Wastewater mercury removal agent, and preparation method and application thereof

Abstract

The invention belongs to the technical field of sewage treatment materials, and particularly relates to a wastewater mercury removal agent, and a preparation method and application thereof. According to the preparation method of the mercury adsorption material, hydrotalcite with an adjustable and controllable interlayer structure and polypyrrole modified montmorillonite are prepared as raw materials, the hydrotalcite is subjected to delamination separation through N, N-dimethylformamide to form a dispersed lamellar structure, then the hydrotalcite and the montmorillonite are subjected to composite intercalation to further form a polyhydroxy-based layered structure composite material with a space domain effect, and then sulfydryl modification is carried out by utilizing the specific polyhydroxy-based layered structure of the material, so as to prepare the modified adsorption material which can be applied to adsorbing Hg<2+> in mercury-containing wastewater. The mercury adsorption material is applied to the mercury adsorption process of mercury-containing wastewater, the content of mercury in adsorbed water is stably lower than 5 [mu]g / L, stable regeneration can be achieved, and the mercury adsorption material is suitable for industrial popularization.

Description

technical field

[0001] The invention belongs to the technical field of sewage treatment materials, and in particular relates to a mercury-removing agent for waste water and its preparation method and application. Background technique

[0002] Mercury, commonly known as mercury, has attracted widespread attention due to its characteristics of being highly toxic, bioaccumulative, volatile, easy to migrate and transform, and difficult to biodegrade. Mercury can accumulate in organisms and is easily absorbed by the skin, respiratory tract and digestive tract. Listed as a global pollutant. Currently, China's discharge standards for mercury-containing wastewater require that the concentration of mercury in the effluent is not higher than 5 μg / L. Therefore, how to effectively remove mercury contained in wastewater is a difficult problem in the field of sewage and wastewater treatment. Traditional mercury treatment processes in the prior art include chemical precipitation, activat...

Examples

Embodiment 1

[0065] The preparation method of waste water mercury removal agent described in the present embodiment comprises the following steps:

[0066] (1) Preparation of hydrotalcite

[0067] Prepare 2L Mg(NO 3 ) 2 ·6H 2 O and Fe(NO 3 ) 3 9H 2 Mixed magnesium-iron salt solution of O, control Mg in the solution 2+ The concentration is 0.6mol / L, Fe 3+ The concentration is 0.15mol / L;

[0068] Prepare 2LNaOH and Na 2 CO 3 The mixed alkali solution, control the Na in the solution 2 CO 3 The concentration of NaOH is 0.3mol / L, and the concentration of NaOH is 1.5mol / L;

[0069] After adding 4L of deionized water into the 10L reactor, add the mixed magnesium-iron salt solution and the mixed alkali solution dropwise into the reactor at a rate of 400ml / h, while vigorously stirring to control the pH value of the mixed stirring solution in the reactor 9; after the titration, the slurry was stirred at 60°C and aged for 12 hours; after aging, the formed hydrotalcite was filtered, washe...

Embodiment 2

[0085] The preparation method of mercury adsorption material described in the present embodiment, comprises the steps:

[0086] (1) Preparation of hydrotalcite

[0087] Prepare 2L Mg(NO 3 ) 2 ·6H 2 O and Fe(NO 3 ) 3 9H 2 Mixed magnesium-iron salt solution of O, control Mg in the solution 2+ The concentration is 0.8mol / L, Fe 3+ The concentration is 0.2mol / L;

[0088] Prepare 2L NaOH and NaOH 2 CO 3 The mixed alkali solution, control the Na in the solution 2 CO 3 The concentration of NaOH is 0.4mol / L, and the concentration of NaOH is 2.0mol / L;

[0089] After adding 4L of deionized water into the 10L reactor, add the mixed magnesium-iron salt solution and the mixed alkali solution dropwise into the reactor at a rate of 600ml / h, while vigorously stirring to control the pH value of the mixed stirring solution in the reactor After the titration, the slurry was kept at 60°C for 12 hours and aged for 12 hours; after aging, the formed hydrotalcite was filtered, washed and ...

Embodiment 3

[0105] The preparation method of mercury adsorption material described in the present embodiment, comprises the steps:

[0106] (1) Preparation of hydrotalcite

[0107] Prepare 2L Mg(NO 3 ) 2 ·6H 2 O and Fe(NO 3 ) 3 9H 2 Mixed magnesium-iron salt solution of O, control Mg in the solution 2+ The concentration is 0.7mol / L, Fe 3+ The concentration is 0.18mol / L;

[0108] Prepare 2LNaOH and Na 2 CO 3 The mixed alkali solution, control the Na in the solution 2 CO 3 The concentration of NaOH is 0.35mol / L, and the concentration of NaOH is 1.8mol / L;

[0109] After adding 5L of deionized water into the 10L reactor, add the mixed magnesium-iron salt solution and the mixed alkali solution dropwise into the reactor at a rate of 500ml / h, while vigorously stirring to control the pH value of the mixed stirring solution in the reactor 9.5; after the titration, the slurry was kept at 60°C and stirred for 12 hours; after aging, the formed hydrotalcite was filtered, washed and filter...

technical field

[0001] The invention belongs to the technical field of sewage treatment materials, and in particular relates to a mercury-removing agent for waste water and its preparation method and application. Background technique

[0002] Mercury, commonly known as mercury, has attracted widespread attention due to its characteristics of being highly toxic, bioaccumulative, volatile, easy to migrate and transform, and difficult to biodegrade. Mercury can accumulate in organisms and is easily absorbed by the skin, respiratory tract and digestive tract. Listed as a global pollutant. Currently, China's discharge standards for mercury-containing wastewater require that the concentration of mercury in the effluent is not higher than 5 μg / L. Therefore, how to effectively remove mercury contained in wastewater is a difficult problem in the field of sewage and wastewater treatment. Traditional mercury treatment processes in the prior art include chemical precipitation, activat...

Examples

Embodiment 1

[0065] The preparation method of waste water mercury removal agent described in the present embodiment comprises the following steps:

[0066] (1) Preparation of hydrotalcite

[0067] Prepare 2L Mg(NO 3 ) 2 ·6H 2 O and Fe(NO 3 ) 3 9H 2 Mixed magnesium-iron salt solution of O, control Mg in the solution 2+ The concentration is 0.6mol / L, Fe 3+ The concentration is 0.15mol / L;

[0068] Prepare 2LNaOH and Na 2 CO 3 The mixed alkali solution, control the Na in the solution 2 CO 3 The concentration of NaOH is 0.3mol / L, and the concentration of NaOH is 1.5mol / L;

[0069] After adding 4L of deionized water into the 10L reactor, add the mixed magnesium-iron salt solution and the mixed alkali solution dropwise into the reactor at a rate of 400ml / h, while vigorously stirring to control the pH value of the mixed stirring solution in the reactor 9; after the titration, the slurry was stirred at 60°C and aged for 12 hours; after aging, the formed hydrotalcite was filtered, washe...

Embodiment 2

[0085] The preparation method of mercury adsorption material described in the present embodiment, comprises the steps:

[0086] (1) Preparation of hydrotalcite

[0087] Prepare 2L Mg(NO 3 ) 2 ·6H 2 O and Fe(NO 3 ) 3 9H 2 Mixed magnesium-iron salt solution of O, control Mg in the solution 2+ The concentration is 0.8mol / L, Fe 3+ The concentration is 0.2mol / L;

[0088] Prepare 2L NaOH and NaOH 2 CO 3 The mixed alkali solution, control the Na in the solution 2 CO 3 The concentration of NaOH is 0.4mol / L, and the concentration of NaOH is 2.0mol / L;

[0089] After adding 4L of deionized water into the 10L reactor, add the mixed magnesium-iron salt solution and the mixed alkali solution dropwise into the reactor at a rate of 600ml / h, while vigorously stirring to control the pH value of the mixed stirring solution in the reactor After the titration, the slurry was kept at 60°C for 12 hours and aged for 12 hours; after aging, the formed hydrotalcite was filtered, washed and ...

Embodiment 3

[0105] The preparation method of mercury adsorption material described in the present embodiment, comprises the steps:

[0106] (1) Preparation of hydrotalcite

[0107] Prepare 2L Mg(NO 3 ) 2 ·6H 2 O and Fe(NO 3 ) 3 9H 2 Mixed magnesium-iron salt solution of O, control Mg in the solution 2+ The concentration is 0.7mol / L, Fe 3+ The concentration is 0.18mol / L;

[0108] Prepare 2LNaOH and Na 2 CO 3 The mixed alkali solution, control the Na in the solution 2 CO 3 The concentration of NaOH is 0.35mol / L, and the concentration of NaOH is 1.8mol / L;

[0109] After adding 5L of deionized water into the 10L reactor, add the mixed magnesium-iron salt solution and the mixed alkali solution dropwise into the reactor at a rate of 500ml / h, while vigorously stirring to control the pH value of the mixed stirring solution in the reactor 9.5; after the titration, the slurry was kept at 60°C and stirred for 12 hours; after aging, the formed hydrotalcite was filtered, washed and filter...