CN106673362A - Combined treatment process of landfill leachate - Google Patents

Abstract

A combination treatment process of landfill leachate, which adopts the traditional combination process of primary treatment mainly based on physical and chemical treatment and secondary treatment mainly based on biochemical treatment. This treatment stage can adopt mature, widely used and economical The traditional treatment process performs the first-stage treatment on the landfill leachate to remove most of the pollutants in the landfill leachate that can be removed by traditional treatment methods; after the secondary effluent is discharged, it enters the advanced oxidation treatment stage, through the strong oxidation of the advanced oxidation process Ability to effectively degrade the main components of pollutants in the secondary effluent, that is, refractory macromolecular organic matter. At this stage, the biodegradability of water quality is greatly improved by effectively degrading refractory macromolecular organic matter; after advanced oxidation treatment The final effluent enters the stage of biochemical treatment with excellent economy again, and then through biochemical treatment, the effluent quality reaches the discharge standard of GB16889‑2008 "National Domestic Waste Landfill Pollution Control Standard".

Description

A combined treatment process for landfill leachate

technical field

The invention relates to a combination treatment process of "biochemical" + "advanced oxidation" of landfill leachate, in particular to a combined treatment process of landfill leachate with biochemical treatment + advanced oxidation treatment + biochemical treatment as the core, which belongs to sewage treatment technology and craft areas.

Background technique

With the increase of my country's urban population, the expansion of city scale and the improvement of people's living standards, the output of urban domestic waste in my country is increasing sharply every year. At present, the treatment methods of municipal solid waste mainly include incineration, high-temperature composting and sanitary landfill. Among them, sanitary landfill has been widely used because of its simple technology and excellent economic advantages. However, this treatment method will produce a large amount of landfill leachate. At present, my country's landfill leachate mainly adopts a combined process of physical and chemical primary treatment and biochemical secondary treatment. However, because landfill leachate contains a large amount of refractory macromolecular organic matter, the water quality after treatment by this traditional and widely used treatment process cannot meet the discharge requirements in GB16889-2008 "National Domestic Waste Landfill Pollution Control Standards".

In response to this situation, there have been a large number of engineering examples in the field of municipal solid waste leachate treatment engineering in my country with the "double-membrane method", that is, membrane bioreactor (MBR) + nanofiltration reverse osmosis (NF/RO) as the main process route. This process has a good treatment effect, but its initial one-time investment cost is too high and the operating cost is high. In particular, nano-reverse osmosis (NF/RO) is a typical membrane filtration, which is essentially a "transfer" process of pollutants. It has not fundamentally removed pollutants, and there are prominent problems such as large volume of concentrated liquid and difficult disposal. In response to this outstanding problem, on the basis of traditional biological treatment processes, advanced oxidation technology is combined with it to form a "dual biochemical" + "advanced oxidation" combined treatment process for landfill leachate. Through a reasonable combination of treatment processes, both The problem of removing the leachate pollutants is solved, and good economy and operability can be obtained.

The advanced oxidation technology is mainly to generate hydroxyl radicals (•OH) with strong oxidizing ability through oxidants under certain reaction conditions, which react with macromolecular refractory organic substances in wastewater, destroy the molecular structure of organic substances, and degrade them into small Molecular substances are even completely degraded into carbon dioxide and water to achieve effective "transformation" of pollutants. Therefore, the biodegradability of the secondary effluent of landfill leachate treated by advanced oxidation technology can be significantly improved, so that the entire "twin biochemical" + advanced oxidation process can be implemented smoothly.

Contents of the invention

The purpose of the present invention is to provide a combined landfill leachate treatment process with biochemical treatment + advanced oxidation treatment + biochemical treatment as the core to solve the deficiencies of the prior art.

The "dual biochemical" + "advanced oxidation" combined treatment process of landfill leachate includes: physical and chemical pretreatment, primary biochemical treatment, advanced oxidation treatment, and secondary biochemical treatment. The process steps are as follows:

The landfill leachate passes through the adjustment tank and the water pump once through the primary sedimentation tank and ammonia stripping tower in the physical and chemical pretreatment stage, and then enters the primary biochemical treatment device, namely the membrane bioreactor. After the above treatment, the biochemical properties of the landfill leachate have been greatly improved. The main pollutants in the water are macromolecular refractory organic substances, and then the biochemical effluent is introduced into the advanced oxidation treatment device, that is, the UV+Fenton advanced oxidation treatment device. After advanced oxidation treatment, the biodegradability of the water quality is improved, and finally the membrane bioreactor is used again , that is, the secondary biochemical treatment technology makes the effluent finally meet the discharge standard.

The physical and chemical pretreatment is a pretreatment process based on physical and chemical methods such as coagulation, precipitation, and stripping;

The primary biochemical treatment is based on anaerobic processes such as UASB (upflow anaerobic sludge bed) and ABR (anaerobic baffle reactor) processes and aerobic processes such as contact oxidation, oxidation ditch, and A/O processes. The main biochemical treatment process;

The advanced oxidation treatment process is an advanced oxidation treatment process based on UV+Fenton and _O3 advanced oxidation technology;

The secondary biochemical treatment is a follow-up biochemical treatment process based on membrane bioreactor (MBR), biological aerated filter (BAF) process, etc.;

The "dual biochemical" + "advanced oxidation" combined treatment process of landfill leachate, its physical and chemical pretreatment and primary biochemical treatment stages can flexibly set specific treatment processes according to specific water quality conditions, so as to pass through the secondary oxidation process with excellent economical efficiency. The combined process of multi-stage treatment removes most of the pollutants in landfill leachate that can be removed by this technology;

The "dual biochemical" + "advanced oxidation" combined treatment process of landfill leachate, the advanced oxidation treatment and the secondary biochemical treatment can be adjusted according to the specific conditions of the secondary effluent water quality by adjusting the advanced oxidation treatment and the secondary biochemical treatment. The synergistic relationship between biochemical treatments enables higher comprehensive economic benefits while ensuring the treatment effect.

The beneficial effects of the present invention are: through the above scheme, the traditional physical and chemical pretreatment and primary biochemical treatment technology can be used to carry out the preliminary treatment of the landfill leachate, and this widely used and economically beneficial process can be used to remove the absolute Most of the pollutants, in view of the characteristics of extremely poor biodegradability of the landfill leachate effluent treated by this traditional process, advanced oxidation technology is used for the next step of treatment, and advanced oxidation technology is used to treat the pollutants contained in the secondary effluent A large number of refractory macromolecular organics are effectively oxidized and degraded, and the biodegradability of the water quality is greatly improved, and then the biochemical treatment technology is used to perform secondary biochemical treatment on the effluent after advanced oxidation treatment, so that the final effluent quality can reach GB16889- Discharge requirements in the 2008 "National Domestic Waste Landfill Pollution Control Standards". In the above process, according to the specific water quality, the advanced oxidation and secondary biochemical treatment processes can be reasonably matched to minimize the comprehensive treatment cost on the premise that the final effluent quality meets the discharge requirements. In addition, the above-mentioned scheme can also be very convenient for carrying out corresponding technical transformation work for a large number of treatment facilities currently existing with physicochemical pretreatment and primary biochemical treatment technology as the core.

Description of drawings

Fig. 1 is the process flow sheet of processing method of the present invention;

Fig. 2 is the process flow sheet of embodiment 1 of the present invention;

Fig. 3 is the process flow chart of embodiment 2 of the present invention;

In the figure: 1. Regulating tank 2. Primary sedimentation tank 3. Ammonia stripping tower 4. Membrane bioreactor 5. Ozone advanced oxidation treatment device 6. Membrane bioreactor A. for recovery as combustion B. for recovery as emission C . For air D. For ozone.

detailed description

The following content will further illustrate the relevant characteristics of the present invention in conjunction with the accompanying drawings, but this does not limit the present invention to the scope of the described embodiments.

Embodiment 1: The "dual biochemical" + "advanced oxidation" combined treatment process of landfill leachate, including physical and chemical pretreatment, primary biochemical treatment, advanced oxidation treatment, and secondary biochemical treatment. The landfill leachate passes through the adjustment tank (1) and the water pump once through the primary sedimentation tank (2) and the ammonia stripping tower (3) in the physical and chemical pretreatment stage, and then enters the primary biochemical treatment device, namely the membrane bioreactor (4). After the above-mentioned treatment, the biochemical properties of the filtrate have been greatly reduced. The main pollutants in the water are macromolecular refractory organic substances. After treatment, the biodegradability of the water quality is greatly improved, and finally the membrane bioreactor (6) is used again, that is, the secondary biochemical treatment technology makes the effluent finally meet the discharge standard. The process flow chart adopted in this scheme is shown in Figure 2.

Adopt the present invention to treat the landfill leachate in Nanchang, and the treatment effect is shown in the following table:

From the test data obtained in the table, it can be seen that the final effluent quality of the landfill leachate treated by the present invention can meet the discharge requirements in GB16889-2008 "National Domestic Waste Landfill Pollution Control Standard".

Embodiment 2: The "dual biochemical" + "advanced oxidation" combined treatment process of landfill leachate, including physical and chemical pretreatment, primary biochemical treatment, advanced oxidation treatment, and secondary biochemical treatment. The landfill leachate passes through the adjustment tank (1) and the water pump once through the primary sedimentation tank (2) and the ammonia stripping tower (3) in the physical and chemical pretreatment stage, and then enters the primary biochemical treatment device, namely the membrane bioreactor (4). After the above treatment, the biodegradability of the filtrate has been greatly reduced, and the main pollutants in the water are refractory macromolecular organic substances. At this time, the biochemical effluent is passed into the advanced oxidation treatment device, that is, the ozone advanced oxidation treatment device (5). , greatly improve the biodegradability of water quality, and finally use the membrane bioreactor (6) again, that is, the secondary biochemical treatment technology to make the effluent finally meet the discharge standard. The process flow chart adopted in this scheme is shown in Figure 3.

Adopt the present invention to treat the landfill leachate in Nanchang, and the treatment effect is shown in the following table:

From the test data obtained in the table, it can be seen that the final effluent quality of the landfill leachate treated by the present invention can meet the discharge requirements in GB16889-2008 "National Domestic Waste Landfill Pollution Control Standard".

Claims (1)

1. A combined treatment process of landfill leachate, characterized in that: said combined treatment process comprises: physical and chemical pretreatment, primary biochemical treatment, advanced oxidation treatment, secondary biochemical treatment; concrete steps are: The landfill leachate passes through the adjustment tank and the water pump once through the primary sedimentation tank and ammonia stripping tower in the physical and chemical pretreatment stage, and then enters the primary biochemical treatment device, namely the membrane bioreactor. After the above treatment, the biochemical properties of the landfill leachate have been greatly improved. The main pollutants in the water are macromolecular refractory organic substances, and then the biochemical effluent is introduced into the advanced oxidation treatment device, that is, the UV+Fenton advanced oxidation treatment device. After advanced oxidation treatment, the biodegradability of the water quality is improved, and finally the membrane bioreactor is used again , that is, the secondary biochemical treatment technology makes the effluent finally meet the discharge standard; The physical and chemical pretreatment is a pretreatment process mainly based on coagulation precipitation and stripping physical and chemical methods; The primary biochemical treatment is a biochemical treatment based on UASB (upflow anaerobic sludge bed), ABR (anaerobic baffle reactor process anaerobic process) and contact oxidation, oxidation ditch, A/O process aerobic process. process; The advanced oxidation treatment process is an advanced oxidation treatment process based on UV+Fenton and _O3 advanced oxidation technology; The secondary biochemical treatment is a follow-up biochemical treatment process mainly composed of membrane bioreactor (MBR) and biological aerated filter (BAF).