The waste water that Yeast Nucleic Acid production emits has the COD(chemical oxygen demand (COD)) high, SS(suspended solid) value greatly, characteristics such as the pH value is on the low side, viscosity is big, and contain ammonia nitrogen in high density, phosphoric acid salt and refractory organic, and refractory organic is to constitute the extremely unmanageable essential reason of Yeast Nucleic Acid waste water based on caramel.Caramel is a kind of gelatinoid, is made up of the macromolecular compound of volatility and nonvolatile low molecular compound and non-dialysis.The colour generation thing of caramel namely is the latter, accounts for 25% of total solid, and the essentially consist of caramel smell namely is aldehyde, the ketone volatile matter in the above-mentioned low molecular compound.
Because Yeast Nucleic Acid manufacturer is less, factory effluent water quality also has more differently with raw materials for production are different with technology, and its concentration for the treatment of is very big, and therefore Processing Technology Research and the engineering practice of Yeast Nucleic Acid waste water quite lack at present.Some limited documents show, adopt the diluted Yeast Nucleic Acid waste water of UASB art breading that COD clearance is preferably arranged, but this studies and be laboratory scale, and water inlet is diluted to COD and is about 3500mg/L.Other has employing coagulating sedimentation-ClO 2 catalyzed oxidation-two stage biological catalytic oxidation combination process to handle nucleic acid waste water, wherein at first by coagulating sedimentation COD is down to 9080 mg/L from 16509mg/L, by ClO 2 catalyzed oxidation COD is down to 537mg/L from 9080 mg/L again, though technical have its feasibility, but in its processing cost only medicament expense namely be difficult to substantially bear, and invest high.The treatment process of research at present and practice is handled the technology of (coagulating sedimentation+advanced oxidation) combination with biochemical treatment (anaerobism+aerobic) and materialization generally, but these technologies are still immature, or exists and invest and problem such as working cost is high.
Nucleic acid waste water complicated component contains pollutents such as polymer caramel in the waste water, waste strength height, CODcr contain amount high in salt and reach 2% up to 16000mg/l in the waste water, and contains the SO that suppresses the biochemical treatment effect
4 2-Ion; Organism, suspended substance, solvability and colloidality solids concn height, biodegradability is poor, and waste water has obvious color and smell, contains the material of difficult degradation and the microbiotic of bacteriostatic action is arranged, and bio-toxicity is arranged, and is more difficult.
At present, be difficult to maybe the polymer organic pollutant that should not handle with biochemical process at this class, some materilization freatment methods have appearred both at home and abroad, as chemical flocculation precipitation method and electrochemical oxidation, ozone oxidation and Fenton oxidation style, catalytic wet oxidation method even depth oxidation technology, but imperfect and ripe as yet, and cost is higher.Developed country generally adopts this type of expensive high-level oxidation technology thoroughly to handle this class waste water, but in developing country, because this type of wastewater flow rate that produces is huge, can't not stint expensive high cost with its thorough processing as developed country.
The domestic company that mainly is engaged in the nucleic acid sewage treatment equipment has:
Blue or green environmental protection company is known in Fujian, adopts acidication+SBR treatment process, and after the biochemistry debugging, CODcr reaches 5000mg/l, can't reach emission standard, and discharging contains H behind the acidication
2The pollutent of S gas.Foochow green bright environmental protection company adopts anaerobic reactor and IC anaerobic reactor, and its effect does not all reach desired design, and CODcr reaches 12000mg/l.
Nanjing film company adopts membrane treatment process, and CODcr reaches below the 1000mg/l, but the dense water after film is handled reaches 30%, and dense water concentration reaches three times of former water, can't propose concentrated water treatment method.
Nucleic acid wastewater biochemical process is subjected to SO
4 2-, polymer caramel and high salt ion interference, cause the biochemical time long, in biological process, produce H
2S foul gas and the requirement that can't reach qualified discharge.Whether the technological development bottleneck is can to develop does not a kind ofly have that secondary pollution, working cost are low, stably reaching standard can make biochemical system start fast treatment process again.
Summary of the invention
The object of the present invention is to provide a kind of nucleic acid method of wastewater treatment, pollute to administer, reclaim precious resources, realize resource circulation utilization.
In order to achieve the above object, technical scheme of the present invention is:
A kind of nucleic acid method of wastewater treatment the steps include:
The first step will be sent into equalizing tank from the nucleic acid waste water in production workshop and all measure homogenizing with the balanced water yield and water concentration;
Second step, be promoted to two-phase anaerobic reactor by pump after all measuring homogenizing, make macromolecule organic and particulate matter fully be hydrolyzed to small organic molecule through hydrolysis acidification pool, multiparity methane pond reduces the concentration of pollutent again, collect and utilize or handle methane, water outlet flows into activated sludge tank;
The 3rd step by aerobic microbiological effect most of organism of degrading, and made ammonia nitrogen be oxidized to nitrite and nitrate at activated sludge tank, was back to hydrolysis acidification pool, is reduced into nitrogen and discharges in anaerobic environment, and the activated sludge tank water outlet flows into second pond;
The 4th step, carry out mud-water separation at second pond, bottom mud part returnedactivatedsludge pond and two-phase anaerobic reactor are to replenish biomass, and excess sludge enters sludge sump, and the second pond supernatant liquor enters the chemical dephosphorization settling tank;
The 5th step added molysite, calcium salt and coagulating agent and coagulant aids at the chemical dephosphorization settling tank, and after solid-liquid separation, supernatant liquor flows into water collecting basin, and bottom mud enters sludge sump;
In the 6th step, waste water is promoted to the multi-medium filtering pond by pump again in the water collecting basin;
In the 7th step, the water outlet in multi-medium filtering pond enters nanofiltration system after by the high-pressure pump supercharging;
In the 8th step, nanofiltration system is filtered, final outflow water qualified discharge, the further concentration extraction caramel product of membrane concentration liquid.
Wherein, after the mud of the excess sludge of the 4th step second pond and the 5th step chemical dephosphorization settling tank drains into sludge sump, dewater to the machine room that dewaters through sludge thickener, dewatered sludge is sent processing (as deliver to refuse landfill and carry out the landfill disposal), the utilization of resources of pressing filtering liquid backflow equalizing tank outside again.
In second step, two-phase anaerobic reactor is selected the anaerobic baffle plate reaction tank for use.
After adopting such scheme, the present invention had both considered the technical feasibility of wastewater treatment, take into account the economic rationality of processing cost again, optimum combination each efficient treatment technology, adopt the treatment process of " anaerobic-aerobic-membrane filtration ", and the reactor of selecting for use respectively efficiently at each processing unit, being suitable for is handled; With principal pollutant COD in the nucleic acid waste water, BOD, TP and ammonia nitrogen are effectively removed, non-secondary pollution; Reactor is efficiently integrated, and floor space is little; (F/M) is low for sludge loading, and surplus sludge volume is little; The journey investment economizes; Working cost is little; Can reclaim caramel product; Realize administering and pollute, reclaim precious resources and resource circulation utilization.
As shown in Figure 1, be preferred embodiment of the present invention.
The first step will be sent into equalizing tank 1 through collection tube from the nucleic acid waste water in production workshop and all measure homogenizing, with the balanced water yield and water concentration.
In second step, the nucleic acid waste water of all measuring after the homogenizing is promoted to two-phase anaerobic reactor 2 by pump (common device, not shown).Two-phase anaerobic reactor 2 is selected the anaerobic baffle plate reaction tank for use.
Anaerobic baffle plate reaction tank (ABR) is that the beginning of the eighties is by a kind of new high-efficiency anaerobic reactor of people such as the McCarty proposition of U.S. Stanford university.Some vertical flow deflectors are set in the reactor, reactor is separated into the several reaction of series connection, each reaction chamber can be regarded a relatively independent UASB as, therefore in the textural series connection that can be regarded as a plurality of UASB.ABR on the fluidised form between plug-flow and fully between the mixing pattern, hydraulic performance in the single compartment is similar to hybrid fully, then be similar to pulling flow type on the whole, this fluidised form is conducive to fully contacting between waste water and the anaerobic sludge, accelerate the transmission of matrix from waste water to microorganism cells, improve the capacity utilization of reactor.The construction features of ABR uniqueness and fluidised form make can inoculate and culture out in each compartment with this compartment in sewage quality, the microflora that envrionment conditions adapts, thereby cause anaerobic reaction to produce acid mutually and the product methane journey of handing down is separated, make ABR be equivalent to a diphasic anaerobic treatment system at overall performance.ABR compares with other anaerobic reactors has following characteristics: 1. than short hydraulic detention time; 2. the mud interception capacity is strong, and the granule sludge settling property that forms in the reactor is good, can long-play and need not spoil disposal; 3. can in wider temperature and concentration range, move; 4. the structural property of pulling flow type makes system have very high stability to waterpower and organic impact load; 5. toxic substance and inhibitory substance had better buffering adaptive faculty; 6. hydraulics is good, the capacity utilization height, and system has more excellent effluent quality.
Two-phase anaerobic reactor is a kind of novel anaerobic biological treatment technology, Ghosh in 1971 and Pohland propose two-phase fermentation concept first, namely form the diphasic anaerobic fermentation system producing acid and producing two stage of methane separate reactors at optimal environmental condition separately and with two reactors in series.Its characteristics: 1. produce acid and produce two stages of methane independently, improve speed of reaction separately; 2. acidification reactor has certain shock absorption, alleviates impact load to the influence of follow-up methane-producing reactor; 3. the acidification reactor reaction process is fast, and hydraulic detention time is short, and COD concentration can be removed 20%-25%, can alleviate the load of methane-producing reactor greatly; 4. load is high, and reactor volume is little, and capital cost is low.
Because it is acid that waste water is, and contain a large amount of macromolecule organics and particulate matter, therefore adopts two-phase anaerobic reactor, and acid-producing microorganisms and methanogen are being played one's part to the full under the adapt circumstance condition respectively separately.Through hydrolysis acidification pool 21, make macromolecule organic and particulate matter fully be hydrolyzed to small organic molecule, multiparity methane pond 22 anaerobic digestion generation methane reduces Pollutant levels greatly again, collects and utilizes or handle methane, and water outlet flows into activated sludge tank 5.
The 3rd step, at activated sludge tank 3 by highly active aerobic microbiological effect, most of organism of degrading, and make ammonia nitrogen be oxidized to nitrite and nitrate, be back to hydrolysis acidification pool 21, be reduced into nitrogen and discharge (nitrogen that the reduction back produces can uncontrollable discharge and do not have pipeline) in anaerobic environment, reach the purpose of denitrification denitrogenation, activated sludge tank 3 water outlets flow into second pond 4.
Activated sludge tank 3 is to adopt activated sludge process to handle, and activated sludge process is the main method based on the biological wastewater treatment of active sludge.Activated sludge process is bubbling air continuously in the waste water, the sludge-like throw out that forms because of the aerobic microbial reproduction behind certain hour.Perch the micropopulation based on zoogloea on it, having very strong absorption and the ability of oxidation of organic compounds.Utilize biological flocculation and precipitation, absorption and the oxygenizement of active sludge, to decompose the organic pollutant of removing in the sewage, remove ammonia nitrogen by effects such as biological nitrations simultaneously.Make mud and water sepn then, most of mud is back to the aeration tank again, and redundance is then discharged Sludge System.
The 4th step, carry out mud-water separation at second pond 4, bottom mud part returnedactivatedsludge pond 3 and two-phase anaerobic reactor 2 are to replenish each reactor organisms amount, and excess sludge enters sludge sump 5, and second pond 4 supernatant liquors enter chemical dephosphorization settling tank 6.
The 5th step added molysite, calcium salt and coagulating agent and coagulant aids at chemical dephosphorization settling tank 6, and after solid-liquid separation, supernatant liquor flows into water collecting basin 7, and bottom mud enters sludge sump 5.
Chemical dephosphorization is finished by the chemical precipitation process, chemical precipitation refers to by adding the inorganic metal salt medicament in sewage, and deliquescent salt in itself and the sewage is after mixing as phosphoric acid salt, form the material of particulate state, non-solubility, what this process related to is so-called phase transition behavior.In fact after adding chemical agent, what carry out in the sewage is not only precipitin reaction, is also carrying out the chemical flocculation reaction simultaneously.The settlement of sewage reaction refers to the material of dissolved form in the water, major part is the process that ion shape material is converted to non-dissolving, Granular forms, flocculation then is the process of the big shape of solids one-tenth adhered to one another of tiny non-dissolved form, so flocculation is not phase transition behavior.
In process for purifying waste water, flocculation and precipitation all are very important, but flocculation is be used to the sedimentation effect that improves settling tank, and precipitation then is used for the removal of sewage dissolved phosphorus.If utilize depositing technology to realize the conversion of phase, then when added deliquescent metal-salt medicament in sewage after, deliquescent phosphorus is converted into the phosphate metal salt of non-solubility on the one hand, also can produce the oxyhydroxide (depending on the pH value) of non-solubility simultaneously.On the other hand, analyse increase and the less non-solubility solids of thing along with precipitation and build up into bigger non-solubility solids, make stable elimination of colloid stability, make by velocity slope or diffusion process and take off steady colloid and contact with each other the generation flocs unit.At last by solid-liquid separating step, the sewage that is purified and a solid liquid enriched material (chemical sludge) reach the purpose of chemical dephosphorization.
According to the basis of chemical precipitation reaction, in order to generate phosphate compounds, the chemical agent that is used for chemical dephosphorization mainly is metal-salt medicament and calcium hydroxide (white lime).After many high volence metal ion medicaments are added in the sewage, all can with sewage in the dissolved phosphorus ionic bond generate difficult deliquescent compound.For economic reasons, the metal-salt medicament for the phosphorus precipitating mainly is Fe
2+Salt and lime.These medicaments use with solution and suspension state.Divalent iron salt only contains aerobic in sewage, could use in the time of being oxidized to trivalent iron salt.The reaction of competing with the precipitating reacting phase is metal ion and OH
-Reaction, so it should be noted the ionic weight of metal for various metal-salt product.Metal hydroxides can form the flocs unit of bulk, and this flocculation for precipitated product is favourable, also can adsorb the material of colloidal, trickle suspended particle simultaneously.It should be noted that organism is less important being that precipitation in the reaction of purpose chemistry precipitating removes with the chemical dephosphorization, but organic property colloid and condensing in the flocs unit of suspended substance then are conclusive processes when separating.
The precipitating effect is influenced by the pH value, and the solvability of metal phosphate equally also is subjected to the influence of pH.Being 5.0～5.5 for molysite optimal ph scope, is 6.0～7.0 for aluminium salt because in above pH value scope FePO
4The solvability minimum.Except the metal-salt medicament, calcium hydroxide is also as the precipitating medicament.In heavy folding process, that play a major role for the formation of the calcium phosphate of insoluble is not Ca
2+, but OH
-Ion, because along with the raising of pH value, the solvability of calcium phosphate reduces, and adopts Ca (OH)
2The pH value that dephosphorization requires is more than 8.5.
In the 6th step, waste water is promoted to multi-medium filtering pond 8 by pump (common device, not shown) again in the water collecting basin 7;
In the 7th step, the water outlet in multi-medium filtering pond 8 enters nanofiltration system 9 after by high-pressure pump (common device, not shown) supercharging;
In the 8th step, nanofiltration system 9 is filtered the final outflow water cities and towns water drain that enters up to standard, the further concentration extraction caramel product of membrane concentration liquid.
Nanofiltration membrane is a kind of novel separatory membrane that comes out the latter stage eighties, and its molecular weight cut-off is about 200-2000Da between reverse osmosis membrane and ultra-filtration membrane, can infer that thus nanofiltration membrane may have the microvoid structure about 1nm, so be referred to as " nanofiltration ".The nanofiltration membrane great majority are composite membranes, and its surface isolation layer is made of polyelectrolyte, thereby inorganic salt are had certain rejection.The principle of work of nanofiltration is under certain pressure, and when the mixed solution that contains the differing molecular quantity of material flow through nanofiltration membrane with certain flow velocity, solvent and see through film less than the small molecules solute in aperture became through liquid and is collected; Greater than the macromole solute of membrane pore size then tunicle hold back as concentrated solution and be recovered, thereby realize separating and the purpose that concentrates.
The effect of nanofiltration NF is to hold back the larger molecular organics COD that those can not be biochemical, nanofiltration molecular weight cut-off boundary is 500～1000, namely can hold back separation to most of macromole organic molecule and divalence, trivalent, the rejection of inorganic dissolved components such as monovalent salt generally is lower than 15%, so the clear liquid of nanofiltration can reach lower COD concentration level, and the osmotic pressure of film both sides is very little, and the rate of recovery can reach more than 85% easily like this.Nanofiltration technique investment and working cost are relatively low, are the more promising technology that comes into one's own at present.
Caramel colorant is the liquid jelly of a kind of sorrel or chocolate, be widely used in foodstuffs industry, in can, candy, beverage, drinks, seasonings, pickles, cake, tobacco and medicinal syrup as tinting material, Food and Argriculture OrganizationFAO, the World Health Organization, the European Economic Community and united States food and drug administration all classify caramel as natural food colour, and it accounts for more than 90% of food color sales volume.The generation of caramel colour is because the non-enzymatically browning reaction has taken place carbohydrate under certain condition.The non-enzymatically browning reaction is divided into two kinds: carbohydrate is subjected to the brown stain of thermal initiation to be called caramelize separately, the browning reaction that produces when aminocompound and carbohydrate exist simultaneously is called sugar-amine reaction or rice Maillard reaction, the result makes carbohydrate generation condensation, dehydration or enolization, colour developing takes place and show the browning reaction of distinguishing the flavor of.Sugar refinery can be with sucrose or molasses as the raw material of producing caramel colour, with it as byproduct exploitation, obvious economic.
The hardly degraded organic substance main component of nanofiltration membrane concentrated solution middle and high concentration is caramel, can take ultrafiltration-ion-exchange-further concentrating and separating of multiple-effect reduction vaporization to make caramel product, this produce market is big, high efficiency, therefore the nanofiltration membrane concentrated solution can be turned waste into wealth, and obtain obvious economic benefit, effectively remedy or reduce running cost, avoid simultaneously the fenton oxidation produce in a large number can't be hopeless predicament.
Can produce the excess sludge of some amount in the above-mentioned nucleic acid biological wastewater treatment process at the 4th step second pond 4, also can produce mud at the 5th step chemical dephosphorization settling tank 6, these mud need be handled, the sludge treatment purpose is to reduce moisture percentage in sewage sludge, reduce sludge volume, reach stable in properties, and create conditions for further disposing.Treatment process is to drain into sludge sump 5, dewaters through sludge thickener 51 to dehydration machine room 52 again, adopts the flow process of mechanical dehydration, and dehydrated sludge is sent processing (as deliver to refuse landfill and carry out the sanitary landfill disposal), the utilization of resources of pressing filtering liquid backflow equalizing tank outside.
The present invention is based on the combined system of ABR-activated sludge process+chemical precipitation dephosphorization-NF membrane sepn, biochemical part adopts the ABR-Activated Sludge Process, waste water reduces pollutant load greatly through biochemical reaction, remainder can not be adsorbed by activated coke Filtration Adsorption method by biochemical polymer pollutent, make discharged wastewater met the national standard, adsorb saturated back activated coke and adopt method for destructive distillation regeneration.The present invention has filled up domestic technological gap of at present still failing effectively to handle nucleic acid waste water, can be widely used in the nucleic acid wastewater treatment of pharmacy, food service industry, foodstuff additive and Health Products Enterprises.
Main innovate point of the present invention is: (1) is optimized combination to technical process, and each processing unit is carried out than choosing, adopts ABR-SBR-activated coke absorbing process to handle nucleic acid waste water; (2) research and develop ABR reactor treatment effect efficiently; (3) research and development activated sludge method processing technique, the impact of effectively resisting the water yield and organic pollutant; (4) research and development NF membrane sepn makes waste water through still there being the part can not biochemical polymer pollutent after the biochemical treatment, by qualified discharge behind the membrane sepn.
The present invention compares with domestic and international similar technology, and the product performance contrast after the processing is as follows:
Below only be a specific embodiment of the present invention, but design concept of the present invention is not limited thereto, allly utilizes this design that the present invention is carried out the change of unsubstantiality, all should belong to the behavior of invading protection domain of the present invention.