CN110342676B

CN110342676B - Treatment method of acid mine wastewater

Info

Publication number: CN110342676B
Application number: CN201910533976.8A
Authority: CN
Inventors: 陈志伟
Original assignee: Fujian Xingwanxiang Construction Group Co ltd
Current assignee: Fujian Xingwanxiang Construction Group Co ltd
Priority date: 2019-06-19
Filing date: 2019-06-19
Publication date: 2020-04-28
Anticipated expiration: 2039-06-19
Also published as: CN110342676A

Abstract

The invention relates to the technical field of water treatment, in particular to a method for treating acid mine wastewater. The method comprises the following steps: (1) adding an oxidant into the wastewater, stirring, and filtering to obtain a filtrate A; (2) adding polyvinyl alcohol and a molecular sieve into the filtrate A, stirring and filtering to obtain filtrate B; (3) and adding alkali into the filtrate B, adjusting the pH value, adding a flocculating agent, stirring and filtering. The treatment method has the advantages of rapidness, effectiveness, economy and environmental protection, and has good treatment effect on improving the pH value of the acidic wastewater and removing heavy metal ions in the wastewater.

Description

Treatment method of acid mine wastewater

Technical Field

The invention relates to the technical field of water treatment, in particular to a method for treating acid mine wastewater.

Background

The treatment of acid mine wastewater is a common problem at home and abroad. The acid mine wastewater mainly comes from pit wastewater discharged in mining production, rain wastewater of a waste stone yard, wastewater of a dressing plant, overflow water of a tailing dam and the like. It features low pH value of waste water, high water content, and complex components.

Since metal mines, especially non-ferrous metal mines, are often associated with a plurality of metal sulfides, during mining or beneficiation, these minerals form sulfuric acid and metal sulfates under the combined action of air, water and bacteria, and dissolve out a plurality of metal ions in the ores, thereby forming acidic wastewater containing copper, iron, zinc, cadmium and the like. After the acid mine wastewater is discharged into the environment, the pH value of the water body can be changed, the natural buffer action of the water body is destroyed, the growth of bacteria and microorganisms is eliminated or inhibited, the self-purification of the water body is hindered, and the water body smells, turns green and the like. And the acidic water can seriously corrode pipelines, water pumps, cement structures and other mechanical equipment, and great threats are brought to the health, life and production of people.

The invention patent application CN 1273944A discloses a method for treating waste water and sewage by using fly ash, which uses a fly ash storage yard of a power plant as a percolation bed and an oxidation field, and conveys the waste water and the sewage to be treated to the fly ash storage yard of the power plant to enable the waste water and the sewage to flow through a fly ash layer, and then the waste water and the sewage are percolated into a water collection structure and then discharged from the water collection structure, and the drainage flow of the water collection structure is adjusted to enable the percolation speed of the waste water and the sewage to be not more than 0.06 meter per hour. The facility for discharging and piling up fly ash in a thermal power plant is utilized to lead the waste water and the sewage to be subjected to the percolation and the absorption of the fly ash and the biological oxidation, decomposition and purification of sunlight and air. The effect reaches or exceeds the secondary biochemical treatment.

However, the invention has many disadvantages: 1) the waste water is conveyed to a fly ash storage yard of a thermal power plant by a pipeline for treatment, a large amount of pipes are consumed, and the engineering investment is large; 2) the fly ash stockpiling field of the thermal power plant needs to be changed into an urban sewage treatment plant, and the operation and the management are inconvenient in the actual operation.

The invention patent application CN 109607971A relates to the field of wastewater treatment, and discloses an ecological treatment system and method for mine acidic wastewater. The ecological treatment system for the acid mine wastewater comprises a reservoir, a limestone pool, a periclase pool, a sedimentation pool and an aerobic wetland which are sequentially communicated; the limestone pool is filled with a mixture of limestone particles and wood shavings; the periclase pool is filled with periclase particles; the aerobic wetland is a wetland planted with vegetation. The system has low use and maintenance cost and good treatment effect. According to the ecological treatment method for the acid mine wastewater, the acid mine wastewater sequentially passes through the reservoir, the limestone pool and the periclase pool of the treatment system for more than 90 minutes, the sedimentation pool for more than 120 minutes and the aerobic wetland. The method has stable process and convenient control, and the treated wastewater reaches the III-class standard of surface water.

However, the wetland method is large in occupied area, so that the treatment is greatly influenced by the environment, and the wetland method is not suitable for treating wastewater in a large volume.

The invention patent application CN 104909497A discloses a method for treating acid wastewater of nonferrous metal mine, which mainly comprises four steps of oxidation treatment, membrane treatment, vulcanization treatment and neutralization treatment, wherein during the treatment of the acid wastewater, divalent iron ions are firstly oxidized into trivalent iron ions by adopting an oxidant or an aeration mode, then iron precipitation reaction is carried out, clear liquid after the reaction enters a membrane treatment system for separation and concentration, concentrated solution is subjected to vulcanization precipitation treatment, valuable metals are recovered, and the clear liquid after the vulcanization reaction is subjected to neutralization precipitation in a neutralization treatment unit. According to the characteristics of low pH value, various heavy metals and the like of the acid wastewater of the nonferrous metal mine, the oxidation treatment, the iron precipitation treatment, the membrane treatment, the vulcanization precipitation, the coagulating precipitation and the neutralization treatment are combined together, and the acid wastewater of the nonferrous metal mine is treated by orderly and synergistic step by step, so that the method has the advantages of good treatment effect, high treatment efficiency, stable system operation, capability of recovering valuable resources in water, easiness in industrial application and the like, and the treated wastewater can be returned to the production process flow to be used as reclaimed water or discharged up to the standard.

However, the method has the advantages of greatly reduced treatment efficiency, higher cost and longer time consumption after membrane treatment.

At present, no method for treating acidic wastewater, which can be used for quickly, effectively, economically and environmentally friendly, is available, can improve the pH value of the acidic wastewater and remove heavy metal ions in the wastewater, so that the acidic wastewater can reach the discharge standard.

Disclosure of Invention

The invention provides a method for treating acid mine wastewater, aiming at solving the problems of low treatment efficiency, high cost, poor effect and the like in the prior art.

A treatment method of acid mine wastewater comprises the following steps:

(1) adding an oxidant into the wastewater, stirring, and filtering to obtain a filtrate A;

(2) adding polyvinyl alcohol and a molecular sieve into the filtrate A, stirring and filtering to obtain filtrate B;

(3) and adding alkali into the filtrate B, then adding a flocculating agent, stirring and filtering.

Further, in the step (1), the oxidizing agent is hydrogen peroxide or hypochlorous acid.

Further, in the step (1), the oxidizing agent is hypochlorous acid.

Further, in the step (1), the weight parts of the wastewater are as follows: 300 and 350: 1.

Further, in the step (1), the stirring speed is 20-60r/min, and the stirring time is 1-2 h.

Further, in the step (2), the weight ratio of polyvinyl alcohol: molecular sieve 1: 10-15; and (3) filtrate A: polyvinyl alcohol 50-80: 1.

Further, in the step (2), the ratio of polyvinyl alcohol: molecular sieve 1: 12; and (3) filtrate A: polyvinyl alcohol 60: 1.

Further, in the step (2), the molecular sieve type is one or more of a ZSM-8 type molecular sieve, a ZSM-11 type molecular sieve and a Silicalite-1 type molecular sieve.

Further, in the step (2), the molecular sieve type is a ZSM-8 type molecular sieve.

Further, in the step (2), the stirring speed is 50-100r/min, and the stirring time is 2-5 h.

Further, in the step (3), the alkali is one or more of sodium hydroxide, calcium oxide or sodium carbonate.

Further, in the step (3), the alkali is calcium oxide.

Further, in the step (3), the flocculant is polyacrylamide.

Further, in the step (3), the weight parts of filtrate B: base 50-100: 1; alkali: and (3) 15-30:1 of flocculant.

Further, in the step (3), the weight ratio of the filtrate B: base 80: 1; alkali: flocculant is 20: 1.

Further, in the step (3), the stirring speed is 200-300r/min, and the stirring time is 2-5 h.

Further, the method comprises the following steps:

(1) adding hydrogen peroxide or hypochlorous acid into the wastewater, wherein the wastewater: stirring hydrogen peroxide or hypochlorous acid at the stirring speed of 20-60r/min for 1-2h at 350: 1-;

(2) adding polyvinyl alcohol and one or more of ZSM-8 type molecular sieve, ZSM-11 type molecular sieve and Silicalite-1 type molecular sieve into the filtrate A, stirring and filtering to obtain filtrate B;

(3) adding one or more of sodium hydroxide, calcium oxide or sodium carbonate into the filtrate B, wherein the filtrate B: adjusting the pH value with 50-100:1 alkali, and then adding polyacrylamide, alkali: 15-30:1, stirring for 2-5h at the stirring speed of 200-.

Further, the method comprises the following steps:

(1) adding hypochlorous acid into the wastewater, wherein the filtrate A: stirring hypochlorous acid 320:1 at 40r/min for 1.2h, and filtering to obtain filtrate A;

(2) adding polyvinyl alcohol and a ZSM-8 type molecular sieve into the filtrate A, stirring and filtering to obtain a filtrate B;

(3) adding calcium oxide into the filtrate B, wherein the filtrate B: base 80:1, pH adjusted, then polyacrylamide was added, base: the flocculant is 20:1, stirred for 3h at a stirring speed of 250r/min and then filtered.

The invention selects proper molecular sieve, has better effect on the adsorption of solid particles and heavy metal ions in the wastewater and also has good effect on the treatment of acidic substances in the wastewater.

Compared with the prior art, the invention has the beneficial effects that:

1. the invention selects proper flocculating agent and proper adding time and stirring speed, so that the flocculating effect is greatly enhanced.

2. The invention has better treatment effect on heavy metals in mining wastewater and has better treatment effect on metal ions such as copper, iron, zinc, cadmium, lead and the like.

3. The invention selects proper molecular sieve, has better effect on the adsorption of solid particles and heavy metal ions in the wastewater and also has good effect on the treatment of acidic substances in the wastewater.

4. The invention selects proper reagent adding sequence and treatment condition in the treatment process, so that the purification efficiency is higher and the treatment effect on the wastewater is better.

5. The method has simple operation process and is easy for industrial production.

Detailed Description

The invention will be further described with reference to specific embodiments, the advantages and features of which will become apparent from the description, but which are given by way of illustration only and are not intended to limit the scope of the invention in any way. It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention, and that such changes and modifications may be made without departing from the spirit and scope of the invention.

The waste water produced by a mining enterprise in Longyan City, Fujian province was used as a research object, and among the waste water used in the examples and comparative examples, the concentration of copper ions was 21.26mg/L, the concentration of iron ions was 279.43mg/L, the concentration of zinc ions was 92.47mg/L, the concentration of cadmium ions was 15.18mg/L, and the concentration of lead ions was 18.77mg/L, pH, which was 2.1.

Example 1

(1) Adding hypochlorous acid into the wastewater, wherein the wastewater: stirring hypochlorous acid 320:1 at 40r/min for 1.2h, and filtering to obtain filtrate A;

(2) adding polyvinyl alcohol and a ZSM-8 type molecular sieve into the filtrate A, stirring for 3 hours at the speed of 80r/min, and filtering to obtain a filtrate B, wherein the mass ratio of the filtrate A to the filtrate B is as follows: polyvinyl alcohol: molecular sieve 60:1: 12;

(3) adding calcium oxide into the filtrate B, wherein the filtrate B: base 80:1, then polyacrylamide was added, base: the polyacrylamide is 20:1, stirred for 3h at a stirring speed of 250r/min and then filtered.

Example 2

(1) Adding hydrogen peroxide into the wastewater, wherein the wastewater: stirring hydrogen peroxide at a stirring speed of 60r/min for 1h, and filtering to obtain filtrate A;

(2) adding polyvinyl alcohol and a ZSM-11 type molecular sieve into the filtrate A, stirring for 5 hours at the speed of 50r/min, and filtering to obtain a filtrate B, wherein the mass ratio of the filtrate A to the filtrate B is as follows: polyvinyl alcohol: molecular sieve 50:1: 10;

(3) adding sodium carbonate into the filtrate B, wherein the filtrate B: base 50:1, then polyacrylamide was added, base: the polyacrylamide is 15:1, stirred for 5h at a stirring speed of 200r/min and then filtered.

Example 3

(1) Adding hypochlorous acid into the wastewater, wherein the wastewater: stirring hypochlorous acid (350: 1) at 20r/min for 2h, and filtering to obtain filtrate A;

(2) adding polyvinyl alcohol and a Silicalite-1 type molecular sieve into the filtrate A, stirring for 2 hours at the speed of 100r/min, and filtering to obtain filtrate B, wherein the filtrate A: polyvinyl alcohol: molecular sieve 80:1: 15;

(3) adding sodium hydroxide into the filtrate B, and filtering the filtrate B: base 100:1, then polyacrylamide was added, base: the polyacrylamide is 30:1, stirred for 2h at a stirring speed of 300r/min and then filtered.

Comparative example 1

The flocculant was stirred at a different rate than in example 1.

Wherein the step (3) is as follows: adding calcium oxide into the filtrate B, wherein the filtrate B: base 80:1, then polyacrylamide was added, base: the polyacrylamide was stirred at 500r/min for 3h at 20:1 and then filtered.

Comparative example 2

The molecular sieve type was different from that of example 1.

Wherein the step (2) is as follows: adding polyvinyl alcohol and an M-type molecular sieve into the filtrate A, stirring for 3 hours at the condition of 80r/min, and filtering to obtain filtrate B, wherein the mass ratio of the filtrate A to the filtrate B is as follows: polyvinyl alcohol: molecular sieve 60:1: 12.

Comparative example 3

The order of the steps is different compared to example 1.

(1) Adding polyvinyl alcohol and a ZSM-8 type molecular sieve into the wastewater, stirring for 3 hours at the speed of 80r/min, and filtering to obtain filtrate A, wherein the wastewater: polyvinyl alcohol: molecular sieve 60:1: 12;

(2) adding calcium oxide to the filtrate A, and filtering the filtrate A: base 80:1, then polyacrylamide was added, base: stirring polyacrylamide at the stirring speed of 250r/min for 3h, and filtering to obtain filtrate B;

(3) adding hypochlorous acid into the filtrate B, wherein the filtrate B: hypochlorous acid 320:1, stirring for 1.2h at 40 r/min.

Test example 1

And detecting the content of the treated metal ions by using an inductively coupled plasma spectrometer (ICP).

High-frequency power: 1.10 kW; flow rate of atomizing gas: 0.75L/min; auxiliary air flow rate: 1.50L/min; plasma gas flow rate: 15.0L/min; analyzing the pump speed: 15.0 r/min; reading time: 5.0 s; sample introduction and time delay: 30.0 s. The elemental analysis wavelength was: cu-327.395 nm; fe-238.204 nm; zn-213.857 nm; cd-214.439 nm; pb-220.353 nm.

Diluting the multi-element mixed standard solution step by step to prepare a series of standard use solutions with the contents of 10, 20, 50, 100, 200, 400 and 600 mug/L, then sequentially feeding samples, and drawing a standard curve of each element by taking mass concentration as an abscissa and intensity as an ordinate. Tests show that the linear correlation coefficient of each element standard curve is 0.999, the analysis requirement can be met, and accurate quantitative determination can be realized.

ICP analysis was performed on the samples treated in each example and comparative example, and the results were as follows:

the comprehensive test result shows that the method has the following advantages:

2. The invention selects proper molecular sieve, has better effect on the adsorption of solid particles and heavy metal ions in the wastewater and also has good effect on the treatment of acidic substances in the wastewater.

3. The invention selects proper reagent adding sequence and treatment condition in the treatment process, so that the purification efficiency is higher and the treatment effect on the wastewater is better.

The technical means disclosed by the scheme of the invention are not limited to the technical means disclosed above, and the technical means also comprises the technical scheme formed by any combination of the technical features. While the foregoing is directed to embodiments of the present invention, it will be appreciated by those skilled in the art that various changes and modifications may be made without departing from the principles of the invention, and it is intended to claim all such modifications and alterations as fall within the true scope of the invention.

Claims

1. A treatment method of acid mine wastewater is characterized by comprising the following steps:

(3) adding alkali into the filtrate B, then adding a flocculating agent, stirring and filtering;

the molecular sieve type is one or more of a ZSM-8 type molecular sieve, a ZSM-11 type molecular sieve and a Silicalite-1 type molecular sieve;

the alkali is one or more of sodium hydroxide, calcium oxide or sodium carbonate;

in the step (3), the stirring speed is 200-300r/min, and the stirring time is 2-5 h.

2. The treatment method according to claim 1, wherein in the step (1), the oxidizing agent is hydrogen peroxide or hypochlorous acid.

3. The treatment method according to claim 1, wherein in the step (1), the weight ratio of wastewater: 300 and 350: 1.

4. The process according to claim 1, wherein in the step (2), the ratio of polyvinyl alcohol: molecular sieve 1: 10-15.

5. The process according to claim 1, wherein in the step (2), the weight ratio of the filtrate A: polyvinyl alcohol 50-80: 1.

6. The process of claim 1, wherein in step (3), the flocculant is polyacrylamide.

7. The process according to claim 1, wherein in the step (3), the weight ratio of filtrate B: base 50-100: 1.

8. The treatment method according to claim 1, wherein in the step (3), the ratio of alkali: and (3) 15-30:1 of flocculant.