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CN-122010227-A - Low-temperature wet type plasma pulse wave wastewater treatment system and treatment process thereof

CN122010227ACN 122010227 ACN122010227 ACN 122010227ACN-122010227-A

Abstract

Aiming at the problems of low efficiency, easy scaling of electrodes and the like of the existing high-concentration organic wastewater treatment, the invention discloses a low-temperature wet type plasma pulse wave wastewater treatment system and a process thereof. The system comprises a pretreatment unit, a reaction conveying unit, a core reaction unit, a plasma generation and control system, a cooling circulation system and a post-treatment unit. The core reaction unit includes a reaction tower mounted with an arc plasma torch and a high frequency induction heating assembly. The plasma power supply integrates an electronic pulse frequency generator, and prevents electrode scaling by utilizing coulomb repulsion through generating nanosecond-level automatic reversal polarity signals. The process comprises the steps of pretreatment, start-up preheating, continuous oxidation and post-treatment. The high-pressure air generates jet flow containing high-energy electrons and free radicals in the plasma torch, and the jet flow initiates a chain reaction to generate hydroxyl free radicals, so that pollutants are efficiently oxidized and decomposed, and efficient and stable treatment of high-concentration wastewater is realized.

Inventors

  • LIU WEI
  • YAO YUEMING
  • YANG XIAOLONG
  • Wang Xiangmo

Assignees

  • 中科瓴威(厦门)应用技术有限公司

Dates

Publication Date
20260512
Application Date
20260228

Claims (8)

  1. 1. A low temperature wet plasma pulse wave wastewater treatment system, comprising: The pretreatment unit comprises an inclined plate sedimentation tank, wherein the inside of the inclined plate sedimentation tank is sequentially divided into a mixing chamber, a reaction chamber and a sedimentation separation chamber along the water flow direction through a partition plate, the mixing chamber is provided with a dosing device and is configured to quickly mix raw wastewater with a medicament, the reaction chamber is positioned between the mixing chamber and the sedimentation separation chamber and is mutually communicated, a slow stirring environment is provided to enable mixed wastewater to perform flocculation reaction so as to form floc alum floc which is easy to settle, and the inclined plate sedimentation tank is configured to carry out dosing mixing and solid-liquid separation on the raw wastewater, and separated supernatant enters the sedimentation separation chamber; The reaction conveying unit comprises a plunger pump and a heat exchanger, wherein an inlet of the plunger pump is connected with a water outlet of a sedimentation separation chamber of the inclined plate sedimentation tank, and the heat exchanger is used as a heat energy recovery component of the system and is provided with a cold side channel and a hot side channel which are physically isolated and can conduct heat; The reactor comprises a core reaction unit, a plasma wet oxidation reaction tower, an arc plasma torch arranged at the top of the plasma wet oxidation reaction tower and a high-frequency induction heating component arranged on the outer wall of the plasma wet oxidation reaction tower, wherein an outlet of a cold side channel of the heat exchanger is connected to a feed inlet of the plasma wet oxidation reaction tower, the plasma wet oxidation reaction tower is used as a high-temperature high-pressure reaction container and is configured to provide a place for mixing reaction of wastewater and plasma jet, and the high-frequency induction heating component comprises an induction coil wound on the outer wall of the plasma wet oxidation reaction tower and a high-frequency heating power supply electrically connected with the induction coil and is configured to heat the tower body and wastewater in the tower in a starting stage through electromagnetic induction; The plasma generation and control system comprises a high-pressure air compressor system and a plasma power supply, wherein the high-pressure air compressor system is connected with a working medium gas inlet of the arc plasma torch to provide pressurized working medium gas, and the plasma power supply is electrically connected with the arc plasma torch to provide excitation voltage; a cooling circulation system comprising a deionized water cooling tower and a deionized water pump configured to pump deionized water into a cooling jacket of the arc plasma torch for cooling and back-flowing to the deionized water cooling tower; The post-treatment unit comprises a gas-liquid separator and a deacidification tower, wherein the plasma wet oxidation reaction tower is provided with a gas-liquid two-phase flow outlet which is connected with an inlet of the gas-liquid separator through a hot side channel of the heat exchanger, the hot side channel is configured to cool high-temperature gas-liquid mixed fluid flowing out of the plasma wet oxidation reaction tower and transfer heat to low-temperature wastewater in the cold side channel, and a gas outlet of the gas-liquid separator is connected to the deacidification tower.
  2. 2. The low temperature wet type plasma pulse wave wastewater treatment system according to claim 1, wherein: The plasma power supply is internally integrated with an electronic pulse frequency generator and is configured to generate nanosecond automatic reversal polarity signals, the plasma power supply controls the polarity of the voltage output to the arc plasma torch to carry out nanosecond periodic reversal according to the signals, and the scaling of the electrode surface is prevented by using alternating electric field force.
  3. 3. The low temperature wet type plasma pulse wave wastewater treatment system according to claim 1, wherein: the plasma wet oxidation reaction tower is internally provided with feeding nozzles, the feeding nozzles adopt spiral solid nozzles, the injection angle is 60 degrees or 90 degrees, the nozzles are uniformly distributed along the circumferential direction of the tower, and the number of the nozzles is a multiple of 2 or 3.
  4. 4. A wastewater treatment process using the low temperature wet type plasma pulse wave wastewater treatment system as claimed in any one of claims 1 to 3, comprising the steps of: The pretreatment step S1, high-concentration wastewater enters a mixing chamber of the inclined plate sedimentation tank, a chemical adding device is used for adding chemical and a stirrer is started to stir 10-30 min at a rotating speed of 40-100 r/min, the mixed liquid overflows into the reaction chamber to continue to react, then enters a sedimentation separation chamber, the Reynolds number of the sedimentation separation chamber is controlled to be less than 400, the hydraulic load is 9-30 m < 3 >/m < 2 > h, the wastewater residence time is 20-40 min, the separated precipitate is discharged into a sludge tank, and the supernatant fluid enters a water chamber; S2, a system starting step: pumping the wastewater from which the suspended matters are removed into the plasma wet oxidation reaction tower through the plunger pump to a specified liquid level; Closing a gas-liquid two-phase flow outlet valve and a plunger pump of the plasma wet oxidation reaction tower; starting the high-frequency heating power supply, heating the temperature in the tower to 160 ℃ through the high-frequency induction heating assembly, and keeping the pressure in the tower to be 1 MPa in the process; when the temperature reaches 160 ℃, a fan of the deionized water cooling tower, a deionized water pump and a high-pressure air compressor system are sequentially started; starting the plasma power supply after the delay time is 1 min, and exciting plasma; When the temperature of the outlet in the tower reaches 200 ℃, maintaining the temperature and the pressure of 1 MPa to operate for 5min, and completing the starting stage; S3, normal oxidation operation steps: Opening the valve of the gas-liquid two-phase outflow port and restarting the plunger pump, so that the wastewater continuously flows through the heat exchanger for preheating and then is sprayed into the plasma wet oxidation reaction tower; Air is used as working medium gas, pressurized by the high-pressure air compressor system, deoiled and dedusted and then enters the arc plasma torch, and active plasma jet containing high-energy electrons, oxygen positive and negative particles, ozone and ultraviolet rays is generated under the action of a plasma electric field; The active plasma jet flow and the sprayed wastewater mist drop are mixed in the tower to generate hydroxyl free radicals through chain reaction, so that pollutants in the wastewater are oxidized and decomposed; S4, post-processing: The gas-liquid two-phase after reaction flows through a hot side channel of the heat exchanger and enters the gas-liquid separator after heat exchange and temperature reduction of the feeding cold wastewater flowing through a cold side channel, the separated liquid is discharged into a liquid storage tank, and the separated gas enters the deacidification tower and is discharged after neutralization by alkali liquor.
  5. 5. The wastewater treatment process of the low-temperature wet type plasma pulse wave wastewater treatment system according to claim 4, wherein: During the starting process of the step S2, along with the operation of the arc plasma torch, the power of the high-frequency heating power supply is adaptively reduced so as to maintain the temperature in the tower to be stable at 200 ℃, and the deviation between the upper and lower parts is not more than 5%.
  6. 6. The wastewater treatment process of the low-temperature wet type plasma pulse wave wastewater treatment system according to claim 4, wherein: in the step S3, the operation pressure of the plasma wet oxidation reaction tower is controlled to be 0.1-1.0 MPa, the operation temperature is controlled to be 60-300 ℃ and the reaction time is 10-30 min, and the air pressure provided by the high-pressure air compressor system is set to be 0.2 MPa higher than the internal pressure of the plasma wet oxidation reaction tower.
  7. 7. The wastewater treatment process of the low-temperature wet type plasma pulse wave wastewater treatment system according to claim 4, wherein: In the step S3, the plasma power control electrode performs automatic polarity inversion, the inversion time is nanosecond, and the deposit on the electrode surface is stripped by charge inversion.
  8. 8. The wastewater treatment process of the low-temperature wet type plasma pulse wave wastewater treatment system according to claim 4, wherein: the chain reaction in the step S3 comprises the steps of ionizing oxygen to generate oxygen free radicals, enabling the oxygen free radicals to react with water to generate hydroxyl free radicals, further inducing chain propagation reaction by the hydroxyl free radicals, oxidizing organic pollutants into carbon dioxide and water by utilizing the hydroxyl free radicals, oxidizing ammonia nitrogen into nitrogen, and oxidizing sulfides into sulfur simple substance precipitates or sulfate.

Description

Low-temperature wet type plasma pulse wave wastewater treatment system and treatment process thereof Technical Field The invention relates to the field of wastewater treatment equipment, in particular to a low-temperature wet type plasma pulse wave wastewater treatment system and a treatment process thereof. Background With the acceleration of industrialization progress, the treatment of high-concentration and nondegradable industrial wastewater has become a significant challenge in the field of environmental protection. Conventional wastewater treatment technologies expose a number of limitations in the face of complex industrial wastewater, and there is a strong need to develop more efficient and economical treatment technologies. In recent years, the combination of plasma technology and wet oxidation technology has provided new solutions for high concentration wastewater treatment. Chinese patent CN118221253a discloses a system for treating high-concentration wastewater by plasma synergistic wet oxidation, which realizes efficient COD degradation without catalyst by the combination of an inclined plate sedimentation tank, a plunger pump, a heat exchanger and a plasma wet oxidation reaction tower. Chinese patent CN109748375A discloses a low-temperature plasma co-processing system for treating refractory organic matter wastewater, which adopts a low-temperature plasma generator and a supercritical water oxidation reactor to work cooperatively, so as to effectively improve oxidation efficiency and shorten reaction time. Chinese patent CN113443769a describes an energy-saving wastewater treatment system based on wet oxidation, which realizes effective recycling of energy by cooperation of a cooling and preheating system and a micro-channel mixing system. However, the prior art still has significant technical drawbacks. The traditional evaporation method has definite treatment effect, but has extremely high energy consumption, and is easy to cause concentration of salts and heavy metals to generate dangerous waste, the biological treatment method has strict requirement on the quality of the inflowing water, is difficult to treat refractory organic matters and high-chroma wastewater, and can generate a large amount of biological sludge, the membrane separation method is faced with serious membrane pollution problem, the equipment investment cost is high, and the generated concentrated solution still needs secondary treatment. In the aspect of advanced oxidation technology, the ozone method has strong oxidation capability, but has expensive equipment, high energy consumption and is easy to generate toxic byproducts, the photocatalysis method is limited by light source conditions and is difficult to treat high-concentration wastewater, the traditional Fenton method cannot generate effective chain reaction, has short free radical service life, and more seriously, the existing plasma treatment system has the common problems of electrode passivation and scaling, and frequent cleaning or electrode replacement is required, so that the continuous operation stability of the system and the feasibility of industrial application are seriously affected. Disclosure of Invention The invention provides a low-temperature wet type plasma pulse wave wastewater treatment system and a treatment process thereof, aiming at solving the technical problems of high energy consumption, poor treatment effect, easy scaling of equipment and the like in the treatment of high-concentration and nondegradable industrial wastewater in the traditional wastewater treatment method. The invention provides a low-temperature wet plasma pulse wave wastewater treatment system which comprises a pretreatment unit, a reaction conveying unit, a core reaction unit, a plasma generation and control system, a cooling circulation system and a post-treatment unit. Preferably, the pretreatment unit comprises an inclined plate sedimentation tank, the interior of the tank is sequentially divided into a mixing chamber, a reaction chamber and a sedimentation separation chamber along the water flow direction by a partition plate, and the pretreatment unit is configured to carry out dosing mixing and solid-liquid separation on raw wastewater. Preferably, the reaction conveying unit comprises a plunger pump and a heat exchanger, wherein the heat exchanger is provided with a cold side channel and a hot side channel, the cold side channel is used for preheating feeding, and the hot side channel is used for cooling discharging. Preferably, the core reaction unit comprises a plasma wet oxidation reaction tower, an arc plasma torch arranged at the top of the tower and a high-frequency induction heating assembly arranged on the outer wall of the tower, wherein the high-frequency induction heating assembly comprises an induction coil wound on the outer wall of a tower body and a high-frequency heating power supply electrically connected with the induction coil and is used for qu