CN-121990678-A - Method for removing chemical oxygen demand by catalyst prepared from acid mine wastewater

Abstract

The method for removing the chemical oxygen demand by the catalyst prepared by the acid mine wastewater comprises the steps of firstly recovering valuable elements in the acid mine wastewater, accurately adding sodium hydrosulfide to control conditions, recovering transition metal elements with catalytic activity in the acid mine wastewater by fractional precipitation, directionally preparing the nano-scale metal catalyst, degrading the chemical oxygen demand in the wastewater by the prepared nano-scale metal catalyst, solving the problem of environmental pollution of the mine wastewater and the wastewater containing the chemical oxygen demand, and realizing the dual effects of resource recovery and environmental treatment.

Inventors

• HUANG JIAXIN
• WU CAISONG
• LI PENGHUI
• LIU YONGFENG
• WANG XINGXING
• DAI XUN
• WANG CHENG

Assignees

• 江西铜业股份有限公司

Dates

Publication Date

20260508

Application Date

20260228

Claims (5)

1. 1. A method for removing chemical oxygen demand by a catalyst prepared from acid mine wastewater, comprising the steps of: preparing a transition metal sulfide nanocatalyst, comprising: Taking acid mine wastewater, wherein the acid mine wastewater comprises manganese ions, copper ions and iron ions, the manganese ion content is more than 50mg/L, and the copper ion content is more than 50mg/L; If the iron ion content in the acid mine wastewater is more than 100mg/L, preprocessing the acid mine wastewater, adding alkali liquor into the acid mine wastewater to adjust the pH value to 4-5, generating flocculent precipitate of ferric hydroxide and ferrous hydroxide, standing after stirring uniformly, precipitating the floccules, and filtering the preprocessed mine wastewater to obtain mine wastewater to be processed; If the iron ion content in the acid mine wastewater is less than 100mg/L, the acid mine wastewater is not required to be pretreated as mine wastewater to be treated; Adding sodium hydrosulfide solution into mine wastewater to be treated at a first stirring rate while stirring at a first dripping rate, wherein the first stirring rate is 250rpm-300rpm, the first dripping rate is 0.5 mL/L.s-2 mL/L.s, the mass concentration of the sodium hydrosulfide solution is 20 wt% -30 wt%, the reaction temperature is 20-30 ℃, and the addition is stopped after the reaction pH value reaches 7-8, wherein the reaction formula is as follows: Cu 2+ +HS - →CuS↓+H + ; Mn 2+ +HS - +H 2 O→Mn(OH) 2 ↓+H 2 S↑; 2Mn(OH) 2 +O 2 →2MnO(OH) 2 ↓; Mn 2+ +S 2- →MnS↓; Centrifuging to collect black solid generated after the reaction, wherein the centrifuging speed is 800rpm-1000rpm, and washing for 2-3 times by ethanol and deionized water; Vacuum drying is carried out on the black solid after washing to obtain a transition metal sulfide nano catalyst; The transition metal sulfide nano catalyst removes S 2- and organic matter reducing substances in a polluted water body in a heterogeneous catalytic oxidation system, and comprises the following components: providing a polluted water body, wherein the concentration of chemical oxygen demand in the polluted water body is 300 mg/L-500 mg/L, and the concentration of S 2- is 50mg/L-200mg/L; adjusting the pH value of the polluted water body to 4-9; And adding an oxidant and the transition metal sulfide nano catalyst into the polluted water body, wherein the adding amount of the oxidant in each liter of the polluted water body is 1g-2g, and the adding amount of the transition metal sulfide nano catalyst in each liter of the polluted water body is 1g-3g.
2. 2. The method for removing chemical oxygen demand by a catalyst prepared from acid mine wastewater according to claim 1, wherein an alkali solution is added to the acid mine wastewater, the alkali solution being one of sodium hydroxide or calcium hydroxide.
3. 3. The method for removing chemical oxygen demand by a catalyst prepared from acid mine wastewater according to claim 1, wherein the oxidizing agent comprises potassium hydrogen persulfate.
4. 4. The method for removing chemical oxygen demand by a catalyst prepared from acid mine wastewater according to claim 1, wherein the black solid after washing is vacuum-dried, wherein the drying temperature is 40 ℃ to 45 ℃ and the drying time is 40h to 48h.
5. 5. The method for removing chemical oxygen demand from a catalyst prepared from acid mine wastewater according to claim 1, further comprising recycling the transition metal sulfide nanocatalyst more than 4 times.

Description

Method for removing chemical oxygen demand by catalyst prepared from acid mine wastewater Technical Field The present disclosure relates to the field of wastewater treatment technologies and resource recovery, and more particularly, to a method for removing chemical oxygen demand by a catalyst prepared from acid mine wastewater. Background Acidic mine wastewater (ACID MINE DRAINAGE, AMD) is wastewater from natural or mine ore mining, transportation, beneficiation and metallurgy processes where sulfur-containing and sulfidic minerals are exposed to air and water, oxidized under the catalysis of microorganisms such as thiobacillus ferrooxidans to form sulfuric acid and ferric sulfate, and dissolved other metallic elements. On one hand, the strong acidity and high concentration of heavy metal ions can cause serious pollution to the ecological environment, and on the other hand, the transition metal elements such as iron, copper, manganese and the like contained in the acid mine wastewater have huge resource recovery potential, so that the transition metal in the acid mine wastewater is not reasonably developed and utilized in the prior art. The prior art 1 (publication No. CN105439357A, application day 2015.12.28) discloses a recycling and deep purifying method for mine acid wastewater, which comprises the steps of 1) adjusting the pH value of the mine acid wastewater to 2.2-2.6 by using a neutralizer, then carrying out solid-liquid separation to obtain gypsum, 2) adjusting the pH value of the mine wastewater to 2.8-3.2 by using the neutralizer, then removing iron ions and recycling iron slag, 3) adding a vulcanizing agent into a solution after removing iron to carry out efficient vulcanization to obtain copper-zinc slag, 4) separating copper-zinc slag by using acid leaching to obtain copper-rich slag and zinc sulfate solution, and recycling the vulcanizing agent, and 5) carrying out deep treatment on final effluent. In the prior art 1, no deep treatment is performed on copper zinc elements, and copper zinc slag is not effectively applied. Therefore, it is highly desirable to provide a method that can treat acidic mine wastewater and also can comprehensively utilize the treated product. Disclosure of Invention In view of the above, the present disclosure provides a method for removing chemical oxygen demand by a catalyst prepared from acid mine wastewater, for treating the acid mine wastewater, and comprehensively utilizing the treated product. The present disclosure provides a method for removing chemical oxygen demand by a catalyst prepared from acid mine wastewater, comprising the steps of: preparing a transition metal sulfide nanocatalyst, comprising: Taking acid mine wastewater, wherein the acid mine wastewater comprises manganese ions, copper ions and iron ions, the manganese ion content is more than 50mg/L, and the copper ion content is more than 50mg/L; If the iron ion content in the acid mine wastewater is more than 100mg/L, preprocessing the acid mine wastewater, adding alkali liquor into the acid mine wastewater to adjust the pH value to 4-5, generating flocculent precipitate of ferric hydroxide and ferrous hydroxide, standing after stirring uniformly, precipitating the floccules, and filtering the preprocessed mine wastewater to obtain mine wastewater to be processed; If the iron ion content in the acid mine wastewater is less than 100mg/L, the acid mine wastewater is not required to be pretreated as mine wastewater to be treated; Adding sodium hydrosulfide solution into mine wastewater to be treated at a first stirring rate at 250-300 rpm while stirring, wherein the first stirring rate is 0.5-2 mL/L.s, the mass concentration of the sodium hydrosulfide solution is 20-30wt%, the reaction temperature is 20-30deg.C, and the reaction pH reaches 7-8, wherein the reaction formula is as follows: Cu2++HS-→CuS↓+H+; Mn2++HS-+H2O→Mn(OH)2↓+H2S↑; 2Mn(OH)2+O2→2MnO(OH)2↓; Mn2++S2-→MnS↓; Centrifuging to collect black solid generated after the reaction, wherein the centrifuging speed is 800rpm-1000rpm, and washing for 2-3 times by ethanol and deionized water; Vacuum drying is carried out on the black solid after washing to obtain a transition metal sulfide nano catalyst; The transition metal sulfide nano catalyst removes S 2- and organic matter reducing substances in a polluted water body in a heterogeneous catalytic oxidation system, and comprises the following components: Providing a polluted water body, wherein the concentration of chemical oxygen demand in the polluted water body is 300mg/L-500mg/L, and the concentration of S 2- is 50mg/L-200mg/L; adjusting the pH value of the polluted water body to 4-9; And adding an oxidant and the transition metal sulfide nano catalyst into the polluted water body, wherein the adding amount of the oxidant in each liter of the polluted water body is 1g-2g, and the adding amount of the transition metal sulfide nano catalyst in each liter of the polluted water body is 1g-3g. Op