The power plant leachate treatment equipment is mainly used to treat the leachate generated by garbage power generation. The power plant leachate is mainly the water content of garbage itself and the water content generated by biochemical reaction in the garbage stacking process. It is a fresh leachate and a high concentration organic wastewater.
1、 Brief introduction of leachate
1. Appearance features: the appearance features of fresh leachate are yellow green and stink, with high chroma and turbidity.
2. Water quality index:

High concentration of heavy metal ions
Conductivity > 20000
Due to the change of region and season, the water quality data of leachate also changes.
2、 Evaluation of current conventional treatment methods
With the development of the research and Practice on the treatment technology of leakage liquid, the treatment technology gradually moves from diversity to consistency. However, in the post-treatment stage, there are various methods, some of which are membrane treatment technology (such as nanofiltration or reverse osmosis technology), some of which are evaporation technology, activated carbon adsorption and so on.
At present, the mainstream technology is nanofiltration or reverse osmosis technology, which is widely accepted by experts in various forms of conferences. But this technology has a fatal defect, the proportion of concentrated water formed in the membrane treatment process is large, and it is difficult to deal with. Due to the lack of appropriate treatment methods for concentrated water, this part of the content is often intentionally or unintentionally ignored in the design of each family.
This kind of system has high maintenance cost and operation cost.
Evaporation technology is just introduced from abroad. In the process of evaporation, in addition to salts, other harmful gases, such as nitrogen oxides and ammonia nitrogen, are also evaporated. It needs more difficult separation technology to be matched. Its maintenance and operation costs are staggering.
Although the mature A2 / O process is used as the pretreatment process, but for the high concentration landfill leachate, copying the mature design parameters will still cause serious problems, so in the actual operation of the project, the nitrification and denitrification system will not operate normally.
3、 Characteristics of treatment process in our company
Our company's treatment process is based on a large number of practical projects and experiments, and has strong pertinence.
The conventional pretreatment process has the following characteristics:
a) The pretreatment process is still A2 / O process, but the design parameters are mostly obtained by experiments.
b) According to the water quality characteristics of leachate, a lot of improvements have been made to all reaction units. In order to ensure the high performance and high efficiency of the reaction process, we should pay special attention to the improvement of the internal details of the reactor.
c) On the basis of the conventional process route, the auxiliary processing unit is added to facilitate the commissioning in a short time, enhance the impact resistance of the system, and ensure the stable operation of the system.
The post-treatment process is essentially different from that of other companies and is a full biochemical process.
In the post-treatment process, the advanced anaerobic ammonia oxidation technology in the world is used for the treatment of total nitrogen, which is a non power system. The residual nitrate nitrogen and ammonia nitrogen in the pre-treatment biological denitrification system are thoroughly treated.
Biochemical decolorization system is the patented technology of the company, and it is also a non dynamic system. After the post-treatment process, the water quality indicators completely meet the gb16889-2008 standard.
The characteristics of post-treatment process are as follows:
a) It is a whole biochemical process, free of secondary pollution and secondary pollution. It is thoroughly treated.
b) The anaerobic ammonia oxidation system and biochemical decolorization system are both non power systems. Except for the residual cod which needs aerobic treatment, there is no other power cost. This is incomparable with other post-treatment methods, so the power cost is very low, less than 5% of other processes.
c) In the operation process, online dosing of chemicals is not required.
d) The system has less sludge discharge, and there is almost no other maintenance work except for sludge discharge and equipment inspection.
e) The equipment is durable, except for the fan, other equipment can be free from maintenance within 10 years.
4、 Brief introduction of the whole biochemical treatment process
1. Process flow chart
2. Process description
This process takes nitrification / denitrification biological denitrification process section as the core, and the process units before nitrification / denitrification process section are used as the pretreatment process of biological denitrification system.
1) Anaerobic reactor A1
Main functions of anaerobic reactor A1:
a) The biological toxicity of heavy metals was eliminated by microorganism.
b) The organic molecules were hydrolyzed to make the refractory organic molecules into easily degradable organic compounds, which prepared electronic donors for the subsequent denitrification and denitrification.
c) N and S combined with organic compounds are dissociated from organic molecules and converted into NH3 and S2 -.
d) The metal atoms combined with or complexed with organic molecules are dissociated from these molecules and become free ions to completely remove the metal.
After the treatment of the reactor, CODcr can be reduced by 50%.
2) Denitrification reactor
Main functions of the reactor:
In this process, the denitrifying bacteria are used to reduce NOx -.
3) Aerobic nitrification reactor
Main functions of nitrification reactor:
It is to oxidize ammonia nitrogen to nitrate nitrogen or nitrite nitrogen, provide it to denitrification reactor for denitrification, and completely oxidize the remaining COD of denitrification.
4) Anaerobic ammonia oxidation reactor:
Main functions of anammox reactor:
The total nitrogen in the effluent of nitrification and denitrification (A / O) system is still more than 200mg / L. at the same time, after the treatment of a / O reactor, the rbcod in the water is very low, which is not enough for denitrification. Therefore, the subsequent denitrification treatment can only use anaerobic ammonia oxidation technology. That is to say, ammonia is used as electronic donor of denitrification and nitrate nitrogen for biological reaction to produce nitrogen, so that the total nitrogen can reach the emission standard, and the total nitrogen can be reduced to within 40 mg / L.
At present, anammox technology is the frontier technology of biological denitrification, and many countries are still carrying out a lot of research. It is difficult to cultivate anammox bacteria in the system