CN112093945A - Method for degrading organic wastewater - Google Patents
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Abstract
The invention provides a method for degrading organic wastewater, which is characterized by comprising the following steps: (1) carrying out electrooxidation pretreatment on industrial heavy metal organic wastewater to obtain a solution A; the electro-oxidation pretreatment is carried out by using a high-performance oxidizer, and a cathode plate and an anode plate used by the high-performance oxidizer are boron-doped diamond film composite electrode plates; (2) adjusting the pH value of the solution A obtained in the step (1), and then sending the solution A into a membrane concentration system for filtration and concentration to obtain a solution B; (3) and (3) sending the solution B obtained in the step (2) into a triple-effect evaporative crystallization system for evaporation and concentration, cooling and crystallizing, separating solids, and recovering crystallized salt to obtain the degraded organic wastewater. The method can effectively realize the degradation of organic wastewater COD and the removal of heavy metal ions, simultaneously reduces the wastewater treatment cost, improves the purity and the recycling value of heavy metal crystallized salt, and has higher desalting rate and wastewater recovery rate. The method has simple and controllable technical parameters and high practicability.
Description
Technical Field
The invention relates to the field of water purification, in particular to a method for degrading organic wastewater.
Background
With the rapid development of industry, the variety and quantity of waste water are rapidly increased, the pollution to water is becoming wide and serious, and the health and safety of human beings are threatened. In the industrial production process, a large amount of organic wastewater is generated, and the organic wastewater generated in the industrial production has complex components, some of the organic wastewater has toxicity, and many acids and alkalis, which often have strong acid or strong alkalinity. The industrial organic wastewater has the following main hazards: firstly, the oxygen hazard: due to biodegradation, high-concentration organic wastewater can cause oxygen deficiency and even anaerobic reaction of a receiving water body, most aquatic organisms die, so that stink is generated, and the water quality and the environment are deteriorated. Secondly, sensory pollution: the high-concentration organic wastewater not only causes the water body to lose use value, but also seriously affects the normal life of people nearby the water body. Thirdly, toxic hazard: the organic wastewater with ultrahigh concentration contains a large amount of toxic organic matters, which can be continuously accumulated and stored in natural environments such as water, soil and the like, and finally enter human bodies to harm human health.
The industrial organic wastewater mainly has the following characteristics: one is high organic concentration. The Chemical Oxygen Demand (COD) is generally above 2000mg/L, some is even as high as tens of thousands to hundreds of thousands mg/L, and relatively speaking, the Biochemical Oxygen Demand (BOD) is lower, and the ratio of BOD to COD of a lot of waste water is less than 0.3. Secondly, the components are complex. The waste water containing toxic substances contains aromatic compounds and heterocyclic compounds as organic substances, and also contains sulfides, nitrides, heavy metals and toxic organic substances. Thirdly, the color is high and the odor is generated. Some waste water emits pungent and foul odor, which causes adverse effects on the surrounding environment. Fourthly, the catalyst has strong acidity and basicity. Industrial organic wastewater can be classified into three main types according to its nature: (1) organic wastewater is easy to biodegrade; (2) organic waste water which is organically degradable but contains harmful substances; (3) organic waste water which is difficult to biodegrade and contains harmful substances.
At present, the treatment method of industrial organic wastewater at home and abroad mainly comprises the following steps:
(1) and (3) an incineration method. The incineration method is suitable for treating high-concentration organic wastewater. The pretreated waste water is pressurized, filtered, metered and then sent to the upper part of a furnace arch, and sprayed into a hearth for evaporation and incineration through a special high-pressure air atomization nozzle. The method can thoroughly treat the high-concentration organic wastewater under the condition of ensuring the safe operation of the boiler. However, the method has the following defects in practical popularization and application: firstly, the water quantity of the waste water is limited by a matched boiler; secondly, the components of the waste water are analyzed in detail to ensure that the combustion of the boiler body is not influenced; the method has higher applicability in the treatment of high-concentration organic wastewater, but has high treatment energy consumption and cost for the treatment of medium-low concentration organic wastewater.
(2) Adsorption method. The adsorption method is a method of enriching one or more components in the waste water on the surface of solid by using a solid adsorbent with strong adsorption capacity. Commonly used adsorbents are activated carbon and resins. The adsorption method mainly has the defects that the service life of the adsorption material is short, the adsorption material is frequently replaced, and the replaced waste adsorption material is used as hazardous waste and needs to be further treated, so that the operation cost is high; the adsorption concentration is easily influenced by the adsorption saturation of the adsorption material to cause unstable water outlet and the like.
(3) SBR biochemical treatment. The SBR sewage treating process is one type of modern active sludge process, and includes the steps of filling water, biochemical reaction, deposition, draining, idling, etc. in one reaction tank with aerator and stirrer. A period is from the beginning of water filling to the end of idling. SBR biochemical treatment is a common method for treating general domestic wastewater. However, as industrial organic wastewater, the organic matter concentration is high, the components are complex, the amount of difficultly-degraded substances is large, the nutrition is less, the fluctuation of the water quality of inlet water is large, the requirement on thalli is high, and the nutrition needs to be added additionally to maintain the vitality of the thalli; meanwhile, heavy metals and other toxic and harmful substances which cannot be degraded and absorbed often exist in the industrial organic wastewater, and the effluent is easy to reach the standard.
(4) Electrochemical oxidation method. The electrochemical oxidation refers to that under the action of an electric field, a modifier existing on the surface of an electrode or in a solution phase can promote or inhibit an electron transfer reaction generated on the electrode, so that the electrode not only has an electron transfer function, but also can promote and select the electrochemical reaction. The electrochemical oxidation method is that under the action of an electric field, hydroxyl radicals with oxidation capacity are generated by means of an anode material with electrochemical activity, and organic matters are oxidized intoCO2And H2O or the organic matter is subjected to ring opening and bond breaking to generate an intermediate product, so that the treated wastewater reaches the standard and is discharged or recycled. The electrochemical oxidation method is a leading-edge technology for treating organic wastewater, and the wastewater electrochemical nitrogen and phosphorus removal technology has the advantages of high efficiency, safety, avoidance of direct addition of chemical substances, no need of using microorganisms, high reaction speed, easiness in operation, easiness in realization of automatic control and the like, so that people gradually pay attention to and apply the technology. But the prior art has higher energy consumption and lower oxidation efficiency. Further development of research and development is required.
Disclosure of Invention
Based on the defects in the prior art, the invention aims to provide a method for carrying out electrooxidation pretreatment on industrial organic wastewater rich in refractory organic matters and heavy metals, removing organic matters in the wastewater and carrying out industrial heavy metal organic wastewater treatment by combining membrane concentration and evaporation concentration technologies.
In order to achieve the purpose, the invention adopts the technical scheme that:
a method for degrading organic wastewater, comprising the steps of:
(1) carrying out electrooxidation pretreatment on industrial heavy metal organic wastewater to obtain a solution A; the electro-oxidation pretreatment is carried out by using a high-performance oxidizer, and a cathode plate and an anode plate used by the high-performance oxidizer are boron-doped diamond film composite electrode plates;
(2) adjusting the pH value of the solution A obtained in the step (1), and then sending the solution A into a membrane concentration system for filtration and concentration to obtain a solution B;
(3) and (3) sending the solution B obtained in the step (2) into a triple-effect evaporative crystallization system for evaporation and concentration, cooling and crystallizing, separating solids, and recovering crystallized salt.
The invention uses electrooxidation to pretreat organic wastewater, adopts boron-doped diamond film electrodes with extremely high oxygen evolution potential, widest electrochemical window, better physical and chemical stability and low adsorption characteristic as composite anode and cathode plates, and energizes the electrodes in wastewater treatment to generate hydroxyl with strong oxidizing property at the plates, so as to decompose macromolecular organic matters in the wastewater into micromolecules and reduce Chemical Oxygen Demand (COD); in addition, through electron gain and loss, hydrogen and oxygen ions finally electrolyzed from the electrode plate partially become fine elementary substance state precipitates or precipitate and separate out in the form of hydroxide precipitates (such as chromium hydroxide) of heavy metal ions through electron transfer, so that the removal of the heavy metal is realized.
According to the method for degrading the organic wastewater, provided by the invention, electrolytic oxidation pretreatment is adopted as a pretreatment process of industrial heavy metal organic wastewater, organic matters which are difficult to degrade in the wastewater are removed, and no reagent or medicament is required to be added in the whole pretreatment process; the heavy metal wastewater without organic matters enters a membrane concentration and evaporation concentration system, can replace flocculation, precipitation, sand filtration, activated carbon, ultrafiltration and other processes in the traditional wastewater treatment, remove dissolved inorganic salts and various organic impurities, and simultaneously use membrane concentration to concentrate the wastewater entering the evaporation system, thereby reducing the treatment capacity of evaporation concentration and reducing the cost of wastewater treatment by evaporation concentration. The degradation is got rid of the organic matter and is played the guard action to membrane system evaporation system, and the organic matter has to exist and leads to the dirty stifled and bacterial growing of membrane easily, leads to the dirty stifled of evaporation system equally easily, reduces the evaporation treatment capacity, increases the evaporation treatment energy consumption. The use of the membrane concentration system and the evaporative crystallization not only reduces the treatment cost of the industrial heavy metal organic wastewater, but also improves the purity and the recycling value of the heavy metal crystalline salt.
Preferably, the electrooxidation pretreatment in the step (1) adopts a steady flow treatment, the voltage is 2.4-2.8V when the electrooxidation pretreatment is used, and the current density is 25-35 mA/cm2The temperature is 25-35 ℃; the time of the electro-oxidation pretreatment is 2.5-3.5 h. The pretreatment process can adjust the pole plate combination, the voltage intensity, the current density, the pH value and the like according to the actual concentration of the wastewater to obtain the optimal treatment effect, reduce the organic pollution and blockage risk in the subsequent filtering and concentrating process, and effectively improve the concentration multiple of a subsequent concentrating system and the purity of the crystallized salt.
Preferably, the pH of the solution after the pH adjustment in the step (2) is 6-7.
Preferably, the membrane concentration system in step (2) comprises a TFS-OF system, a TFS-RO system and a TFS-SIRO system; the TFS-OF system is a microfiltration membrane system, the TFS-RO system is a reverse osmosis concentration system, and the TFS-SIRO system is a high-pressure reverse osmosis concentration system. And (3) sending the organic wastewater subjected to electrooxidation pretreatment and pH adjustment into a TFS-OF system, carrying out microfiltration treatment by the TFS-OF system to remove insoluble substances in the wastewater, treating TFS-OF concentrated water by a filter press, and refluxing filtrate to the TFS-OF system. And (3) sending the TFS-OF produced water into a TFS-RO system for membrane concentration, then entering the TFS-SIRO system, treating by a high-pressure membrane system, and concentrating and separating to obtain clean produced water and concentrated solution. More preferably, the organic wastewater treated by the TFS-RO system and the TFS-SIRO system also directly produces part of the produced water. The produced water can be directly discharged or reentered into the system for utilization, so that the water purification efficiency is effectively improved, and the water purification cost is saved.
Preferably, the pore diameter OF the filter membrane used by the TFS-OF system is 0.1-0.01 μm; the flow velocity OF the organic wastewater in the TFS-OF system is 3-6 m/s. The TFS-OF system adopts a cross-flow filtration mode, the flow direction OF organic wastewater in the system is parallel to the direction OF a membrane plane, the flow velocity and the flow are increased, the turbulence degree can be improved, the thickness OF a boundary layer is reduced, and the pollution on the surface OF the membrane is reduced; however, too high a flow velocity generates strong turbulence and large shear force on the membrane surface, so that the particles deposited on the micropores of the membrane surface are returned to the fluid. The filter membrane with the optimized pore diameter range and the specific water flow rate can effectively treat organic wastewater to release metal simple substances, metal salt precipitates, flocs and organic particles after electrolysis, replace the processes of flocculation, precipitation, sand filtration, activated carbon, ultrafiltration and the like in the traditional wastewater treatment, and ensure the water quality entering a TFS-RO system and a TFS-SIRO system. The membrane concentration can remove dissolved inorganic salts and various organic impurities, has higher desalting rate and water reuse rate, and simultaneously has long cleaning period and low operating cost.
Preferably, the running pressure of the TF-RO system is 2-3 Mpa, the used filter membrane is reverse osmosis membrane, and the aperture of the filter membrane is 0.1-0.7 nm. The TFS-RO system adopts a reverse osmosis separation technology, can separate solute and water under the condition of normal temperature without change, has wide impurity removal range, can remove dissolved inorganic salts, can also remove various organic impurities, has higher desalination rate and water reuse rate, and can intercept solute with the grain diameter of more than a few nanometers.
Preferably, the operation pressure of the TFS-SIRO system is 6-12 MPa, the used filter membrane is a high-pressure sea desert, and the aperture of the filter membrane is 0.1-0.7 nm. The TFS-SIRO system adopts a high-pressure reverse osmosis separation technology, has the same action principle as the TFS-RO system, but has higher pressure and higher desalination rate.
Preferably, in the step (3), the triple-effect evaporation crystallization system comprises single-effect evaporation, double-effect evaporation and triple-effect evaporation; the temperature of the primary evaporation is 100-110 ℃, and the pressure is 0.1-0.15 MPa; the temperature of the double-effect evaporation is 81-86 ℃, and the pressure is-0.04 to-0.05 MPa; the temperature of the triple effect evaporation is 54-60 ℃, and the pressure is-0.08-0.085 MPa. In the multi-effect evaporation process, the less the evaporation process is, the more the consumption is; if the evaporation process is too much, the steam consumption and the cooling water consumption are reduced, and the energy consumption and the cost in the evaporation crystallization process are increased. The evaporative crystallization adopts parallel flow and forced circulation modes, so that the steam utilization rate can be effectively improved, the energy and equipment cost can be saved, and the concentration multiple can be improved; meanwhile, the waste liquid after triple-effect evaporation and concentration treatment can be saturated and crystallized crystals are separated out, and the purity of the separated crystals is high.
Preferably, the triple-effect evaporation is implemented by collecting organic wastewater concentrated solution crystals by using a crystal catcher, and then cooling to 25-35 ℃ to recrystallize and secondary separate out crystals. More preferably, after the triple-effect evaporative crystallization system is evaporated and concentrated, a part of distillate can be obtained, and the distillate can be directly discharged or reflowed to the evaporative crystallization system for continuous use, so that the water purification efficiency is further improved, and the water purification cost is saved.
The invention has the beneficial effects that: the invention uses the boron-doped diamond film electrode as the electrooxidation pretreatment organic wastewater of the composite anode and cathode plates, decomposes macromolecular organic matters in the wastewater, and degrades the micromolecular organic matters; and (3) precipitating and separating out partial heavy metal ions in a hydroxide precipitation form through electron transfer, and then entering a membrane concentration and evaporation concentration system to concentrate the wastewater degraded by electrooxidation and enrich inorganic salts dissolved in the wastewater. The method can effectively realize the purification of the wastewater, and the produced water is pure water which can be directly recycled while concentrating and enriching the inorganic salt. The method realizes the removal of heavy metal ions, simultaneously reduces the wastewater treatment cost, improves the purity and the recycling value of the heavy metal crystallized salt, and has higher desalting rate and wastewater recovery rate. In addition, each part of the method has simple and controllable technical parameters, can carry out technical adjustment according to actual conditions, and has high practicability.
Drawings
FIG. 1 is a schematic flow chart of a method for degrading organic wastewater according to the present invention;
FIG. 2 is a schematic view showing the flow OF the treatment stages OF the electrooxidation pretreatment and TFS-OF system in the method for degrading organic wastewater according to the present invention;
FIG. 3 is a schematic flow diagram of the treatment stage of the TFS-RO system in the method for degrading organic wastewater according to the present invention;
FIG. 4 is a schematic flow chart of the treatment stage of the TFS-SIRO system in the method for degrading organic wastewater.
Detailed Description
In order to better illustrate the objects, technical solutions and advantages of the present invention, the present invention will be further described with reference to specific examples and comparative examples, which are intended to be understood in detail, but not intended to limit the invention. All other embodiments obtained by a person skilled in the art without making any inventive step are within the scope of protection of the present invention. The industrial heavy metal organic wastewater used in the embodiment and the comparative example of the invention is the same in source, and the COD and the concentration of each heavy metal ion are the same.
Example 1
An embodiment of the method for degrading organic wastewater according to the present invention is shown in fig. 1, and the flow diagram of the method for degrading organic wastewater according to the present embodiment includes the following specific steps:
(1) sending industrial heavy metal organic wastewater into a high-performance electrooxidator by using a water inlet pump to perform electrooxidation pretreatment for 3 hours at the temperature of 30 ℃; the high-performance electrooxidator uses a boron-doped diamond film composite cathode electrode and an anode electrode plate, and the electrooxidation electrode area is 25cm2The electrical oxidation current was 0.75A, electricityThe pressure is 2.6V;
(2) adjusting the pH value of the organic wastewater subjected to electrooxidation pretreatment in the step (1) to 7, and then sending the organic wastewater into a membrane concentration system for filtration and concentration, wherein the processing schematic diagrams of the high-performance electrooxidator and the membrane concentration system are shown in fig. 2-4; the aperture OF a filter membrane used by a TFS-OF system in the membrane concentration system is 0.05 mu m; the flow rate OF the organic wastewater in the TFS-OF system is 5 m/s; the running pressure of the TF-RO system is 2.5Mpa, the used filter membrane is a reverse osmosis membrane, and the aperture of the filter membrane is 0.5 nm; the operation pressure of the TF-SIRO system is 8Mpa, the used filter membrane is high-pressure sea desert, and the aperture of the filter membrane is 0.5 nm. After being treated by the TFS-OF system, the concentrated solution is subjected to pressure filtration by a pressure filter, filtrate flows back to the TFS-OF system, and filter residue is transferred to solid waste treatment; and the produced water OF the TFS-OF system enters a TFS-RO system, the produced water is discharged or recycled after reaching the standard under the treatment OF the TFS-RO system, concentrated water is sent into the TFS-SIRO system and treated by the TFS-SIRO system, and the produced water is recycled or reflowed to the TFS-RO system for treatment. The concentrated water is sent to an evaporative crystallization system.
(3) Sending the concentrated water subjected to interception and concentration treatment in the step (2) into an evaporative crystallization system for triple-effect evaporative crystallization and cooling crystallization, separating solids, recovering crystallized salt, and recycling or discharging distillate after evaporative crystallization treatment; the temperature of the first effect evaporation in the three-effect evaporation crystallization is 105 ℃, and the pressure is 0.12 MPa; the temperature of the double-effect evaporation is 83 ℃, and the pressure is-0.045 MPa; the temperature of triple effect evaporation is 56 ℃, and the pressure is-0.083 MPa; directly separating out crystals after the wastewater is subjected to triple-effect evaporation concentration treatment, collecting the organic wastewater concentrated solution subjected to triple-effect evaporation by a crystal catcher, discharging the organic wastewater concentrated solution out of a triple-effect evaporation system, feeding the organic wastewater concentrated solution into a cooling crystallization tank for cooling for secondary crystallization, and cooling to 30 ℃ to separate out crystals; and the evaporation distillate after the triple-effect evaporation concentration is recycled or discharged. And refluxing the mother liquor after solid-liquid separation after crystallization to an evaporation system for concentration and crystallization.
Example 2
The invention relates to an embodiment of a method for degrading organic wastewater, which comprises the following steps:
(1) industrial heavy metal organic wastewater is sent into a high-performance electric oxidizer by using a water inlet pumpCarrying out electrooxidation pretreatment for 2.5h at 35 ℃; the high-performance electrooxidator uses a boron-doped diamond film composite cathode electrode and an anode electrode plate, and the electrooxidation electrode area is 25cm2The electric oxidation current is 0.875A, and the voltage is 2.4V;
(2) adjusting the pH value of the organic wastewater subjected to electrooxidation pretreatment in the step (1) to 7, and then sending the organic wastewater into a membrane concentration system for filtration and concentration; the aperture OF a filter membrane used by a TFS-OF system in the membrane concentration system is 0.05 mu m; the flow rate OF the organic wastewater in the TFS-OF system is 5 m/s; the running pressure of the TF-RO system is 2Mpa, the used filter membrane is reverse osmosis desert, and the aperture of the filter membrane is 0.7 nm; the operation pressure of the TF-SIRO system is 12Mpa, the used filter membrane is high-pressure sea desert, and the aperture of the filter membrane is 0.3 nm. After being treated by the TFS-OF system, the concentrated solution is subjected to pressure filtration by a pressure filter, filtrate flows back to the TFS-OF system, and filter residue is transferred to solid waste treatment; and the produced water OF the TFS-OF system enters a TFS-RO system, the produced water is discharged or recycled after reaching the standard under the treatment OF the TFS-RO system, concentrated water is sent into the TFS-SIRO system and treated by the TFS-SIRO system, and the produced water is recycled or reflowed to the TFS-RO system for treatment. The concentrated water is sent to an evaporative crystallization system.
(3) Sending the concentrated water subjected to interception and concentration treatment in the step (2) into an evaporative crystallization system for triple-effect evaporative crystallization and cooling crystallization, separating solids, recovering crystallized salt, and recycling or discharging distillate after evaporative crystallization treatment; the temperature of the first effect evaporation in the three-effect evaporation crystallization is 105 ℃, and the pressure is 0.12 MPa; the temperature of the double-effect evaporation is 83 ℃, and the pressure is-0.045 MPa; the temperature of triple effect evaporation is 56 ℃, and the pressure is-0.083 MPa; directly separating out crystals after the wastewater is subjected to triple-effect evaporation concentration treatment, collecting the organic wastewater concentrated solution subjected to triple-effect evaporation by a crystal catcher, discharging the organic wastewater concentrated solution out of a triple-effect evaporation system, feeding the organic wastewater concentrated solution into a cooling crystallization tank for cooling for secondary crystallization, and cooling to 30 ℃ to separate out crystals; and the evaporation distillate after the triple-effect evaporation concentration is recycled or discharged. And refluxing the mother liquor after solid-liquid separation after crystallization to an evaporation system for concentration and crystallization.
Example 3
The invention relates to an embodiment of a method for degrading organic wastewater, which comprises the following steps:
(1) sending the industrial heavy metal organic wastewater into a high-performance electrooxidator by using a water inlet pump to perform electrooxidation pretreatment for 3.5 hours at the temperature of 25 ℃; the high-performance electrooxidator uses a boron-doped diamond film composite cathode electrode and an anode electrode plate, and the electrooxidation electrode area is 25cm2The electric oxidation current is 0.75A, and the voltage is 2.8V;
(2) adjusting the pH value of the organic wastewater subjected to electrooxidation pretreatment in the step (1) to 7, and then sending the organic wastewater into a membrane concentration system for filtration and concentration; the aperture OF a filter membrane used by a TFS-OF system in the membrane concentration system is 0.05 mu m; the flow rate OF the organic wastewater in the TFS-OF system is 5 m/s; the running pressure of the TF-RO system is 3Mpa, the used filter membrane is reverse osmosis desert, and the aperture of the filter membrane is 0.2 nm; the running pressure of the TF-SIRO system is 6Mpa, the used filter membrane is high-pressure sea desert, and the aperture of the filter membrane is 0.7 nm. After being treated by the TFS-OF system, the concentrated solution is subjected to pressure filtration by a pressure filter, filtrate flows back to the TFS-OF system, and filter residue is transferred to solid waste treatment; and the produced water OF the TFS-OF system enters a TFS-RO system, the produced water is discharged or recycled after reaching the standard under the treatment OF the TFS-RO system, concentrated water is sent into the TFS-SIRO system and treated by the TFS-SIRO system, and the produced water is recycled or reflowed to the TFS-RO system for treatment. The concentrated water is sent to an evaporative crystallization system.
(3) Sending the concentrated water subjected to interception and concentration treatment in the step (2) into an evaporative crystallization system for triple-effect evaporative crystallization and cooling crystallization, separating solids, recovering crystallized salt, and recycling or discharging distillate after evaporative crystallization treatment; the temperature of the first effect evaporation in the three-effect evaporation crystallization is 105 ℃, and the pressure is 0.12 MPa; the temperature of the double-effect evaporation is 83 ℃, and the pressure is-0.045 MPa; the temperature of triple effect evaporation is 56 ℃, and the pressure is-0.083 MPa; directly separating out crystals after the wastewater is subjected to triple-effect evaporation concentration treatment, collecting the organic wastewater concentrated solution subjected to triple-effect evaporation by a crystal catcher, discharging the organic wastewater concentrated solution out of a triple-effect evaporation system, feeding the organic wastewater concentrated solution into a cooling crystallization tank for cooling for secondary crystallization, and cooling to 30 ℃ to separate out crystals; and the evaporation distillate after the triple-effect evaporation concentration is recycled or discharged. And refluxing the mother liquor after solid-liquid separation after crystallization to an evaporation system for concentration and crystallization.
Example 4
Example 4 differs from example 1 only in that: the aperture OF the filter membrane used by the TFS-OF system in the membrane concentration system in the step (2) is 0.1 μm; the flow rate OF the organic wastewater in the TFS-OF system was 3 m/s.
Example 5
Example 5 differs from example 1 only in that: the aperture OF the filter membrane used by the TFS-OF system in the membrane concentration system in the step (2) is 0.02 μm; the flow rate OF the organic waste water in the TFS-OF system was 6 m/s.
Example 6
Example 6 differs from example 1 only in that: the flow rate OF the organic wastewater in the TFS-OF system in the step (2) is 10 m/s.
Comparative example 1
The method for degrading organic wastewater in comparative example 1 is different from that of example 1 only in that: the industrial heavy metal organic wastewater is directly sent into a membrane concentration system by using a water inlet pump without being subjected to electrooxidation pretreatment by a high-performance electrooxidator.
Comparative example 2
The method for degrading organic wastewater in comparative example 2 is different from that of example 1 only in that: the electric oxidation pretreatment process is carried out by using an electric oxidizer, the electric oxidizer uses a common graphite cathode electrode and an anode electrode plate, and the area of the electric oxidation electrode is 25cm2The electric oxidation current is 0.4A, and the voltage is 3V;
comparative example 3
The method for degrading organic wastewater in comparative example 3 is different from that of example 1 only in that: sending the organic wastewater subjected to interception and concentration treatment in the step (3) into an evaporative crystallization system for single-effect evaporative crystallization, separating solids, and recovering crystallized salt; the temperature of the single-effect evaporative crystallization is 105 ℃, and the pressure is 0.12 MPa.
COD, copper ion concentration, nickel ion concentration and chromium ion concentration content in the organic wastewater before and after the degradation treatment in example 1 and comparative examples 1-2 were measured, and whether fouling existed in the filter membrane of TFS-RO in the membrane concentration system was observed. The COD determination method is an ultraviolet spectrophotometry, and the determination method of each ion is an atomic absorption method.
TABLE 1
| Index (I) | CODcr(mg/L) | Cu2+(mg/L) | Ni+(mg/L) | Cr6+(mg/L) | Cr3+(mg/L) | Whether the filter membrane is dirty or not |
| Raw water content | 5800 | 26.2 | 5.8 | 4.9 | 3.6 | / |
| Example 1 | 250 | 0.1 | 0.05 | 0.01 | 0.1 | Whether or not |
| Example 2 | 320 | 0.2 | 0.06 | 0.03 | 0.1 | Whether or not |
| Example 3 | 270 | 0.1 | 0.05 | 0.01 | 0.12 | Whether or not |
| Example 4 | 360 | 0.3 | 0.1 | 0.02 | 0.1 | Whether or not |
| Example 5 | 380 | 0.3 | 0.08 | 0.03 | 0.13 | Whether or not |
| Example 6 | 710 | 0.35 | 0.15 | 0.05 | 0.16 | Whether or not |
| Comparative example 1 | 4700 | 19.5 | 4.2 | 3.8 | 2.9 | Severe fouling |
| Comparative example 2 | 2700 | 8.6 | 2.4 | 1.8 | 1.6 | Small amount of dirt block |
As shown in Table 1, in examples 1-5, the COD of the industrial heavy metal organic wastewater treated by the method for degrading organic wastewater of the invention is reduced from 5800mg/L to below 500mg/L, and the concentration of each heavy metal ion is reduced to below 0.5mg/L, so that the treatment effect is obvious; the comparative example 6 has higher values than those OF examples 1 to 5, and is caused by that the particles deposited on the surface OF the filter membrane return to the water body due to the overhigh flow velocity OF the wastewater in the TFS-OF. Comparative example 1 no electro-oxidation pretreatment was performed on the wastewater, the water purification effect was low and a large amount of organic fouling was caused on the filtration membrane in the subsequent membrane concentration system, affecting the subsequent concentration and evaporation effects; the cathode electrode and the anode electrode plate used in comparative example 2 were common graphite electrode plates, and the electrooxidation effect was weak, and the overall wastewater purification effect was also weak as in example 1.
The results of comparing the steam used in example 1 and example 3, which treated an equal amount of organic wastewater of the same nature at the same time, are shown in table 2.
TABLE 2
| Item | Steam/organic waste water used (ton/ton) |
| Example 1 | 1.3/1.25 |
| Comparative example 3 | 0.51/1.25 |
As shown in Table 2, the mass ratio of the steam required by the traditional single-effect evaporation to the wastewater to be treated is close to 1:1 in comparative example 3, while the steam quantity required by the method for degrading the organic wastewater in example 1 is only 41 percent of that of the wastewater, and the steam quantity is saved by more than half.
Finally, it should be noted that the above embodiments are only used for illustrating the technical solutions of the present invention and not for limiting the protection scope of the present invention, and although the present invention is described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that modifications or equivalent substitutions can be made on the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.
Claims (9)
1. A method for degrading organic wastewater is characterized by comprising the following steps:
(1) carrying out electrooxidation pretreatment on industrial heavy metal organic wastewater to obtain a solution A; the electro-oxidation pretreatment is carried out by using a high-performance oxidizer, and a cathode plate and an anode plate used by the high-performance oxidizer are boron-doped diamond film composite electrode plates;
(2) adjusting the pH value of the solution A obtained in the step (1), and then sending the solution A into a membrane concentration system for filtration and concentration to obtain a solution B;
(3) and (3) sending the solution B obtained in the step (2) into a triple-effect evaporative crystallization system for evaporation and concentration, cooling and crystallizing, separating solids, and recovering crystallized salt.
2. The method for degrading organic wastewater according to claim 1, wherein the electrooxidation pretreatment in step (1) is carried out by a steady-flow treatment at a voltage of 2.4-2.8V and a current density of 25-35 mA/cm2The temperature is 25-35 ℃.
3. The method for degrading organic wastewater according to claim 1, wherein the time of the electro-oxidation pretreatment is 2.5 to 3.5 hours.
4. The method for degrading organic wastewater according to claim 1, wherein the membrane concentration system in step (2) comprises a TFS-OF system, a TFS-RO system and a TFS-SIRO system.
5. The method for degrading organic wastewater according to claim 1, wherein the pH of the solution after the pH adjustment in the step (2) is 6 to 7.
6. The method for degrading organic wastewater according to claim 4, wherein the TFS-OF system uses a filter membrane having a pore size OF 0.1 to 0.01 μm; the flow velocity OF the organic wastewater in the TFS-OF system is 3-6 m/s.
7. The method for degrading organic wastewater according to claim 4, wherein the operating pressure of the TFS-SIRO system is 6-12 MPa, the used filter membrane is high pressure sea desert, and the pore diameter of the filter membrane is 0.1-0.7 nm; the operating pressure of the TFS-RO system is 2-3 MPa, the used filter membrane is a reverse osmosis membrane, and the aperture of the filter membrane is 0.1-0.7 nm.
8. The method for degrading organic wastewater according to claim 1, wherein in the step (3), the triple-effect evaporation crystallization system comprises single-effect evaporation, double-effect evaporation and triple-effect evaporation; the temperature of the primary evaporation is 100-110 ℃, and the pressure is 0.1-0.15 MPa; the temperature of the double-effect evaporation is 81-86 ℃, and the pressure is-0.04 to-0.05 MPa; the temperature of the triple effect evaporation is 54-60 ℃, and the pressure is-0.08-0.085 MPa.
9. The method for degrading organic wastewater according to claim 6, wherein the triple effect evaporation is performed by collecting organic wastewater concentrated solution crystals by using a crystal catcher, and then the crystals are crystallized and secondarily precipitated after cooling to 25-35 ℃.
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114032558A (en) * | 2021-12-14 | 2022-02-11 | 北京科技大学 | Method for preparing NiP micron particles from chemical nickel plating waste liquid through electrolysis |
| CN114477602A (en) * | 2022-01-25 | 2022-05-13 | 安尔达技术(北京)有限责任公司 | Comprehensive utilization treatment method for heavy metal wastewater |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103058331A (en) * | 2012-12-04 | 2013-04-24 | 江苏丰山集团有限公司 | Process for treating wastewater containing pyridin alcohol sodium by adopting BDD (boron-doped diamond) film electrode |
| CN105110535A (en) * | 2015-08-10 | 2015-12-02 | 江苏九九久科技股份有限公司 | Treating method for 3,5,6-trichloropyridine-2-sodium alkoxide waste water |
-
2020
- 2020-08-24 CN CN202010860370.8A patent/CN112093945A/en active Pending
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103058331A (en) * | 2012-12-04 | 2013-04-24 | 江苏丰山集团有限公司 | Process for treating wastewater containing pyridin alcohol sodium by adopting BDD (boron-doped diamond) film electrode |
| CN105110535A (en) * | 2015-08-10 | 2015-12-02 | 江苏九九久科技股份有限公司 | Treating method for 3,5,6-trichloropyridine-2-sodium alkoxide waste water |
Non-Patent Citations (1)
| Title |
|---|
| 朱亮: ""TFS-OF +RO 工艺处理重金属工业废水工程应用"", 《工业水处理》 * |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114032558A (en) * | 2021-12-14 | 2022-02-11 | 北京科技大学 | Method for preparing NiP micron particles from chemical nickel plating waste liquid through electrolysis |
| CN114477602A (en) * | 2022-01-25 | 2022-05-13 | 安尔达技术(北京)有限责任公司 | Comprehensive utilization treatment method for heavy metal wastewater |
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