CN113003769A - Closed cycle treatment method for soil leaching waste liquid - Google Patents
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Abstract
The invention provides a closed cycle treatment method of soil leaching waste liquid, belonging to the technical field of water pollution treatment. The invention utilizes the reaction of soluble aluminum salt and As and Sb metals to generate precipitates of aluminum arsenate and aluminum antimonate and Al (OH) generated by hydrolysis of the soluble aluminum salt3The flocculation adsorption effect of the method realizes the effective removal of metalloid As and Sb in the soil leaching waste liquid; and then the heavy metal capture agent reacts with the heavy metal in the EDTA-Me to generate heavy metal chelate precipitates, so that the removal of various complex heavy metals in the soil leaching waste liquid is realized, the EDTA is recycled, no waste water is discharged, and the closed cycle treatment of the soil leaching waste liquid is realized.
Description
Technical Field
The invention relates to the technical field of water pollution treatment, in particular to a closed cycle treatment method for soil leaching waste liquid.
Background
At present, soil pollution remediation has become the third major pollution abatement environmental protection industry following water pollution abatement and atmospheric pollution abatement. The soil leaching remediation technology with Ethylene Diamine Tetraacetic Acid (EDTA) as a main effective component well realizes the efficient removal of various complex heavy metals in the polluted soil, and simultaneously brings the problem of the disposal of a large amount of soil leaching waste liquid of EDTA chelates containing various complex heavy metals after the soil is leached. At present, an effective treatment method for the soil leaching waste liquid containing high-concentration EDTA is still lacked, which will certainly limit the wider application of the EDTA-based soil leaching remediation technology.
At present, the following methods are mainly used for the EDTA complex soil leaching waste liquid containing the compound heavy metals:
(1) the method comprises the steps of firstly removing EDTA in soil leaching waste liquid by oxidation by adopting an advanced oxidation process (ozone oxidation, Fenton oxidation, ultraviolet oxidation and electrolysis), realizing EDTA-heavy metal complex breaking, releasing heavy metals, and then removing the heavy metals by adopting a coagulating sedimentation process. This method not only consumes a large amount of oxidizing agent, but also wastes EDTA contained therein (FinzgarN, et al. advanced oxidation for treatment of aqueous extract from EDTA extract of Pb and Zn contained in water. journal of environmental Engineering,2006,132(10): 1376-1380.).
(2) Treating the leaching waste liquid of the soil containing the EDTA-heavy metal chelate by an electrochemical method. In the electrochemical treatment process, electrons obtained by heavy metal ions in the EDTA-heavy metal chelate at the cathode are reduced into a heavy metal simple substance, and the EDTA is released. This method can recover only 88% of EDTA, and the rest of EDTA is oxidized by electrolysis. Meanwhile, the removal rates of Pb, Zn and Cd can reach 98%, 73% and 66% (Pb, Zn and Cd recycled soil. journal of hazardous Materials,2011,192:714-2And is not beneficial to the use of large-scale soil leaching waste liquid treatment.
(3) Treating the waste soil leaching liquid by an acid precipitation method, wherein EDTA is mainly subjected to protonation to form H4EDTA is precipitated. The acid separation method mainly realizes the recovery of free EDTA in the soil leaching waste liquid and the complexation constant is less than H4EDTA (logs ks ═ 23.76) was recovered from EDTA-Me, but the heavy metals were not removed, and only the soil washing waste liquid was pretreated. At a pH of 1, the recovery of EDTA is only around 50% (Pociecha M, et al. recycling of EDTA solution soil washing of Pb, Zn, Cd and As stabilized soil. Chemospere, 2011,86(8): 843-.
(4) The sulfide precipitation method is adopted to treat the soil leaching waste liquid, the removal effect on part of heavy metals (Pb and Cd) is good, the recovery of EDTA can be realized, and the removal effect on metalloid As and Sb in the EDTA is basically not good. Meanwhile, in the EDTA acidification regeneration process, residual S2-in the soil washing waste liquid is converted into toxic gas H2S, has great engineering application safety hazard, and can not realize the effective treatment of the leaching waste liquid of the soil containing the composite heavy metal (Wang Q, et al. biochemistry of Cd-EDTA complex and recovery of EDTA from the complex soil-washing solution with the sodium sulfate. chemosphere,2019,220: 1200-.
(5) And treating the soil leaching waste liquid by adopting a heavy metal catching agent. Heavy metals (Pb, Cd, Cu and the like) in the EDTA-Me and heavy metal capture agents generate chelate precipitates with extremely strong stability, and the chelate precipitates are removed, and the EDTA is released and recovered. However, the heavy metal scavenger has no substantial effect on removing metalloids As and Sb in the waste soil washing liquid (Deng T, et al. segment washing by EDTA and its recycling by sodium polyamine-multi dithiocarbanate. Chemosphere,2017,168: 450-.
Disclosure of Invention
In view of the above, the present invention aims to provide a closed cycle treatment method for soil washing waste liquid. The treatment method provided by the invention can realize the high-efficiency removal of metalloids As and Sb and composite heavy metals in the soil leaching waste liquid, and can also realize the recycling of the effective component EDTA in soil leaching.
In order to achieve the above object, the present invention provides the following technical solutions:
the invention provides a closed cycle treatment method of soil leaching waste liquid, which comprises the following steps:
adding coagulant and coagulant aid into the soil leaching waste liquid, and sequentially carrying out coagulating sedimentation and solid-liquid separation to obtain aluminum arsenate, aluminum antimonate and Al (OH)3Precipitating and filtering the first filtrate; the soil leaching waste liquid contains metalloid, EDTA-heavy metal complex and EDTA, the metalloid is As or Sb, and the heavy metal in the EDTA-heavy metal complex comprises one or more of Pb, Cd, Cr, Cu, Zn, Co, Hg, Sn, Ti and V; the coagulant is soluble aluminum salt;
adding a heavy metal capture agent and a coagulant aid into the first filtrate, and sequentially carrying out chelate precipitation and solid-liquid separation to obtain a heavy metal chelate precipitate, an EDTA complex and a second filtrate;
and directly recycling the second filtrate and the EDTA complex for leaching the heavy metal contaminated soil.
Preferably, the soluble aluminium salt comprises one or more of aluminium chloride, aluminium sulphate, polyaluminium chloride, polyaluminium sulphate, polyaluminium ferric silicate, polyaluminium ferric sulphate and polyaluminium ferric chloride.
Preferably, the ratio of the sum of the molar amounts of EDTA and metalloid to the molar amount of aluminum in the soluble aluminum salt is 1 (1.5-2.0).
Preferably, the pH value of the reaction end point of the coagulating sedimentation is 5.0-6.0.
Preferably, the heavy metal trapping agent is a sulfur-based heavy metal trapping agent.
Preferably, the molar ratio of the heavy metal capture agent to the heavy metal in the EDTA-heavy metal complex is (1.0-3.0): 1.
Preferably, the pH value of the reaction end point of the chelate precipitation is 5.5-6.5.
Preferably, the coagulant aid in the coagulating sedimentation and the chelating sedimentation is polyacrylamide.
Preferably, the adding amount of the coagulant aid in the coagulating sedimentation and the chelating sedimentation is independently 2-5 mg/L.
Preferably, the pH adjusting agent for adjusting the pH is independently hydrochloric acid or sodium hydroxide.
The invention provides a closed cycle treatment method of soil leaching waste liquid, which comprises the following steps: adding coagulant and coagulant aid into the soil leaching waste liquid, and sequentially carrying out coagulating sedimentation and solid-liquid separation to obtain aluminum arsenate, aluminum antimonate and Al (OH)3Precipitating and filtering the first filtrate; the soil leaching waste liquid contains metalloid, EDTA-heavy metal complex and EDTA, the metalloid is As or Sb, and the heavy metal in the EDTA-heavy metal complex comprises one or more of Pb, Cd, Cr, Cu, Zn, Co, Hg, Sn, Ti and V; the coagulant is soluble aluminum salt; adding a heavy metal capture agent and a coagulant aid into the first filtrate, and sequentially carrying out chelate precipitation and solid-liquid separation to obtain a heavy metal chelate precipitate, an EDTA complex and a second filtrate; and directly recycling the second filtrate and the EDTA complex for leaching the heavy metal contaminated soil.
The invention utilizes the reaction of soluble aluminum salt and As and Sb metals to generate precipitates of aluminum arsenate and aluminum antimonate and Al (OH) generated by hydrolysis of the soluble aluminum salt3The flocculation adsorption effect of the method realizes the effective removal of metalloid As and Sb in the soil leaching waste liquid; then, a heavy metal chelating precipitate is generated by the reaction of a Heavy Metal Capture Agent (HMCA) and the heavy metal in the EDTA-Me, so that the effect of the heavy metal chelating precipitate in the soil leaching waste liquid is realizedAnd heavy metals are removed, and EDTA is recycled, so that closed cycle treatment of the soil leaching waste liquid is realized.
Compared with the prior art, the invention has the beneficial effects that: the invention can simultaneously realize the high-efficiency removal of metalloids As, Sb and heavy metals in the soil leaching waste liquid and the recycling of EDTA. Wherein, the removal rate of As and Sb metals is more than 80 percent, the removal rate of Pb, Cd and Cu is more than 98 percent, the removal rate of Cr is more than 75 percent, and the recovery rate of EDTA is more than 90 percent. The invention is an environment-friendly closed cycle treatment process for the waste soil leaching solution, and realizes near zero emission of the waste soil leaching solution treatment. The invention has the advantages of clear and reasonable process principle, low treatment cost and no secondary pollution problem.
Drawings
FIG. 1 is a flow chart of a closed cycle treatment method of the waste soil washing liquid in example 1.
Detailed Description
The invention provides a closed cycle treatment method of soil leaching waste liquid, which comprises the following steps:
adding coagulant and coagulant aid into the soil leaching waste liquid, and sequentially carrying out coagulating sedimentation and solid-liquid separation to obtain aluminum arsenate, aluminum antimonate and Al (OH)3Precipitating and filtering the first filtrate; the soil leaching waste liquid contains metalloid, EDTA-heavy metal complex and EDTA, the metalloid is As or Sb, and the heavy metal in the EDTA-heavy metal complex comprises one or more of Pb, Cd, Cr, Cu, Zn, Co, Hg, Sn, Ti and V; the coagulant is soluble aluminum salt;
adding a heavy metal capture agent and a coagulant aid into the first filtrate, and sequentially carrying out chelate precipitation and solid-liquid separation to obtain a heavy metal chelate precipitate, an EDTA complex and a second filtrate;
and directly recycling the second filtrate and the EDTA complex for leaching the heavy metal contaminated soil.
In the present invention, unless otherwise specified, all the raw materials used are commercially available in the art.
The invention adds coagulant and coagulant aid into the soil leaching waste liquid, and sequentially carries out coagulating sedimentation and coagulation aidingSolid-liquid separation to obtain aluminum arsenate, aluminum antimonate and Al (OH)3Precipitating and filtering the first filtrate; the soil leaching waste liquid contains metalloid, EDTA-heavy metal complex and EDTA, the metalloid is As or Sb, and the heavy metal in the EDTA-heavy metal complex comprises one or more of Pb, Cd, Cr, Cu, Zn, Co, Hg, Sn, Ti and V; the coagulant is soluble aluminum salt. The source of the soil washing waste liquid and the content of each substance in the soil washing waste liquid are not particularly limited, and the soil washing waste liquid with EDTA as a main component is preferred.
In the present invention, the soluble aluminum salt preferably includes one or a mixture of aluminum chloride, aluminum sulfate, polyaluminum chloride, polyaluminum sulfate, polyaluminum ferric silicate, polyaluminum ferric sulfate and polyaluminum ferric chloride.
In the present invention, the ratio of the sum of the molar amounts of EDTA and metalloid to the molar amount of aluminum in the soluble aluminum salt is preferably 1 (1.5 to 2.0).
In the invention, the coagulant aid in the coagulating sedimentation is preferably Polyacrylamide (PAM), and the adding amount of the coagulant aid is preferably 2-5 mg/L.
In the invention, the pH value of the reaction end point of the coagulating sedimentation is preferably 5.0-6.0. In the invention, the pH value regulator for regulating the pH value is preferably hydrochloric acid or sodium hydroxide, the dosage of the pH value regulator is not specially limited, and the pH value at the end of the reaction can be ensured to be 5.0-6.0.
In the present invention, the solid-liquid separation is preferably filtration, and specific parameters of the filtration are not particularly limited in the present invention.
In the invention, the pH value of the soil leaching waste liquid is preferably adjusted to 5.0-6.0 before use, and the pH value regulator for adjusting the pH value is preferably hydrochloric acid or sodium hydroxide, and the dosage of the pH value regulator is not specially limited, so that the reaction end point pH value can be ensured to be 5.0-6.0.
In a specific embodiment of the present invention, the order of adding the coagulant and the coagulant aid into the soil washing waste liquid is preferably: adjusting the pH value of the soil leaching waste liquid to 5.0-6.0 by using hydrochloric acid or sodium hydroxide, then adding a soluble aluminum salt, adjusting the pH value of the solution to 5.0-6.0 by using hydrochloric acid or sodium hydroxide, sequentially carrying out mechanical rapid stirring and first mechanical slow stirring under the condition of normal temperature, then adding PAM, and carrying out second mechanical slow stirring under the condition of normal temperature. In the invention, the rotation speed of the mechanical rapid stirring is preferably 360r/min, and the time is preferably 5 min; the rotation speed of the first mechanical slow stirring and the rotation speed of the second mechanical slow stirring are both preferably 160r/min, and the time is both preferably 30 min. In the invention, the mechanical rapid stirring is a rapid mixing process in the coagulating sedimentation, and can ensure that the pH value of a reaction system quickly reaches stable balance; the first mechanical slow stirring is used for increasing the contact time of the coagulant and target pollutants and ensuring the coagulation removal effect of the coagulant on arsenic and antimony.
In the processes of coagulating sedimentation and solid-liquid separation, the soluble aluminum salt reacts with As and Sb metalloid to generate precipitates of aluminum arsenate and aluminum antimonate, and Al (OH) generated by hydrolysis of the soluble aluminum salt3The flocculation adsorption effect of the method realizes the effective removal of metalloid As and Sb in the soil leaching waste liquid.
After the first filtrate is obtained, adding a heavy metal capture agent and a coagulant aid into the first filtrate, and sequentially carrying out chelate precipitation and solid-liquid separation to obtain a heavy metal chelate precipitate, an EDTA complex and a second filtrate.
In the present invention, the heavy metal scavenger is preferably a sulfur-based heavy metal scavenger.
In the present invention, the molar ratio of the heavy metal scavenger to the heavy metal in the EDTA-heavy metal complex is preferably (1.0-3.0): 1.
In the invention, the pH value of the reaction end point of the chelate precipitation is preferably 5.5-6.5, and more preferably 6.0. In the invention, the pH value regulator for regulating the pH value is preferably hydrochloric acid or sodium hydroxide, the dosage of the pH value regulator is not specially limited, and the pH value at the end of the reaction can be ensured to be 5.5-6.5.
In the present invention, the coagulant aid in the chelated precipitate is preferably polyacrylamide.
In the invention, the adding amount of the coagulant aid in the chelate sediment is preferably 2-5 mg/L.
In the chelating and precipitating process, the heavy metal capture agent reacts with heavy metal in EDTA-Me to generate heavy metal chelating precipitate, so that the heavy metal in the soil leaching waste liquid is removed.
In a specific embodiment of the present invention, the pH of the first filtrate is preferably adjusted to 5.5 to 6.5, and more preferably to 6.0 before use, and the pH adjusting agent for adjusting the pH is preferably hydrochloric acid or sodium hydroxide, and the amount of the pH adjusting agent used in the present invention is not particularly limited, and the pH at the end of the reaction can be ensured to be 5.5 to 6.5.
In a specific embodiment of the present invention, the order of adding the heavy metal capturing agent and the coagulant aid to the first filtrate is preferably: adjusting the pH value of the first filtrate to 5.5-6.5 by using hydrochloric acid or sodium hydroxide, then adding a heavy metal capture agent, adjusting the pH value of the solution to 5.5-6.5 by using hydrochloric acid or sodium hydroxide, mechanically and rapidly stirring at normal temperature, then adding PAM, and mechanically and slowly stirring at normal temperature. In the invention, the rotation speed of the mechanical rapid stirring is preferably 360r/min, and the time is preferably 8 min; the rotation speed of the mechanical slow stirring is preferably 160r/min, and the time is preferably 30 min.
After the EDTA complex and the second filtrate are obtained, the second filtrate and the EDTA complex are directly reused for leaching the heavy metal contaminated soil, so that the closed cycle treatment of the waste soil leaching solution is realized.
In the invention, the EDTA complex preferably comprises EDTA-Al and EDTA-Ca, and the chelating coefficients of the EDTA-Al and the EDTA-Ca are both far smaller than that of EDTA-heavy metal, so that the EDTA complex can be directly reused for leaching heavy metals such as Pb in soil again.
In order to further illustrate the present invention, the method for treating waste soil washing liquor by closed cycle is described in detail below with reference to examples, but they should not be construed as limiting the scope of the present invention.
Example 1
FIG. 1 is a flow chart of a closed cycle treatment method of the waste soil washing liquid in example 1.
Ultrapure water, arsenic acid (chemical purity), cadmium chloride pentahydrate (analytical purity), chromium nitrate nonahydrate (analytical purity) and lead nitrate (analytical purity) are adopted to prepare the simulated soil leaching waste liquid, wherein the concentrations of As, Cd, Cr and Pb are respectively 99.01mg/L, 9.93mg/L, 19.36mg/L and 59.24mg/L, and the concentration of EDTA is 0.01 mol/L.
400mL of the simulated waste liquid is placed in a 500mL beaker, and the pH value of the solution is adjusted to 5.0 by hydrochloric acid or sodium hydroxide. Then 900mg/L (calculated by Al) of polymeric aluminum ferric silicate (the mass content of Al in the polymeric aluminum ferric silicate is 18.9 percent) is added, and hydrochloric acid or sodium hydroxide is adopted to adjust the pH value of the solution to 5.0. Mechanically stirring at normal temperature for 5min at high speed (360r/min), and mechanically stirring at low speed (160r/min) for 30 min. Then, 2mg/L PAM is added, and mechanical slow stirring (160r/min) is carried out for 30min under the normal temperature condition. And finally, standing and precipitating for 30min, taking supernatant, filtering and measuring the concentrations of As, Cd, Cr and Pb.
200mL of the filtrate was taken, and placed in a 400mL beaker, and the pH of the solution was adjusted to 6.0 with hydrochloric acid or sodium hydroxide. Then adding 800mg/L heavy metal catching agent (wherein the mass concentration of the sulfur-based heavy metal catching agent is 10%), and adjusting the pH value of the solution to 6.0 by using hydrochloric acid. Mechanically stirring rapidly (360r/min) for 8min at normal temperature. Then, 2mg/L PAM is added, and mechanical slow stirring (160r/min) is carried out for 30min under the normal temperature condition. And finally, standing and precipitating for 30min, taking supernatant, filtering and measuring the concentrations of As, Cd, Cr and Pb. The effect of the two-stage treatment of coagulation and chelate precipitation is shown in table 1 (average of three replicates). As can be seen from Table 1, when the simulated soil leaching waste liquid is treated by the process, the removal rate of the metalloid As can reach 88.83%, and the removal rates of the heavy metals Cd, Cr and Pb can reach 97.88%, 78.00% and 99.37%, respectively, which shows that the method disclosed by the invention realizes the removal of the metalloid As and the composite heavy metals Cd, Cr and Pb.
TABLE 1 two-stage treatment effect of coagulating sedimentation and chelating sedimentation
Example 2
Ultrapure water, arsenic acid (chemical purity), potassium hexahydroxyantimonate (analytical purity), cadmium chloride pentahydrate (analytical purity), chromium nitrate nonahydrate (analytical purity), lead nitrate (analytical purity), copper sulfate heptahydrate (chemical purity) and zinc chloride (analytical purity) are adopted to prepare the simulated soil leaching waste liquid, wherein the concentrations of As, Sb, Cd, Cr, Pb, Cu and Zn are 1261.32mg/L, 745.42mg/L, 13.04mg/L, 27.37mg/L, 193.56mg/L, 183.37mg/L and 64.71mg/L respectively, and the concentration of EDTA is 0.1 mol/L.
400mL of the simulated waste liquid is placed in a 500mL beaker, and the pH value of the solution is adjusted to 5.0 by hydrochloric acid or sodium hydroxide. 3600mg/L (calculated by Al) of polymeric aluminum ferric silicate is added (the mass content of Al in the polymeric aluminum ferric silicate is 18.9 percent), and hydrochloric acid is adopted to adjust the pH value of the solution to 5.0. Mechanically stirring at normal temperature for 5min at high speed (360r/min), and mechanically stirring at low speed (160r/min) for 30 min. Then, 2mg/L PAM is added, and mechanical slow stirring (160r/min) is carried out for 30min under the normal temperature condition. And finally, standing and precipitating for 30min, and then filtering.
200mL of the filtrate is taken and placed in a 400mL beaker, and the pH value of the solution is adjusted to 6.0 by adopting hydrochloric acid or sodium hydroxide. Then adding 1500mg/L heavy metal catching agent (wherein the mass concentration of the sulfur-based heavy metal catching agent is 10%), and adjusting the pH value of the solution to 6.0 by using hydrochloric acid. Mechanically stirring rapidly (360r/min) for 8min at normal temperature. Then, 2mg/L PAM is added, and mechanical slow stirring (160r/min) is carried out for 30min under the normal temperature condition. And finally, standing and precipitating for 30min, taking supernatant, filtering and measuring the concentrations of As, Sb, Cd, Cr, Pb, Cu and Zn. The effect of the two-stage treatment of coagulation and chelate precipitation is shown in Table 2 (average of three replicates). As can be seen from Table 2, when the simulated soil leaching waste liquid is treated by the process, the removal rates of metalloid As and Sb can reach 84.36% and 92.33%, and the removal rates of heavy metals Cd, Cr, Pb, Cu and Zn can reach 98.77%, 82.39%, 99.62%, 99.67% and 45.31% respectively. The method disclosed by the invention realizes the removal of metalloid As and Sb and composite heavy metals Cd, Cr, Pb and Cu, has a slightly low removal rate of Zn, has a high environmental background value of Zn and has low biological toxicity.
TABLE 2 two-stage treatment effect of coagulating sedimentation and chelating sedimentation
Example 3
In this example, the actual soil washing waste liquid was used as a treatment target. The concentrations of As, Sb, Cd, Cr, Pb, Cu and Zn in the soil leaching waste liquid are 1264.36mg/L, 120.78mg/L, 8.94mg/L, 1.21mg/L, 64.21mg/L, 8.31mg/L and 98.14mg/L respectively, the concentration of EDTA is 0.05mol/L, and the concentration of sodium citrate is 0.01 mol/L.
400mL of the simulated waste liquid is placed in a 500mL beaker, and the pH value of the solution is adjusted to 5.0 by hydrochloric acid or sodium hydroxide. 3600mg/L (calculated by Al) of polymeric aluminum ferric silicate is added (the mass content of Al in the polymeric aluminum ferric silicate is 18.9 percent), and hydrochloric acid or sodium hydroxide is adopted to adjust the pH value of the solution to 5.0. Mechanically stirring at normal temperature for 5min at high speed (360r/min), and mechanically stirring at low speed (160r/min) for 30 min. Then, 2mg/L PAM is added, and mechanical slow stirring (160r/min) is carried out for 30min under the normal temperature condition. And finally, standing and precipitating for 30min, taking supernatant, filtering and measuring the concentrations of As, Sb, Cd, Cr, Pb, Cu and Zn.
200mL of the filtrate was taken, and placed in a 400mL beaker, and the pH of the solution was adjusted to 6.0 with hydrochloric acid or sodium hydroxide. Then adding 1500mg/L heavy metal catching agent (wherein the mass concentration of the sulfur-based heavy metal catching agent is 10%), and adjusting the pH value of the solution to 6.0 by using hydrochloric acid or sodium hydroxide. Mechanically stirring rapidly (360r/min) for 8min at normal temperature. Then, 2mg/L PAM is added, and mechanical slow stirring (160r/min) is carried out for 30min under the normal temperature condition. And finally, standing and precipitating for 30min, taking supernatant, filtering and measuring the concentrations of As, Sb, Cd, Cr, Pb, Cu and Zn. The effect of the two-stage treatment of coagulation and chelate precipitation is shown in Table 3 (average of three replicates). As can be seen from Table 3, when the actual soil leaching waste liquid is treated by the process, the removal rates of the metalloids As and Sb can reach 89.34% and 86.11%, and the removal rates of heavy metals Cd, Cr, Pb, Cu and Zn can respectively reach 99.44%, 91.73%, 99.20%, 99.39% and 55.93%. Meanwhile, EDTA is recovered in the form of EDTA-Ca and EDTA-Al, the recovery rate is 95%, and the EDTA can be directly reused in the leaching of the heavy metal contaminated soil.
TABLE 3 two-stage treatment effect of coagulating sedimentation and chelating sedimentation
The embodiment shows that the optimal removal rates of the metalloids As and Sb in the soil leaching waste liquid are respectively 89.34% and 86.11%, and the optimal removal rates of the heavy metals Cd, Cr, Pb, Cu and Zn are respectively 99.44%, 91.73%, 99.20%, 99.39% and 55.93%.
The method has the biggest characteristics that on one hand, As and Sb metals and composite heavy metals in the soil leaching waste liquid are converted into precipitates to be used As hazardous waste for safe disposal, and on the other hand, the method realizes the recovery and reutilization of the main effective component EDTA of the soil leaching agent, has no waste water discharge, and is an environment-friendly soil leaching waste liquid treatment process. This is a different area from the prior art, a combined treatment process.
The foregoing is merely a preferred embodiment of the invention and is not intended to limit the invention in any manner. It should be noted that, for those skilled in the art, without departing from the principle of the present invention, several improvements and modifications can be made, and these improvements and modifications should also be construed as the protection scope of the present invention.
Claims (10)
1. A closed cycle treatment method of soil leaching waste liquid is characterized by comprising the following steps:
coagulant is added into soil leaching waste liquidAnd coagulant aid, which are sequentially subjected to coagulating sedimentation and solid-liquid separation to obtain aluminum arsenate, aluminum antimonate and Al (OH)3Precipitating and filtering the first filtrate; the soil leaching waste liquid contains metalloid, EDTA-heavy metal complex and EDTA, the metalloid is As or Sb, and the heavy metal in the EDTA-heavy metal complex comprises one or more of Pb, Cd, Cr, Cu, Zn, Co, Hg, Sn, Ti and V; the coagulant is soluble aluminum salt;
adding a heavy metal capture agent and a coagulant aid into the first filtrate, and sequentially carrying out chelate precipitation and solid-liquid separation to obtain a heavy metal chelate precipitate, an EDTA complex and a second filtrate;
and directly recycling the second filtrate and the EDTA complex for leaching the heavy metal contaminated soil.
2. The closed cycle process of claim 1, wherein the soluble aluminum salt comprises one or a mixture of aluminum chloride, aluminum sulfate, polyaluminum chloride, polyaluminum sulfate, polyaluminum ferric silicate, polyaluminum ferric sulfate, and polyaluminum ferric chloride.
3. The closed cycle treatment method according to claim 1 or 2, wherein the ratio of the sum of the molar amounts of EDTA and metalloid to the molar amount of aluminum in the soluble aluminum salt is 1 (1.5-2.0).
4. The closed cycle treatment method according to claim 1 or 2, wherein the reaction end point pH of the coagulating sedimentation is 5.0 to 6.0.
5. The closed loop treatment method of claim 1, wherein the heavy metal scavenger is a sulfur-based heavy metal scavenger.
6. The closed cycle treatment method according to claim 1 or 5, wherein the molar ratio of the heavy metal scavenger to the heavy metal in the EDTA-heavy metal complex is (1.0-3.0): 1.
7. The closed cycle treatment method of claim 1, wherein the pH at the end of the chelating precipitation reaction is 5.5 to 6.5.
8. The closed loop treatment process of claim 1 wherein the coagulant aid in both the coagulating and chelating precipitations is polyacrylamide.
9. The closed loop treatment method according to claim 1 or 8, wherein the coagulant aid is added in the coagulating sedimentation and the chelating sedimentation independently in an amount of 2 to 5 mg/L.
10. The closed cycle process of claim 4 or 7, wherein the pH adjusting agent for adjusting the pH is independently hydrochloric acid or sodium hydroxide.
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Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102500612A (en) * | 2011-10-28 | 2012-06-20 | 中南大学 | Chemical leaching restoring method for soil polluted by heavy metals |
| CN103342429A (en) * | 2013-07-30 | 2013-10-09 | 北京矿冶研究总院 | Method for recovering, treating and recycling valuable metals in waste acid |
| CN105858958A (en) * | 2016-04-28 | 2016-08-17 | 湖南浩美安全环保科技有限公司 | Arsenic-antimony-cyanogen-containing mine wastewater treatment method |
| CN108298666A (en) * | 2018-04-11 | 2018-07-20 | 北京师范大学 | A method of using vulcanized sodium contact break heavy metal-EDTA complex compounds and recycling EDTA |
| CN111484161A (en) * | 2020-04-10 | 2020-08-04 | 中冶一局环境科技有限公司 | Regeneration treatment method of leaching waste liquid generated by soil remediation, regenerated leaching liquid and application |
-
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Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102500612A (en) * | 2011-10-28 | 2012-06-20 | 中南大学 | Chemical leaching restoring method for soil polluted by heavy metals |
| CN103342429A (en) * | 2013-07-30 | 2013-10-09 | 北京矿冶研究总院 | Method for recovering, treating and recycling valuable metals in waste acid |
| CN105858958A (en) * | 2016-04-28 | 2016-08-17 | 湖南浩美安全环保科技有限公司 | Arsenic-antimony-cyanogen-containing mine wastewater treatment method |
| CN108298666A (en) * | 2018-04-11 | 2018-07-20 | 北京师范大学 | A method of using vulcanized sodium contact break heavy metal-EDTA complex compounds and recycling EDTA |
| CN111484161A (en) * | 2020-04-10 | 2020-08-04 | 中冶一局环境科技有限公司 | Regeneration treatment method of leaching waste liquid generated by soil remediation, regenerated leaching liquid and application |
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