and pH controllers, 15 purified gas discharge ports, 16 spray water tanks, 17 spray pumps and 18 waste gas pressure controllers.
Detailed Description
The following detailed description of the present invention will be made in conjunction with the accompanying drawings and the technical solutions, but the present invention is not limited to the following examples.
Waste gas is sent to the lower part of an absorption tower 3 from a waste gas inlet 1 through a booster fan 2 arranged in the process, absorption liquid is slightly alkaline solution, the waste gas in the absorption tower is in countercurrent contact with the absorption liquid which is sent to the upper part of the absorption tower from an absorption liquid circulating pump 4, hydrogen sulfide, ammonia and soluble VOCs in the waste gas are absorbed by alkali liquor to generate sulfide, ammonia salt and organic matters, the waste gas enters a
The absorption liquid in the absorption tower flows into a bioreactor 5 by gravity, and the sulfide and the ammonia are respectively converted into elemental sulfur and N by the combined action of sulfur oxidizing bacteria, ammonia oxidizing bacteria, denitrifying bacteria and sulfur autotrophic denitrifying bacteria in a micro-aerobic reactor2(7 discharging), and maintaining the dissolved oxygen concentration in the bioreactor in a certain range by stirring the system.
The mixed liquor after aerobic microbe conversion treatment enters a
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