CN106517577A - Process for processing acidic arsenic-containing waste water - Google Patents

Abstract

The invention provides a process for processing acidic arsenic-containing wastewater. According to the process, chlorate or/and perchlorate is adopted as an oxidizing agent to oxidize trivalent arsenic into pentavalent arsenic, and inorganic flocculating agent and organic flocculating agent are sequentially added for flocculating, precipitating and removing arsenic. By adopting the process, a solution can be oxidized more completely by adopting the oxidizing agent, so that the dosage of inorganic flocculating agent can be reduced, the amount of arsenic-containing residue can be reduced, and subsequent arsenic-containing residue treatment cost can be reduced. The process is simple, has the advantages of low cost, high arsenic removing rate and wide application range, enables the arsenic-containing amount of treated wastewater to be less than 50ppb, and can meet the emission requirement of different emission standards.

Description

Treatment process of acidic arsenic-containing wastewater

technical field

The invention belongs to the technical field of heavy metal industrial wastewater treatment, in particular to a treatment process suitable for industrial wastewater with high arsenic concentration, high acidity and complex water quality discharged from industries related to arsenic chemical industry and arsenic smelting, and belongs to the depth of acidic arsenic-containing wastewater Approach.

Background technique

Arsenic is recognized as a highly toxic carcinogen, and is widely used in the preparation of semiconductor materials such as gallium arsenide. Because semiconductor materials have high requirements for the purity of arsenic, it is necessary to purify arsenic at the front end. During the purification process, a large amount of arsenic vapor is passed through hydrochloric acid After absorption, acidic high-concentration arsenic-containing wastewater is formed, and the arsenic content of this wastewater is often as high as 1~10g/L or more.

At present, the treatment methods of arsenic-containing wastewater mainly include chemical methods, physical methods, and biological methods. The biological method mainly uses the heat-resistant acidophilic ferric oxidizing bacteria to convert arsenic into scorodite with high arsenic content, so as to achieve the purpose of treating arsenic in wastewater. This method requires a high reaction temperature, no other impurities in the wastewater, and It only has a good effect on As ⁵⁺ , so the scope of application is greatly reduced. The physical method mainly uses a special ion exchange resin to exchange the arsenic in the wastewater with the cations in the resin, so as to achieve the purpose of removing arsenic. This method is generally used to treat low-concentration arsenic-containing wastewater or advanced treatment of arsenic-containing wastewater.

Chemical methods mainly include lime precipitation method, sulfide precipitation method, calcium-iron salt combined arsenic removal method, iron salt precipitation method, etc. The main principle of the lime precipitation method: add lime with 4 to 10 times the molar amount of arsenic to the wastewater, adjust the pH of the wastewater to above 12, and make the As ³⁺ and As ⁵⁺ in the wastewater form insoluble arsenic with the added calcium. calcium arsenite, calcium arsenite, etc., so as to effectively reduce the arsenic content in the water, and finally adjust the pH of the wastewater by adding acid and other methods, so that the wastewater can meet the requirements of discharge or subsequent treatment; the main principle of the sulfide precipitation method: under acidic conditions, use As ^m+ in different valence states can form insoluble precipitates with S ^2- As ₂ S _m ; the main principle of calcium-iron salt combined arsenic removal method: After pre-oxidizing the wastewater, add iron salt to adjust the pH, add calcium precipitant to form calcium Arsenic slag. The arsenic-containing solid waste obtained by the sulfide precipitation method and the calcium-iron salt combined arsenic removal method is easy to dissolve, and there are hidden dangers in open storage. The waste residue produced by the traditional iron salt precipitation method can be stored stably, but there are disadvantages such as slow precipitation speed and high viscosity of waste residue. Therefore, how to reduce the amount of arsenic-containing iron slag and improve the removal rate of arsenic is the key to deal with the problem of arsenic-containing wastewater.

Patent CN103043812A discloses a method for advanced treatment of arsenic-containing wastewater. This method oxidizes trivalent arsenic to pentavalent arsenic by oxidation, and then adds iron salt and polymer organic flocculant to precipitate arsenic, which speeds up the precipitation speed, shortens the settling time, and increases The removal efficiency of arsenic is improved, but the amount of iron salt is added to make the molar ratio of Fe/As in the solution reach 5-50, and the amount of arsenic-containing iron slag obtained is large.

Therefore, it is necessary to provide a treatment process for acidic arsenic-containing wastewater to solve the problem of a large amount of arsenic-containing iron slag.

Contents of the invention

In order to solve the above problems, the present invention provides a treatment process for acidic arsenic-containing wastewater with high arsenic removal efficiency, less waste residue and stable preservation.

In order to achieve the aforementioned purpose, the present invention adopts the following technical scheme: the treatment process of acidic arsenic-containing wastewater, which includes pre-oxidation and primary flocculation precipitation:

Pre-oxidation: adding an oxidizing agent to the acidic arsenic-containing wastewater for oxidation reaction to obtain the first solution;

First-stage flocculation and precipitation: add the first inorganic flocculant to the first solution, stir and react, adjust the pH to 7~12, then add the first organic flocculant, stir and react to obtain the first mixed solution, and the first mixed solution is naturally After sedimentation and stratification, solid-liquid separation is carried out to obtain the second solution and the first arsenic-containing slag, and the arsenic content in the second solution is detected;

The concentration of free H ⁺ in the acidic arsenic-containing wastewater is greater than 0.1mol/L;

The oxidizing agent is any one or more of sodium perchlorate, sodium chlorate and calcium chlorate.

As a further improvement of the present invention, the second solution needs to undergo secondary flocculation and precipitation. The specific operation is: add a second inorganic flocculant to the second solution, stir and react, adjust the pH to 7~13, and then add a second organic flocculant. The flocculant is stirred and reacted to obtain the second mixed solution. After the second mixed solution is naturally settled, the solid-liquid separation is carried out to obtain the third solution and the second arsenic-containing slag, and the arsenic content in the third solution is detected.

As a further improvement of the present invention, the third solution needs to be adsorbed by a chelating ion exchange resin at an adsorption rate of 0.1m ³ /h~2 m ³ /h to obtain wastewater after adsorption, which is discharged after being tested to meet the discharge requirements.

As a further improvement of the present invention, the second solution needs to be adsorbed by a chelating ion exchange resin at an adsorption rate of 0.1m ³ /h to 2 m ³ /h to obtain wastewater after adsorption, which is discharged after being tested to meet the discharge requirements.

As a further improvement of the present invention, the molar ratio of the added oxidant to arsenic is (0.2-0.9):1.

As a further improvement of the present invention, the first inorganic flocculant is any one or more of polyferric sulfate, ferric chloride, and ferric sulfate; the second inorganic flocculant is polyferric sulfate, ferric chloride, Any one or more of iron sulfate.

As a further improvement of the present invention, the molar ratio of the first inorganic flocculant to arsenic added to the first-stage flocculation precipitation is (0.8-1):1.

As a further improvement of the present invention, the dosage of the second inorganic flocculant is 1-10 g/L.

As a further improvement of the present invention, the first organic flocculant is one or more of polyacrylamide and sodium polyacrylate; the second organic flocculant is one or more of polyacrylamide and sodium polyacrylate Various.

As a further improvement of the present invention, the mass fraction of the first organic flocculant added is 0.01-1.0%, and the dosage is 1-10ml; the mass fraction of the second organic flocculant added is 0.01-1.0% , the dosage is 1~10ml/L.

The present invention adopts one or more of sodium perchlorate, sodium chlorate, and calcium chlorate as the oxidizing agent. Under acidic conditions, the oxidation effect on arsenic is more thorough than other oxidizing agents, and the cost is low; the amount of oxidizing agent is only It is 1/3~1/2 of the dosage of other traditional oxidizing agents (hydrogen peroxide, calcium hypochlorite, sodium hypochlorite, potassium permanganate, etc.), compared with aeration oxidation and other chemical agent oxidation, the energy consumption is greatly reduced and the cost is saved ; The amount of inorganic flocculant added is reduced by 1/2~2/3 times, and the arsenic removal rate is over 99.998%, which reduces the amount of arsenic-containing iron slag and saves costs. This process can treat acidic arsenic-containing wastewater with different concentrations. The process is simple, the arsenic removal efficiency is high, the amount of arsenic-containing iron slag is small, the waste slag is stable in storage, and the cost is low. It really achieves the purpose of saving resources and harmless treatment of industrial arsenic-containing wastewater.

detailed description

The technical solution will be clearly and completely described below in conjunction with the embodiments of the present invention. Apparently, the described embodiments are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

The present invention adopts the following technical scheme: the treatment process of acidic arsenic-containing wastewater, which includes pre-oxidation and primary flocculation precipitation:

Pre-oxidation: adding an oxidizing agent to the acidic arsenic-containing wastewater for oxidation reaction to obtain the first solution;

First-stage flocculation and precipitation: add the first inorganic flocculant to the first solution, stir and react, adjust the pH to 7~12, then add the first organic flocculant, stir and react to obtain the first mixed solution, and the first mixed solution is naturally After sedimentation and stratification, solid-liquid separation is carried out to obtain the second solution and the first arsenic-containing slag, and the arsenic content in the second solution is detected;

The concentration of free H ⁺ in the acidic arsenic-containing wastewater is greater than 0.1mol/L;

The oxidizing agent is any one or more of sodium perchlorate, sodium chlorate and calcium chlorate.

In the process provided by the present invention, an oxidizing agent is firstly added to the acidic arsenic-containing wastewater, and the oxidation reaction is carried out for 0.5-4 hours to oxidize the trivalent arsenic in the wastewater to pentavalent arsenic to obtain the first solution. The oxidizing agent is any one or more of sodium perchlorate, sodium chlorate, and calcium chlorate; the molar ratio of oxidizing agent to arsenic is preferably (0.2~0.9):1, more preferably (0.3~0.7):1 ; Oxidation time is preferably 0.5 ~ 4h, more preferably 1 ~ 2h. The concentration of free H ⁺ in the acidic arsenic-containing wastewater treated by the invention is greater than 0.1 mol/L, and Cu ²⁺ , Ni ²⁺ and the like may also be contained in addition to arsenic.

In the present invention, add the first inorganic flocculant to the first solution, stir and react, adjust the pH to 7~12, then add the first organic flocculant, stir and react to obtain the first mixed solution, and the first mixed solution is naturally After sedimentation and stratification, solid-liquid separation is carried out to obtain the second solution and the first arsenic-containing slag, and the arsenic content in the second solution is detected. The first inorganic flocculant is preferably any one or more of polyferric sulfate, ferric chloride, and ferric sulfate, more preferably solid polyferric sulfate; the molar ratio of the first inorganic flocculant to arsenic is ( 0.8~1): 1; the adjusted pH value is preferably 7~12, more preferably 7~8; the stirring reaction time of the first inorganic flocculant is preferably 10~60min, more preferably 30~60min; The first organic flocculant is preferably one or more of polyacrylamide and sodium polyacrylate, more preferably polyacrylamide; the mass fraction of the first organic flocculant is preferably 0.01-1.0%, more preferably 0.1-0.3%; the dosage of the first organic flocculant is preferably 1-10ml/L, more preferably 2-5ml/L.

In the present invention, in order to further deeply remove arsenic, the second solution can be subjected to secondary flocculation and sedimentation, that is, the second inorganic flocculant is added to the second solution, stirred and reacted for 10-60 minutes, the pH is adjusted to 7-13, and then the second inorganic flocculant is added. Two organic flocculants, stirred and reacted for 1-30 minutes to obtain the second mixed solution, after the second mixed solution was naturally settled, solid-liquid separation was carried out to obtain the third solution and the second arsenic-containing slag, and the arsenic content in the third solution was detected. The second inorganic flocculant is preferably any one or more of polymeric ferric sulfate, ferric chloride, and ferric sulfate, more preferably solid polymeric ferric sulfate; the dosage of the second inorganic flocculant is preferably 1~ 10g/L, more preferably 4~8g/L; the pH adjustment is preferably 7~13, more preferably 7.5~9; the second organic flocculant is preferably one of polyacrylamide and sodium polyacrylate one or more, more preferably polyacrylamide; the mass fraction of the second organic flocculant is preferably 0.01~1.0%, more preferably 0.1~0.3%; the dosage of the second organic flocculant is preferably 1 ~ 10ml/L, more preferably 2 ~ 5ml/L.

In the present invention, in order to further deeply remove arsenic, the second solution or the third solution can also be passed through a chelating ion exchange resin dedicated to arsenic removal, and the adsorption rate is 0.1m ³ /h~2 m ³ /h, and the obtained adsorption The final waste water can be discharged directly after being tested up to the standard.

In the present invention, the chelating ion exchange resin is suitable for adsorbing waste water with arsenic concentration of 0.05 mg/L-1 mg/L, especially for low-concentration arsenic-containing waste water with arsenic concentration of 0.05 mg/L-0.1 mg/L. Commonly used chelating ion exchange resins for arsenic include DTMA-200, MIEX-DOC(R), 201*7, etc. DTMA-200 is used in the following examples.

The process provided by the present invention can treat acidic arsenic-containing wastewater with different concentrations under natural conditions. When As<0.5g/L in acidic arsenic-containing wastewater, and the treated wastewater is required to reach the first in the "Industrial Wastewater Discharge Standard", When the discharge standard of similar pollutants (As<0.5mg/L) or reaches As<0.1mg/L, pre-oxidation-one-time flocculation and sedimentation process can be used to remove arsenic; when As>0.5g/L in acidic arsenic-containing wastewater, and require When the treated wastewater reaches the first-class pollutant discharge standard (As<0.5mg/L) in the "Industrial Wastewater Discharge Standard" or reaches As<0.1mg/L, it can be pre-oxidized-first-level flocculation-sedimentation-secondary flocculation Arsenic removal during the precipitation process; when As>0.5g/L in acidic arsenic-containing wastewater, and the treated wastewater is required to meet the standard of Class III water (As<0.05mg/L) in the "Environmental Quality Standard for Surface Water" GB3838-2002) , can carry out oxidation-first flocculation precipitation-secondary flocculation precipitation-resin adsorption process to remove arsenic; when As in acidic arsenic-containing wastewater is<0.5g/L, and the treated wastewater is required to meet the "Environmental Quality Standard for Surface Water" GB3838- 2002) Class III water standard (As<0.05mg/L), the pre-oxidation-first-stage flocculation precipitation-resin adsorption process can be used to remove arsenic.

In the present invention, under the same other conditions, the above-mentioned oxidizing agent is used to reduce the theoretical amount of the added oxidizing agent by 2/3, and the amount of the inorganic flocculant is reduced by 1/2 to 2/3, and the obtained first arsenic-containing slag and the second Second, arsenic-containing slag, less slag, high stability of waste slag, not easy to dissolve, which is beneficial to the subsequent hazardous waste treatment of arsenic-containing slag and reduces costs.

Example 1.

The present invention is used to treat arsenic-containing wastewater generated in the production process of a metallurgical company. The treated water volume is 2m ³ , the arsenic concentration is 1.87g/L, and the free acid concentration is 1.19mol/L.

1) Pre-oxidation: Add 2.6554 kg of sodium chlorate solid with 0.5 times the molar amount of arsenic to the arsenic-containing wastewater, and carry out the oxidation reaction for 2 hours to obtain the first solution.

2) Primary flocculation precipitation: Add 8.976 kg of solid polyferric sulfate with 0.90 times the molar amount of arsenic to the first solution, stir and react for 30 minutes, add solid sodium hydroxide to adjust the pH to 7.5, mix thoroughly for 20 minutes, and then add the mass fraction 4L of 0.3% polyacrylamide solution was stirred for 5 minutes to form a large amount of arsenic-containing slag flocs, forming the first mixed solution.

3) First-level solid-liquid separation: the first mixed liquid is naturally settled for 2 hours and then stratified, and the supernatant and the lower layer of slag are respectively filtered with a bag filter. After the filter residue is blown and dried, it is stored according to the requirements of hazardous waste; the filtrate After mixing, a second solution was formed, which was analyzed and detected by ICP-MS, and the concentration of As in the filtrate was measured to be 27.4 ppm.

4) Secondary flocculation precipitation: Add polymeric ferric sulfate solid at 1g/L to the second solution, stir and react for 20 minutes, add solid sodium hydroxide to adjust the pH to 8.3, mix thoroughly for 10 minutes, and then add 0.3% 5 L of polyacrylamide solution was stirred and reacted for 3 minutes, and a large amount of arsenic-containing slag flocs appeared to form the second mixed solution.

5) Secondary solid-liquid separation: the second mixed liquid is naturally settled for 0.5h and then stratified, the supernatant and the lower layer of slag are respectively filtered with a bag filter, and the filter residue is blast-dried and stored according to the requirements of hazardous waste; The filtrates were mixed to form a third solution, which was analyzed and detected by ICP-MS, and the concentration of As in the filtrate was measured to be 95 ppb.

6) Resin adsorption: The third solution was passed through 1.5 tons of DTMA-200 chelating ion exchange resin at a passing rate of 1m ³ /h. The wastewater after adsorption was analyzed and detected by ICP-MS, and the concentration of As in the wastewater was measured to be 9.4ppb .

Example 2.

The present invention is used to treat arsenic-containing wastewater generated in the production process of a metallurgical company. The treated water volume is 2.5m ³ , the arsenic concentration is 5.93g/L, and the free acid concentration is 1.95mol/L.

1) Pre-oxidation: Add 12.1071 kg of sodium perchlorate with 0.5 times the molar amount of arsenic to the arsenic-containing wastewater, and carry out the oxidation reaction for 2.5 hours to obtain the first solution.

2) Primary flocculation precipitation: Add 30.515 kg of ferric chloride solid with 0.95 times the molar amount of arsenic to the first solution, stir and react for 40 minutes, add solid sodium hydroxide to adjust the pH to 7.8, mix thoroughly for 20 minutes, and then add the mass fraction 5.5L of 0.5% polyacrylamide solution was stirred for 8 minutes to form a large amount of arsenic-containing slag flocs, forming the first mixed solution.

3) First-level solid-liquid separation: the first mixed liquid is naturally settled for 2.5 hours and then stratified, the supernatant and the lower layer of slag are respectively filtered with a bag filter, and the filter residue is blast-dried and stored according to the requirements of hazardous waste; The filtrates were mixed to form a second solution, which was analyzed and detected by ICP-MS, and the arsenic concentration in the filtrate was measured to be 57.2 ppm.

4) Secondary flocculation precipitation: Add polymeric ferric sulfate solid at 3g/L to the second solution, stir and react for 30min, add solid sodium hydroxide to adjust the pH to 7.7, mix thoroughly for 10min, then add 0.3% 5 L of polyacrylamide solution was stirred and reacted for 3 minutes, and a large amount of arsenic-containing slag flocs appeared to form the second mixed solution.

5) Secondary solid-liquid separation: The second mixed liquid is naturally settled for 1 hour and then separated into layers. The supernatant and the lower layer of slag are respectively filtered with a bag filter. After the filter residue is blown and dried, it is stored according to the requirements of hazardous waste; the filtrate After mixing, a third solution was formed, which was analyzed and detected by ICP-MS, and the concentration of arsenic in the filtrate was measured to be 91 ppb.

6) Resin adsorption: Pass the third solution through 1.5 tons of DTMA-200 chelating ion exchange resin at a passing rate of 1.2m ³ /h. The wastewater after adsorption is analyzed and detected by ICP-MS, and the concentration of arsenic in the wastewater is measured to be 8.2 ppb.

Example 3.

The present invention is used to treat arsenic-containing wastewater generated in the production process of a metallurgical company. The treated water volume is 5m ³ , the arsenic concentration is 8.75g/L, and the free acid concentration is 2.41mol/L.

1) Pre-oxidation: Add 43.49 kg of sodium chlorate solids with 0.7 times the molar amount of arsenic to the arsenic-containing wastewater, and carry out the oxidation reaction for 3.5 hours to obtain the first solution.

2) Primary flocculation and precipitation: Add 116.67 kg of polyferric sulfate solid with 1.0 times the molar amount of arsenic to the first solution, stir and react for 60 minutes, add solid sodium hydroxide to adjust the pH to 7.3, mix thoroughly for 30 minutes, and then add the mass fraction 15L of 0.8% polyacrylamide solution was stirred for 6 minutes to form a large amount of arsenic-containing slag flocs, forming the first mixed solution.

3) First-level solid-liquid separation: the first mixed liquid is naturally settled for 3 hours and then stratified, the supernatant and the lower layer of slag are respectively filtered with a bag filter, and the filter residue is dried by blasting and stored in accordance with the requirements of hazardous waste; the filtrate After mixing, a second solution was formed, which was analyzed and detected by ICP-MS, and the concentration of arsenic in the filtrate was measured to be 98.5 ppm.

4) Secondary flocculation precipitation: Add polymeric ferric sulfate solid at 2g/L to the second solution, stir and react for 30 minutes, add solid sodium hydroxide to adjust the pH to 8.6, mix thoroughly for 10 minutes, and then add 0.3% 15 L of sodium polyacrylate solution was stirred and reacted for 2 minutes, and a large amount of arsenic-containing slag flocs appeared to form the second mixed solution.

5) Secondary solid-liquid separation: The second mixed liquid is naturally settled for 1.5 hours and then separated into layers, the supernatant and the lower layer of slag are respectively filtered with a bag filter, and the filter residue is blast-dried and stored according to the requirements of hazardous waste; The filtrates were mixed to form a third solution, which was analyzed and detected by ICP-MS, and the concentration of arsenic in the filtrate was measured to be 87 ppb.

6) Resin adsorption: The third solution was passed through 1.5 tons of DTMA-200 chelating ion exchange resin at a passing rate of 0.9m ³ /h. The wastewater after adsorption was analyzed and detected by ICP-MS, and the concentration of As in the wastewater was measured to be 11.1 ppb.

Example 4.

The present invention is used to treat arsenic-containing wastewater generated in the production process of a metallurgical company. The treated water volume is 5m ³ , the arsenic concentration is 0.17g/L, and the free acid concentration is 0.8mol/L.

1) Pre-oxidation: Add 0.423 kg of sodium chlorate solid with 0.35 times the molar amount of arsenic to the arsenic-containing wastewater, and carry out oxidation reaction for 2 hours to obtain the first solution.

2) Primary flocculation and precipitation: Add 2.15 kg of polyferric sulfate solid with 0.95 times the molar amount of arsenic to the first solution, stir and react for 30 minutes, add solid sodium hydroxide to adjust the pH to 9.4, mix thoroughly for 20 minutes, and then add the mass fraction 15L of 0.7% polyacrylamide solution, stirred and reacted for 2 minutes, a large amount of arsenic-containing slag flocs were formed to form the first mixed solution.

3) First-level solid-liquid separation: the first mixed liquid is naturally settled for 1 hour and then stratified, and the supernatant liquid and the lower layer residue are respectively press-filtered with a filter press. After the filter residue is blast-dried, store it according to the requirements of hazardous waste; the filtrate After mixing, a second solution was formed, which was analyzed and detected by ICP-MS, and the concentration of arsenic in the filtrate was measured to be 73 ppb.

4) Resin adsorption: Pass the second solution through 1.5 tons of DTMA-200 chelating ion exchange resin at a passing rate of 1.1m ³ /h. The wastewater after adsorption is analyzed and detected by ICP-MS, and the arsenic concentration in the wastewater is measured to be 9.6 ppb.

This process can treat acidic arsenic-containing wastewater with different concentrations. The process is simple, the arsenic removal efficiency is high, the amount of arsenic-containing iron slag is small, the waste slag is stable in storage, and the cost is low. It really achieves the purpose of saving resources and harmless treatment of industrial arsenic-containing wastewater. This process not only has a high removal rate of arsenic, but also can remove most of the heavy metal ions in the wastewater. The process is simple and the investment is low. The arsenic content in the treated wastewater is stable below 20ppb, which meets the "Environmental Quality Standard for Surface Water" (GB3838 -2002) Class III water standards provide an economical and effective way for enterprises to treat arsenic-containing wastewater.

Although preferred embodiments of the present invention have been disclosed for illustrative purposes, those of ordinary skill in the art will appreciate that various Improvements, additions, and substitutions are possible.

Claims (10)

1. a kind of handling process of acidic arsenic-containing waste water, it is characterised in that including pre-oxidation, one-level flocculation sediment：

Pre-oxidation：Oxidant is added in oxytropism arsenic-containing waste water, oxidation reaction is carried out, the first solution is obtained；

One-level flocculation sediment：To in the first solution, add the first inorganic flocculating agent, stirring reaction to adjust pH to 7 ~ 12, add First organic flocculant, stirring reaction obtain the first mixed liquor, after the first mixed liquor natural subsidence is layered, carry out solid-liquid point From obtaining the second solution and the first slag containing arsenic, arsenic content in the second solution of detection；

Dissociate in the acidic arsenic-containing waste water H⁺Concentration is more than 0.1mol/L；

The oxidant is sodium perchlorate, sodium chlorate, in calcium chlorate any one or more.

2. the handling process of acidic arsenic-containing waste water according to claim 1, it is characterised in that second solution needs Jing bis- Level flocculation sediment, concrete operations are：

To in the second solution, add the second inorganic flocculating agent, stirring reaction to adjust pH to 7 ~ 13, add the second organic-flocculation Agent, stirring reaction obtain the second mixed liquor, by the second mixed liquor natural subsidence after, carry out solid-liquid separation, obtain the 3rd solution and Second slag containing arsenic, arsenic content in the 3rd solution of detection.

3. the handling process of acidic arsenic-containing waste water according to claim 2, it is characterised in that the 3rd solution need through Chelating ion exchange resin adsorbs, and the rate of adsorption is 0.1m³/h~2 m³/ h, waste water after being adsorbed reach discharge after testing Discharge after requirement.

4. the handling process of acidic arsenic-containing waste water according to claim 1, it is characterised in that second solution need through Chelating ion exchange resin adsorbs, and the rate of adsorption is 0.1m³/h~2 m³/ h, waste water after being adsorbed reach discharge after testing Discharge after requirement.

5. the handling process of acidic arsenic-containing waste water according to claim 1, it is characterised in that the oxidant of the addition with The mol ratio of arsenic is（0.2~0.9）：1.

6. the handling process according to the arbitrary described acidic arsenic-containing waste water of claim 1 ~ 4, it is characterised in that described first is inorganic Flocculant is bodied ferric sulfate, iron chloride, any one or more in iron sulfate；Second inorganic flocculating agent is polymerised sulphur Any one or more in sour ferrum, iron chloride, iron sulfate.

7. the handling process according to the arbitrary described acidic arsenic-containing waste water of claim 1 ~ 4, it is characterised in that the one-level flocculation The first inorganic flocculating agent is added with the mol ratio of arsenic to be in precipitation（0.8~1）：1.

8. the handling process according to the arbitrary described acidic arsenic-containing waste water of claim 1 ~ 4, it is characterised in that described second is inorganic Flocculant dosage is 1 ~ 10g/L.

9. the handling process of acidic arsenic-containing waste water according to claim 1, it is characterised in that first organic flocculant For one or more in polyacrylamide, sodium polyacrylate；Second organic flocculant is polyacrylamide, polyacrylic acid One or more in sodium.

10. the handling process according to the arbitrary described acidic arsenic-containing waste water of claim 1 ~ 4, it is characterised in that the addition The mass fraction of the first organic flocculant is 0.01 ~ 1.0%, and dosage is 1 ~ 10ml；Second organic flocculant of the addition Mass fraction is 0.01 ~ 1.0%, and dosage is 1 ~ 10ml/L.