Landfill Leachate Evaporation Crystallization System

Abstract

The invention discloses a landfill leachate evaporation and crystallization system, a coagulation and turbidity removal subsystem, a heat recovery subsystem, an MVR evaporation subsystem and an exhaust gas deodorization subsystem; The heat recovery subsystem is connected to the MVR evaporation subsystem; the clear liquid return port of the heat recovery subsystem is connected back to the coagulation and turbidity removal subsystem; the concentrated liquid return port of the MVR evaporation subsystem is connected back to the A heat recovery subsystem; the tail gas deodorization subsystem is connected to the heat recovery subsystem. The reflux front end of the concentrated liquid produced in the system of the present invention is mixed with the original liquid and then recycled; the coagulation and turbidity removal subsystem has a small dose of medicament, and has a significant removal effect on turbidity and SS; the evaporator of the MVR evaporation subsystem adopts sand water circulation The self-cleaning system realizes the long-term stable operation of the evaporation subsystem.

Description

technical field [0001] The invention relates to the field of landfill leachate treatment, in particular to a landfill leachate stock solution evaporation crystallization system. Background technique [0002] Pollution control of landfill leachate has always been a thorny issue in urban waste management systems at home and abroad. Foreign research started earlier, and has decades of experience, and has developed a variety of processing technologies and processes. However, domestic research on landfill leachate treatment technology started late, and most of them copied foreign technologies. Therefore, it is an urgent problem to promote the development of waste disposal technology to seek a set of economical and reasonable technology suitable for landfill leachate treatment in my country. [0003] In 2008, my country promulgated and implemented the "Pollution Control Standards for Domestic Waste Landfill Sites" (GB16889-2008), which put forward higher standards for the treatme...

AI Technical Summary

Problems solved by technology

Due to the characteristics of leachate, such as large fluctuations in water quality and volume, high ammonia nitrogen content, and imbalanced nutrients, it is difficult to meet the treatment standards and the operating cost is high.

At present, domestic waste treatment manufacturers mainly adopt the "pretreatment + biochemical + membrane" process, including multiple treatment processes such as flocculation, anaerobic, aerobic, ultrafiltration (MBR), NF / RO, etc. The system is complex and there are many affected factors , and due to the limited membrane recovery rate, more than 30% of concentrated liquid with high pollution concentration will be produced during operation

[0004] At present, the treatment methods of membrane concentrate mainly include recharge cycle treatment and evaporation treatment. If recharge cycle treatment is used, it is easy to cause the salt to not be discharged in time and accumulate, which will affect the activity of microorganisms in the biochemical treatment process, and the cleaning and replacement of the membrane Frequency will go up, resulting in higher operating costs, so not a long-term solution

If evaporation treatment is adopted, the "MVC+DI" evaporation mode is currently used. Since landfill leachate contains high salt and high organic matter, there are six major problems in evaporation, that is, there is no pretreatment system before entering the evaporation system, resulting in pretreatment. The heater is seriously blocked; after entering the evaporator, as the leachate evaporates and concentrates, crystals such as salt, calcium, and magnesium in the leachate precipitate and adhere to the heat exchange tube, resulting in serious fouling of the evaporator; the feed temperature varies with the weather The temperature difference changes greatly, and after entering the evaporation, the heat balance of the system will be invalid; the cold material entering the system after evaporation starts completely depends on the electric heating method, which takes a long time; the concentrated liquid and condensed water produced by the evaporation system can not be obtained after DI treatment. Effective disposal, causing secondary pollution

These problems seriously affect the long-term stable operation of landfill leachate evaporation treatment system

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