Classifications

• • 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
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10S210/00—Liquid purification or separation
  • Y10S210/902—Materials removed
  • Y10S210/906—Phosphorus containing
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10S210/00—Liquid purification or separation
  • Y10S210/902—Materials removed
  • Y10S210/908—Organic
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10S210/00—Liquid purification or separation
  • Y10S210/902—Materials removed
  • Y10S210/911—Cumulative poison
  • Y10S210/912—Heavy metal
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10S210/00—Liquid purification or separation
  • Y10S210/902—Materials removed
  • Y10S210/915—Fluorine containing

Definitions

• composition and method for treating metal ions and water containing organic and / or inorganic contaminants Composition and method for treating metal ions and water containing organic and / or inorganic contaminants
• the invention relates to a composition for treating water containing metal ions and organic and / or inorganic contaminants, and to a process for their preparation and their use in the separation of heavy and non-ferrous metals and dissolved, suspended or emulsified organicchon and / or inorganic constituents from aqueous systems .
• Heavy and non-ferrous metals are widely used as components of alloys in steels and finishing or corrosion-inhibiting coatings in connection with plastics and natural materials in all industrialized countries.
• According to cautious estimates, around 5% of the metallic elements produced or used in production or processing processes are again obtained as residual or waste materials in pure form or in compounds which, according to the previously known methods, cannot be economically recycled.
• the environmentally relevant aspects of the reduction of hazardous waste are those that are mostly toxic for almost all biological species Heavy and non-ferrous metals are important.
• the solubility products of the metal hydroxides are at least 7 to 10 powers of ten greater than those of the corresponding sulfides. Depending on the matrix ratio of the solutions, the solubility of the metal hydroxides is roughly up to ten million times higher than that of the adequate sulfides.
• organosulfides In the practice of wastewater treatment, various organosulfides have been introduced for special areas in recent years.
• the organosulfides work on the same principle as the sulfides and Copper, cadmium, mercury, lead, nickel, tin and zinc as sulfides.
• Their disadvantage is that the permissible pH is limited to values above 7, since the inactive free acid is precipitated in the acidic range.
• alkali or alkaline earth polysulfides are used instead of the toxic hydrogen sulfide.
• polysulfidic precipitants known hitherto are that they have poor solubility in water and therefore lead to an increase in the amount of material required and in terms of equipment.
• their effect is limited to the precipitation of metal ions only, while in practice there is also a strong need for compositions for simultaneous removal e.g. of mineral oil contaminants.
• the object of the invention is therefore to provide a composition for treating contaminated water, which has a very high water solubility, complexed and non-complexed metal ions and possibly organic or inorganic contaminants with excellent separability of the precipitates, can be used over a very wide pH range, suppresses the emission of hydrogen sulfide and is also very inexpensive to manufacture.
• this object is achieved by a composition for treating metal ions and, if appropriate, water additionally containing organic and / or inorganic compounds, which can be obtained by reacting sulfur with an alkali and / or alkaline earth metal hydroxide in the presence of water.
• the use of the moderate composition is the subject of claim 18.
• compositions according to the invention are based on the idea of causing elemental sulfur to undergo a disproportionation reaction by chemical means, namely by reaction with alkali or alkaline earth lyes. Another priority is to bring as much sulfur as possible into solution and to activate it as described below:
• composition of the composition of the invention corresponds to the general formula I.
• M is alkali or alkaline earth
• x 2 or 1
• z range from 0.1 to 2.5.
• M is an alkali metal, particularly preferably sodium or potassium, in particular sodium, where x is 2 and y is in the range from 2.0 to 5.0, preferably 3.0 to 4.0 , in particular 3.5 to 3.7 and z in the range from 0.1 to 2.5, preferably from 0.3 to 1.5, in particular from 0.5 to 1.0.
• Mass spectrometric analysis by means of HPLC-MS-MS shows that it comprises reduced and oxidized sulfur compounds. It contains, for example, polysulfide components and polysulfane mono-, di-, trisulfonates and sulfur, which can be present as elemental, dissolved sulfur.
• composition obtained an aluminum salt.
• Aluminum has an amphoteric character, which leads to a different behavior in alkaline or acidic media.
• an aluminum salt is added to the composition, aluminates form in the alkaline medium, with AI 3+ ions occurring in acidic media.
• the added aluminum salts form large-volume hydroxides with strong adsorptive activity, which, among other things, co-precipitate the sulfur of the wastewater, which may still be colloidal.
• the composition according to the invention preferably contains 10 to 30 g, particularly preferably 15 to 25 g, and in particular 18 to 22 g of aluminum sulfate in 11 composition.
• a thiosulfate or a sulfide is added to the composition obtained.
• These two substances increase the O 2 content and the SO 2 content of the composition and thus strengthen the Wackenroder see trapping reaction by direct formation of polythionic acids (Wacken- Roder's liquid) and polysulfan oxides (Wackenroder's sulfur) from SO 2 and H 2 S.
• water, sulfur and alkali and / or alkaline earth hydroxide are used in a molar ratio of from 4.0 to 6.5: 1.0 to 3.0: 1, preferably from 5.0 to 6.0 : 1.5 to 2.5: 1, particularly preferably from 5.4 to 5.6: 1.7 to 1.9: 1 and in particular from 5.6: 1.8: 1.
• the order in which the reactants are added is of secondary importance.
• sulfur is first slurried in water with stirring to ensure good surface wetting with water, and then the alkali metal or alkaline earth metal hydroxide is added.
• the addition of the alkali or alkaline earth hydroxide is also carried out with vigorous stirring.
• the sulfur contains an additive to prevent caking and encapsulation, such as a silicic acid additive.
• composition according to the invention in the precipitation recipient is an essential factor for the effectiveness in large-scale precipitation plants.
• the composition obtained can e.g. can be rediluted by adding a certain amount of water.
• the resulting solution is significantly less viscous and therefore easier to distribute in the precipitation recipient than the concentrate.
• the post-diluted product contains 14.57% sulfur 4.54 mol / Kg per kg, 75% thereof in polysulfidic form. This corresponds to 10.93% or 109.3 g / kg or 3.41 mol / kg of polysulfidically activated sulfur.
• the composition according to the invention can be regarded as a "liquid compressed" hydrogen sulfide substitute which contains the advantages thereof without having to accept the disadvantages of the hydrogen sulfide.
• 1 kg corresponds to 102 l of hydrogen sulfide theoretically rediluted with twice the amount of water in the concentrated batch. Due to the poor entry rate of the H, S gas into aqueous systems, only about 15% of the entry is dissolved in the liquid, which can then be used for precipitation.
• the activated sulfur of the composition according to the invention can be used almost 100% in the precipitation recipient.
• Sulfur, water and alkali and / or alkaline earth hydroxide pointed out, because these determine the disproportionation reaction of the sulfur and influence it directly, the ratio of reduced to oxidized sulfur compounds and thus the monosulfonate concentration in the claimed composition.
• the claimed composition can be used for treating metal ions and, if appropriate, additionally water containing orcaniseand / or anorcanishe compounds.
• the composition according to the invention and, if appropriate, an anerganized compound containing a polyvalent cation are added to a water to be cleaned, soluble equipment and water containing organic and / or inorganic impurities, the pH being set to values in the range. 2 to 12 is set.
• composition according to the invention for water from water is adjusted so that an aqueous mixture of activated sulfur and metal to be precipitated ion exists.
• a favorable practical ratio of the composition according to the invention to waste water is 1/1000 i. Volume.
• the pH of the water to be purified is adjusted to a value of 2.5 to 5.5, preferably 3 to 3.5, before treatment with the claimed composition.
• a pH value below 3.0 is not particularly advantageous since, when the composition according to the invention is added, in particular when circulating with air lances, outgassing of large amounts of hydrogen sulfide occurs.
• composition according to the invention can be used, for example, in a pH-fractionated step precipitation process.
• This type of use is particularly suitable for the separation of acidic and neutral or alkali-precipitable sulfides if subsequent processing of the metals by recycling is provided.
• it can e.g. be useful for the pre-separation of copper and nickel sulfides.
• the valuable metals can be recovered from exhausted nickel plating baths.
• the waste water to be cleaned is adjusted, for example with a mineral acid, preferably hydrochloric acid, to a pH in the range from 2 to 5, preferably from 2.5 to 4, in particular from 2.8 to 3.3.
• a mineral acid preferably hydrochloric acid
• the amount of the composition according to the invention corresponding to the above statements, possibly after previous dilution, is added with stirring.
• the mixture is then transferred through a pipe 2 into an acidic precipitation basin 3, in which the mixture is stirred for the duration of the reaction.
• the solution is then transferred through a pipeline 4 into an acidic settling tank 5.
• a white, gray or black precipitate can be observed with a milky, initially colloidal fraction which is due to elemental sulfur. lead is.
• the supernatant decantate is piped through pipeline 7 into a neutralization basin 8 provided with a stirrer.
• the pH value is increased to values in the range from, with addition of, for example, sodium hydroxide solution from line 9 3.5 and 4.5, preferably from 3.5 to 4.2, and after a reaction time of about 5 to 20 minutes, the acid precipitates which may have formed are separated off in a downstream intermediate clarifier, not shown in FIG. 1.
• the decantate is then adjusted to pH values in the range from 6 to 12, preferably from 7 to 10, particularly preferably from 7.8 to 9.6, with the addition of further sodium hydroxide solution and optionally a precipitant, in some cases a polyelectrolyte, depending on the metal ions contained. set.
• the mixture is then transferred via a pipeline 16 into an alkaline settling tank 10, in which, after a reaction time of 5 to 20 minutes, the precipitate of metal sulfide which can be precipitated in alkaline is separated off.
• the pH in the waste water to be purified in the acidification basin 1 should be preset in the individual case to values in the range from 2.0 to 3.5, preferably 2.3 to 2.8
• the acidic reaction tanks should be covered because of a low emission of H_S, and the exhaust air can be treated in an alkaline oxidative exhaust air cleaning device 11.
• the HS emissions. stayed in the exhaust air with all MAK tests without exception below the MAK values of 10 opm.
• the cleaned water phase can be subjected to an oxidative aftertreatment in order to eliminate residues of reduced sulfur by oxidation and thus to comply with the sulfide limit values before the cleaned water is released into channels or receiving water.
• the decantate of an alkaline sedimentation tank 10 is transferred through a pipeline 12 into a container for the oxidative aftertreatment 13, in which the device 14 represents, for example, an oxygen lance and in which, for example, by adding a mineral acid, preferably hydrochloric acid, through the feed line 15
• the pH of the purified water is adjusted to values in the range from 6.5 to 8.0.
• the claimed composition can also be used for treating metal ions and, if appropriate, additionally water containing organic and / or inorganic compounds in a simultaneous attack process.
• the use of the claimed composition in a shallow precipitation process is appropriate if the amount of metal present in the wastewater to be cleaned is small, i.e. pH fractional step precipitation with recycling is not sensible, or if the metal ions contained all precipitate in the same pH range.
• the DH value of the precipitation medium is adjusted to values in the range of 2 in an acidification tank 20 by adding, for example, a mineral acid, preferably hydrochloric acid from a feed line 21. 5 to 5.5, preferably from 2.8 to 3.3. Thereafter, the amount of the composition according to the invention corresponding to the previous statements is added from a feed line 22 into an acidification basin 20 with stirring. The mixture is then passed through a pipe 23 into an acidic precipitation tank 24 and stirred for 5 to 30 minutes.
• a mineral acid preferably hydrochloric acid
• Exhaust air from the acidic precipitation tank 24 can also be freed of H 2 S emissions here by means of an alkaline-oxidative exhaust air cleaning device 25.
• the mixture is then transferred through a pipe 26 into the neutralization basin 27.
• the pH of the precipitation medium is slowly raised to values from 6 to 12, preferably 7.5 to 11.5.
• the metal sulfides falling in the neutral and weakly alkaline environment largely fail.
• the optimum point for the precipitation of the poorly soluble chromium III hydroxide is also reached.
• the final pH value is preferably set to values in the range from 8.0 to 11.5, preferably 9.0 to 11.0, in particular 9.5 to 9.7.
• a pH of 8.0 to 11, preferably 9 to 10, in particular 9.6, is the empirically determined optimum range or point for the simultaneously minimized residual solubility of the two metal sulfides.
• the pH end point is set to 9.6, the residual nickel and zinc contents dissolved in the water are equally below C, l mg / 1.
• the mixture is transferred through a pipeline 29 to a settling basin 39, from which the precipitates which have precipitated are removed by pipeline 31, while the cleaned decantate is optionally fed through a pipeline 32 to a container for the oxidative aftertreatment 33.
• mineral acid can be added by setting a pH in the range, for example, from 6.5 to 8.0.
• a device 35 in the container for the oxidative aftertreatment 33 is, for example, an oxygen plant.
• neutralization in the neutralization basin 27 with a suspension of calcium hydric in lime water (lime milk) is to improve the settling behavior and the drainability of the precipitation, e.g. with Karnmer filter presses, particularly preferred and e.g. to be preferred to sodium hydroxide neutralization.
• the claimed composition can be used not only in a step and simultaneous precipitation process, but also in a so-called collector precipitation process for treating metal ions and, if appropriate, water additionally containing organic and / or inorganic compounds.
• collector precipitation process for treating metal ions and, if appropriate, water additionally containing organic and / or inorganic compounds.
• Composition by one modification of the previously described simultaneous attack process, in particular for aqueous phases with Contained in metal ions and complexing agents, rather mainly in organic and / or inorganic.
• Impurities such as mineral oils, paraffins, emulsions, as well as ionic and non-ionic surfactants. If the wastewater to be cleaned is only contaminated with metal ions, then in this case the cleaning process described in the following with reference to FIG. 1 leads to outstanding cleaning effects.
• a feed line 50 is in a Sau fürsbeeksr. 51 the water body to be cleaned is filled in and by adding, for example, a "mineral acid, preferably hydrochloric acid, through feed line 52 with stirring to a pH in the range 2-5, preferably from 2.5 to 3.5, in particular from 1.9 to 1.9 3.2
• the acidic wastewater to be purified is then passed through pipeline 53 into an acidic precipitation basin 54, in order to first sub-set there an ancrcanic compound from Zuieitunc 55 containing a polyvalent catio Calcium, aluminum eder Iron connection.
• An iron compound, in particular iron (II) suifate, is preferably added.
• a weak sulfuric iron sulfate solution with a concentration of vcr. 1/3 mol Fe 2+ / 1 (approx. 18.5 g / 1) was used.
• ferric III salts can also be used.
• composition per m of wastewater to be treated more than: the simultaneous processes are used.
• the compound containing a polyvalent cation can be added before or after, but preferably before adding the composition according to the invention.
• the mixture is then transferred through a pipeline 57 into a neutralization basin 58, after which, after a reaction time of 5 to 30 minutes, a liquor, preferably e.g. Sodium hydroxide solution or whitewash.
• a liquor preferably e.g. Sodium hydroxide solution or whitewash.
• Lime milk is used in particular when the sludge is not to be recycled, since lime milk improves sludge drainage.
• a pH is in the range before. 8.0 to 11.0, preferably from 9.0 to 10, in particular from 9.5 to 9.7.
• This optimal pH mean value range from 9.0 to 10.5 should preferably be set when nickel and zinc sulfide are eliminated at the same time.
• the alkaline mixture is passed through a pipeline 60 into a settling basin 61 and the sulfide sludge removed there, if necessary, through a pipeline 62, while the decantate via a pipeline 63 from a container 64z.3. is supplied for an oxidative aftertreatment.
• a mineral acid, preferably acidic acid, for example, is optionally added via a feed line 65, thereby achieving a pH division of the purified wastewater body in the range of, for example, 6.5 to 8.0.
• a device 66 serves for the oxidative aftertreatment and, for example, renders an oxygen lance.
• the cleaned water leaves the collector precipitation device via the drainage solution 67.
• the inorganic compound containing a polyvalent cation preferably an iron compound, in particular iron (II) sulfate, used in connection with the composition according to the invention, or the metal ions contained therein, have a catalytic precipitation-proofing effect in the neutral and alkaline range and moreover precipitate the organic and / or inorganic impurities aasorptiv with from the water body.
• the excess polysulfide content of the claimed composition in the acidic medium is reduced in the neutral region by the iron sulfide precipitation in the aqueous phase, as a result of which the redissolving effect of acid-precipitated heavy and non-ferrous metal sulfides is kept csrinc.
• the chromium VI ions are reduced by the polysulfanes contained in the composition.
• the reducing agent requirement from the composition according to the invention is only 1/4 of the requirement for sulfite sulfur from the Bisulfite lye, since the sulfide absorbs 8 oxidation units up to the sulfate, the sulfite only 2.
• the salting of the medium due to the reduction is considerably lower.
• the chromium-III is then also precipitated as poorly soluble Cr (OH) 3 at a pH in the range from 8.0 to 10, preferably from 8.3 to 9.6, in the course of the possible uses of the claimed composition.
• the residual chromium contents for chromium-III when using the compositions according to the invention and the uses according to the invention of the claimed composition were, without exception, below 0.1 mg / l in the water body.
• the chromium VI levels here were less than 0.01 mg / l and were no longer detectable even with the finest measuring methods.
• the heavy and non-ferrous metal sulfides obtained when the claimed composition is used can be separated off in the usual way by sedimentation.
• the sulfides can be roasted after neutralization with sodium hydroxide solution after dewatering and directly in the normal metal smelting process to recover the metals be smuggled in. They represent valuable, easily usable metal concentrates. In principle, this means that the metals can be completely recovered.
• The: is of particular interest when separated heavy metal wastewater with a uniform composition has to be processed and thus practically pure metal sulfides (in addition to sulfur, which does not interfere with the treatment) are produced.
• the separation of cer less valuable.
• Iron and zinc suifides of copper and nickel sulfide can be removed in an effective manner by an acid treatment with simultaneous recycling of the hydrogen sulfide formed.
• This use of the composition according to the invention thus includes, in addition to a high level of operational safety and simplest implementation, also largely the possibility required by law to cheaply recover the valuable materials the Law on the Prevention and Disposal of Waste.
• composition according to the invention is obtained in the form of a dark yellow to deep red liquid which is virtually odorless after several hours of cooling and stirring.
• the sulfur grouping distribution of the sulfur contained in this composition according to the invention is as follows: 1.Polysuifide proportions:
• composition according to the invention thus obtained has the following properties.
• the composition according to the invention is obtained as a deep red liquid which is almost odorless after several hours of cooling with stirring.
• the composition of the sulfur contained in the composition according to the invention corresponds to the sulfur grouping distribution mentioned above.

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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)
• Treatment Of Water By Oxidation Or Reduction (AREA)

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• 1989
  • 1989-05-29 DE DE3917412A patent/DE3917412C2/de not_active Expired - Lifetime
  • 1989-05-29 DE DE8915591U patent/DE8915591U1/de not_active Expired - Lifetime
• 1990
  • 1990-07-04 DE DE59010762T patent/DE59010762D1/de not_active Expired - Fee Related
  • 1990-07-04 WO PCT/DE1990/000499 patent/WO1992000917A1/de not_active Ceased
  • 1990-07-04 US US07/972,479 patent/US5451327A/en not_active Expired - Fee Related
  • 1990-07-04 EP EP90910100A patent/EP0537143B1/de not_active Expired - Lifetime

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