Removal of calcium and magnesium ions of concentrated liquor in urban refuse landfill by virtue of multiple precipitation method

A technology of municipal waste and precipitation method, applied in the field of magnesium ion, multiple precipitation method to remove calcium from concentrated liquid of municipal waste landfill, can solve the problem of large sludge output, achieve less sludge production, simple control, and reduce dosage amount of effect

CN105217751AInactive Publication Date: 2016-01-06胡明成
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Applications(China)
Current Assignee / Owner
Publication Date
2016-01-06
Estimated Expiration
Not applicable · inactive patent

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Abstract

The invention relates to removal of calcium and magnesium ions of concentrated liquor in a urban refuse landfill by virtue of a multiple precipitation method. The agent added into the concentrated liquor is ammonium phosphate and sodium hydroxide, and ammonia dissociated from ammonium phosphate serves as a ligand substance of a precipitate. The adding quantity is 500-2000 ppm and the accurate value of the added quantity is determined according to the actual content of the calcium and magnesium ions in the waste water. To add sodium hydroxide is to maintain the pH value of a mixed liquid at about 8, and the input quantity is determined according to the pH value of the wastewater. The removal provided by the invention has the advantages of being small in mud output and high in reliability. As the precipitate product of the concentrated liquor in the treatment process can be prevented from returning into a percolate treatment system as being finally solidified and buried, a metal hydroxide precipitation method and a metal carbonate precipitation method which are relatively large in mud output are not suitable for treatment of the concentrated liquor.
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Description

technical field

[0001] The invention relates to a multiple precipitation method for removing calcium and magnesium ions from concentrated liquids of urban refuse landfills. Background technique

[0002] Because the leachate produced in urban landfills is very harmful to the environment, many countries in the world attach great importance to the treatment of leachate. Even some traditional pure water preparation technologies such as nanofiltration and reverse osmosis have been applied on a large scale in the field of landfill leachate treatment. In China, the "Standards for Pollution Control of Domestic Garbage Landfill" (GB16889-2008) promulgated a few years ago put forward stricter requirements for the treatment of landfill leachate. This means that more advanced water treatment technologies must be adopted in the design process of new construction and reconstruction of leachate treatment facilities. Due to the poor biodegradability of landfill leachate, it is difficult t...

Examples

Embodiment Construction

[0025] The device for removing calcium and magnesium ions in landfill leachate in the present invention includes a cylindrical reactor made of steel structure and an automatic water inlet device. Since the amount of landfill leachate is small, the present invention adopts the treatment mode of intermittent water inflow and intermittent drainage. The automatic water inlet device includes a water pump and a water pipe. The water pump transports the landfill leachate to the reactor through the water pipe. The water pipe is equipped with a valve to control the water flow; the inside of the reactor is equipped with an agitator driven by a motor, which can realize continuous automatic stirring. , the stirring speed can be adjusted, and the middle and lower part of the reactor is provided with a water outlet. The water outlet is connected with the filter in the reactor through a pipeline, and is used to discharge the precipitated supernatant. A sludge discharge port is provided at t...