Evaporation residue solidification process based on landfill leachate full-quantitative treatment

Abstract

The invention discloses an evaporation residue solidification process based on landfill leachate full-quantitative treatment, and belongs to the technical field of solid waste treatment. The evaporation residue solidification process based on landfill leachate full-quantitative treatment comprises the following steps: mixing evaporation residues with a neutralizing curing agent, wherein the neutralization curing agent is selected from the group consisting of water-quenched slag, steel slag and furnace slag. The process provided by the invention completely replaces lime required to be added inthe existing process, saves the cement consumption, improves the compressive strength of the cured body while ensuring higher curing efficiency, avoids the generation of ammonia gas, and is environment-friendly, efficient and economic.

Description

technical field [0001] The invention belongs to the field of solid waste treatment, and in particular relates to an evaporation residue solidification process based on the full quantitative treatment of landfill leachate. Background technique [0002] The leachate of landfill has complex components, and has the characteristics of high organic matter content, high SS content and high electrical conductivity. Most of the landfills in my country have entered the aging stage, and the biochemistry of the leachate is poor. At present, the combined process of "pretreatment + biological treatment + advanced treatment" has been widely used, and advanced treatment mostly uses membrane separation technology, including nanofiltration and reverse osmosis. The combined process can ensure that the effluent is discharged up to the standard, but the resulting 20% ​​to 30% membrane filtration concentrate is difficult to dispose of. At present, the concentrated liquid recharge is a common tr...

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Problems solved by technology

[0003] Lime and cement are used for solidification of conventional garbage concentrated liquid evaporation residue, which has the following problems: First, sulfuric acid is added to adjust the pH of the garbage concentrated liquid during the evaporation process to prevent ammonia nitrogen from entering the condensed water, which causes the pH of the evaporated residue to be between 3 to 5, so the residue is directly added to the lime for adjustment, which will increase the amount of lime, and will generate calcium sulfate with a retarding effect, which will affect the curing effect; second, adding a large amount of lime will lead to the release of ammonia gas during the curing process. It not only pollutes the environment, but also causes the solidified body to have a honeycomb shape, resulting in a decrease in the strength of the solidified body in the later stage, or even pulverization, and the strength of the solidified body is lost

In the above curing method, more than 10 types of curing base materials, curing agents, and stabilizers are added, and the amount of chemical agents added is too large. Although industrial solid waste is used as the curing base material, the adding device will be very complicated in practical applications. , greatly increase the operating cost; the mass ratio of the garbage concentrate to all solid materials is 0.5:1 to 1:1, obviously the water content is greater than 30%; in addition, the stabilizer is added with a strong alkaline substance sodium hydroxide, which is bound to be incompatible with the concentration Ammonia nitrogen in the liquid reacts to release ammonia gas

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