Method for treating sulfate in wastewater

Abstract

The invention relates to a method for treating sulfate in wastewater, which comprises the following steps: crushing aluminum-containing oil shale waste residue, grinding into fine powder, and heating the oil shale waste residue for 3 hours; the method comprises the following steps: soaking heated oil shale waste residues in an HCl solution to dissolve the waste residues, filtering out solids, adding a Na2CO3 solution to adjust the pH value to 4.8-5.0 to remove Ca < 2 + > and Mg < 2 + >, filtering out the solids, adding a NaOH solution to adjust the pH value to be alkaline to remove Fe < 3 + >, filtering out the solids again, and adding an HCl solution to adjust the pH value to be acidic to obtain a liquid which is pickle liquor containing Al < 3 + >; the method comprises the following steps: mixing pickle liquor containing Al < 3 + > with wastewater to obtain first mixed liquor, adding quick lime or slaked lime into the first mixed liquor to adjust the pH value to be alkaline to obtain second mixed liquor, reacting the second mixed liquor in a constant-temperature environment, and after the reaction is finished, standing, precipitating and filtering to remove sulfate in the wastewater. The method disclosed by the invention is simple to operate, low in cost, environment-friendly, green and good in removal effect, and the problem of environmental pollution caused by accumulation of a large amount of oil shale waste residues is solved while sulfate pollution is removed.

Description

technical field

[0001] The invention relates to the technical field of water treatment, in particular to a method for treating sulfate in waste water. Background technique

[0002] Sulphate is contained in the waste water in the industrial production, the waste water containing the sulfate is serious to the environmental pollution, the harm is strong, the sulfuric acid reducing bacteria will further make the sewage water produce a large amount of H 2 S, seriously affected the quality of life of residents. Therefore, sulfate wastewater needs to be treated urgently.

[0003] Sulfate removal methods in wastewater mainly include adsorption method, membrane separation method, biological method, and chemical precipitation method. The adsorption method and membrane separation method have high treatment costs, while the biological method takes a long time to start up, has low treatment efficiency, and has high requirements on water quality. The chemical precipitation method can r...

Examples

Embodiment 1

[0065] A kind of treatment method of sulfate in waste water, its steps are as follows: 50g oil shale waste residue obtains 130mLAl after high temperature and multiple leaching treatments 3+ Leachate, Al measured by 3+ The concentration was 2.42g / L, that is, 0.3146g Al was extracted in total. Al in oil shale residue 2 O 3 The content accounts for 28% of the total mass, and the extraction rate of Al element is calculated to be about 4.25%.

Embodiment 2

[0067] figure 1 shows that it contains Al 3+ The effect of pH of the acid leaching solution and the sulfate reaction system in the wastewater on the sulfate removal rate in the wastewater. When pH=8 or 9 in the reaction system, SO 4 2- The removal rate is only 26%, less than 30%; when pH=11, SO 4 2- The removal rate reached 52%, and the treatment effect was significantly improved; when pH=12, SO 4 2- The removal effect is the best, and the removal rate reaches more than 95%, and when the pH continues to increase, the SO 4 2- The removal rate did not change much. This shows that the pH of SO 4 2- The removal effect has a great influence on the pH value, and it is more likely to generate aluminum calcium sulfate complex or ettringite precipitation when the pH value is higher. When the pH reaches 12, SO 4 2- The removal rate is close to the peak value.

Embodiment 3

[0069] figure 2 shows that contain Al 3+ The effect of acid leaching solution dosage on sulfate removal rate in wastewater. while keeping SO 4 2- Under the condition of 1.0g / L of acid leaching solution, the removal rate gradually increases with the increase of acid leaching solution dosage. When the acid leaching solution dosage is 16.27%, the removal rate reaches the maximum value. To consider, the acid leaching solution dosage of 16.27% is the most suitable.

technical field

[0001] The invention relates to the technical field of water treatment, in particular to a method for treating sulfate in waste water. Background technique

[0002] Sulphate is contained in the waste water in the industrial production, the waste water containing the sulfate is serious to the environmental pollution, the harm is strong, the sulfuric acid reducing bacteria will further make the sewage water produce a large amount of H 2 S, seriously affected the quality of life of residents. Therefore, sulfate wastewater needs to be treated urgently.

[0003] Sulfate removal methods in wastewater mainly include adsorption method, membrane separation method, biological method, and chemical precipitation method. The adsorption method and membrane separation method have high treatment costs, while the biological method takes a long time to start up, has low treatment efficiency, and has high requirements on water quality. The chemical precipitation method can r...

Examples

Embodiment 1

[0065] A kind of treatment method of sulfate in waste water, its steps are as follows: 50g oil shale waste residue obtains 130mLAl after high temperature and multiple leaching treatments 3+ Leachate, Al measured by 3+ The concentration was 2.42g / L, that is, 0.3146g Al was extracted in total. Al in oil shale residue 2 O 3 The content accounts for 28% of the total mass, and the extraction rate of Al element is calculated to be about 4.25%.

Embodiment 2

[0067] figure 1 shows that it contains Al 3+ The effect of pH of the acid leaching solution and the sulfate reaction system in the wastewater on the sulfate removal rate in the wastewater. When pH=8 or 9 in the reaction system, SO 4 2- The removal rate is only 26%, less than 30%; when pH=11, SO 4 2- The removal rate reached 52%, and the treatment effect was significantly improved; when pH=12, SO 4 2- The removal effect is the best, and the removal rate reaches more than 95%, and when the pH continues to increase, the SO 4 2- The removal rate did not change much. This shows that the pH of SO 4 2- The removal effect has a great influence on the pH value, and it is more likely to generate aluminum calcium sulfate complex or ettringite precipitation when the pH value is higher. When the pH reaches 12, SO 4 2- The removal rate is close to the peak value.

Embodiment 3

[0069] figure 2 shows that contain Al 3+ The effect of acid leaching solution dosage on sulfate removal rate in wastewater. while keeping SO 4 2- Under the condition of 1.0g / L of acid leaching solution, the removal rate gradually increases with the increase of acid leaching solution dosage. When the acid leaching solution dosage is 16.27%, the removal rate reaches the maximum value. To consider, the acid leaching solution dosage of 16.27% is the most suitable.

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