Background technology
Blue charcoal also known as semicoke, it be with low-temperature pyrolysis (600 ~ 800 DEG C) pyrolysis in the processes such as long-flame coal, non-caking coal and weakly caking coal obtain compared with the solid carbonaceous product of low volatile, its waste water quality composition is similar to coking chemical waste water.In coke production, pyrolysis temperature is about 1000 DEG C, and in the production of blue charcoal, pyrolysis temperature is low.Therefore containing a large amount of not by low molecule pollutent in high temperature oxidation in blue charcoal waste water, its concentration exceeds about 10 times than coking chemical waste water.Blue charcoal waste water is mainly containing high-enriched organics and inorganics, and organic pollutant is mainly containing coal tar oily substance, and wherein the content of phenols is very high, also has the aromatics of monocycle and many rings, and nitrogenous, sulphur, oxygen heterogeneous ring compound etc.; Inorganic pollutant, mainly based on ammonium salt, also contains the objectionable impuritiess such as sulfide, thiocyanide, prussiate; Wherein COD is up to 30000-40000mg/L, and ammonia nitrogen is up to 2500-3000mg/L; If unprocessed direct discharge will cause severe contamination to water surrounding.At present, blue charcoal waste water has become one of used water difficult to degradate of generally acknowledging both at home and abroad.
Existing blue charcoal scale wastewater treatment system many employings Physical, chemical method and biological process: its main process method has absorption method, flue gas treatment method, activated sludge process, burning method, catalyzed oxidation-biochemical process, ammonia still process dephenolize-SBR method and emulsion liquid membrane etc., their Problems existing: cost of investment is high, processing cost is high, suitability is not strong, difficult treatment or generation secondary pollution problems, as high in absorption method processing cost, absorption regeneration difficulty, inapplicable high concentration wastewater treatment, flue gas method requires that in waste water, ammonia content must balance with ammonia amount needed for stack gas, use restricted, burning method process investment is large, and require high to water quality treatment, suitability is not strong, catalytic oxidation will carry out under high-temperature and high-pressure conditions, and processing cost is high, scale of investment and working cost large, ammonia still process dephenolize-SBR method needs to use organic solvent dephenolize, secondary pollution can be produced, and affect NH_3-N treating efficiency after first carrying out phenol removal, add the difficulty of subsequent disposal, these all may make water outlet can not reach table 2 directly emission standard in " coking chemistry emission of industrial pollutants standard " GB16171-2012.
Summary of the invention
Proposition of the present invention is to overcome above treatment process Problems existing, proposes that a kind for the treatment of effect for blue charcoal waste water is good, suitability is strong, the treatment process of reliable and stable and easy to operate, process working cost is lower decarburization removing total nitrogen.
To achieve these goals, the technical solution used in the present invention is:
A kind of blue charcoal waste water decarburization removing total nitrogen treatment process, comprise pretreatment system, biochemical treatment system, advanced treatment system, pretreatment system comprises oil trap and two-stage air-flotation process, biochemical treatment system comprises multi-functional denitrification tank, first Aerobic Pond, second settling tank, anoxic pond, second Aerobic Pond, 3rd settling tank, multi-functional denitrification tank, first Aerobic Pond, anoxic pond and the second Aerobic Pond add HSBEMBM environmental improvement microbial preparation respectively, the mixed solution of the first Aerobic Pond is partly refluxed to multi-functional denitrification tank, advanced treatment system comprises photocatalytic ozonation unit, it is characterized in that:
A sludge absorption bed bioreactor and the first settling tank is also comprised in biochemical treatment system, waste water after pretreatment system process enters sludge absorption bed bioreactor, by the first settling tank mud-water separation, and then enter multi-functional denitrification tank, the first Aerobic Pond and subsequent biochemical unit and carry out biochemical reaction; And then enter multi-functional denitrification tank, the first Aerobic Pond and subsequent biochemical unit and carry out biochemical treatment; Throw the excess sludge having biochemical treatment system to produce in this sludge absorption bed bioreactor, add sorbing material and biological enzyme inducible factor simultaneously; In described sludge absorption bed reaction tank, mixture concentration controls at 4000-5000mg/L;
First Aerobic Pond has several refluxing openings in its flow direction, is all communicated with reflux line, and wherein the refluxing opening of end keeps often opening; When ammonia nitrogen concentration ratio reaches 1:1.6 ~ 2.5 in the nitroso-group nitrogen concentration on all the other refluxing opening positions and multi-functional denitrification tank, open the reflux pump at this refluxing opening place, make mixed solution be back to multi-functional denitrification tank from here simultaneously;
Photocatalytic ozonation reaction tower top is provided with effuser, causes in described first step cavitation air flotation pond after collecting the residual ozone overflowed from the water surface.
Multi-functional denitrification tank, is called for short HLA pond, under anoxic conditions, is nitrogen by denitrifying bacterium by nitrate, nitroso-group nitrogen transformation, or is the process of nitrogen by anaerobic ammonia oxidizing bacteria by nitroso-group nitrogen and mineralized nitrogen, thus reaches the function of denitrogenation; Organism is converted into the material of intermediate state, small molecules or CO by all the other the heterotroph microorganisms simultaneously in bacterium colony group
2deng, play the effect of decarburization, therefore named multi-functional denitrification tank.
HSBEMBM environmental improvement microbial preparation is commercially available conventional bacterial classification, is that current effect is best, commercial applications one of microbial strains the most widely.
Described waste water is first through oil trap and two-stage air supporting pre-treatment, pre-treatment water outlet is through PASAB(sludge absorption bed bioreactor) reactor absorption degradation, again through " HLA+O-A/O " biochemical treatment, bio-chemical effluent flows through the advanced treatment system of RBAF, photocatalytic ozonation, BAF, more medium filter, UF/RO membranous system successively, makes the effluent quality qualified discharge after process or reuse.
Described preprocessing process is that first blue charcoal waste water enter oil trap, remove most heavy oil and part light oil, connect after water outlet enters equalizing tank homogenization treatment and enter the process of secondary cavitation air flotation, by loose gas impeller, " microbubble " is distributed in sewage uniformly, add emulsion splitter simultaneously, remove most oil in water emulsion and oil slick and most of undissolved suspended matter, as added quaternary amine multipolymer, dosage about 20mg/L, obviously reduces (conventional P AC adds more than 100mg/L) than dosages such as traditional medicament PAC, scum silica frost generation is only 1/3 of PAC in addition, accessed residual ozone at the cavitation air flotation pond air supporting section ullage of the first step simultaneously, it is made to pass in water body with the form of microbubble, recycling ozone, ozone oxidation is very capable, it has been generally acknowledged that (under alkaline condition, ozone produces the intermediate products such as the very strong hydroxyl radical free radical of oxidisability after decomposing in water body to ozone by direct reaction (ozone carries out direct reaction with the organism in oxygen molecule form and water body) and indirect reaction, there is indirect oxidation reaction) two kinds of approach and many organism or functional group react, as C=C, C ≡ C, aromatic compound, heterogeneous ring compound, N=N, C=N,-OH,-SH,-NH
2,-CHO etc., also apolar substance can be changed into polar material, change macromolecule organic into low molecule organic matter, change organic for wetting ability micelle into inorganics that hydrophobicity easily condenses filtration, thus, air supporting section in first step cavitation air flotation pond introduces residual ozone, not only recycling ozone, and improve air supporting section deoiling effect, add the removal amount of objectionable impurities simultaneously, alleviate the processing load of biochemical section, reduce the running cost (processing cost of rear end residual ozone when avoiding system cloud gray model of system, raising system pre-treatment efficiency, reduce the processing cost etc. of biochemical system and advanced treatment system) etc. advantage, therefore, pretreatment stage petroleum-type, total oil removing rate reach respectively 93.3% and 90%(do not utilize residual ozone reach 85.3% and 76%), have good removal effect to COD, clearance reaches more than 20% (the pretreatment stage COD clearance of unreferenced residual ozone is 11%), also has certain removal effect to volatile phenol, ammonia nitrogen and total nitrogen simultaneously.Delivering a child of pre-treatment outlet unit.
In described biochemical treatment unit, described PASAB reactor is called sludge absorption bed bioreactor, biochemical leading portion pre-treatment is formed with the first settling tank, mud in pond is residual active sludge, the abundant mixing and absorption of waste water and excess sludge (excess sludge in the second settling tank or the 3rd settling tank) is realized in PASAB reactor, simultaneously by proof dry powder feeding device, the sorbing materials such as Zeolite Addition powder, gac, play carrier, strengthen the effect of flocculation and absorption, and need to add biological enzyme inducible factor in right amount according to water-quality guideline, such as: Ca
2+, Mo
2+deng; Promote particular organisms degrading enzymatic activity in bacterium, improve and adsorb and the ability of hazardous and noxious substances of degrading.Therefore PASAB reactor is by the adsorptive power of carrier and excess sludge and utilize the microorganism in excess sludge can remove the objectionable impuritiess such as most COD, ammonia nitrogen, volatile phenol, aromatic hydrocarbon, adsorb saturated mud and sorbing material afterwards to enter the first settling tank and realize mud-water separation, thus realize removing effective separation of Recalcitrant chemicals in water inlet, the hydraulic detention time of PASAB reactor controls in 35-60min, according to water quality and system disposition spoil disposal, the first clarifier sludge directly enters sludge thickener.
HLA and the first Aerobic Pond add HSBEMBM environmental improvement microbial preparation respectively, HLA mainly bears acidication function, also bear denitrification and Anammox function simultaneously, first Aerobic Pond bears the function of main decarburization and short distance nitration, multiple refluxing opening is set in the gallery of the first Aerobic Pond, as adopted on " S " type gallery at the first Aerobic Pond, multiple refluxing opening installed by whole gallery, as at 1/3 of gallery, 2/3, end all installs back head piece, running condition according to influent quality and whole system adjusts backwash deployment and quantity of reflux, namely the nitroso-group nitrogen concentration in the first Aerobic Pond gallery refluxing opening position and HLA pond ammonia nitrogen concentration ratio can reach 40%-60%, the pump opening this refluxing opening carries out mixed-liquor return, short-cut nitrification and denitrification or anaerobic ammonium oxidation process can be in, the denitrification effect of effective raising system, thus multiple refluxing opening is installed so that the different backwash deployment of adjustment and quantity of reflux realize the function (short-cut nitrification and denitrification of regulator control system of efficient denitrification in time in implementation process, Anammox function) while remove COD, the nitric efficiency of raising system and anti-surge capability, thus reduce rear end A(anoxic pond)/O(second Aerobic Pond) load of system, by the mud-water separation of the second settling tank, water outlet enters anoxic pond and the second Aerobic Pond forms traditional A/O system, and further removal of carbon and nitrogen guarantees the qualified discharge of the final outflow water of system, mud-water separation is carried out again, bio-chemical effluent access advanced treatment system by the 3rd settling tank.
To reflux in 2/3 gallery position of the first Aerobic Pond and end and its quantity of reflux ratio is respectively 60% and 40% simultaneously, have preferably removal effect to decarburization and denitrogenation.Biochemical stage water outlet COD is down to below 120mg/L simultaneously, ammonia nitrogen < 0.5mg/L, total nitrogen < 20mg/L, volatile phenol < 0.2mg/L, petroleum-type < 1mg/L, colourity is down to less than 140 times.And only end backflow, water outlet total nitrogen near 40-60mg/L in, add advanced treatment load, final outflow water total nitrogen (in GB16171-2012, table 2 directly discharges) not up to standard may be caused.
Described advanced treatment system comprises the advanced treatment system of RBAF, photocatalytic ozonation, BAF (BAF), more medium filter, UF/RO membranous system, finally reaches the function of reuse.Described inner circulating aerating biological filtering tank (RBAF) is arranged and water inlet aeration mode by the filter material layer in adjustment filter tank, realize the internal recycle of water inlet in filter tank, thus improving decomposition and the separating effect of BAF, the organism for bio-chemical effluent is effectively removed.Described photocatalytic ozonation bear decomposing organic matter be can be biochemical small-molecule substance and remove part COD, remove the function of prussiate and decolouring, waste water enters from lower end, ozone (ozonizer generation) enters water body from lower end by microporous aeration disc simultaneously, react in photocatalytic ozonation reaction tower, waste water flows out from upper end, remaining ozone overflows the water surface, first step cavitation air flotation pond air supporting section ullage is drained to by top duct, as one of air supporting section source of the gas, recycling residual ozone removes part objectionable impurities, saving resource and cost.Photocatalytic ozonation water outlet again through BAF, more medium filter, the process of UF/RO film etc., table 3 directly emission standard in effluent quality reaches " coking chemistry emission of industrial pollutants standard " GB16171-2012.
Embodiment
According to the process flow sheet of Fig. 1, specific implementation process is described below:
In Fig. 1, A is blue charcoal waste water; B is residual ozone; C is excess sludge; D is sludge reflux; E is mixed-liquor return, and F is water outlet or reuse.Blue charcoal waste water in this engineering from certain Lan Tan factory via the waste water after ammonia still process, dephenolize, oil removing pre-treatment, be made up of phenolic wastewater and oily(waste)water two portions (flooding quantity with 4:6), water-quality guideline is as shown in table 1, is 1m by the process design flooding quantity of Fig. 1
3the plant running of/h, treating processes is as follows:
1) pretreatment system:
Blue charcoal waste water enters oil trap, remove most heavy oil and part light oil, the process of secondary cavitation air flotation is entered after entering equalizing tank homogenization treatment, every grade adds quaternary amine multipolymer and is about 10mg/L, remove most oil in water emulsion and oil slick, remove most of undissolved suspended matter simultaneously, and utilize residual ozone as one of source of the gas in first step cavitation air flotation pond air supporting section, recycling ozone, oxide treatment moieties, reduce the objectionable impurities such as COD, ammonia nitrogen, volatile phenol in waste water, air supporting water outlet access biochemical system.With regard to the effect of water outlet after pre-treatment ozone introduced to air supporting section in following table 2 and utilize air source and be described (under the condition that other controling parameters are the same), the pre-treatment water outlet petroleum-type of recycling residual ozone, always oil removing rate reach respectively 93.3% and 90%(do not utilize residual ozone reach 85.3% and 76%); Have good removal effect to COD, clearance reaches more than 20% (the pretreatment stage COD clearance of unreferenced residual ozone is 11%), also has certain removal effect to volatile phenol, ammonia nitrogen and total nitrogen simultaneously.
2) biochemical system:
Pre-treatment water outlet enters PASAB reactor, fully mix with excess sludge, simultaneously according to practical situation, add carrier and biological enzyme inducible factor, choosing mixture concentration is the mixed liquid concentration that in 5000mg/L(PASAB reactor, interior control is different, its effluent quality situation is as shown in table 3), hydraulic retention 60min, enter the first settling tank afterwards and realize mud-water separation, water outlet enters HLA+ first Aerobic Pond, multiple refluxing opening 11 is set in the gallery of the first Aerobic Pond, 12, 13, " S " type of employing gallery (is equally divided into 1/3 gallery 31, 2/3 gallery 32 and end 33) on, to reflux in 2/3 gallery position of the first Aerobic Pond and end and its reflux ratio 60% and 40%(table 4 show at gallery 2/3 simultaneously, the water quality situation of the whole bio-chemical effluent of the different reflux ratio of end), mud-water separation is carried out again through the second settling tank, after enter the further denitrification and decarburization of A/O system, the qualified discharge of the water outlet total nitrogen of safeguards system.Draw in this process of the test, biochemical stage water outlet COD is down to below 120mg/L, ammonia nitrogen < 0.5mg/L, total nitrogen < 20mg/L, volatile phenol < 0.2mg/L, petroleum-type < 1mg/L, colourity is down to less than 140 times; And only end backflow, water outlet total nitrogen near 40-60mg/L in, add advanced treatment load, also may cause final outflow water total nitrogen (in GB16171-2012, table 2 directly discharges) not up to standard.In whole biochemical treatment process, the second clarifier sludge is back to HLA pond, and the 3rd clarifier sludge is back to anoxic pond; Simultaneously also according to water quality and system disposition spoil disposal, excess sludge enters PASAB reactor or sludge thickener.
3) advanced treatment:
Described advanced treatment system comprises the advanced treatment system of RBAF, photocatalysis and ozone reaction tower, BAF (BAF), more medium filter, UF/RO membranous system, finally reaches the function of reuse.Described inner circulating aerating biological filtering tank (RBAF) is arranged and water inlet aeration mode by the filter material layer in adjustment filter tank, realize the internal recycle of water inlet in filter tank, thus improving decomposition and the separating effect of BAF, the organism for bio-chemical effluent is effectively removed.Described photocatalytic ozonation bear decomposing organic matter be can be biochemical small-molecule substance and remove part COD, remove the function of prussiate and decolouring, waste water enters from lower end 51, ozone (ozonizer generation) enters water body from lower end 52 by microporous aeration disc 23 simultaneously, reacted by the irradiation of ultraviolet source 22 in photocatalytic ozonation reaction tower, waste water flows out from upper end 53, remaining ozone overflows the water surface, first step cavitation air flotation pond air supporting section ullage is drained to by top duct 24, as one of air supporting section source of the gas, recycling residual ozone removes part objectionable impurities, saving resource and cost.Photocatalytic ozonation water outlet again through BAF, more medium filter, the process of UF/RO film, table 3 directly emission standard in effluent quality reaches " coking chemistry emission of industrial pollutants standard " GB16171-2012.Degree of depth effluent quality is as shown in table 5: