CN203173927U - Electrochemical and micro-electrolysis combined pretreatment device for landfill leachate - Google Patents

Abstract

The utility model discloses a device of landfill leachate is jointly pretreated with little electrolysis to electrochemistry, mainly include an electrochemical treatment device, a little electrolytic treatment device and two water outlets, wherein electrochemical treatment device mainly gets rid of the high concentration ammonia nitrogen in landfill leachate, gets rid of difficult biodegradable pollutant through little electrolytic treatment device again, goes out water from water outlets, can play fine removal effect to landfill leachate pretreatment, improves landfill leachate pretreatment effect. Because ammonia nitrogen electrolysis is prior to COD electrolysis in the electrochemical oxidation process, but if the ammonia nitrogen electrolysis is finished in COD electrolysis, the consumed energy is very high, if on the basis of reasonably removing ammonia nitrogen, the COD in the leachate is treated by adopting a low-cost micro-electrolysis technology, meanwhile, the biodegradability of the leachate can be improved, the important effect is played on ensuring the subsequent biochemical treatment, and the landfill leachate treatment can reach the national discharge standard by combining with the biochemical treatment technology and the advanced treatment technology.

Description

Electrochemical and micro-electrolysis combined pretreatment device for landfill leachate

technical field

The utility model relates to the field of landfill leachate treatment, in particular to a device that combines electrochemical and micro-electrolysis devices to pretreat landfill leachate. the

Background technique

Urban waste refers to the solid waste generated in the daily life of urban residents or in the activities of providing services for urban daily life. It has the characteristics of complex composition and high organic content. The world produces 490 million tons of municipal waste every year, while China alone produces nearly 150 million tons every year. my country has become one of the most serious countries in the world where cities are surrounded by garbage. the

Municipal solid waste sanitary landfill is a disposal method commonly used at home and abroad. About 95% of domestic waste in the world is disposed of by landfill, and there are more than 150,000 landfills worldwide. 90.5% of domestic waste in my country is disposed of through landfill. Landfill leachate is high-concentration organic wastewater produced by solid waste under the action of physics, chemistry and microorganisms due to leaching of atmospheric precipitation and immersion of surface water and groundwater after landfill treatment. It has the characteristics of high concentration of NH ₃ -N , BOD ₅ and CODcr, large changes in water quality and quantity, many types of toxic and harmful pollutants, and imbalanced microbial nutrition ratio. If landfill leachate is not treated, it will seriously pollute surface water and groundwater if it is directly discharged into the environment. In 2008, China promulgated and implemented the newly revised "Pollution Control Standards for Domestic Waste Landfill Sites" (GB 16889-2008), which proposed more stringent discharge indicators for landfill leachate BOD ₅ , CODCr, ammonia nitrogen, total nitrogen, and heavy metals. However, as far as landfill leachate treatment technology is concerned, there is still a large technical gap. At present, the technical route of combining biological treatment technology and membrane technology is adopted in the construction of landfill leachate treatment projects in most areas. However, due to the complex characteristics of landfill leachate and the characteristics of easy clogging and high operating costs of membrane technology, Often in the actual application process, there is a problem that landfill leachate cannot be discharged up to the standard.

At present, the main problems in landfill leachate treatment are as follows:

1. The problem of high ammonia nitrogen in landfill leachate is difficult to solve. Due to the difference in hydrogeological conditions, landfill methods and waste components of landfill sites, the concentration of ammonia nitrogen in landfill leachate ranges from tens to thousands of mg/L. As the landfill time prolongs, the ammonia nitrogen in landfill leachate still tends to increase. The high concentration of ammonia nitrogen causes the C/N imbalance of the landfill leachate, which has an inhibitory effect on the microorganisms in the biochemical treatment of the landfill leachate, resulting in the unstable operation of the biochemical treatment system of the landfill leachate.

2. The biodegradability of landfill leachate is poor. BOD ₅ and CODCr in landfill leachate, especially "old" landfill leachate are relatively low, and BOD5/CODCr is also relatively low. Generally, BOD ₅ /CODCr is 0.05~0.2, and leachate Contains large amounts of humic and fulvic acids which are difficult to biodegrade. Therefore, biological treatment technology cannot be used alone to treat landfill leachate.

Contents of the invention

Aiming at the deficiencies of the prior art, the utility model provides a method for effectively removing high-concentration ammonia nitrogen in landfill leachate, so as to reduce the impact of high ammonia nitrogen on the subsequent biochemical treatment, remove part of COD and improve the biodegradability of landfill leachate, and provide further benefits for subsequent biological treatment. A device that provides protection for the treatment of landfill leachate. the

In order to achieve the above object, the utility model adopts the following technical solutions:

A device for combined electrochemical and micro-electrolysis pretreatment of landfill leachate, characterized in that it mainly includes an electrochemical treatment device, a micro-electrolysis treatment device and two outlet tanks, wherein the electrochemical treatment device mainly removes high-concentration landfill leachate Ammonia nitrogen, and then through the micro-electrolysis treatment device to remove refractory biodegradable pollutants, and finally the water is discharged from the outlet tank.

Described electrochemical treatment device mainly comprises an electrochemical cell, and electrochemical cell anode adopts high oxygen evolution potential electrode, can be ruthenium iridium electrode; Negative electrode adopts titanium electrode, adopts multiple groups of electrodes to carry out, and electrode spacing is controlled at 1-2cm, The current density is controlled at 30mA/cm2. the

The bottom of the electrochemical tank is provided with a water inlet, the upper part is provided with a water outlet, the top of the reaction tank is provided with a foam collection tank, and the bottom is provided with an air aeration pipe. Air is used for stirring. the

The micro-electrolysis treatment device mainly includes a micro-electrolysis tank, an Fe-C electrode is arranged in the micro-electrolysis tank, a foam collection tank is arranged on the top of the micro-electrolysis tank, and an air pipe is arranged on the bottom for aeration and stirring. the

Sulfuric acid or hydrochloric acid is used in the micro-electrolyzer to adjust the leachate to be acidic, and the dosage is controlled by a pH meter, and the pH is controlled at about 3. the

A dripping alkali device is arranged in the water outlet tank, and the dropping alkali device drops alkaline substances to control the pH value of the discharged water at about 6-9. the

After adopting the above-mentioned scheme, it can play a good role in removing landfill leachate pretreatment to improve the effect of landfill leachate pretreatment. Since ammonia nitrogen electrolysis is prior to COD electrolysis in the electrochemical oxidation process, but if ammonia nitrogen electrolysis If the COD in the electrolysis is finished, the energy consumed will be very high. If the low-cost micro-electrolysis technology is used to treat the COD in the leachate on the basis of reasonable removal of ammonia nitrogen, the biodegradability of the leachate can be improved at the same time. The treatment plays an important role, and the combination of the utility model and the biochemical treatment technology and advanced treatment technology can make the landfill leachate treatment reach the national discharge standard. the

Description of drawings

Fig. 1 is the structural representation of the utility model.

Detailed ways

The utility model is described in further detail below according to the accompanying drawings:

As shown in Figure 1, the device for combined electrochemical and micro-electrolysis pretreatment of landfill leachate mainly includes an electrochemical treatment device, a micro-electrolysis treatment device and two outlet tanks, wherein the electrochemical treatment device mainly removes high-concentration landfill leachate Ammonia nitrogen, micro-electrolysis treatment device to remove refractory biodegradable pollutants. The electrochemical treatment device includes an electrochemical reaction tank 2, the electrochemical reaction tank 2 is provided with a water inlet pipe 1, the bottom of the electrochemical reaction tank 2 is provided with an air aeration tube 3, and an anode plate 4 and a cathode plate 5 are arranged in the electrochemical reaction tank 2. The ruthenium-iridium electrode is used as an electrode plate, which is respectively connected to the positive and negative poles of the DC power supply.

The micro-electrolysis treatment device includes a micro-electrolysis tank 6, a reaction tank 7 is arranged on the micro-electrolysis tank 6, and an acid adding pipe 8 is arranged in the micro-electrolysis reaction tank 7; Apparatus 10 and mixer 11. the

During work, the landfill leachate enters the electrochemical reaction tank 2 through the water inlet pipe 1, and the air aeration tube 3 is arranged at the bottom of the electrochemical reaction tank 2, and the aeration is performed by air aeration, and the anode plate 4 in the electrochemical reaction tank 2, The cathode plate 5 is not connected to the positive and negative poles of the DC power supply, and the ammonia nitrogen in the landfill leachate is removed through electrolysis, the electrochemical oxidation reaction is controlled at 0.5-1h, the current density is controlled at 10-50mA/cm2, and the Ph value is controlled at 8- 9 or so, the hydraulic retention time in the micro-electrolysis process is controlled at 1--2h, and the pH is controlled at 2--4. Since the landfill leachate contains relatively high chlorine ions, chlorine ions are oxidized at the anode of the electrode plate to form chlorine gas, and chlorine gas dissolves in water to form a strong oxidizing hypochlorous acid, which then oxidizes and decomposes the ammonia nitrogen in the landfill leachate into nitrogen gas, controlling The electrochemical current density is 30mA/cm2, the oxidation rate of ammonia nitrogen is about 7-10mg/l.min, and the electrochemical oxidation of ammonia nitrogen can be controlled below 200-500mg/L. the

The effluent landfill leachate enters the micro-electrolysis tank 6, and the COD in the landfill leachate is further removed through the Fe-C reaction tank 7 to improve the biodegradability of the landfill leachate. Add sulfuric acid dropwise to tube 8 to adjust the pH. the

After the landfill leachate undergoes micro-electrolysis, the effluent enters the water outlet tank 9, and through the dripping alkali device 10, the mixer 11 stirs to adjust the pH value to neutrality and passes through the outlet pipe 12 to enter the subsequent biochemical treatment; the electrolyzer can pass through the emptying pipe during repair and cleaning. 13 is empty, and the landfill leachate will produce a large amount of foam in the electrolysis process, which is collected and processed by the foam collection tank 14. the

The landfill leachate enters the reaction tank 7, and iron-carbon electrolysis is used to remove COD and other pollutants in the landfill leachate, and at the same time improve the biodegradability of the landfill leachate. The landfill leachate needs to be processed under acidic conditions during the micro-electrolysis process. , the pH value is controlled at about 3, electrolysis for 2 hours, the COD removal rate can reach 50%-70%, at the same time, the biodegradability of the landfill leachate can be increased from 0.1 to about 0.3, which greatly improves the biodegradability of the landfill leachate. Subsequent biological treatment creates favorable operating conditions. the

Claims (1)

1. A device for combined electrochemical and micro-electrolysis pretreatment of landfill leachate, characterized in that it mainly includes an electrochemical treatment device, a micro-electrolysis treatment device and two outlet tanks, wherein the electrochemical treatment device mainly removes landfill leachate Medium and high concentrations of ammonia nitrogen, and then through the micro-electrolysis treatment device to remove refractory biodegradable pollutants, and finally the water is discharged from the outlet tank. 2. The device for combined pretreatment of landfill leachate by electrochemical and micro-electrolysis according to claim 1, characterized in that: the electrochemical treatment device mainly includes an electrochemical cell, and multiple groups of ruthenium iridium are arranged in the electrochemical cell For electrodes and titanium electrodes, the electrode spacing is controlled at 1-2cm, and the current density is controlled at 30mA/cm2. 3. The device for electrochemical and micro-electrolysis combined pretreatment of landfill leachate according to claim 1, characterized in that: the bottom of the electrochemical tank is provided with a water inlet, the top is provided with a water outlet, the top of the reaction tank is provided with a foam collection tank, and the bottom Set up the air aeration tube. 4. The device of electrochemical and micro-electrolysis combined pretreatment landfill leachate according to claim 1, is characterized in that: described micro-electrolysis treatment device mainly comprises a micro-electrolyzer, and Fe-C electrode is set in the micro-electrolyte , A foam collection tank is set on the top of the micro-electrolyzer, and an air pipe is set at the bottom for aeration and stirring. 5. The device for combined electrochemical and micro-electrolysis pretreatment of landfill leachate according to claim 4, characterized in that: the pH value in the micro-electrolysis cell is controlled at about 3. 6. The device for electrochemical and micro-electrolysis combined pretreatment of landfill leachate according to claim 1, characterized in that: an alkali dropping device is set in the outlet tank, and the alkali dropping device controls the pH value of the discharged water at 6 -9 or so.