Biological treatment device for acid mine wastewater

Abstract

The utility model discloses a biological treatment device for acid mine wastewater. The biological treatment device comprises a connecting pipe, a peristaltic pump, an aeration device with an air compressor and an aeration pipe, a biological oxidation component, a biological reduction component, a water outlet tank and a water inlet tank, the biological oxidation part consists of an AMD tank, a peristaltic pump, a biological oxidation reactor, an iron precipitation reactor, a settling tank and a connecting pipe; the biological oxidation reactor is filled with biological filler, is provided with an aeration device, enters from the lower part and exits from the upper part and is beneficial to growth and attachment of microorganisms; the iron precipitation reactor is provided with a stirring device and can adjust the pH value of a solution; the settling tank is used for solid-liquid separation after an iron precipitation reaction and clarification of the solution; the biological reduction part consists of three peristaltic pumps, a biological reduction reactor 7 capable of realizing internal water circulation, heating, temperature measurement, sampling and bacterial liquid addition, two peristaltic pumps, two connecting pipes, three connecting pipes and a water outlet tank for solid-liquid separation and solution clarification; and the wastewater subjected to biological oxidation treatment is received by the water inlet tank and then flows to biological reduction for continuous treatment. The device has the advantages of purifying water and recycling Fe and Cu under the condition of low loss of Cu with low pH value, and being high in cost performance and the like.

Description

TECHNICAL FIELD

[0001] The utility model relates to the field of environmental protection equipment and environmental governance technology, concretely relates to a biological treatment device of mine acid wastewater. BACKGROUND

[0002] According to statistics, 10% of industrial wastewater discharge in China comes from mining activities every year, of which only 4.23% is discharged after treatment, and the rest is naturally discharged. Naturally discharged wastewater poses a serious threat to the environment, of which the most influential and most widespread pollution is acid mine drainage (AMD). AMD refers to the acid wastewater produced by the chemical action and biological oxidation of sulfide minerals in ore exposed to water and air during mining activities. Once formed, mine wastewater is difficult to control its production process, and a large amount of manpower, material resources and financial resources are needed to govern it. Since the pH value of AMD is generally between 4.5 and 6.5, and some are even lower than 2.0, and it contains high concentrations of heavy metal ions such as copper, lead, zinc, iron, manganese, nickel, chromium and aluminum, as well as other toxic non-metallic elements such as arsenic and cyanide, AMD will cause serious environmental pollution on a large scale if it is not treated before being discharged. It will have a significant and far-reaching impact on water resources, aquatic life and soil, which has obviously become a problem that cannot be ignored globally.

[0003] The main treatment methods of AMD at present include chemical neutralization, artificial wetland method and microbial method, etc. Various AMD control and treatment technologies at the present stage play an important role in reducing AMD formation, reducing AMD acidity and removing metal pollution, especially the chemical neutralization method and its improved methods are widely used due to their high efficiency and stability. However, this method requires a large amount of chemicals to reduce metals to an acceptable discharge level, and the excess sludge needs further treatment, which has a large sludge treatment cost. The metal hydroxide precipitation is slow, the settling performance is poor, the metal precipitate aggregates, there is a risk of secondary pollution, the water content is high, especially when the water quality is poor and the water quantity is large. Moreover, there is no effective way to recover the heavy metals in lime neutralization slag, which causes further waste of metal resources and further increase in disposal cost.

[0004] To solve the above problems, Chinese patent CN217627969U discloses "a neutralization pretreatment device for acid mine water", which includes an oxidation sedimentation tank provided with a screen, a sediment storage tank provided with a connecting screen link, a pH adjusting tank filled with carbonate, and commonly used connecting pipes, peristaltic pumps and aeration devices, in order to reduce the content of H+ in water and thus increase the pH, improve the speed of subsequent Fe2+ oxidation, make most of the iron hydroxide precipitate exist in the screen, and improve the wastewater treatment efficiency, but it is limited to the precipitation treatment of iron in wastewater before neutralization; Patent CN111777224A discloses "a method for comprehensive utilization of non-ferrous metal mine multi-metal acid wastewater", which aims to recover sulfuric acid radicals in acid wastewater and produce calcium sulfate whiskers by controlling the acidity of the solution through neutralization, realizing product high value, and is limited to a method; Patent CN102816931A discloses "a method for recovering copper and iron from copper-containing acid wastewater and producing gypsum", which includes lime neutralization and iron precipitation, hydrochloric acid leaching, lime neutralization and iron precipitation again, calcium precipitation with sulfuric acid and regeneration with hydrochloric acid, lime / plate alkali neutralization and copper precipitation, and sulfuric acid leaching steps, and is also limited to a method.

[0005] Therefore, it is of practical significance to develop a biological treatment device for mine acid wastewater. SUMMARY

[0006] The task of the utility model is to overcome the shortcomings of the prior art, and provide a biological treatment device for mine acid wastewater, which can recover Fe and Cu under the condition of low pH value and less Cu loss.

[0007] To complete the above task, the utility model adopts the following technical scheme:

[0008] A biological treatment device for mine acid wastewater, which comprises a connecting pipe, a peristaltic pump and an aeration device with an air compressor and an aeration pipe, and further comprises a biological oxidation component, a biological reduction component, a water outlet tank and a water inlet tank shared by the two; the biological oxidation component sequentially comprises an AMD tank, a first peristaltic pump, a biological oxidation reactor with biological filler inside, an aeration device, a downward inlet and upward outlet, and is beneficial to the growth and adhesion of microorganisms, a sedimentation tank for iron precipitation, a stirring device and a NaOH solution for adjusting the pH value of the solution, a solution clarification and solid-liquid separation tank after iron precipitation reaction, and a first connecting pipe, which can recover iron; the biological reduction component sequentially comprises a third peristaltic pump, a biological reduction reactor with internal water circulation and heating, temperature measurement, sampling and addition of bacterial solution, a second peristaltic pump, a second connecting pipe, a third connecting pipe, a water outlet tank for solid-liquid separation and solution clarification after biological reduction reaction, which can recover copper; the water inlet tank receives the wastewater treated by the biological oxidation component and then flows to the biological reduction component for further treatment.

[0009] Compared with the prior art, the utility model has the following advantages or effects:

[0010] Because the wastewater is biologically oxidized at low pH with less Cu loss, Fe can be recovered first; because the wastewater after biological oxidation is further biologically reduced, Cu can also be recovered; in addition, because the device is simple, it can both make the wastewater meet the discharge standard and recover valuable metals, so the cost performance is high. BRIEF DESCRIPTION OF DRAWINGS

[0011] The specific structure of the utility model is shown in the following drawings.

[0012] Figure 1 A biological treatment device for mine acid wastewater according to the utility model is shown in the figure.

[0013] The various marks in the drawings respectively represent:

[0014] 1.AMD pool 2.first connecting pipe 3.first peristaltic pump 4.biological oxidation reactor 41.aeration device 5.iron precipitation reactor 51.stirring device 6.sedimentation tank 7.biological reduction reactor 8.second connecting pipe 9.second peristaltic pump 10.water inlet tank 11.third connecting pipe 12.third peristaltic pump 13.water outlet tank

[0015] The embodiments of the utility model are further described in detail below in combination with the drawings. DETAILED DESCRIPTION

[0016] As Figure 1 shown, the biological treatment device for mine acid wastewater provided by the utility model comprises a connecting pipe, a peristaltic pump and an aeration device 41 with an air compressor and an aeration pipe, further comprises a biological oxidation component, a biological reduction component and a water inlet tank 10 shared by the two, the biological oxidation component is sequentially composed of an AMD pool 1, a first peristaltic pump 3, a biological oxidation reactor 4 with biological fillers inside, an aeration device 41 at the lower inlet and upper outlet and conducive to the growth and adhesion of microorganisms, an iron precipitation reactor 5 with a stirring device and capable of adding NaOH to adjust the pH value of the solution, a sedimentation tank 6 for solid-liquid separation after iron precipitation and solution clarification and a first connecting pipe 2, and can recover iron; the biological reduction component is sequentially composed of a third peristaltic pump 12, a biological reduction reactor 7 capable of internal water circulation and heating, temperature measurement, sampling and adding bacteria solution, a second peristaltic pump 8, a second connecting pipe 8, a third connecting pipe 11, a water outlet tank 13 for solid-liquid separation after biological reduction reaction and solution clarification, and can recover copper; the water inlet tank 10 receives the wastewater treated by the biological oxidation component and then flows to the biological reduction component for further treatment.

[0017] The application can further be:

[0018] The biological reduction reactor 7 is externally wrapped with thermal insulation cotton.

[0019] The distance between the outlet of the biological oxidation reactor 4 and the bottom is about 86 cm.

[0020] The inner diameter of the biological oxidation reactor 4 is 17.2 cm.

[0021] The distance between the inlet and the outlet of the biological reduction reactor 7 is about 126 cm, the inner diameter of the lower bottom is 6 cm, and the inner diameter of the upper top is 12 cm.

[0022] Four branch pipes are arranged on the pipe wall of the biological reduction reactor 7, which are respectively used for heating, temperature measurement, sampling and adding bacteria liquid.

[0023] In operation, the mine acid wastewater first enters the AMD pool 1 for storage, and then is pumped into the biological oxidation reactor 4 through the first connecting pipe 2 by the first peristaltic pump 3, and the iron-oxidizing bacteria which have been cultured are introduced into the biological oxidation reactor 4, and the inoculation amount is about 10%, most of the iron-oxidizing bacteria grow and enrich on the biological filler, and the iron-oxidizing bacteria are used to quickly oxidize Fe 2+ to Fe 3+ , the flow rate of the mine acid wastewater is controlled to be about 1 L / d, the aeration device 41 is used to re-oxygenate the biological oxidation reactor 4, the aeration amount is about 4 L / min, the oxidized wastewater flows into the iron precipitation reactor 4, NaOH is added to adjust the pH value of the wastewater to about 3.2, and the stirring device 51 is started to fully stir the wastewater, at this time, Fe 3+ reacts, the wastewater enters the sedimentation pool 6, the prepared 1‰ flocculating agent is added to accelerate the settlement of the precipitate, the clarified wastewater flows into the water inlet tank 10, Na2SO4, glycerol and NH4Cl are added in the water inlet tank 10, then the wastewater is pumped into the biological reduction reactor 7 through the third connecting pipe 11 by the peristaltic pump 3, the water circulation in the biological reduction reactor 7 is realized by the peristaltic pump 9 through the second connecting pipe 8, the sulfate-reducing bacteria which have been cultured are introduced into the biological reduction reactor 7, and the inoculation amount is 10%, most of the sulfate-reducing bacteria grow and enrich on the biological filler, and the sulfate-reducing bacteria are used to quickly reduce SO4 2- to S 2- , S 2- reacts with Cu 2+ in the wastewater to generate CuS precipitate, the precipitate flows into the water outlet tank 13 with the outlet water, and the clarified water is directly discharged, and all the reagents are continuously added.

[0024] The above embodiment is only a preferred embodiment of the present application, but the embodiments of the present application are not limited by the above embodiment, and changes, modifications, substitutions, combinations and simplifications made without departing from the spirit and principles of the present application should be equivalent replacement methods, and all are included in the protection scope of the present application.

Claims

1. A device for biological treatment of mine acidic wastewater, comprising a connection pipe, a peristaltic pump and an aeration device (41) with an air compressor and an aeration pipe, characterized in that It also includes biological oxidation components, biological reduction components and water tank (13) and water tank (10) shared by both; the biological oxidation components are sequentially composed of AMD pool (1), first peristaltic pump (3), biological oxidation reactor (4) with aeration device (41) inside filled with biological filler, which is lower inlet and upper outlet and conducive to the growth and attachment of microorganisms, iron precipitation reactor (5) with stirring device and adding NaOH to adjust the pH value of solution, solution clarification and solid-liquid separation tank (6) after iron precipitation and first connecting pipe (2), which can recover iron; the biological reduction components are sequentially composed of third peristaltic pump (12), biological reduction reactor (7) which can internally circulate and heat water, measure temperature, take samples and add bacteria solution, second peristaltic pump (9), second connecting pipe (8), third connecting pipe (11), water tank (13) for solid-liquid separation and solution clarification after biological reduction reaction, which can recover copper; the water tank (10) receives wastewater treated by the biological oxidation components and then flows to the biological reduction components for further treatment.

2. The apparatus of claim 1 wherein The biological reduction reactor (7) is externally wrapped with thermal insulation cotton.

3. The apparatus of claim 1 wherein The distance between the outlet and the bottom of the biological oxidation reactor (4) is 86 cm.

4. The apparatus of claim 1 or 3, wherein The inner diameter of the biological oxidation reactor (4) is 17.2 cm.

5. The apparatus of claim 1 wherein The distance between the inlet and the outlet of the biological reduction reactor (7) is 126 cm, the lower bottom inner diameter is 6 cm, and the upper top inner diameter is 12 cm.

6. The apparatus of claim 1 or 2 or 5 wherein Four branch pipes are provided on the wall of the biological reduction reactor (7) for heating, temperature measurement, sampling and adding bacteria solution.

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