Good-applicability treatment method of mercury-containing wastewater

Abstract

The invention provides a good-applicability treatment method of mercury-containing wastewater. The treatment method comprises the following steps of 1, taking an appropriate amount of the mercury-containing wastewater, adding any one of a calcium hydroxide solution, mixed alkali liquor composed of calcium hydroxide and sodium hydroxide or a sulfuric acid solution as a PH regulator, and regulating PH value to be 8-11; 2, adding an organic sulfur heavy metal ionic capturing agent as a mercury removing agent, so that mercury ions precipitate to generate insoluble chelate particles; 3, adding an aluminum sulfate series solution as a coagulant, so that the chelate particles are destabilized for coalescence to form coarse small particles; 4, adding the pH regulator to regulate the pH value back to be 6-9; 5, adding a polyacrylamide series solution as an organic flocculant, so that the coarse small particles generate coalescence, the precipitation is accelerated, solid and liquid are separated, and supernatant is taken to test the mercury content. The treatment method of the mercury-containing wastewater with the good applicability not only achieves efficient and high-quality treatment of the mercury-containing wastewater, but also has the advantages of being wide in applicability, easy to operate and high in industrialized degree.

Description

technical field [0001] The invention relates to the technical field of mercury-containing wastewater treatment, in particular to a method for treating mercury-containing wastewater with good applicability. Background technique [0002] Mercury pollution in water bodies caused by human activities mainly comes from the production process of mercury-related industries, which produces a large amount of mercury-containing wastewater. If the discharge exceeds the health standards stipulated by the state, it will cause harm to human and animal health. In recent years, many regions in China have The mercury content in the water body is seriously exceeding the standard; and the occurrence of mercury pollution incidents is due to the serious consequences of the discharge of mercury-containing wastewater into the water body due to the failure of control. Therefore, it is necessary to strengthen the treatment of mercury-containing wastewater and control its discharge. [0003] At presen...

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Problems solved by technology

It is found through experiments that this method has the following disadvantages: 1) it is only for inorganic laboratory wastewater, and the treatment is single; 2) according to this method, the mercury-containing wastewater is treated, and the precipitation mentioned in the literature is not produced after standing for 1 hour, and the wastewater is pale yellow ; 3) process mercury-containing wastewater according to this method, filter the supernatant after standing for 1 hour, and measure mercury far greater than the standard of 50ug / L

[0013] 1) The amount of sodium sulfide is difficult to control, and a large amount of malodorous gas is generated during the treatment process;

[0014] 2) Excessive sulfur ions will lead to an increase in water body COD;

[0015] 3) If ferrous sulfate is added to eliminate excessive sulfur ions, its dosage is difficult to control and the dosage is large, and the final water color will be light green to light yellow, and the water color is difficult to meet the standard;

[0016] 4) The settling speed is slow. After dosing, the standing time is as long as 8 hours, which is difficult to operate. In practice, it is found that the waste water containing organic matter will become turbid if the standing time is long;

[0017] 5) Polyaluminum chloride is used as a flocculant, which still cannot make the water clear and transparent;

[0018] 6) A large amount of black odorous sludge is produced, which is not conducive to personnel operation, and if it is left for a long time, the color of the water will turn yellow, because there are ferric ions (Fe 3+ )exist

However, these three methods have their own shortcomings that cannot be widely used in industry: they are not suitable for wastewater with complex components, not suitable for oily wastewater, or have low treatment capacity or high cost, etc.

In theory, sodium sulfide, TMT-18F and other substances can form precipitation with mercury, but in actual operation, because the formed precipitation particles are extremely small, they cannot be precipitated, and the mercury concentration after filtration still far exceeds the limit of environmental protection emission standards

[0020] In summary, no matter the traditional process or the improved method, the treatment effect is not ideal, so the treatment method for mercury-containing wastewater needs to be further improved

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