[ summary of the invention ]
The to-be-solved technical problem of the utility model lies in providing a mariculture tail water treatment system, and it has advantages such as nitrogen and phosphorus removal treatment effeciency height, area are little, energy-conservation, with low costs, no secondary pollution, management are simple and convenient.
The utility model discloses a realize like this:
a mariculture tail water treatment system which is characterized in that: the tail water treatment system comprises a sewage collecting tank, a physical filtering device, an air floatation tank, an electrode-suspended filler coupling biological filter treatment unit and a sludge concentration and dehydration device; the sewage collecting tank, the physical filtering device, the air floating tank and the electrode-suspended filler coupled biofilter treatment unit are all connected with the sludge concentration and dehydration device;
the electrode-suspended filler coupled biofilter treatment unit comprises a biofilter, suspended fillers, a direct-current positive and negative electrode array combination, an electric stirring device and a carbon source supplementing device, wherein the suspended fillers are arranged in the biofilter, the direct-current positive and negative electrode array combination is arranged at the upper part of the biofilter, the electric stirring device is arranged at the lower part of the biofilter, a sludge hopper is arranged at the bottom of the biofilter, the electric stirring device is arranged above the sludge hopper, and the carbon source supplementing device is connected to the biofilter through a pipeline; the bottom of the air floatation tank is provided with an air bubble diffuser;
the volume ratio of the suspended filler to the water body in the biological filter is 20-50%; in the direct current cathode and anode array combination, the anode is iron, and the cathode is iron, carbon or copper.
Further, the suspension filler is made of high-density polyethylene, and the specific surface area is more than 500m2/m3。
Further, the distance between the adjacent electrodes of the direct current positive and negative electrode array combination is 2-30 cm.
Furthermore, the biological filter is formed by combining more than 2 filter bodies in series, and a direct current positive and negative electrode array combination can be arranged on part or all of the filter bodies.
Further, the physical filtering device is an automatic backflushing screen filter, a micro-filter or a sieve bend.
The utility model has the advantages of as follows:
the utility model discloses mainly through the series physics that produces in the biological filter, chemistry and microbial action, synthesize iron cation phosphate precipitation reaction, iron cation hydrate and polymer to the flocculation and precipitation effect, nitration and the denitrification reaction etc. of phosphorus and other particulate matters, reach continuously, stable, efficient dephosphorization denitrogenation, degradation organic matter and reduce suspended solid concentration effect. Has the advantages of simple structure, less sludge production, no secondary pollution and the like.
The utility model provides a current mariculture tail water nitrogen and phosphorus removal treatment effeciency is not high, and area is big, the relatively poor problem of treatment effect stability, it is high to have nitrogen and phosphorus removal treatment effeciency, economizes on the land, can stably accord with "mariculture tail water emission requirement" (SC/T9103), investment and running cost are lower, advantages such as the management is simple and convenient. Use the utility model discloses a device facility, mariculture tail water is through handling the back, and factor index such as inorganic nitrogen, active phosphate, chemical oxygen demand COD, suspended solid, pH in the discharge water all can accord with the one-level emission standard of mariculture tail water emission requirement (SC/T9103) regulation.
[ detailed description ] embodiments
Referring to fig. 1-2, the utility model relates to a mariculture tail water treatment system, which comprises a sewage collecting tank 1, a physical filtering device 2, an air flotation tank 3, an electrode-suspended filler coupling biofilter treatment unit 4 and a sludge concentration and dehydration device 5; the sewage collecting tank 1, the physical filtering device 2 and the air floating tank 3 are sequentially connected, the air floating tank 3 is connected to an electrode-suspended filler coupled biofilter treatment unit 4, and the sewage collecting tank 1, the physical filtering device 2, the air floating tank 3 and the electrode-suspended filler coupled biofilter treatment unit 4 are all connected with a sludge concentration and dehydration device 5;
the electrode-suspended filler coupled biofilter treatment unit 4 comprises a biofilter 41, suspended fillers 42, a direct-current positive and negative electrode array combination 43, an electric stirring device 44 and a carbon source supplementing device 45, wherein the suspended fillers 42 are arranged in the biofilter 41, the direct-current positive and negative electrode array combination 43 is arranged at the upper part of the biofilter 41, the electric stirring device 44 is arranged at the lower part of the biofilter 41, a sludge hopper 46 is arranged at the bottom of the biofilter 41, the electric stirring device 44 is arranged above the sludge hopper 46, and the carbon source supplementing device 45 is connected to the biofilter 41 through a pipeline; the bottom of the air floatation tank 3 is provided with an air bubble diffuser;
the volume ratio of the suspended filler 42 to the water body in the biological filter 41 is 20-50%, and the density of the suspended filler 42 is 0.92-0.98 g/cm3(ii) a In the direct current cathode-anode array combination 43, the anode is iron, and the cathode is iron, carbon or copper; the rotating speed of the electric stirring device 44 is 100-300 r/min.
The suspension filler 42 is made of high-density polyethylene and has a specific surface area of more than 500m2/m3。
The distance between the adjacent electrodes of the direct current positive and negative electrode array combination 43 is 2-30cm, and the operating voltage and current are respectively: the direct current voltage is 12-36V, and the micro-current density is 0.1-1.0 mA/cm2。
The biological filter 41 is formed by combining more than 2 filter bodies in series, and a direct current positive and negative electrode array combination 43 can be arranged on part or all of the filter bodies.
The physical filtering device 2 is an automatic backflushing screen filter, a micro-filter or a curved screen.
The utility model discloses the working process is as follows: after the culture tail water enters a sewage collecting tank 1, the culture tail water is extracted by a water pump and enters a physical filtering device 2, the filtered water enters an air floatation tank 3, and backwash water (less than or equal to 1.5 percent) containing large granular substances such as residual baits, excrement and the like enters a sludge concentration and dehydration device 5; in the air floatation tank 3, some suspended substances, medium and small particles, partial soluble protein and the like in water overflow (less than or equal to 0.5 percent) along with the air bubbles floating upwards and are discharged into a sludge concentration dehydration device 5, and bottom flowing water enters an electrode-suspended filler coupled biofilter treatment unit 4; forming sludge cake organic fertilizer in the sludge concentration and dehydration device 5, transporting the sludge out of the system, and returning the concentrated and dehydrated water to the sewage collection tank 1; in the electrode-suspended filler coupled biological filter treatment unit 4, the bottom of the biological filter 41 is provided with a sludge hopper 46 which can discharge sewage periodically, and the sludge water (less than or equal to 3 percent) is discharged into a sludge concentration dehydration device 5; the effluent treated by the electrode-suspended filler coupled biofilter treatment unit 4 can meet the first-level standard of marine culture tail water discharge requirement (SC/T9103) and achieve standard discharge.
The working principle of each device is as follows:
1. the sewage collecting pool 1 is mainly used for collecting culture tail water discharged from a culture pool, more than 2 submersible pumps (1 of which is standby) are arranged in the pool, and the pool water is extracted to the physical filtering device 2.
2. The physical filtering device 2 is a physical filtering device such as an automatic backflushing screen filter, a micro-filter or a sieve bend and the like, separates large granular substances in water, automatically leads the backflushing water (less than or equal to 1.5 percent) containing large granular substances such as residual bait, excrement and the like to enter the sludge dewatering and concentrating device 5, and leads the water filtered by the screen to enter the air flotation tank 3.
3. The bottom of the air flotation tank 3 is provided with a bubble diffuser which is externally connected with an air pump, a great number of micro bubbles can be formed in water, some suspended substances, medium and small particles, partial soluble protein and the like in the water entering the tank from the physical filtering device 2 can float upwards to overflow (less than or equal to 0.5 percent) along with the bubbles and are discharged into a sludge concentration and dehydration device 5, and bottom flowing water enters an electrode-suspended filler coupling biological filter tank treatment unit 4.
4. The working principle of the electrode-suspended filler coupled biological filter treatment unit 4 is as follows:
(1) due to the action of the DC electric field of the DC positive and negative electrode array combination 43, iron (anode) generates a large amount of iron cations, and a large amount of Fe is generated2+And Fe3+Carrying out precipitation reaction with phosphate in the culture tail water to form granular and insoluble substances which are deposited in a bottom sludge hopper 46 of the biological filter 41; meanwhile, iron cations are subjected to a series of hydrolytic polymerization reactions, and Fe2+And Fe3+And their hydrates such as ferric hydroxide have strong flocculation and precipitation effects on phosphorus, and can also generate polymer with adsorption coagulation effect, such as part of Fe3+Produced by hydrolysis, e.g. [ Fe ]2(OH)2]4+、[Fe3(OH)4]5+、[Fe5(OH)9]6+The polynuclear hydroxyl complex can play the role of a flocculating agent, can be subjected to the sedimentation with suspended substances (containing suspended phosphorus, including biological phosphorus and indissolvable phosphate particles), granular substances, electrolytes and the like in the culture tail water, and is settled in a bottom sludge hopper 46 of the biological filter 41. In addition, the method can be used for producing a composite materialThe high salinity of the seawater can ensure enough conductivity, which is beneficial to reducing the energy consumption for treating the tail water of the mariculture.
(2) The micro-current density is strictly controlled to be 0.1-1.0 mA/cm2In this range, seawater electrolysis cannot generate and accumulate free chlorine or hydroxyl radicals due to low current density. It is known that free chlorine or hydroxyl radicals in seawater, if any, can react with organic substances to produce halogenated byproducts, and trihalomethanes (such as trichloromethane) among them are genotoxic to farmed animals and also carcinogenic. Therefore, the utility model ensures the safety of seawater treatment, completely avoids the conventional use of electrolysis electrochemical oxidation treatment of seawater wastewater, and solves the problem of secondary pollution caused by the production of trihalomethane or the need of additionally arranging a safety treatment facility of trihalomethane.
(3) Iron ions generated by the electrode can be combined with chloride ions in the seawater to form ferric trichloride which is a flocculating agent, and FeCl in water3·6H2The coagulation of the O flocs can form composite flocs with suspended substances, particulate substances, electrolytes and the like in water, and the composite flocs are settled in a bottom sludge hopper 46 of the biological filter 41.
(4) Dissolved oxygen contained in the seawater culture tail water can provide dissolved oxygen required for nitrification reaction for a large amount of nitrosation and nitrifying bacteria in a biological membrane attached to the suspended filler 42, so that ammonia nitrogen is converted into nitrite nitrogen and nitrate nitrogen, and meanwhile, due to rapid consumption of the dissolved oxygen, a water body in the pool, particularly a lower layer of the pool water, rapidly forms an anoxic or anaerobic water environment to promote denitrification reaction.
(5) Heterotrophic denitrifying bacteria in the pond utilize an organic carbon source in culture water as an electron donor to perform denitrification reaction, so that nitrate nitrogen is finally generated through denitrification reaction to overflow the system and is removed.
(6) The hydrogen generated by cathode electrolysis of water can be used as an electron donor of hydrogen autotrophic denitrifying bacteria, and CO in tail water2Can provide inorganic carbon source for the autotrophic bacteria to generate autotrophic denitrification reaction, so that nitrate nitrogen is generated through denitrification reaction to generate nitrogen gas which overflows the system and is removed.
In addition, the hydrogen generated by the electrolysis of water can stimulate the growth and metabolism of autotrophic denitrifying bacteria attached to the surface of the suspended filler 42, and meanwhile, redox substances generated by electrolysis provide a suitable environment for the growth and propagation of microorganisms, provide an inorganic carbon source and an electron donor for the denitrification process of the autotrophic denitrifying bacteria, and further promote the autotrophic denitrification process, so that the removal of total nitrogen is improved.
(7) The density (0.92-0.98 g/cm) of the suspended filler 42 is used3) Close to seawater, a uniform suspended state is easily formed in the water body of the biological filter, and simultaneously, a fluidized state can be formed under the continuous slow stirring of the electric stirring device 44 and the flowing of water flow, so that a biological film attached to the suspended filler 42 is easily in continuous flowing contact with pollutants in the culture wastewater, the speed of nitration reaction and denitrification reaction is improved, the continuous friction and the flowing through of the suspended filler 42 and the water flow on the surface of an electrode are facilitated, and the density is 0.92-0.98 g/cm under the same volume3The friction force of the suspended filler is larger, the surface of the (anode) iron can be better removed by the oxide, the surface of the (anode) iron is prevented from being passivated by the oxide which forms a compact covering layer, the normal operation of electrode electrolytic reaction is influenced, and the passivation problem of the (anode) iron is effectively solved.
(8) The micro-current can strengthen the microorganisms such as bacteria and the like in the biological membrane on the suspended filler 42, can change the permeability of the bacterial cell membrane, is beneficial to the enzyme in the bacterial cell membrane to carry out a series of enzymatic reactions in the wastewater through the cell membrane, increases the contact between the enzyme in the cell membrane and a reaction substrate in the water, and further enhances the effect of degrading nitrogen and phosphorus in the aquaculture wastewater to a certain extent; in addition, the micro-current can also directly stimulate and strengthen the activity of extracellular enzymes secreted by certain bacteria and promote the degradation of nitrogen, phosphorus and other pollutants in water.
(9) As the concentration of organic carbon in the culture tail water is generally low and is consumed soon, in order to promote the heterotrophic denitrification reaction in the pond, the carbon source supplementing device 45 is used for supplementing carbon sources such as brown sugar and the like. An automatic feeding device can be configured, a certain amount of brown sugar is added into the solution barrel at regular intervals, the stirring machine is started to dissolve, and the brown sugar is automatically fed into the tank through a metering pump according to a certain amount through a pipeline so as to continuously and rapidly promote the heterotrophic denitrification reaction. The reaction rate of heterotrophic denitrification is several times (about 7 times) faster than that of autotrophic denitrification reaction, and meanwhile, the population growth and propagation speed of heterotrophic denitrifying bacteria are higher than that of autotrophic denitrifying bacteria. Therefore, organic carbon sources such as brown sugar and the like are added to supplement the nitrogen, so that denitrification can be obviously accelerated.
The TP removal rate and the TN removal rate have a certain positive correlation, namely when the TN removal effect is good, the TP also has a good removal effect. The utility model discloses in, the iron electrode can provide the electron that the denitrification needs, has certain enhancement denitrification, promotes NO3- -N and TN mass concentration's decline, is favorable to promoting the biological dephosphorization of the phosphorus-accumulating bacteria in the filler biomembrane and the water, promotes getting rid of TP in coordination. In addition, the utility model discloses a supplementary carbon source high efficiency promotes denitrification device has greatly promoted the continuation of denitrification and has gone on, promotes the decline of NO3- -N and TN mass concentration. The synergy promotes sustained deep removal of TP concentration. Therefore, the utility model discloses an electrode-suspension filler coupling technique promotes the integrated integration of denitrification technique with supplementary carbon source high efficiency and fuses integratively, in coordination mutually, has promoted nitrogen and phosphorus removal efficiency and clearance.
5. The sludge concentration and dehydration device 5 adopts a sludge filter press device or is provided with a water filtering layer drying pool facility, sludge after concentration and dehydration is formed into a sludge cake (organic fertilizer) and is transported out of the system, and the filtered water returns to the sewage collecting pool 1.
The present invention will be further described with reference to the following specific examples.
Utilize the utility model discloses a mariculture tail water processing system who founds handles large yellow croaker sea water pond culture and batch production breed tail water, and the discharge outlet water quality of water after handling all accords with, and monitoring result data is as follows:
remarking: the inlet water refers to tail water of mariculture, and the outlet water refers to discharge water treated by the treatment tank.
In conclusion, the inorganic nitrogen, active phosphate, chemical oxygen demand COD, pH, suspended matters and the like in the discharged water after the seawater culture tail water is treated by the treatment system all meet the first-level discharge standard specified in the seawater culture tail water discharge requirement (SC/T9103).
In a word, the utility model discloses mainly through the series physics that produce in the biological filter, chemistry and microbiological action, synthesize iron cation phosphate precipitation reaction, iron cation hydrate and polymer to the flocculation and precipitation effect, nitration and the denitrification of phosphorus and other particulate matters etc. reach and last, stabilize, efficient dephosphorization denitrogenation, degradation organic matter and reduce suspended solid concentration effect. Has the advantages of simple structure, less sludge production, no secondary pollution and the like.
The utility model provides a current mariculture tail water nitrogen and phosphorus removal treatment effeciency is not high, and area is big, the relatively poor problem of treatment effect stability, it is high to have nitrogen and phosphorus removal treatment effeciency, economizes on the land, can stably accord with "mariculture tail water emission requirement" (SC/T9103), investment and running cost are lower, advantages such as the management is simple and convenient.
Although specific embodiments of the present invention have been described, it will be understood by those skilled in the art that the specific embodiments described are illustrative only and are not limiting upon the scope of the invention, and that equivalent modifications and variations can be made by those skilled in the art without departing from the spirit of the invention, which is to be limited only by the claims appended hereto.