Processing method of landfill leachate film concentrated solution

Abstract

The invention discloses a processing method of landfill leachate film concentrated solution. The processing method comprises the following steps of: (1) softening the landfill leachate film concentrated solution and then carrying out micro-filtration, to obtain trapped fluid and penetrating fluid; and (2) filtering the penetrating fluid by a DTRO (disk tubular reverse osmosis) membrane and then discharging directly; wherein the softening process comprises the following steps of: (a) adding calcium hydroxide into the landfill leachate film concentrated solution, adjusting pH value to 10-10.5; (b) adding sodium hydroxide and magnesium salt, adjusting the pH value to 11-12; and (c) settling, carrying out solid-liquid separation, carrying out plate-frame pressure filtration on the solid phase, and returning the filtrate to the step (1); adding a precipitant into the liquid phase, controlling the content of calcium and magnesium ions to be less than 20mg / L, and controlling the content of soluble silicon dioxide to be less than 10mg / L, and then carrying out micro-filtration. By utilizing the method, the content of heavy metal ion, calcium and magnesium ions in the concentrated solution can be reduced furthest, the scaling problem in the subsequent film system is controlled effectively, and therefore the recovering efficiency of the landfill leachate film concentrated solution is improved.

Description

technical field [0001] The invention relates to the technical field of sewage treatment, in particular to a method for treating landfill leachate membrane concentrate. Background technique [0002] At present, water pollution has seriously restricted my country's economic development, social progress and improvement of people's living standards, and it is very urgent to solve the problem of water pollution. In 2003, more than 200,000 tons of waste water was discharged for every 100 million yuan of GDP produced in my country, which was an increase of 84.8% compared with 1990; the aggravation of environmental pollution has continuously increased the cost of environmental governance. For this reason, my country's annual investment in environmental governance exceeds 100 billion yuan, accounting for about 2% of the country's GDP; it can be seen that water pollution has a great impact on my country. Among the many waste waters, landfill leachate has always been a difficult probl...

AI Technical Summary

Problems solved by technology

[0006] Although the above methods have improved the recovery efficiency of the landfill leachate membrane concentrate to a certain extent, because the above method only undergoes a first-level softening treatment before the membrane treatment, the heavy metal ions and calcium and magnesium ions in the concentrate are precipitated. A certain amount of heavy metal ions and calcium and magnesium ions still remain in the concentrated solution, so that the concentrated solution is not completely softened, and after passing through the microfiltration membrane, it enters the subsequent reverse osmosis, which makes the reverse osmosis prone to fouling, and the recovery efficiency of the above method cannot be further improved. improve

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