Method of processing waste solutions

 

(57) Abstract:

The method of processing the treated solutions containing organic complexes of heavy metals, sulfur compounds and nitrogen and other compounds that may be present in the fixing and the like photographic baths and photochemical production, is that the spent solution is sprayed in the at least one spray chamber or device in the flow of hot oxidizing gas, in particular, generated in industrial plants or incineration, with the addition of nitrate ions and calcium ions. 7 C.p. f-crystals, 1 table.

The invention relates to a method of processing waste solutions from fixing, etc., of the photographic baths and photochemical production containing organic complexes of heavy metals and compounds of sulfur and nitrogen.

Up to the present time of fixing, bleaching and fixing other baths, for example, baths containing silver, silver was extracted by electrolysis, ion exchange (with iron filters) or by reacting with a solution of sulfide. The result has been a complete removal of the silver solution and possibly other heavy metals, such what's solutions were burned or incinerated together with household garbage. This, however, there are problems associated with environmental pollution. Fixing baths, in particular, have a high chemical oxygen demand (COD), high nitrogen content in Kjeldal and contain complex compounds of heavy metals. The COD value of such solutions is to 80000 mg/l, and nitrogen content on Kjeldal 20000 mg/l At the discharge into the sewer amount of pollution equivalent number of people (i. e. ) is determined by the formula i.e. 0/136 (COD + 4,57 N). When the discharge into the sewer for 24 h 1000 l of spent solution contamination will be i.e. 1/136x(80000+4,h) 1257.

Thus, 365 m3waste solutions in the year cause pollution in 1257 i.e. Burning waste solutions together with household waste due to the high sulphur content leads to severe environmental pollution by sulphur dioxide.

It was proposed to oxidize waste solutions of hydrogen peroxide, chromic acid, potassium permanganate, chlorine bleaching solution, and so on, However, the oxidation process in this way is not until the end, and, furthermore, the method is very expensive.

A method of processing waste solutions by atomization exhaust RA is x calcium ions and nitrate, and recycling the spent solution. However, this method is environmental pollution.

The present invention is to provide a method for processing waste solutions of the above type, which would not have these disadvantages. The object of the present invention, therefore, is the above method, in which the spent liquor is sprayed into the flow of hot oxidizing gas, in particular, generated in industrial plants or the combustion furnace and at least one spray chamber or in the same place with the addition of nitrates and calcium ions.

In particular, the spent solution is sprayed into the hot gas stream so that the temperature of only the sprayed material with additives increased to more than 50, sometimes up to more than 100aboutC. Preferably, the pH of the spent solution was reduced to less than 5. This can be done by using acid or by acid gas components that are often present in industrial waste gases. In these conditions occur numerous reactions between the hot gas and sprayed liquid, resulting from the spent solution is removed of razli calcium sulfate, which can be removed as sludge. Heavy metals, in particular, in the acidic environment, leaving the organic complex compounds, and the latter is decomposed with the formation of exhaust gases, such as nitrogen, carbon dioxide and water vapor. Heavy metal ions can be precipitated from the spent solution by alkalizing and silver may be removed, for example, by adding sodium chloride.

The exhaust products from the combustion chamber waste solutions it is advisable to return and again sprayed into the hot gas stream. In the return flow each time it passes through the stage at which it can be removed by various components. For example, the circulating stream may be subjected to electrolysis or cementation with iron for separation of metals. The advantage of cementation in addition is that the solution process is enriched with iron. With increasing pH of the circulating flow above 5 can be precipitated hydroxides of heavy metals. For this purpose it is preferable to add calcium hydroxide. Residues at various stages, can be removed by conventional means, for example by sedimentation or filtration. the de Kitchen salt or other soluble chloride. You can however enter the halide and the flow of hot oxidizing gas. In many cases, the halide is already present in industrial gases.

Below the invention will be explained on the example of the treatment of spent fixing solutions in the photographic industry. Such waste solutions containing various metal complexes, in particular ethylenedinitrilotetraacetic (EDTA) complexes of copper, iron, silver, chromium and Nickel. To ensure adequate content of nitrate and calcium such spent solutions add calcium nitrate. The thus treated exhaust solution is subjected to reaction with the hot oxidizing gas is formed, for example, in a furnace for burning. This interaction is performed by spraying the spent solution in the hot gas stream so that the temperature of the solution together with additives would rise above 50, and in certain places even above 100aboutC. in Addition, it is necessary that the pH of the spent solution was below 5, which can be done by acidification or by acidic components already present in the gas stream.

Under these conditions, the spent solution with additives as b is="ptx2">

So, present in the waste solution of the thiosulfate transformed into an insoluble calcium sulfate according to the following reaction scheme

S2O-3-+2H+H2S2O3H2O+S+SO

SO2+oxidant+(cat.Cu++Fe+++Ag+euz.) _ SO3< / BR>
SO3+H2O _ 2H++SO-4-< / BR>
SO-4-+Ca++_ CaSO4< / BR>
Precipitated calcium sulfate can be easily removed.

In addition to the calcium sulphate may be precipitated sulphate of lead according to the following reaction

SO-4-+Pb++_ PbSO4< / BR>
Thus, ions Pb++can be removed from the used hot gas.

Ammonium ions present in the waste solution or hot gas, interact with nitrate-ions in the spent solution from the reaction

NH+4+NO-3NH4NO3N +2H2O+(1/2)O

Released during oxygen contributes to the further degradation due to oxidation of complex compounds present in the extract solution.

Similar transformations occur with the present amines, such as R-NH and R1-NH-R2to finish.

Organic compounds of heavy metals such as EDTA complexes, gradually oxidized by the oxidizing agents contained in the hot gas stream. These reactions are catalytically accelerated eye-catching free ions of Fe++, Cu++Hg++and Ag++.

As the EDTA complex of iron is the most stable complex, all other above-mentioned metals are in the form of free ions from their EDTA complexes due to an excess of Fe+++. Last, if necessary, is introduced into the system. In the EDTA decomposes according to the following reaction scheme:

EDTA complex metal MeH2EDTA

MeH2EDTA Me+++H2EDTA

H2EDTA+oxidant+cat __ N +xCO +yH2O

the pH of the liquid withdrawn from the stage of spraying wash liquid), is brought to a value higher than 5 by adding thereto calcium hydroxide. The result is the precipitation of heavy metals as hydroxides.

Ag+remaining in solution can be precipitated by adding a solution of chloride or bromide. The halides may be introduced in the gas flow or already be present in it. Deposition of silver occurs by the following reactions

Ag++Cl-__ AgCl4and PbSO4. Ammonium salts and amines are removed in the form of N2H2O and oxygen. And finally EDTA complexes and other organic compounds are completely oxidized to CO2N2O, and N2. The spent solution, purified during continuous circulation from harmful components, can be together with gas quietly dropped. The precipitated solid components can be collected for recycling or disposal in such a way as not to harm the environment.

P R I m m e R. the Flow of hot gas produced in the furnace for combustion, is subjected to contacting in a reactor of the type Venturi with waste fixing the washing liquid. Obtained when the combustion gas contains fly ash, which is a large number of heavy metals, acid gases HB5, HCl, HF, SO2, NOx and gases such as N2O2, CO and CO2. To exhaust solution, playing the role of a washing liquid in a continuous process that systematically add auxiliary materials, namely "Ajax" and M. I. R.". "Ajax" is a mixture of CA(OH)2and Ca(NO3)2and "M. I. R." a mixture of Cu(NH3)++, NH4+, NO3-, Cl-BF4, CrO "M. I. R." determined the content of NH4and Cu++.

In the used fixing solution was determined by the content of heavy metals, NH4+Ca++, SO4--, Br-, Cl-and the amount of dry matter.

During the process was continuous deposition of a solid material, composed of CaSO4, PbS4CaF2, AgBr, AgCl, SiO2and hydroxides of heavy metals.

In the beginning of the process contents of the reactor was 12 m3waste fixing solution. At the end of test 17 days after the start, the reactor was 12 m3wash liquid. During the test through the reactor was dropped to 75 m3waste fixing solution and added 1.3 m3"M. I. R., and 15 m3"Ajax".

The results are shown in the table. From the table of results we can draw the following conclusions:

1. Is almost complete decomposition of the complexes, since the solution heavy metals are not detected. Significantly reduced COD.

2. Is almost complete decomposition of NH4+ and NO3-.

3. Thiosulfate decomposes to form sulfur and sulfate.

4. Perhaps almost postulados decomposition of waste fixing solution of photochemical production. Similarly you can, however, decompose, and other waste solutions containing complex compounds of metals, for example, from the electronic industry and electroplating plants, wastewater from laboratories with high COD, ammonia baths, sulfamethazine waste water, etc.

Although the inventive method is illustrated using the above example, it is obvious that other variants and modifications within the present invention.

1. METHOD of PROCESSING WASTE SOLUTIONS mainly photographic baths and photochemical production by atomization of the spent solution into the flow of flue gases at a temperature above the 50oWith the addition of absorbers containing calcium ions and nitrates, and recycling the spent solution, characterized in that the spent solution is acidified to pH < 5.

2. The method according to p. 1, wherein the exhaust solution is added an excess of ions of Fe+++.

3. The method according to PP.1 and 2, characterized in that make up the contents of F+++in the recycled stream.

4. The method according to PP. 1 and 3, characterized in that zirconium, what is the pH of the circulating solution to support more than 5.

6. The method according to p. 5, characterized in that the pH of the circulating solution provide by the introduction of calcium hydroxide.

7. The method according to PP.1 to 6, characterized in that the worked solution add halide.

8. The method according to p. 7, characterized in that the halide is introduced into the waste gas stream.

 

Same patents:

The invention relates to techniques for thermal treatment of liquid hydrocarbons polygalacturonic

The invention relates to a thermal treatment of liquid waste fuels and can be used for neutralization in different areas of the economy
The invention relates to metallurgy, and more specifically to the refractory lining of metallurgical vessels
The invention relates to chemical technology disposal of toxic substances, in particular, lewisite and receiving on its base metal arsenic
The invention relates to chemical technology disposal of toxic substances, in particular, lewisite and receiving on its base metal arsenic

The invention relates to a device for neutralizing the liquid process waste method and can be used in chemical, petrochemical, industrial, energy and other sectors of the economy that generate combustible liquid waste with a high-boiling components

The invention relates to techniques for thermal cleaning of waste gases from toxic impurities and can be used in industrial ecology in detoxification of exhaust air and in the food industry for drying of food products and flue gases

The invention relates to equipment for combustion of viscous liquids such as resins of the filters for the treatment of gas or similar, consisting of a tank or container with heating elements, burners and tubes connecting the burner with the tank

FIELD: reworking silicon-containing vegetable raw materials, including rice and oats.

SUBSTANCE: proposed method includes carbonization of initial raw material performed in vortex flow of oxidizing gas-heat carrier followed by separation of intermediate solid product and gaseous combustion products removed from roasting zone; proposed method includes also oxidizing roasting of carbonized intermediate product by passing the oxidizing gas through layer of product at rate ensuring "filtering layer" mode. Plant proposed for realization of this method includes two cylindrical furnaces interconnected through separation unit. First cylindrical furnace has branch pipe in its upper part for loading the raw material and pipe mounted inside furnace and used for tangential delivery of oxidizing gas-heat carrier through branch pipe fitted in lower part of said pipe. Second cylindrical furnace is provided with adjustable external heating system and oxidizing gas supply unit mounted in lower part and final product unloading unit mounted at its outlet. Separation unit includes device for removal of gaseous combustion products; initial raw material supply branch pipe, cylindrical furnaces, inner pipe and separation unit are located coaxially. Proposed method is used for production of silicon from vegetable raw material due to continuity of process at preset physico-chemical properties: purity, structure, specific furnace.

EFFECT: optimization and intensification of process.

10 cl, 1 dwg, 1 tbl

FIELD: incineration of waste.

SUBSTANCE: device comprises charging device, working chamber with plasma heaters, system for purifying combustion products and removing decomposition products, and system for automatic control. The working chamber is made of two plasma heaters which form reaction and combustion chambers which form flowing cylindrical passage. The passage receives the charging device provided with sealed valve and batcher for supplying waste. The system for purifying and removing decomposition products is made of liquid emulsifying device of vortex type provided with heat exchanger, settler, and smoke exhauster. The automatic control system is provided with indicating unit, control unit, unit for control of parameters of the plasma heaters, and system unit on the base of a computer. The decomposition process is performed with oxygen deficiency in the first reaction chamber in the plasma flow. The flow is generated by injecting electric-arc plasma from the external zone of the chamber. The air jets are set in rotation around their axes, whereas the plasma charge is set in rotation about the central electrode. The decomposition products are burnt up in the second chamber, expanded, cooled, and purified. The flow rates of waste, ejecting air, and purifying emulsifying liquid as well as the power of the arcs of the plasma generators are controlled in such a way to provide a given value of pH in the settler.

EFFECT: enhanced efficiency and ecological safety of the process.

12 cl, 9 dwg

FIELD: rocketry.

SUBSTANCE: proposed installation contains accumulating reservoir, dust trap and adsorber, all connected with engine nozzle by gas lines and arranged in technological sequence. Dust trap is made in form of hermetically sealed chamber provided with upper and lower rows of plates arranged at tilting at equal angle. Plates of upper and lower rows alternate, and their outer edges overlap each other. Coarse and fine filters are installed between dust trap and adsorber. Said filters made in one housing are arranged on wire skeleton. Adsorber is made in form of vertical cylinder whose lower part is filled with crushed stone, and upper part, with activated charcoal.

EFFECT: provision of ecologically safe combustion of solid-propellant charges of small-size rocket engine in the air.

4 dwg

FIELD: recovery of plastics or other constituents of waste materials.

SUBSTANCE: method includes heat processing of used tires and industrial rubber articles in recirculating pyrolysis gases in a reactor at 200-500°C and separating the pyrolysis products in a separation apparatus. The pyrolysis products, C1-C4 hydrocarbons, are fed to the bottom section of the reactor from the separation apparatus. The flue gases outflow from the furnace of the reactor, flow through the heat exchanger mounted inside the reactor in order to heat the recirculating gases and material to be processed, and are fed to the hopper for heating grinded material.

EFFECT: reduced power consumption.

2 cl, 1 dwg, 1 tbl

FIELD: burning waste gases of pyrolysis furnaces in reworking solid domestic wastes.

SUBSTANCE: proposed combustion chamber includes mixing chamber with active and passive nozzles mounted at its inlet; active and passive nozzles are connected respectively to compressed air source and to waste gas source; mixing chamber is made in form of diffuser at aperture angle of 10-18 deg; ratio of diameters of active and passive nozzles is equal to: Dact:Dpas=0.35-0.4.

EFFECT: enhanced economical efficiency of use of vapor-and-gas cycle.

2 cl, 1 dwg

FIELD: heat power engineering.

SUBSTANCE: furnace comprises front, back , and side shields on the corresponding furnace walls. In its top part, the back shield forms a narrow section which divides the furnace into the bottom and top chambers. Within the bottom chamber, the front wall of the furnace is provided with a slopping fuel supplying device which points downward. The bottom chamber receives nozzles for air blowing. The bottom part of the back shield goes into a hearth shield which has an elevation from the front to the back shield. In the bottom section of the hearth shield between pipes there are interrupted clearances. The ash bin underlies the hearth shield in the zone of the clearances. The nozzles for air blowing are arranged in longitudinal rows in series between the pipes of the front hearth, and back shields and are directed along the hearth and back shields off the frontal shield toward the furnace exit. The nozzles of each longitudinal row are arranged in a single vertical plane. The sides of the furnace in the zone of the boundary between the bottom and top chambers are provided with additional blowing nozzles for the complete combustion.

EFFECT: enhanced efficiency.

3 cl, 6 dwg

FIELD: the invention refers to apparatus of regenerative thermal oxidation with multi pass valves.

SUBSTANCE: the apparatus for regenerative thermal oxidation for gas processing has a combustion zone, the first heat exchanging layer keeping heat exchanging surroundings and connecting with the combustion zone; the second heat exchanging layer keeping heat exchanging surroundings and connecting with the combustion zone; a valve for alternate direction of the gas flow between the first and the second heat exchanging layers. At that the valve has the first valve passage and the second valve passage separated from the first valve passage; a flow distributor having an admission passage communicates with the help of fluid medium with the admission opening of the surroundings and an exhaust passage communicates with the help of fluid medium with exhaust opening of fluid surroundings. At that the distributor is fulfilled with possibilities of its the first and the second valve passages between the first position in which the first valve passage communicates with the help of liquid with the admission passage and the second valve passage communicates with the help of liquid surroundings with exhaust passage and the second position in which the indicated the first valve passage communicates with the help of the fluid surrounding with exhaust passage and the second passage of the entry of the valve with the help of liquid surroundings communicates with the admission passage. At that the distributor of flow has a blocking surface which blocks the flow through the first part of the first valve passage and through the second part of the second valve passage when the distributor of the flow is between the first and the second positions and is fulfilled with possibility of its turning to 180o between the first and thesecond positions. At that valve passage is divided as the first so is the second at least into two chambers and the first and the second parts of the valve passages are congruous.

EFFECT: simplifies the construction, provides comfort of controlling and exploitation and deep removal of volatile organic combinations.

22 cl, 12 dwg

FIELD: thermal processing of domestic, industrial and other sorts of waste.

SUBSTANCE: assembly for hydrocarbon waste thermal decomposition has thermal reactor and thermal decomposition gases discharge system. Thermal reactor is mounted in vertical and is made to have vertical loading. Layer of electroconductive coal and layer of insulator are disposed at exit area of thermal reactor. The layers make the reactor gas-proof. Gas-discharge tube is mounted inside the thermal reactor. Casing is put on the top part of the tube in such a way that lower part casing is submerged into electroconductive coal. Filter-catalyst is located in area between gas-discharge tube and casing. Case of the thermal reactor is provided with heat-protective envelope. Case of reactor and gas-discharge tube are connected to corresponding terminals for feeding power voltage. Gas-discharge tube is connected with thermal decomposing gases discharge system through rectifier.

EFFECT: complete processing of components.

3 cl, 1 dwg

Incinerator burner // 2265157

FIELD: burning separated oil-containing wastes formed during operation of ships.

SUBSTANCE: proposed incinerator burner includes several injectors for delivery of oil and diesel fuel wastes sprayed by air. Air injector equipped with swirler is located in front of oil and diesel fuel waste injectors; oil waste injector is located closer and distance of both fuel injectors may be changed relative to air injector whose axis lies at right angle relative to axes of fuel injectors; mounted in front of fuel injectors are jets whose orifices have diameter lesser than that of injectors.

EFFECT: enhanced efficiency of burning fuel; reduction of toxic emissions from reactor.

3 dwg

FIELD: combustion.

SUBSTANCE: method comprises grinding organic agents, heating without air access first in the chamber for removing moisture and then in the chamber for pyrolysis, and condensing portion of vapor phase to provide liquid fuel. The device comprise grinder, charging-batching device, chamber for removing moisture, chamber for heat treatment (pyrolysis), separating device and condensing device. The charging-batching device is provided with a pickup detecting the moisture of organic agent. The pickup is mounted upstream of the chamber for removing moisture and is connected with the signal converter.

EFFECT: enhanced efficiency.

4 cl, 6 dwg

Up!