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WO1998050304A1 - Procede de traitement d'une solution contenant du selenium - Google Patents

Procede de traitement d'une solution contenant du selenium Download PDF

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Publication number
WO1998050304A1
WO1998050304A1 PCT/JP1998/002033 JP9802033W WO9850304A1 WO 1998050304 A1 WO1998050304 A1 WO 1998050304A1 JP 9802033 W JP9802033 W JP 9802033W WO 9850304 A1 WO9850304 A1 WO 9850304A1
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Prior art keywords
selenium
iron
treating
solution
metal
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PCT/JP1998/002033
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English (en)
Japanese (ja)
Inventor
Junya Watanabe
Katsuhiko Yano
Koji Kusabe
Tatsuya Sakurai
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Kawasaki Kasei Chemicals Ltd
Mitsubishi Chemical Corp
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Kawasaki Kasei Chemicals Ltd
Mitsubishi Chemical Corp
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Publication of WO1998050304A1 publication Critical patent/WO1998050304A1/fr
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    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F1/00—Treatment of water, waste water, or sewage
    • C02F1/52—Treatment of water, waste water, or sewage by flocculation or precipitation of suspended impurities
    • C02F1/5236—Treatment of water, waste water, or sewage by flocculation or precipitation of suspended impurities using inorganic agents

Definitions

  • the present invention relates to a method for treating a selenium-containing solution and efficiently reducing the selenium concentration in the solution or recovering selenium.
  • Selenium and selenium compounds are used in a variety of manufacturing industries, such as glass decolorizing agents, photocopier photoconductors, rectifiers, semiconductor materials, battery materials, and electrolytic coloring agents for metals such as aluminum.
  • the wastewater discharged from the manufacturing process usually contains a relatively high concentration of selenium.
  • Selenium is also present in wastewater from selenium refinery factories and selenium compound manufacturing factories.
  • selenium has been found to be present in the wastewater discharged from thermal power plants. Since selenium is a very toxic environmental pollutant, its amount in the effluent is strictly regulated, and in recent years its allowable amount has been stricter, and the effluent standard has been set at 0.1 to 0.1 mg / l. It has been.
  • a neutralization coagulation precipitation method As a method of recovering selenium, generally, a neutralization coagulation precipitation method, an iron hydroxide precipitation method, a funilite precipitation method, an ion exchange membrane method, an activated carbon adsorption method and the like are known.
  • these methods require special equipment and equipment for the combined use of multiple treatment methods in order to efficiently remove selenium. Disadvantageous.
  • the present inventors have conducted intensive studies with the aim of solving the above problems and providing a method for efficiently removing and recovering selenium in wastewater, and as a result, when depositing selenium on the surface of an iron-based metal,
  • the selenium concentration can be effectively reduced in a short period of time by removing the selenium compound after removing compounds that exhibit a buffering action near neutrality among the compounds other than selenium in the wastewater. They have found that they can be reduced, and have arrived at the present invention based on this finding. Disclosure of the invention
  • the gist of the present invention is that a solution containing selenium and another metal inorganic acid salt is allowed to flow through a packed bed of an iron-based metal to deposit selenium on the surface of the iron-based metal.
  • the present invention relates to a method for treating a selenium-containing solution by contacting with a ferrous metal at a temperature of not less than ° C.
  • the pH value of the solution containing selenium and another metal inorganic acid is adjusted to 3 to 7; Being a sulfate of lithium earth metal; flowing a solution containing selenium and other metal inorganic acid in an upward flow through a bed of iron-based metal;
  • a solution containing another metal inorganic acid salt is brought into contact with a packed layer of an iron-based metal, the solution is maintained while maintaining the PH value of the solution in the packed layer at 3 to 7; selenium and other metals Adjusting the pH value of the solution containing the inorganic acid salt to 3 to 7 and contacting the pH-adjusted solution with the packed bed of iron-based metal a plurality of times;
  • an acid is added to the packed bed to maintain the PH value of the solution in the bed at 3 to 7.
  • a solution containing selenium and other metal inorganic acid salts and a dilute acid are added to a reaction vessel containing an iron-based metal, and the pH value is adjusted to 3 to 7
  • This is a method for treating a selenium-containing solution by subjecting it to a contact reaction at a temperature of 30 ° C or higher while stirring while maintaining the temperature.
  • the iron-based metal is fibrous, porous, fine plate-like, granular, or powdery; the iron-based metal is fibrous; The ferrous metal is fibrous by a cutting method; the ferrous metal is fibrous with a diameter of 0.1 to 0.3 mm; the ferrous metal is steel wool; The iron-based metal must be porous; the iron-based metal must be iron having a surface area of at least 0.001 m 2 Zg; and the iron-based metal has an iron surface area of 0.0 per column volume. 0.1 m 2 Zm 1 or more iron; This is a method in which the amount of iron-based metal supported on the column is from 0.01 gZm 1 to 3 gZm 1.
  • Preferred treatment solutions for the method of the present invention include a solution containing selenium and another metal inorganic acid salt containing a sulfate ion having a concentration of 100 times or more the selenium concentration;
  • the solution containing a metal inorganic acid salt of (a) contains a weak acid strong base salt, a strong acid weak base salt, a weak acid weak base salt and / or a metal complex salt; a weak acid strong base salt, a strong acid weak base salt, a weak acid weak base salt and
  • the Z or metal complex salt may be an ammonium salt, a carbonate, a phosphate, a borate, a carboxylate, an aluminum complex, a copper complex, a cobalt complex and a Z or iron complex.
  • the present invention provides a solution containing selenium and another metal inorganic acid salt at a temperature of 30 ° C. or more, and flows through a packed layer of an iron-based metal to precipitate selenium on the surface of the iron-based metal.
  • a method of treating a selenium-containing solution comprising a step of incinerating or recovering selenium deposited on the surface of the iron-based metal by incineration or stripping treatment. Contact or ultrasonic treatment; regenerating the iron-based metal by contact with a dilute acid or ultrasonic treatment.
  • a solution containing selenium and other metal inorganic acid salts is used.
  • the present invention also provides a treatment method comprising a step of recovering and recovering the solution and a step of increasing the solution temperature in accordance with the decrease in the selenium recovery ability in the step, decreasing the pH value of the solution, and decreasing the flow rate of the solution or solution. Included in the method.
  • a buffer action from the solution to near neutrality is obtained.
  • the treating agent having the ability to reduce and remove the selenium compound from neutral to acidic side is an iron-based metal; and the compound having a buffering action near neutral is a boron compound and Z or an aluminum compound; a compound exhibiting a buffering action near neutrality; a boron compound; removing a compound having a buffering action near neutrality using a boric acid selective resin; boric acid
  • the selective resin is a glucamine-type chelating resin; the compound having a buffering action near neutrality is an aluminum compound, which includes a method comprising removing the aluminum compound by coagulation and precipitation; is there.
  • FIG. 1 is a diagram illustrating a N a 2 S 0 4 a (NH 4) 2 SC titration curve.
  • the selenium-containing solution to be treated in the present invention is mainly a decolorizing agent for glass, copying Wastewater from various factories such as photoconductors, rectifiers, semiconductor materials, battery materials, aluminum, etc., wastewater from selenium refineries, selenium compound manufacturing plants, or thermal power plants
  • the selenium contained therein exists as various selenium compounds depending on the source of the wastewater.
  • the selenium concentration in the solution also differs depending on the type of wastewater, but for example, wastewater from thermal power plants usually contains 0.2 to 5 pp
  • these wastewaters usually contain inorganic salts of metals other than selenium.
  • alkali metals such as sodium sulfate, magnesium sulfate, sodium chloride, magnesium chloride, etc.
  • sulfuric acid of alkaline earth metals Heavy metal salts such as salts, chlorides, copper, chromium, and nickel are contained together with selenium, and it is effective to apply a solution containing these salts to the treatment method of the present invention.
  • the solution containing selenium and other metal inorganic salts which is the treatment liquid of the method of the present invention, is a solution containing sulfate ions having a concentration of 100 times or more the selenium concentration, and other metal inorganic acid salts other than selenium. Is preferably a sulfate of an alkaline metal or an alkaline earth metal.
  • the solution containing a metal inorganic acid salt other than selenium may be a weak acid strong base salt, a strong acid weak base salt, or a weak acid weak base.
  • the solution containing the salt and Z or metal complex salts i.e., preferably has an acid dissociation constant is a solution containing a substance that is in the range of 1 0- 2 ⁇ 1 0- 1 ⁇ .
  • the weak acid strong base salt, strong acid weak base salt, weak acid weak base salt and / or metal complex salt include ammonium salt, carbonate, phosphate, borate, carboxylate, aluminum complex, copper complex, cobalt complex and It is preferred that the compound is either ⁇ or an iron complex salt.
  • a solution containing the above-mentioned selenium and other metal inorganic acid salts is powerful, and is effective even when the solution contains a compound having a buffering action near neutrality.
  • Compounds having an action generally include a weak acid strong base salt, a strong acid weak base salt, a weak acid weak base salt, a complex compound, or a metal ion compound forming a hydroxide. I can do it.
  • a compound ranging acid dissociation constant of 1 0 2 to 1 0 1 2 Anmoniumu salts, carbonates, phosphates, borates, carboxylates, aluminum complex salts, copper complex , Cobalt complex salts, iron complex salts, and metal hydroxides such as aluminum hydroxide.
  • a selenium-containing solution in which such a substance is present causes a decrease in selenium removal ability due to contact with an iron-based metal.
  • a step of removing these buffer components is performed by removing selenium as described later. By performing the removal step sequentially or simultaneously, a decrease in the selenium removal ability can be prevented.
  • the amount of the buffer component contained in the selenium-containing solution is preferably as small as possible, but is not particularly limited, and is preferably 100 ppm or less, more preferably 10 ppm or less.
  • the pH of the solution increases due to the presence of the buffer component during contact with the iron-based metal, As a result, it is considered that the pH exceeds the neutral to acidic pH range at which the selenium compound can be optimally removed.
  • the pH value of the selenium-containing solution to be treated by the method of the present invention is usually adjusted in the range of 2 to 10, preferably 3 to 7, and particularly preferably 3 to 4.
  • the lower the pH the faster the removal of selenium by iron; therefore, the lower the pH, the better the reaction rate.However, when the pH is low, the reaction between iron and protons elutes iron ions. In addition to this, the amount of acid added for pH adjustment also increases. For this reason, a pH lower than 2 is not practical. On the other hand, when the pH exceeds 10, the reactivity decreases, and the effect of the present invention is not achieved, which is not preferable.
  • the pH is adjusted by using an acid or an alkali.
  • an acid an inorganic acid such as hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid or the like is used.
  • an alkali sodium hydroxide, hydroxide hydroxide And the like.
  • an iron-based metal is used for precipitating selenium.
  • the iron-based metal includes pure metal iron and alloyed iron containing other metals such as chromium and manganese. is there.
  • Specific examples of iron-based metals include electrolytic iron, low-carbon steel, medium-carbon steel, high-carbon steel, mild steel, mild steel, alloy steel, pig iron, gray iron, rimmed steel, capped steel, semi-killed steel, Examples include killed steel, clad steel, crude steel, and ingots.
  • these ferrous metals can be used as molded products formed into a desired shape, but they are hot-rolled products, cold-rolled products, compressed products, extruded products, drawn products. , Plastic work, curtain, steel, etc.
  • the shape of the iron-based metal used in the present invention is not particularly limited. However, in the treatment method of the present invention, selenium in the solution is precipitated on the surface of the iron-based metal by a catalytic reduction reaction with the selenium-containing solution to be treated. It is desirable to have a shape having as large a contact surface area as possible, and further, a shape capable of easily forming a homogeneous packed bed when filled in a treatment tower is preferred. Specifically, a steel fibrous wire rod such as steel wool, a plate-like strip, a powdery substance, a granular substance, a fine chip, and the like are cited, and a steel wool is preferable.
  • Plates have the drawback that it is difficult to pack them into columns and the surface area is small.
  • the particle size is reduced, there is a problem of consolidation in the column. If the particle size is increased, the surface area cannot be increased. Further, there is a problem that the weight of the whole apparatus is increased because iron is filled most densely in the form of particles or powder.
  • the fibrous material is easily used for adjusting the surface area and the filling density, and is optimally used.
  • the fibrous iron iron having a small fiber diameter is suitable.
  • the preferred fiber diameter is from 0 to 3 mm.
  • Examples of the method for processing the fibrous iron-based metal include a drawing method, a melt spinning method, and a cutting method. (Takeo Nakagawa et al., Textile Society Journal, Vol. 39, No. 4, pp. 121-127, 1983), but among them, those manufactured by the cutting method are preferable.
  • the cutting method refers to cutting a metal block with a knife and discharging fine chips to obtain a desired shape.
  • a fiber that uses these chips as fibers is a fibrous metal obtained by the cutting method. is there.
  • a wire cutting method is a method for constantly cutting fibers having a finer cross section, and a typical example is the production of steel wool by the wire cutting method. This steel wool is most suitable for the selenium removal of the present invention.
  • the iron porous body can be manufactured by a sintering method, a plating method, a foaming method, a pressure forming method, or the like, and can be used with no particular limitation on the pore diameter, the pore shape, and the like.
  • the surface area of the iron-based metal it is preferable that the surface area is not less than 0.001 lm 2 Zg regardless of the shape of the iron. Since the reaction between iron and selenium proceeds from the iron surface, if the surface area of iron is small, the reaction rate is low and selenium cannot be removed efficiently. For the same reason, the surface area of the iron-based metal per column volume is also limited, and is preferably 0.001 m 2 Zm 1 or more per column volume.
  • the amount of iron carried on the column is limited in terms of equipment.
  • the specific gravity of iron is 7.86 g / cm 3, which is much higher than the specific gravity of a carrier such as ordinary ion exchange resin, which is around 1.
  • special equipment that is different from equipment that normally carries ion exchange resins is required. Therefore, it is practical to reduce the amount of charge to the column. If the supported amount is too low, the selenium removability will be reduced. Therefore, it is preferably from 0.01 g / ml to 3 g Zml, more preferably from 0.05 g Zm 1 in terms of column volume. Not less than 1 g / m 1.
  • a packed bed formed by filling a treatment tower with an iron-based metal having an appropriate shape such as a fibrous, porous, granular, or powdery material is coated with selenium and other metal salts.
  • the treatment solution is brought into contact by passing water to precipitate selenium on the surface of a metal such as iron.At this time, the contact treatment needs to be performed at 30 ° C or higher, and preferably 45 to 9 ° C. It is performed in a temperature range of 0 ° C. If the contact temperature is lower than 30 ° C, the reduction reaction of selenium with iron hardly proceeds, and it is difficult to recover and remove selenium from the solution. Further, it is not desirable to raise the temperature to an unnecessarily high temperature in terms of operability and economy, and in some cases, it may be affected by other components coexisting in the waste liquid.
  • the contact temperature can be controlled by heating the solution to be treated to a predetermined temperature and supplying it to the packed tower. May be maintained.
  • Flow of the solution to be treated into the packed tower may be either a downward flow or an upward flow, but in order to make sufficient contact with the iron metal, the solution is passed upward from the bottom of the packed tower. Is preferred.
  • temperature, pH, and SV are factors that determine the reaction rate of selenium removal.
  • a method of adjusting the pH of a solution containing selenium and other metal inorganic acid salts and adding the solution to a column filled with an iron-based metal can be mentioned.
  • an iron-based metal is brought into contact with an acidic solution, the metal is consumed over time, and the PH value gradually rises, exceeding the range of 3 to 7, which is a pH at which selenium can be optimally removed.
  • the concentration or flow rate of the iron-based metal in the column the pH value in the column is maintained in the range of 3 to 7 in which selenium can be optimally removed, and selenium removal is performed in that state. It is preferred to do so.
  • the operating conditions vary depending on the composition of the solution containing selenium and other metal inorganic acid salts and the buffering action. Conditions may be appropriately selected according to the conditions.
  • a solution containing a metal inorganic acid salt other than selenium is a solution containing a weak acid strong base salt, a strong acid weak base salt, a weak acid weak base salt and Z or a metal complex salt, that is, an acid.
  • dissociation constant is 1 0 2 to 1 0 - If a solution containing a substance that is in the range of 1 Y is often necessary to control the p H value occurs. In such a case, the consumption of metallic iron by acid increases even near neutrality, and the pH value often rises to 7 or more. In the region where the pH value is 7 or more, selenium is not removed, and only metallic iron is consumed, which is not economical.
  • the selenium and other selenium obtained in the primary treatment Readjust the pH value of the solution containing the metal inorganic acid salt to 3 to 7 and repeat the process consisting of pH adjustment of the solution and contact treatment several times so that it comes into contact with the iron-based metal layer. Thus, a desired value can be achieved. Usually, the operation just repeat the process two or three times.
  • the column used for the primary treatment may be used, or may be added to another new column.
  • a method in which the solution is passed while adding an acid to the ⁇ layer column can be used.
  • the acid can be added from the upper part of the packed bed together with the selenium-containing solution.
  • a column in which the solution can be added from the middle of the packed bed as a packed bed, and add the acid from the middle of the column. Is preferred.
  • the concentration and amount of the acid to be added are most preferably controlled so that the pH value in the column is in the range of 3 to 7.
  • the acid can be added continuously or intermittently.
  • the contact treatment with an iron-based metal can be performed not only by a column method using a packed bed of an iron-based metal but also by a batch method.
  • a reaction vessel capable of stirring the iron-based metal is used, and a solution containing selenium and other metal inorganic acid salts and a dilute acid are added, and the mixture is stirred at a temperature of 30 ° C or more, so that p during the contact treatment is reduced. What is necessary is just to make it contact with ferrous metal, keeping H in the range of 3-7.
  • the treatment can be performed by continuously discharging the treatment solution after the contact treatment from the reaction vessel while continuously supplying the solution containing selenium or the like and the acid to the reaction vessel.
  • the removal of selenium by the catalytic reduction reaction of selenium with iron is promoted by oxygen dissolved in the liquid to be treated, so that the contact treatment between a metal such as iron and the liquid to be treated is carried out by air. It is preferably performed in an oxygen-containing atmosphere such as
  • a flue gas desulfurization wastewater of a coal-fired power plant which is a wastewater containing selenium and a buffer component.
  • a flue gas desulfurization wastewater of a coal-fired power plant which is a wastewater containing selenium and a buffer component.
  • thermal Nuclear Power Vol. 35, No. 10, (1984), p. 1083, shows an example of water quality of flue gas desulfurization effluent of a coal-fired power plant.
  • F there is a S 0 4, C and Ca, Mg, Al, and B exist.
  • Al and B are substances that may have a buffering effect near neutrality.
  • No. (1984), p. 1083 shows that A1 is present at 100 to 800 ppm and B is present at 10 to 130 ppm. This amount is sufficient to exhibit a buffering effect near neutrality, indicating that this component hinders the removal of selenium compounds from flue gas desulfurization effluent by contact with the selenium removing agent. The inventors have found out.
  • the boron compound is usually present in a solution in the form of a borate.
  • a boric acid selective resin As a boric acid-selective resin, a glucamine-type chelating resin is commercially available. With this resin, boric acid can be selectively removed even in the presence of several thousand ppm of coexisting salt.
  • a specific example is Diaion CRB02 manufactured by Mitsubishi Chemical Corporation.
  • the contact method with the boric acid-selective resin may be a batch method or a column method, but is usually used in a column method.
  • the contact be made at a pH of about 4 to 12, and the contact be made at a normal temperature and a flow rate of about SV1 to about 50.
  • removal of the aluminum compound removal by a chelating resin, removal by coagulation and precipitation, etc. can be considered, but removal by coagulation and precipitation is effective.
  • the aluminum compound may be neutralized with an acid or an alkali, and the aluminum compound may be precipitated as a hydroxide, followed by solid-liquid separation.
  • the solution obtained above is then subjected to a step of removing a selenium compound.
  • the selenium compound is removed by contacting the selenium compound with a treating agent capable of reducing and removing the selenium compound from the neutral to acidic side.
  • Treatment agents capable of reducing and removing selenium compounds from the neutral to acidic side include iron-based metals, reducing agents such as hydrazine, thiourea, borohydride compounds, anthrahydroquinone, and resins carrying them.
  • Other metals such as zinc and copper, and reducing salts such as copper (I) and Fe (II) salts.
  • the type of ferrous metal and contact method It can be used without any particular limitation.
  • a ram method in which the ⁇ ⁇ of the solution obtained in the previous step is adjusted as necessary and added to a column filled with an iron-based metal as described above Can be adopted.
  • Selenium deposited on the surface of a metal such as iron by the method of the present invention can be recovered as metallic selenium by burning it.
  • the method of incineration is not particularly limited, and any type of selenium can be easily recovered from the incineration residue such as a rotary incinerator such as a single kiln and a crucible-type incinerator. But it can be adopted. Further, a method in which a dilute acid is brought into contact with a metal surface on which selenium is deposited, and the separated selenium is recovered as a solid can also be adopted. In this case, 0.01 to 6 mL of hydrochloric acid may be passed through the column to separate solid selenium that separates with the dissolution of iron from the column.
  • Other methods include the separation of selenium coming off by ultrasonically treating the metal on which selenium is deposited, and the separation of selenium coming off by passing hot water through the metal on which selenium is deposited.
  • a transmission frequency of 20 to 100 ° and a processing time of 1 to 30 minutes are preferably used. The higher the temperature, the more effective it is, but it can be used without particular limitation. Since the adsorption power of selenium on the metal surface is not strong, a method of separating selenium by some physical action is also used without limitation.
  • the reactivity of selenium-containing wastewater decreases
  • the reactivity can be changed over time to prevent the decrease in reactivity.
  • the reaction conditions at the stage where the reactivity decreases, that is, at the stage where the leaked selenium concentration increases, raise the temperature after treatment, lower the pH of the processing solution, or lower the SV.
  • the reactivity can be increased to the same level as before the decrease in reactivity.
  • Changing these conditions is more effective when used in combination, which can extend the life of the iron-based metal and increase the amount of processing solution per weight of the iron-based metal.
  • decreasing the pH also has the effect of regenerating the iron-based metal.Therefore, the selenium is removed while temporarily reducing the pH and regenerating the iron-based metal. The method of returning can also be adopted.
  • iron ions are eluted in the liquid after the treatment.
  • a method of removing as a precipitate by adding an alkali a method of removing with a chelating resin, a method of removing with an ion exchange membrane, a method of removing with manganese sand, and the like can be used. Also, by making the pH of the selenium-containing solution relatively high, elution of iron ions can be suppressed.
  • a method of separating selenium that separates by sonicating the metal on which selenium is deposited a method of separating selenium that separates by passing hot water through the metal on which selenium is deposited, etc. Is mentioned. Since selenium does not have a strong adsorptive power on the metal surface, a method of separating selenium by some physical action is also used without limitation.
  • the treatment method of the present invention may be used in combination with conventional methods such as neutralization precipitation method for recovering selenium, iron hydroxide precipitation method, ferrite precipitation method, ion exchange membrane treatment method, and activated carbon adsorption method, if necessary. Can be implemented.
  • neutralization precipitation method for recovering selenium iron hydroxide precipitation method, ferrite precipitation method, ion exchange membrane treatment method, and activated carbon adsorption method, if necessary.
  • ICP emission method ICP emission spectroscopy
  • Example 1 was repeated except that the temperature of the jacket was maintained at 80 ° C. As a result, the concentration of selenium in the solution after passing 10 B.V. was 0.7 ppm.
  • Example 1 was repeated except that the temperature of the jacket was maintained at 20 ° C. As a result, the concentration of selenium in the solution after passing 10 B.V. was 5. Oppm, and selenium in the solution was hardly removed.
  • Example 3 was repeated in the same manner as in Example 3 except that the diameter of the steel wool was changed to 00.04 mni (iron surface area: 0.013 m 2 / g-iron, per iron column volume: 0.0013 m 2 / m 1, iron Column carrying amount: 0.1 lOgZm 1). The concentration of selenium in the solution after passing 20 BV was 0.1 lOppm.
  • Example 3 was carried out in the same manner as in Example 3, except that iron wool having a fiber diameter of 0.5 (0.5 mm metal wire : manufactured by Mitsuwa Chemicals Co., Ltd.) was used instead of steel wool (surface area of iron: 0.001 m 2). / g-iron, per iron column volume: 0.0001 m 2 Zm 1, iron force Ram loading: 0.1 lOgZm 1). The concentration of selenium in the solution after passing through 2 O BV was 0.47 ppm.
  • the filtered components were placed in a 100 ml eggplant type flask equipped with a Dimroth condenser, 5 ml of concentrated nitric acid was added, and the mixture was reacted at 90 ° C. for 30 minutes with stirring to dissolve all solid components. Cooling water at 5 ° C was passed through the Jimroth condenser. After cooling, the reaction solution was diluted to 50 ml and the selenium and iron concentrations were measured. The selenium concentration was 14.9 ppm and the iron concentration was 11.2 ppm.
  • Example 8 About one sixth of the weight of the steel wool after the passage of the selenium solution carried out in Example 8 was removed, placed in a 100 ml Erlenmeyer flask, further added with 50 ml of INHC1, and shaken at 50 spm for 30 minutes. At this time, a reddish brown solid component was released from the steel wool. The iron component was magnetically separated from this liquid, and the remaining precipitated component was filtered through a 0.45 zm nitrocellulose membrane filter. The selenium concentration in the filtrate was 0.1 ppm or less, and the iron concentration was 1580 ⁇ 1.
  • the filtered components were placed in a 100 ml eggplant-shaped flask equipped with a Dimroth condenser, 5 ml of concentrated nitric acid was added, and the mixture was reacted at 90 ° C. for 30 minutes with stirring to dissolve all solid components. Cooling water at 5 ° C was supplied to the Jimroth condenser. After cooling, the reaction solution was diluted to 50 ml and the selenium and iron concentrations were measured. The selenium concentration was 42.7 ppm and the iron concentration was 3.6 ppm.
  • Example 8 About one sixth of the weight of the steel wool after passing the selenium solution carried out in Example 8 was removed, put into a 100 ml Erlenmeyer flask, and further added with 50 ml of demineralized water. The treatment was performed at a frequency of 46 KHZ) for 30 minutes. At this time, a brown solid component was released from the steel wool. The iron component was magnetically separated from this solution, and the remaining precipitated component was filtered through a 0.45 ⁇ m nitrocellulose membrane filter. The selenium concentration in the filtrate was less than 0.1 ppm and the iron concentration was less than 0.1 ppm.
  • the filtered components were placed in a 100-ml eggplant type flask with a Dimroth condenser, 5 ml of concentrated nitric acid was added, and the mixture was reacted at 90 ° C for 30 minutes with stirring to dissolve all solid components. Cooling water at 5 ° C was passed through the Jimroth condenser. After cooling, the reaction solution was diluted to 50 ml and the selenium and iron concentrations were measured. The selenium concentration was 20.6 ppm and the iron concentration was 76.8 ppm.
  • Example 8 About 1/6 of the weight of the steel wool after the passage of the selenium solution carried out in Example 8 was removed, put into a 100 ml Erlenmeyer flask, and further added with 50 ml of 0.001N HC1, and added with 50 spm for 30 minutes. Shake. At this time, no solid components were released from the steel wool. The iron component was magnetically separated from this solution, and the remaining precipitated component was filtered through a 0.45 / 1-nitrocellulose membrane filter. In this filtrate The selenium concentration was less than 0.1 ppm and the iron concentration was 37.6 ppm.
  • Example 11 As the primary treatment, the same method as in Example 11 was performed.
  • the outlet liquid (selenium concentration: 0.25 ppm) was adjusted to pH 4 with hydrochloric acid, and used as a secondary treatment liquid to be added to the column.
  • the liquid was passed through the same column again in the same manner as in Example 11.
  • the selenium concentration in the solution after passing through 20 B.V. was 0.08 ppm.
  • the pH at this time was 6.3.
  • Example 11 The columns used in 1 were connected in series in two stages, and 50 mM phosphate buffer (solution containing selenium) containing 0.50 ppm (converted to selenium) of sodium selenate adjusted to pH 4 was added to the column. The liquid was passed upward at a flow rate of 50 m 1 / hour. The temperature of the jacket was maintained at 50 ° C during the passage. The concentration and pH of selenium in the solution after passing through 20 BV were 0.25 ppm, pH 6.5 at the outlet of the first column, and 0.21 ppm, pH 7.25 at the outlet of the second column. It was eight.
  • Example 11 The columns used in Example 1 were connected in series in three stages, and 50 mM phosphate buffer (solution containing selenium) containing 0.50 ppm (converted to selenium) of sodium selenate adjusted to pH 4 was added to the column. The liquid was passed upward at a flow rate of 50 m 1 Zhour. The temperature of the jacket was maintained at 50 ° C during the passage. The concentration of selenium in the solution after passing through 20 BV and the selenium concentration at the outlet of the first-stage column were 0.25 ppm, pH 6.5, and the second-stage column. The selenium concentration at the outlet was 0.21 ppm, pH 7.7, and the selenium concentration at the third outlet was 0.21 ppm, pH 8.1.
  • Example 13 at the inlet of the second-stage column, 0.5N Zhour of 0.1N HC1 was continuously added in addition to the treatment solution. 20
  • the selenium concentration and pH of the solution after passing through the solution were 0.25 ppm, pH 6.3 at the outlet of the first column and 0.09 ppm, pH 6.6 at the outlet of the second column.
  • the selenium concentration and pH of the solution after passing through the solution were 0.25 ppm, pH 6.3 at the outlet of the first column and 0.09 ppm, pH 6.6 at the outlet of the second column.
  • Example 15 the same method as in Example 15 was carried out except that the pH in the reactor was maintained at pH 9 to 10 by appropriately adding 0.1 IN HC1 and 0.1 IN NaOH. .
  • One liter of solution was processed and its selenium concentration was 0.50 ppm.
  • the boron concentration in the solution after the passage was less than 1 ppm.
  • This solution is adjusted to pH 3 with hydrochloric acid, placed in a 300 ml square flask, and 0.20 g of steel wool (00.04 substitute: trade name: Bonstar: manufactured by Nippon Steel Wool Co., Ltd.) is added.
  • the solution is heated to 50 ° C in a water bath.
  • the mixture was heated and reacted under stirring.
  • the selenium concentration at a reaction time of 4 hours was 3.0 ppm, and the selenium concentration at a reaction time of 6 hours was 0.3 ⁇ ).
  • Selenium concentration was measured by the ICP emission method.
  • the pH of this solution was adjusted to 4 with hydrochloric acid, and steel wool (0.04 mm: trade name Bonstar: manufactured by Nippon Steel Wool Co., Ltd.) l. Og-filled jacketed column (inner diameter 11 difficult, high
  • the selenium concentration at the time of passing 500 ml of liquid was 0.1 ppm.
  • 04 mm Trade name: Bonstar: manufactured by Nippon Steel Wool Co., Ltd. l
  • the selenium concentration at the time of passing through 500 ml was 0.13 ppm.
  • wastewater containing other inorganic acid salts such as a compound having a buffering action near neutrality, such as an alkali metal sulfate and a boron compound, together with selenium in a solution is efficiently treated by a simple treatment operation. Processing to reduce selenium concentration.

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  • Chemical & Material Sciences (AREA)
  • Inorganic Chemistry (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Hydrology & Water Resources (AREA)
  • Engineering & Computer Science (AREA)
  • Environmental & Geological Engineering (AREA)
  • Water Supply & Treatment (AREA)
  • Organic Chemistry (AREA)
  • Removal Of Specific Substances (AREA)

Abstract

L'invention concerne un procédé de mise au rebut d'eau résiduaire contenant du sélénium et des sels d'acide inorganique ayant un effet tampon sur une région neutre, tels que des sulfates de métaux alcalins et des composés de bore, selon une manière de traitement simple avec une bonne efficacité, et de réduction efficace de la concentration de sélénium dans l'eau résiduaire en un temps court. Le procédé de traitement d'une solution contenant du sélénium consiste à faire passer une solution contenant du sélénium et des sels d'acide organique ainsi que d'autres métaux dans un lit garni comprenant un métal à base de fer afin de précipiter le sélénium à la surface du métal à base de fer, dans lequel on met la solution en contact avec le métal à base de fer à une température de 30 °C ou plus, de préférence à un pH compris entre 3 et 7 et, si nécessaire, on retire les composés ayant un effet tampon autour d'une région neutre et contenus dans les eaux résiduaires avant le contact de la solution avec le métal à base de fer.
PCT/JP1998/002033 1997-05-08 1998-05-07 Procede de traitement d'une solution contenant du selenium Ceased WO1998050304A1 (fr)

Applications Claiming Priority (10)

Application Number Priority Date Filing Date Title
JP13299397 1997-05-08
JP9/132993 1997-05-08
JP9/182116 1997-07-08
JP18211697 1997-07-08
JP29959997 1997-10-17
JP9/299599 1997-10-17
JP29687297 1997-10-29
JP9/296872 1997-10-29
JP9/321021 1997-11-21
JP32102197 1997-11-21

Publications (1)

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WO1998050304A1 true WO1998050304A1 (fr) 1998-11-12

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Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2007004664A1 (fr) * 2005-07-06 2007-01-11 Kobelco Eco-Solutions Co., Ltd. Procédé de récupération de métaux et équipement idoine
WO2007015392A1 (fr) * 2005-08-04 2007-02-08 Kobelco Eco-Solutions Co., Ltd. Procédé et appareil de récupération d’indium d’un affichage à cristaux liquides mis au rebut
JP2007039788A (ja) * 2005-07-06 2007-02-15 Kobelco Eco-Solutions Co Ltd 金属の回収方法とその装置

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH072502A (ja) * 1993-05-20 1995-01-06 Daiwa Kasei Kenkyusho:Kk セレン含有廃液の処理法
JPH0959007A (ja) * 1995-08-21 1997-03-04 Miyoshi Oil & Fat Co Ltd セレンを含む溶液からのセレンの回収方法

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH072502A (ja) * 1993-05-20 1995-01-06 Daiwa Kasei Kenkyusho:Kk セレン含有廃液の処理法
JPH0959007A (ja) * 1995-08-21 1997-03-04 Miyoshi Oil & Fat Co Ltd セレンを含む溶液からのセレンの回収方法

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2007004664A1 (fr) * 2005-07-06 2007-01-11 Kobelco Eco-Solutions Co., Ltd. Procédé de récupération de métaux et équipement idoine
JP2007039788A (ja) * 2005-07-06 2007-02-15 Kobelco Eco-Solutions Co Ltd 金属の回収方法とその装置
WO2007015392A1 (fr) * 2005-08-04 2007-02-08 Kobelco Eco-Solutions Co., Ltd. Procédé et appareil de récupération d’indium d’un affichage à cristaux liquides mis au rebut

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