CN204310899U - Rubbish leachate total hardness Transformatin system - Google Patents

Abstract

The utility model discloses a treatment system for removing total hardness of garbage leachate. The garbage leachate total hardness removal treatment system includes a primary treatment device connected to the garbage leachate for primary treatment, a primary dosing clarification equipment and a secondary dosing clarification equipment for coagulation, sedimentation and clarification of the garbage leachate , and a ceramic membrane filtration device for filtering the supernatant of the garbage leachate, the primary chemical addition and clarification equipment and the secondary chemical addition and clarification equipment are sequentially connected between the primary treatment device and the ceramic membrane filtration device Between; wherein, the primary dosing and clarification equipment includes a sodium hydroxide mixed reaction tank, and the secondary dosing and clarification equipment includes a sodium carbonate mixed reaction tank. The utility model can remove the hardness of the garbage leachate to the greatest extent, reduce the fouling frequency of the subsequent treatment system (such as the evaporation system), ensure the continuous operation of the evaporation system, and improve the stability and reliability of the garbage leachate treatment system. .

Description

Landfill leachate total hardness removal treatment system

technical field

The utility model relates to the technical field of garbage treatment, in particular to a treatment system for removing total hardness of garbage leachate.

Background technique

With the rapid development of the economy and the continuous improvement of living standards, the output of urban domestic waste has also increased rapidly. Compared with sanitary landfill methods, composting methods, etc. etc. have great advantages and meet the requirements of sustainable development. Domestic waste incineration power generation has become a new direction to solve urban domestic waste in recent years. The construction of waste incineration plants has developed rapidly in recent years. During the storage, transfer, transportation, and stacking of garbage, a variety of metabolites and water are produced due to anaerobic fermentation, decomposition of organic matter, rainwater leaching, etc., forming a high-concentration organic wastewater with extremely complex components—garbage leachate. Untreated leachate not only pollutes soil and surface water, but also pollutes water sources through groundwater flow, posing a permanent threat to human health and the environment. Therefore, the pollution control of garbage leachate has become an important part of the harmless treatment of garbage incineration.

Of course, in addition to the leachate pollution produced by domestic waste, the leachate produced in other places, such as power plant leachate, industrial waste leachate, etc., also affects people's health and environmental pollution.

At present, there are usually the following methods for the treatment of landfill leachate: biological treatment technology, membrane treatment technology, physical and chemical treatment technology and evaporation treatment technology. Since the heat source of the waste incineration plant is sufficient to meet the energy required for evaporation treatment, and the concentrated liquid of the evaporation treatment can be sprayed back into the incinerator for incineration treatment, therefore, the evaporation treatment technology has a good application prospect in the leachate treatment technology of the waste incineration plant .

Garbage leachate contains Ca ²⁺ and Mg ²⁺ , the concentrations of which are about 3500mg/L and 1000mg/L respectively, and the total hardness is about 12950mg/L. If it is not treated, scaling will easily occur in the subsequent evaporation treatment. It will affect the stable operation of the subsequent evaporation treatment, so it is generally necessary to pre-treat the leachate to remove hardness before evaporation treatment. The existing pretreatment system generally filters the garbage leachate through the grid first, then enters the garbage leachate adjustment tank for homogeneous treatment, uses a water pump to transport it to the mixing tank, and adds lime and sodium carbonate to adjust the pH value. Then it is transported to the mechanical stirring sedimentation tank through the water pump for stirring and clarification, and finally flows into the clear liquid tank.

In the pretreatment, although adding lime can adjust the pH value of the leachate and have a certain coagulation and sedimentation effect, it inevitably brings the following problems: 1. The slaked lime input is a powdery substance that will be produced in the mixing tank. Scum, these scums are difficult to discharge, and will also affect the stirring effect of the agitator; 2. Calcium ions will be generated after adding lime, increasing the concentration of calcium ions and hardness, and the amount of sodium carbonate will also increase accordingly, increasing the cost of the medicament, and It is also easier to foul in the subsequent evaporation system, which is not conducive to the continuous operation of the evaporation system.

Utility model content

The technical problem to be solved by the utility model is to provide a treatment system for removing total hardness of garbage leachate which effectively removes total hardness of garbage leachate and reduces scaling frequency of subsequent treatment systems.

The technical scheme adopted by the utility model to solve the technical problem is: to provide a total hardness removal treatment system of garbage leachate, including a primary treatment device connected to the garbage leachate for primary treatment, coagulation and sedimentation of the garbage leachate The primary dosing clarification equipment and the secondary dosing clarification equipment for clarification treatment, and the ceramic membrane filter device for filtering the supernatant of the garbage leachate, the first dosing clarification equipment and the second dosing clarification equipment The clarification equipment is sequentially connected between the primary treatment device and the ceramic membrane filter device;

Wherein, the primary dosing and clarification equipment includes a sodium hydroxide mixing reaction tank, and the secondary dosing and clarification equipment includes a sodium carbonate mixing reaction tank.

Preferably, the treatment system also includes a pH meter for detecting the pH value of the garbage leachate in the sodium hydroxide mixing reaction tank;

The sodium hydroxide mixed reaction tank includes a first reaction tank body connected to the primary treated garbage leachate, adding sodium hydroxide to the first reaction tank body according to a pH preset value and combining the pH meter The measured pH value adjusts the first automatic dosing device for adding the amount of sodium hydroxide, and the first feeding system for providing sodium hydroxide to the first automatic dosing device.

Preferably, the treatment system also includes a hardness detection device for detecting the hardness of the supernatant of the landfill leachate before filtering;

The sodium carbonate mixing reaction tank includes a second reaction tank body connected to the garbage leachate treated by the primary dosing and clarification equipment, adding sodium carbonate to the second reaction tank body and combining the hardness detection The hardness value measured by the device adjusts the second automatic dosing device of the added amount of sodium carbonate, and provides the second feeding system of sodium carbonate for the second automatic dosing device.

Preferably, the primary dosing and clarification equipment also includes a primary sedimentation tank for primary sedimentation of the garbage leachate reacted with sodium hydroxide in the sodium hydroxide mixing reaction tank, and the primary sedimentation tank is connected to Between the sodium hydroxide mixed reaction tank and the sodium carbonate mixed reaction tank.

Preferably, the primary sedimentation tank includes a tank body, a mud scraper arranged at the bottom of the tank body, and a scum scraper arranged at the upper part of the tank body.

Preferably, the secondary dosing clarification equipment also includes a secondary sedimentation tank that will react the garbage leachate after reacting with sodium carbonate in the sodium carbonate mixing reaction tank for secondary precipitation, and the secondary sedimentation tank is connected to Between the sodium carbonate mixing reaction tank and the ceramic membrane filter device.

Preferably, the secondary sedimentation tank includes a tank body, a mud scraper arranged at the bottom of the tank body, and a scum scraper arranged at the upper part of the tank body.

Preferably, the primary treatment device includes a grid for preliminary filtration of the incoming garbage leachate, and a leachate adjustment tank for homogenizing and equalizing the garbage leachate filtered through the grid; The grid is arranged at the water inlet of the leachate adjustment tank.

Preferably, the ceramic membrane of the ceramic membrane filter device is an inorganic ceramic membrane with a filtration precision of 50-100 nm and a filtration pressure of 3-5 bar.

Preferably, the treatment system further includes a clear liquid tank connected downstream of the ceramic membrane filter device for storing and outputting the filtered garbage leachate supernatant.

Beneficial effects of the utility model: by reacting and precipitating the garbage leachate with sodium hydroxide and sodium carbonate in sequence and then filtering, the concentration of Ca ²⁺ and Mg ²⁺ in the garbage leachate is greatly reduced, and the garbage leachate can be removed to the greatest extent. Filtrate hardness, the removal rate can reach more than 99%. At the same time, it can also remove suspended solids, colloidal substances, heavy metal ions, etc. in the garbage leachate. Compared with adding lime, the amount of sludge is greatly reduced, and the scaling frequency of subsequent treatment systems (such as evaporation systems) is also reduced. The continuous operation of the evaporation system improves the stability and reliability of the landfill leachate treatment system.

Description of drawings

The utility model will be further described below in conjunction with accompanying drawing and embodiment, in the accompanying drawing:

Fig. 1 is a flow diagram of a system for removing total hardness of landfill leachate according to an embodiment of the present invention.

Detailed ways

In order to have a clearer understanding of the technical features, purposes and effects of the utility model, the specific implementation of the utility model is described in detail with reference to the accompanying drawings.

The system and method for removing the total hardness of garbage leachate according to the utility model are used for pretreatment before garbage leachate treatment (such as evaporation), and are suitable for pretreatment of garbage leachate in garbage incineration plants, garbage incineration power plants, etc. .

As shown in Figure 1, the total hardness removal treatment system of garbage leachate according to an embodiment of the present utility model includes a primary treatment device, a primary dosing clarification equipment, a secondary dosing clarification equipment, and a ceramic membrane filtration device 4, and a primary processing device. The medicine clarification equipment and the secondary medicine addition clarification equipment are sequentially connected between the primary treatment device and the ceramic membrane filtration device 4 . Among them, the primary treatment device is used to access the garbage leachate for primary treatment; the first-level chemical dosing and clarification equipment and the second-level chemical dosing and clarification equipment carry out coagulation, sedimentation and clarification treatment on the garbage leachate in order to reduce the Ca in the garbage leachate. ²⁺ concentration and Mg ²⁺ concentration can remove the hardness of the landfill leachate to the greatest extent; the ceramic membrane filtration device 4 filters the supernatant of the landfill leachate.

In this embodiment, the primary treatment device includes a grid 11 for preliminary filtration of the connected garbage leachate, and a leachate adjustment tank 12 for homogenizing and equalizing the garbage leachate filtered by the grid 11; The grid 11 is arranged at the water inlet of the leachate adjustment tank 12, and is used for preliminary filtration of the leachate of the garbage to remove solid particles with a particle size larger than 0.75-1mm. The garbage leachate filtered by the grid 11 naturally flows into the leachate regulating tank 12, and the leachate regulating tank 12 performs homogeneous treatment on the garbage leachate to reduce the variation range of the hydraulic and water quality loads of the subsequent treatment facilities. Create pre-conditions for maintaining the stable operation of the system. The hydraulic retention time of the leachate regulating tank 12 is 7-10 days, so that the garbage leachate can achieve the purpose of homogeneity and quantity. One or more grids 11 and leachate adjustment tanks 12 can be provided according to different landfill leachate water quality requirements, and there can be one or more types.

It can be understood that the treatment system also includes setting between the primary treatment device and the primary chemical addition clarification equipment, between the primary chemical addition clarification equipment and the secondary chemical addition clarification equipment, and the secondary chemical addition clarification equipment and ceramic membrane filtration One or more water pumps 10 between the devices 4 are used to transport garbage leachate.

The garbage leachate treated by the primary treatment device can be transported to the primary chemical addition and clarification equipment through the water pump 10 for treatment. The primary dosing and clarification equipment includes a sodium hydroxide mixing reaction tank 21, which performs coagulation and sedimentation, pH adjustment and other treatments on the garbage leachate; the garbage leachate reacts with sodium hydroxide in the sodium hydroxide mixing reaction tank 21 , so that Ca ²⁺ and Mg ²⁺ in the garbage leachate react with sodium hydroxide to precipitate, reduce the concentration of Ca ²⁺ and Mg ²⁺ in the garbage leachate, and initially remove the hardness of the garbage leachate. The sodium hydroxide mixing reaction tank 21 may include a first reaction tank body connected to the primary treated garbage leachate, a first automatic dosing device, and a first feeding system for providing sodium hydroxide to the first automatic dosing device. The first automatic dosing device can adjust the amount of sodium hydroxide added according to the pH value of the garbage leachate and the like, and adjust the pH value of the garbage leachate.

In order to obtain the pH value of the garbage filtrate, the treatment system also includes a pH meter 6 for detecting the pH value of the garbage leachate in the sodium hydroxide mixing reaction tank 21, which can realize real-time detection of the pH value of the garbage leachate. The first automatic dosing device adjusts the amount of sodium hydroxide added according to the pH preset value combined with the pH value measured by the pH meter 6 . By adjusting the addition of sodium hydroxide, the pH value of the garbage leachate in the sodium hydroxide mixing reaction tank 21 is adjusted to 11-12, and the volume percentage concentration of the sodium hydroxide solution in the sodium hydroxide mixing reaction tank 21 is controlled to be 20%. -30%.

In order to better remove the hardness of the garbage leachate by precipitation, the primary dosing and clarification equipment also includes a primary sedimentation tank 22, which is connected to the downstream of the sodium hydroxide mixed reaction tank 21, that is, connected to the sodium hydroxide mixed reaction tank 21 Between this and the secondary dosing and clarification equipment, the garbage leachate reacted with sodium hydroxide in the sodium hydroxide mixing reaction tank 21 is subjected to primary precipitation. The garbage leachate reacted with sodium hydroxide can be transported to the primary sedimentation tank 22 through the water pump 10 . The primary sedimentation tank 22 may include a tank body, a sludge scraper arranged at the bottom of the tank body, and a scum scraper arranged at the upper part of the tank body. The sludge scraper is used to scrape off the settled sludge at the bottom of the tank body, The scum scraper is used to scrape off the scum floating on the tank body. The mud scraper and scum scraper can regularly scrape the sludge and scum to avoid the accumulation of sludge and scum. The sludge and scum scraped off by the primary sedimentation tank 22 can be regularly discharged into the sludge treatment system for subsequent treatment of the sludge.

The garbage leachate treated by the first-level chemical addition and clarification equipment is then transported to the second-level chemical addition and clarification equipment for treatment. The secondary dosing and clarification equipment includes a sodium carbonate mixing reaction tank 31, and the garbage leachate reacts with sodium carbonate in the sodium carbonate mixing reaction tank 31 for coagulation and precipitation, so that Ca ²⁺ , Mg ²⁺ and Sodium carbonate reacts and precipitates again to reduce the concentration of Ca ²⁺ and Mg ²⁺ in the garbage leachate, and further remove the hardness of the garbage leachate. The primary sedimentation tank 22 is connected between the sodium hydroxide mixed reaction tank 21 and the sodium carbonate mixed reaction tank 31 .

This sodium carbonate mixing reaction tank 31 can comprise the second reaction tank body that inserts the garbage leachate that is processed through primary dosing clarification equipment, the second automatic dosing device and the second automatic dosing device that provides sodium carbonate. Feeding system; the second automatic dosing device is used to add sodium carbonate to the second reaction pool. The processing system also includes a hardness detection device 7 for detecting the hardness of the supernatant of the leachate of the garbage before filtering, which can realize real-time detection of the hardness of the leachate of the garbage. The second automatic dosing device also adjusts the amount of sodium carbonate added in conjunction with the hardness value recorded by the hardness detection device 7, and can increase the amount of sodium carbonate added when the hardness value exceeds a preset value. By adjusting the addition of sodium carbonate, the volume percentage concentration of the sodium carbonate solution in the sodium carbonate mixing reaction tank 31 is controlled to be 10%-30%.

The secondary dosing clarification equipment also includes a secondary sedimentation tank 32, which is connected between the sodium carbonate mixing reaction tank 31 and the ceramic membrane filter device 4, and the garbage leachate after reacting with sodium carbonate in the sodium carbonate mixing reaction tank 31 Secondary precipitation is carried out to obtain the supernatant of landfill leachate for subsequent filtration. The hardness of the supernatant after the secondary precipitation is detected online by the hardness detection device 7, and the second automatic dosing device adjusts the amount of sodium carbonate added according to the detection data. The garbage leachate reacted with sodium carbonate can be transported to the secondary sedimentation tank 32 through the water pump 10 . The secondary sedimentation tank 32 may include a tank body, a mud scraper arranged at the bottom of the tank body, and a scum scraper arranged at the upper part of the tank body. The mud scraper is used to scrape off the sedimented sludge at the bottom of the tank, and the scum scraper is used to scrape off the scum floating on the tank body. The mud scraper and scum scraper can regularly remove the sludge Scrape off the scum and scum to avoid the accumulation of sludge and scum. The sludge and scum scraped by the secondary settling tank 32 can be regularly discharged into the sludge treatment system for subsequent treatment of the sludge.

The ceramic membrane of the ceramic membrane filter device 4 is an inorganic ceramic membrane, which has good chemical stability, is stable under acidic and alkaline conditions, and has a wide range of applicable pH values. Preferably, the filtration precision of the ceramic membrane is 50nm-100nm, and the filtration pressure is 3-5bar. The ceramic membrane has high precision and uniform distribution, and a clearer supernatant of landfill leachate can be obtained after filtration.

In addition, the treatment system also includes a clear liquid tank 5 connected downstream of the ceramic membrane filter device 4, the clear liquid tank 5 is used to access the filtered garbage leachate supernatant, and the filtered garbage leachate supernatant The liquid is stored and exported. The clear liquid bucket 5 can output the supernatant liquid of the garbage leachate to the evaporation system 8 for evaporation treatment. Through the pretreatment of the garbage leachate by the treatment system of the utility model, while removing the total hardness of the garbage leachate, it can also remove suspended solids, colloidal substances, heavy metal ions, etc. in the leachate, and the amount of sludge is significantly larger than that of adding lime. It also reduces the fouling frequency of the follow-up treatment system (such as the evaporation system 8), ensures the continuous operation of the evaporation system, and improves the stability and reliability of the garbage leachate treatment system.

In a specific actual implementation process, after the garbage leachate passes through the sodium hydroxide mixed reaction tank 21, it is subjected to primary precipitation by the primary sedimentation tank 22, and the Ca ²⁺ and Mg ²⁺ concentrations of the supernatant after the precipitation are respectively changed from the original 3500mg/L and 1000mg/L are reduced to 2100mg/L and 70mg/L, and the total hardness is reduced from the original 12950mg/L to 5550mg/L. The garbage leachate after the primary precipitation is reacted by the sodium carbonate mixed reaction tank 31 again, and then the secondary precipitation ^is carried out by the secondary sedimentation tank 32, and the Ca and ^Mg concentrations of the supernatant after the precipitation are respectively 40mg/L and About 15mg/L, the total hardness is about 162mg/L. The supernatant of the garbage leachate after the sedimentation treatment in the secondary sedimentation tank 32 flows into the ceramic membrane filter device 4 for filtration, further separates and clarifies the leachate, and the Ca ²⁺ and Mg ²⁺ concentrations of the filtered supernatant are respectively The total hardness is about 15mg/L and 10mg/L, and the total hardness is about 80mg/L. It can be seen that, after the treatment system, the hardness removal rate of the landfill leachate reaches more than 99%.

Through the pretreatment of the garbage leachate by the above-mentioned treatment system, the total hardness of the garbage leachate can be removed, and the removal rate can reach more than 99%, which reduces the scaling frequency of the subsequent treatment system (such as the evaporation system) and ensures the continuity of the evaporation system. The operation improves the stability and reliability of the landfill leachate treatment system.

The above is only an embodiment of the utility model, and does not limit the patent scope of the utility model. Any equivalent structure or equivalent process conversion made by using the utility model specification and accompanying drawings, or directly or indirectly used in other Related technical fields are all included in the patent protection scope of the present utility model in the same way.

Claims (10)

1. A total hardness removal treatment system for garbage leachate, characterized in that it includes a primary treatment device connected to the garbage leachate for primary treatment, and a primary dosing clarification for coagulation and sedimentation of the garbage leachate and clarification treatment equipment, secondary dosing and clarification equipment, and a ceramic membrane filtration device for filtering the supernatant of the landfill leachate, the primary dosing and clarification equipment and the secondary dosing and clarification equipment are connected in turn to the primary treatment between the device and the ceramic membrane filtration device; Wherein, the primary dosing and clarification equipment includes a sodium hydroxide mixing reaction tank, and the secondary dosing and clarification equipment includes a sodium carbonate mixing reaction tank. 2. garbage leachate total hardness removal treatment system according to claim 1, is characterized in that, this treatment system also comprises the pH meter that detects the pH value of garbage leachate in described sodium hydroxide mixed reaction tank; The sodium hydroxide mixed reaction tank includes a first reaction tank body connected to the primary treated garbage leachate, adding sodium hydroxide to the first reaction tank body according to a pH preset value and combining the pH meter The measured pH value adjusts the first automatic dosing device for adding the amount of sodium hydroxide, and the first feeding system for providing sodium hydroxide to the first automatic dosing device. 3. garbage leachate total hardness removal treatment system according to claim 1, is characterized in that, this treatment system also comprises the hardness detection device that the hardness of described garbage leachate supernatant before filtering is detected; The sodium carbonate mixing reaction tank includes a second reaction tank body connected to the garbage leachate treated by the primary dosing and clarification equipment, adding sodium carbonate to the second reaction tank body and combining the hardness detection The hardness value measured by the device adjusts the second automatic dosing device of the added amount of sodium carbonate, and provides the second feeding system of sodium carbonate for the second automatic dosing device. 4. the garbage leachate total hardness removal treatment system according to claim 1, is characterized in that, described one-level dosing clarification equipment also comprises will react with sodium hydroxide in described sodium hydroxide mixed reaction tank A primary sedimentation tank for primary precipitation of the garbage leachate, the primary sedimentation tank is connected between the sodium hydroxide mixed reaction tank and the sodium carbonate mixed reaction tank. 5. The total hardness removal treatment system of landfill leachate according to claim 4, wherein said primary sedimentation tank comprises a tank body, a mud scraper arranged at the bottom of said tank body, and a mud scraper arranged at the bottom of said tank body. The scum scraper on the upper part of the body. 6. the garbage leachate total hardness removal treatment system according to claim 1, is characterized in that, described secondary dosing clarification equipment also comprises the garbage leachate after reacting with sodium carbonate in described sodium carbonate mixed reaction tank The filtrate is subjected to a secondary sedimentation tank for secondary precipitation, and the secondary sedimentation tank is connected between the sodium carbonate mixing reaction tank and the ceramic membrane filter device. 7. The total hardness removal treatment system of landfill leachate according to claim 6, wherein the secondary sedimentation tank comprises a tank body, a mud scraper arranged at the bottom of the tank body, and a mud scraper arranged at the bottom of the tank body The scum scraper on the upper part of the body. 8. The total hardness removal treatment system of landfill leachate according to claim 1, wherein the primary treatment device includes a grid for preliminary filtration of the landfill leachate connected, and will be filtered through the grid The final leachate of the garbage is subjected to a homogeneous leachate adjustment tank; the grid is arranged at the water inlet of the leachate adjustment tank. 9. The total hardness removal treatment system of garbage leachate according to claim 1, wherein the ceramic membrane of the ceramic membrane filter device is an inorganic ceramic membrane, the filtration accuracy is 50-100nm, and the filtration pressure is 3-5bar . 10. according to any one of claim 1-9 described landfill leachate total hardness removal treatment system, it is characterized in that, this treatment system also comprises the downstream that is connected in described ceramic membrane filtration device, to the landfill leachate through filtering The supernatant is stored and exported to the supernatant bucket.