NL7909090A - METHOD FOR TREATING WASTE WATER. - Google Patents

Description

793559 / vdVeken 4 f

Applicant: OSAKA GAS COMPANY, LIMITED, Osaka-Shi, Japan. Short designation: method of treatment for wastewater.

The invention relates to a method by which waste water containing ammonia or chemically oxidisable compounds, suspended solids, etc. in combination with ammonia is subjected to wet oxidation in the presence of a catalyst to convert these impurities into nitrogen, 10 carbon dioxide, water and the like and thus render the waste water harmless.

The ammonia present in the wastewater includes ammonia compounds which, when dissociated in water, provide ammonium ions. The chemically oxidizable compounds are phenol, cyanides, thiocyanates, oils, thio sulfuric acid, sulfurous acid, sulfides, nitrous acid, etc.

It has recently been deemed necessary for the control of water pollution to remove nitrogen-containing components, in particular ammonia nitrogen, as well as chemically oxidizable compounds from the water. The nitrogenous constituents serve as nutrients, which contribute mainly to an abnormal growth of algae in rivers and lakes, red tide at sea and the formation of fungi in water reservoirs, causing city water to become stale. As a result, stricter provisions against nitrogen pollutants will be adopted.

In view of existing methods of treating ammonia-containing waste water, intensive research has been carried out to develop an easy and economically feasible method for treating waste water, whereby ammonia or 50 simultaneously contains ammonia and chemically oxidizable components regardless of the ammonia concentration and it has been found that this could be achieved by subjecting wastewater to a wet oxidation reaction in the presence of a particular catalyst and under certain conditions. This is based on the method described in US patent 4,141,828, which will hereinafter be referred to as the method according to the earlier invention. With the method according to the previous invention, ammonia-containing waste water can be treated very efficiently 39 by subjecting it to wet oxidation at a pH of 7909090 fc-2 -ψ at least 9%, but a subsequent investigation has shown that this method still involves problems in the treatment of some types of wastewater * When wastewater with a pH of about 9 to about 11.5 is introduced into the reactor, the pH of the reaction system usually becomes strong as the reaction proceeds and consequently leads to an increasingly less efficient decomposition of the harmful components, possibly requiring a greater amount of catalyst and accelerating the consumption or degradation of the catalyst. Acidic liquids cause serious damage to the reactor, lines, heat exchanger, etc. * and make it necessary to neutralize the effluent prior to disposal. In connection with this, a further investigation has been conducted and found that all of the above process problems according to the previous invention, can be eliminated by adding a basic compound to the wet oxidation reactor in such an amount that at least about 80% of the waste water supplied to the reactor near the reactor water supply at all times the pH is maintained at least about 8 and the liquid obtained by the wet oxidation has a pH of about 5 to about 8. The present invention is based on this.

Examples of effluent water that can be treated by the present process are ammonia-containing effluent, which may further contain oxidisable organic and / or inorganic compounds, such as gas water, which is produced in coke ovens, gasification and coal liquefaction plants , waste water from gas treatment in these factories, oil-containing waste water, water from activated sludge processes, settled activated sludge, waste water from chemical plants and oil refineries, waste water from 30 cities, liquid and solid waste discharged through sewage, sewage sludge, etc. * Wastewater from high temperature and / or high pressure systems can advantageously be treated according to the present process with lower costs for heating ery or pressurizing the wastewater. * When the wastewater contains a large amount of suspended solids, will the 7909090

Jt-3 solids adhere to the components of the treatment equipment, thereby reducing efficiency, for example, by lowering the heat transfer coefficient on the surface of the heat exchanger or by reducing the catalytic activity due to the deposition of solids on the surface of the catalyst particles in the reactor. Accordingly, depending on the concentration and composition of the solids, it is preferable to remove them partially or completely from the wastewater before treatment. Alternatively, the waste water can be subjected to an uncatalyzed wet oxidation known as the Zimmermann process to partially or completely decompose suspended solids before carrying out the present process and poisoning the associated - \ prevent catalyst. The waste water to be treated according to the present method has a pH of about 8.5 to about 11.5 for efficient removal of the chemically oxidizable compounds and the ammonia, the pH is preferably about 9 to about 11. It is therefore desirable to adjust the pH of the waste water | to be regulated for the reaction with a basic compound such as sodium hydroxide, calcium hydroxide, sodium carbonate or the like, depending on the nature of the wastewater »

The basic compound is introduced into the wet reaction system at the desired time and in the required amount to at least time at least about 8Ga of the waste water supplied to the reactor near the water supply of the reactor at a pH of at least about 8 and the keep the treated liquid at a pH of about 5 to about 8. The same basic compound (s) used for controlling the waste water pi can be used as such basic compounds.

Examples of suitable active catalyst components are iron, cobalt, nickel, ruthenium, rhodium, palladium, iridium, platinum, copper, gold and tungsten and compounds of these metals which are insoluble or slightly soluble in water. or be used in a combination of at least two * Examples of suitable little or no water? 3 ö 0 ö 9 0 κ - 4 - soluble compounds are: (i) oxides such as iron sesquoxide, tri iron tetroxide, cobalt monoxide, nickel monoxide, ruthenium dioxide, rhodium sesquoxide, palladium monoxide , iridium dioxide, cuprous oxide, tungsten dioxide, etc »(ii) chlorides such as ruthenium dichloride, platinum dichloride, etc» (iii) sulfides such as ruthenium sulfide, rhodium sulfide, etc »»

These metals and compounds thereof are conventionally applied to a support such as titanium oxide, zirconium oxide, aluminum oxide, silicon oxide, silica-alumina or active carbon, a porous support of nickel, nickel-chromium, nickel-chromium-aluminum or nickel Chromium iron, etc. Depending on the treatment conditions, the waste water to be treated by the present process, if it has a pi of more than 11 ", would dissolve the carrier or convert part of the water into the water. present ammonia can cause nitric nitrogen and / or nitrate nitrogen, whereby nitrogen can optionally be removed from the system with the treated liquid. If, in such a case, titanium oxide and / or zirconium oxide as carrier dissolution is prevented, while the conversion of ammonia is effectively inhibited. The amount of the active ingredient applied to the carrier amounts to about 0.05 to about 25%, preferably about 0.5 to about 3%, relative to the weight of the support. The catalyst may be used in the form of spheres, pellets, cylindrical rods, crushed pieces, particles or in any other desired form »When the reactor is equipped for a fixed bed, the wastewater is preferably passed through at a spatial rate of about 0.5 to about 10 hours", in particular about 1 to about 5 hours "* * Based on an empty column, 30 Le grains or particles of the supported fixed bed catalyst are usually sized from about 3 to about 50 µm, preferably about 5 to about 25 mm. In the case of fluidized beds it is preferable to use the supported catalyst suspended in slurry wastewater 35 in such an amount, 79 0 SO 90

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That a fluidized bed is formed in the reactor, that is, in an amount of usually about 0.1 to about 20 weight percent, preferably about 0.5 to about 10 weight percent based on the suspension obtained. working with the fluidized bed 5, it is preferable to feed the supported catalyst suspended in the waste water to the reactor, separate the catalyst from the treated water by sedimentation, centrifugation or by a similar suitable method and the separated to reuse the catalyst. To facilitate the separation of the catalyst from the treated water, the particle size of the fluidized bed catalyst with | advantage about 0.15 to about 0.5 mm.

Examples of suitable oxygen-containing gases are | air, oxygen-enriched air, oxygen, oxygen-containing waste gases [waste gases, etc. Under oxygen-containing waste gases, gas | that have a lower oxygen concentration than! air and one or more compounds such as hydrogen cyanide, hydrogen sulfide, ammonia, sulfur dioxide, organic sulfur compounds,! nitrogen oxides, hydrocarbons, etc., for example, a waste gas from the regenerator of a redox desulfurization process. The use of such oxygen-containing waste gases offers the advantage that the harmful components of the gas, together with those in the waste water, can be rendered harmless. The rate of supply of the oxygen-containing gas can be determined from the theoretical amount of oxygen required for the oxidation of the inorganic and / or inorganic compounds in the wastewater and for (the decomposition of ammonia to nitrogen. Generally, the oxygen-containing gas is supplied in an amount from about 1 to about 1.5 times, preferably from about 1.05 to about 1.2, 30 times the theoretical amount of oxygen When the absolute amount of oxygen is insufficient when used of an oxygen-containing waste gas, the gas is replenished with oxygen by supplying air, oxygen-enriched air or oxygen as such The oxygen-containing gas may be introduced at two or more points at a single point or via branched lines. The reactor can be recycled for efficient use, 7909090 - 6- * oxygen flowing from the reactor for reuse, if this is economical and advantageous. or the operation is.

The reaction is carried out at a temperature of usually about 100 to about 370 ° C, preferably about 200 to about 300 ° C. As the reaction temperature is higher, the removal of ammonia, organic and / or inorganic compounds more efficient and the residence time of the waste water in the reactor shorter, but the costs of the installation are higher. As a result, the reaction temperature is selected in view of the nature of the wastewater, the desired degree of treatment and the combined work and installation costs. The reaction pressure need only be such that the waste water remains at least in the liquid phase at the predetermined temperature, although higher pressures lead to a more efficient removal of ammonia.

The wet oxidation can be advantageously combined with the following gas purification and / or reverse osmosis treatment of the treated water.

For the purification of gases containing harmful components such as hydrogen cyanide, hydrogen sulphide, ammonia, etc., various methods have been proposed. For example, a method is known in which a gas containing such harmful components is contacted with water or an aqueous basic solution to dissolve and remove the harmful components. The main drawback of this method is that the treatment of the dissolved harmful components is laborious, difficult and economically very inexpensive. As a result, the harmful components are now usually removed separately from the gas. However, this method is also disadvantageous in terms of operation and cost, since the harmful components must be removed separately. Moreover, this method has the drawback that the collected harmful component has to be subjected to a troublesome treatment before it can be discarded or the products recovered from the harmful components are of little value because of the - - - ---- - ------- - - 7909090 <f - 7 - presence of contaminants. However, when the liquid used for the purification of the gas, which contains chemically oxidisable components such as cyanides and sulphides, as well as ammonia, are subjected to the wet oxidation treatment according to the invention, the chemically oxidisable components and the ammonia can be converted into nitrogen, carbon dioxide, water, etc. Thus, the gas can be purified without the above drawbacks of the known processes.

According to the invention, fuel gas, waste gas, etc.

Purified by contacting the gas with water or an aqueous solution of ammonia, sodium hydroxide, potassium hydroxide or a similar base, thereby absorbing hydrogen cyanide, hydrogen sulfide, ammonia and similar deleterious components by the solution.

15 1 The liquid with the harmful components is then subjected to the wet oxidation described as such, or in combination with another waste water,

I Eat by wet oxidation. Wastewater has a pH

I from about 5 to about 8, is nearly colorless and transparent, and can usually be discharged as such. However, if it is desired to reuse the water obtained for industrial purposes or if the water contains large concentrations of sodium sulfate and other substances derived from sulfur compounds, the effluent discharged under pressure from the wet oxidation stage can be directly fed to a reverse osmosis. device, whereby the water can be separated very effectively into purified water and a concentrate. For example, the purified water can be reused as part of the scrubbing liquid for scrubbing, while sodium sulfate and similar useful compounds 50 can be easily recovered from the concentrate.

The invention will be further elucidated with reference to the annexed drawing, in which:

Fig. 1 is a diagram for explaining an embodiment of the method of the invention, in which a fixed bed is used, FIG. 2 is a diagram for explaining another embodiment of the process of the invention, using a fluidized bed and recycling the recovered catalyst for a subsequent use,

Fig. 3 Scheme illustrating another embodiment of the process of the invention, wherein the purification of a gas containing ammonia and chemically oxidizable compounds such as hydrogen cyanide and hydrogen sulfide is combined with the wet oxidation reaction and uses a reactor with a fixed bed, Fig. 4 is a diagram for explaining yet another embodiment of the method of the invention similar to that in Fig. 3 where a wet-type reactor with a fluidized bed is fitted,

Fig. 5 is a diagram for explaining an embodiment of the method of the invention similar to that in Fig. 3, where purified water from a reverse osmosis device is recycled to be used as part of the water for gas purification , and

Fig. 6 is a diagram for explaining an embodiment of the method of the invention similar to that in Fig. 4 where the purified water from a reverse osmosis device is recycled to be used as part of the water for gas purification , shows »

In Figures 1 to 6, like parts are labeled with 25 like numbers »

As shown in Fig. 1, waste water is supplied from a tank 1 through line 2 to a pump 3 »whereby the water is compressed at a predetermined pressure» The water is then passed through line 4 a heat exchanger 5 and a line 6, mixed with an oxygen-containing gas and passed through a line 11 into a catalyst-filled reactor 12. As previously described, the pH of the wastewater is controlled with a base depending on its nature. The base can be added to the water at one or more points in the tank 1, pipes 2, 4 »6 and 11» 35 The oxygen-containing gas 7909090 - 9 - 1, which is pressurized by a compressor 7, is passed through pipe 8, a humidifier 9 and a line 10, as previously mentioned, are mixed with the wastewater and passed through line 11 into reactor 12. It is preferable, but not critical, to use the humidifier which serves to prevent evaporation of the water in the reactor and to obtain an improved heat recovery efficiency. However, when an oxygen-containing waste gas is used as an oxygen source, the humidifier is not used to prevent the transfer of harmful components from the waste gas into the treated water. For a better liquid-gas contact and a higher reaction efficiency in the reactor 12, it is advantageous to finely distribute the gas bubbles in the mixed stream of water and gas. Methods for distributing such bubbles are described, for example, in Japanese Patent Applications 49873/1974 and 49874/1974 "The Oxygen-15! containing gas can be added to the waste water at the discharge of the pump 5 or partly directly in the reactor 12 at a | single point or guided at two or more points. If necessary, the waste water can be added to pipe 6 or a lower part of | the reactor 12 is heated. However, if the required amount of heat 20 I can be provided by the reaction heat, the waste water need not be heated. When heating is applied, | the waste water during the passage through line 6 is heated in an oven (not shown) or by heat exchange with a heating medium. On the other hand, the water can be subjected to heat exchange with a heating medium in a lower part of the reactor.

A base, usually in the form of an aqueous solution, is fed from a tank 21 through line 22, pump 23 and line 24 into reactor 12 in an amount such that at least about 50 ° / o of the feed to the reactor waste water has a pH of at least about 8 at all times and the water discharged from the reactor through line 13 is maintained at a pH of about 5 to about 8. Since the pH of the wastewater decreases as the water rises in the reactor 12 during the course of the reaction, 55 the pE of the water is measured by known means at a number of 7909090> 10 points, which are equally spaced about 80% of the entire length of the reactor is from the bottom, so that the base is fed at the point where a reduction in pH to about 8 has been observed. Depending on the reaction conditions, the line 24 may therefore be branched into a number of lines for supplying the base at two or more points as the reaction proceeds.

After the waste water has reacted with the oxygen in the gas under the stated conditions in the reactor 12, the resulting mixture is discharged from an upper part of the reactor 12 through a pipe 13 and passed to a soiling drum 14, in which the mixture is separated in a gas and liquid.

The treated water flowing out of the soiling drum 14 can pass through line 15 into the humidifier 9, partially entrained into the oxygen-containing gas, and pass through lines 10 and 11 into the reactor 12. The rest of the treated outflow from the humidifier 9 water is led through a conduit 16 to a cooler 17, cooled and brought to atmospheric pressure and discharged. Alternatively, the treated water at elevated pressure from cooler 20 17 can be directly fed to a reverse osmosis device 25 to obtain purified water from line 26 and a concentrate from line 27e

The gas flowing out of the separating drum 14 is passed through a pipe 19 to the heat exchanger 5, in which the gas is heated 25 to be discharged to the waste water, then / relaxed to atmospheric pressure and discharged through the pipe 20, on the other hand it can be discharged from the reactor 12 discharged liquid-gas mixture is passed directly into the heat exchanger 5 and then separated into a gas and a liquid in the separating drum 14. When the constituents of the concentrate from line 27 can be further decomposed, the concentrate can be fed into the tank 1 and again subjected to wet oxidation.

As illustrated in Fig. 2, wastewater is passed from a tank 1 into a mixing vessel 34, in which the water is mixed with a catalyst fed through line 33 from vessel 32 to form a 7909090-11.

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mash. The slurry is brought under a certain pressure by means of a pump 3 and is then conveyed in the same manner as in Fig. 1 through a line 4, heat exchanger 5 and lines 6, 11 to a reaction vessel 31 which does not contain a catalyst. An oxygen-containing gas can usually be introduced into the reaction vessel in the same manner as in Figure 1 · To further fluidize the slurry, a portion of the gas can be introduced directly into the reaction vessel 31 via at least one line branched from line 10 · As in the embodiment of Figure 1, an aqueous basic solution from a tank 21 is introduced through line 22, pump 23 and line 24 into the reaction vessel 31 in an appropriate amount to at least about 80p of the waste water fed into the reaction vessel near the water supply of the reaction vessel at all times at a pH of at least about 8 and keeping the treated water at a pH of about 5 to about 8 ·

The pressurized treated water with the catalyst is passed through line 13, liquid-gas separator 14, line 15, humidifier 9, line 16, cooler 17, and line 18 to a solid-liquid separator 28 such as a filter press. The separated liquid is discharged from the system after relaxation to atmospheric pressure or otherwise, passed directly through a conduit 29 into a reverse osmosis device 25, in which the liquid is separated into purified water which is discharged through conduit 26, and a concentrate which is discharged through line 27 · The recovered catalyst is returned through line 30 to the vessel 32 and reused * 3 Using an oxygen-containing waste gas as the oxygen source, the humidifier 9 becomes as in the case of FIG. 1 not used.

As shown in Fig. 3, a fuel gas, waste gas 30 or a similar gas containing ammonia and chemically oxidizable components such as hydrogen cyanide and hydrogen sulfide are passed through a conduit 35 in a lower portion of an absorption tower 36 and flushed with water or an aqueous basic solution, which is supplied through line 38 from a vessel 37 and is sprayed from the top of tower 36 · The waste water discharged from the absorption tower 36, containing the ammonia and chemically oxidisable constituents, is passed through line 39 into a vessel 1 »The purified gas is discharged from an upper part of the tower 36 via line 40« The washing water can be mixed with other waste water, which is supplied through line 41 · The waste water is discharged from vessel 1 and a fixed bed type reactor 12 subjected to wet oxidation in the same manner as in the embodiment of FIG. 1

In the embodiment illustrated in FIG. 4, a gas containing ammonia and chemically oxidisable components such as hydrogen cyanide and hydrogen sulfide is first purified in the same manner as in FIG. 3 and the resulting wastewater or mixture thereof is mixed with other wastewater. in the same manner as in FIG. 2, in a fluidized-bed reactor 31 subjected to wet oxidation. The catalyst is recycled as in FIG. The liquid phase obtained from a liquid-solid-state separator 28 can be discharged from the system after decompression via a conduit 29 or can be led without decompression to a reverse osmosis device (not shown) for separation into purified water and a concentrate.

In the embodiment illustrated in FIG. 5, wastewater is first subjected to wet oxidation in a fixed bed type reactor 12 and then passed into a reverse osmosis device 25. The purified water obtained is passed through a conduit 42 to a vessel 37 for an absorbing liquid returned and reused as part of the absorbing liquid »In this case, the vessel 37 is of course replenished with an amount of water corresponding to the amount of the concentrate discharged from the system through line 27» Fig. 6 shows another embodiment wherein the fluidized bed fluidized oxidation reactor 31 treated waste water is fed to a solid-liquid separator 28 in which the liquid phase is separated from the catalyst. The catalyst is returned through a line 30 to a catalyst vessel 52 and reused, while the liquid phase 7909090-13 under pressure is passed through line 29 to a reverse osmosis unit 25 and separated into purified water and a concentrate, The purified water is passed through line 42 into an absorbent liquid vessel 57 and reused as part of the absorbent liquid.

In contrast to the present method, the known methods require many steps and are expensive. For example, the gas water produced in coke ovens for the preparation of coke is usually treated by successive treatments such as (1) removal of phenol, (2) pretreatment, (3) removal of ammonia by stripping, (4) treatment with activated sludge and (5) coagulation and sedimentation, optionally further followed by (6) oxidation with chemical agents, (j) adsorption by means of active j: j carbon and (8) reverse osmosis, The method of the invention consists in j main flavor from a single stage, in which the gas water from the coke oven i I nada | it has been pressurized without being cooled directly into a reaction vessel and is catalytically oxidized with an oxygen-containing gas, whereby the ammonia and chemically oxidisable constituents such as phenol, cyanides, thiocyanates, oils, thio-sulfur Acid, sulfurous acid, sulfides, etc., which are present in the gas water, can all be decomposed and rendered harmless. The present process therefore involves a very simplified operation, which with very much reduced costs (of the device and the operation can be carried out. The method according to the invention obviates the problems which arise in the method according to the earlier invention, when the waste water is supplied with a pE of about 9 to about 11, The addition of a basic substance reduces the noticeable drop in the pH which takes place in the reactor in the known process, thus decreasing the decomposition efficiency, breakdown of the catalyst and damage to the reactor, heat exchanger, piping system, etc. are prevented.

The method of the invention also has the advantage that if it is not possible to treat waste water with a pH of about 8.5 using the method according to the previous invention, 7909090 ψ - 14- because of the low efficiency. in the case of the ammonia decomposition, the present process ensures a high efficiency in carrying out such a treatment »

When high temperature and pressure conditions for the treatment of wastewater with a pH greater than 11 give rise to the dissolution of the carrier or the formation of a large amount of nitrile and / or nitrate nitrogen, the use of titanium oxide and / or zirconium oxide occurs such a drawback for the carrier. »The combination of the purification of a gas containing ammonia and chemically oxidisable constituents, such as hydrogen hydrogen acid and hydrogen sulfide, and the treatment of waste water by wet oxidation considerably facilitates the removal of such impurities from the the washing liquid originating from the gas purification, the treatment of which has hitherto been considered difficult »15 Furthermore, the combination of the wet oxidation of waste water and a reverse osmosis is economically very advantageous, since the high pressure of the effluent from the wet oxidation stage can be applied efficiently for the separation of the effluent into a concentrate and gel purified water, which can be used as such in industry »

The invention will be further elucidated by means of the following examples »

Example I »

The process of the invention is carried out continuously for 25,000 hours in the manner illustrated in FIG.

Gas water obtained from a coke oven with a pH of about 9 »5 is introduced into a lower portion of a cylindrical stainless steel reactor at a spatial rate of 0.99 hours based on an empty column. liquid is 3 * 45 ton / m2 »hour» Air is introduced into the lower part of the reactor at a spatial speed of 50.8 hours - based on an empty column under standard conditions »The reactor is filled with a catalyst in the form of tablets with a diameter of 5 en and consisting of 2.0 wt., ruthenium deposited on 35 α-aluminum oxide. The interior of the reactor is maintained at a temperature of 275 ° C and a temperature of 275 ° C. pressure of 75 kg / cm 2 G, while introducing a 48 J aqueous solution of sodium hydroxide into the reactor in such an amount that the portion of the water filling the reactor is at all times over 8% of its length from the bottom to a pH of at least 8.5 and the water from the wet oxidation maintains a pH of about 7 »5 * The liquid-gas mixture from the catalytic reaction is continuously discharged from an upper part of the reactor and then passed into a liquid-gas separator to separate into a liquid and 10 gas, which are respectively indirectly cooled and discharged from the system *

It was found that the gas phase obtained after 4,000 hours from the start of the operation was 2.5 ppm ammonia and 0.05 PP® nitrogen. oxides, the remainder consisting of nitrogen, oxygen and carbon dioxide, but no sulfur oxides, hydrogen sulfide and hydrogen cyanide was present * j In Table A, the properties of the liquid phase and the amount of dissolved catalyst support were determined after 4 * 000 hours from the start of the operation ^ stated * 20 Ka 4 * 000 hours, the reactor was vertically divided in two and the inner surface viewed with the naked eye, with no significant corrosion observed *

Example II *

The procedure is the same as in Example 1, but titanium oxide is used as a catalyst instead of oc alumina *

The gas phase obtained after 4 * 000 hours from the start of the operation contained 0.5 ppm of ammonia and 0.01 ppm of nitrogen oxides, the remainder consisting of nitrogen, oxygen and carbon dioxide, and no sulfur oxides, hydrogen sulfide and cyanohydric acid were found * 30 of the liquid phase and the amount of catalyst carrier dissolved after 4 * 000 hours from the start of the operation are shown in Table A * - After 4 * 000 hours, no significant corrosion was found on the inner surface of the reactor. Comparative Example I * 35 Ken treats wastewater continuously for 4 * 000 hours at 79 0 SO 9 0 - 16 - in the same manner as in Example I, but does not introduce 4ps sodium hydroxide solution into the reactor »

The gas phase obtained after 4,000 hours from the start of the operation contained 5 ppm ppm of ammonia and 096 ppm of nitrogen oxides, while the remainder consisted of nitrogen, oxygen and carbon dioxide, and no sulfur oxides, hydrogen sulfide and hydrogen cyanide were found *

The capacity of the liquid phase and the amount of dissolved catalyst support after 4,000 hours from the start of the operation are given in table Δ »UTa 4,000 hours, the reactor was vertically divided in two and the inner surface with the bare substance. at which corrosion pits were found at various points * Microscopic observation showed that some of the pits had developed into trans-crystalline cracks »t 7909090 - 17-! ί i j ® j

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Based on the concentration of dissolved aluminum listed in Table A, the amount of dissolved carrier relative to the originally used amount of the carrier is 0.96 $ in Example I and 21.3% in Comparative Example I »5 Example IIIe

The process of the invention is carried out on the FIG. 1 explained working method »

Gas water and a coke oven effluent from a sulfur recovery desulfurization effluent of 5si is mixed in a ratio of 5si and the combined wastewater is brought to about 10pi with a sodium hydroxide solution and then passed into a lower part of a reactor with a spatial speed of 1.73 hours "" * * based on an empty column »The feed rate of the water is 5» 20 tons / o2 »hours" 15 air is fed into the lower part of the reactor at a spatial speed of 244 hours based on an empty column under standard conditions. The reactor is filled with a catalyst in the form of spheres about 10 mm in diameter and consisting of 1.5 wt. # of palladium deposited on a alumina support »20 The interior of the reactor is maintained at a temperature of 2 ° C and a pressure of 80 kg / cm 2 G, while a 48% aqueous sodium hydroxide solution is introduced into the reactor in such a high It is appreciated that the portion of the water which fills the reactor is at all times maintained at a pH of at least about 8 from its bottom over 80% of its length from the bottom and the water from the wet oxidation a pH of about 8.0. The liquid-gas mixture from the catalytic wet oxidation reaction is continuously discharged from an upper part of the reactor, it is led to a liquid-gas separator and it is separated into a liquid and gas, respectively. indirectly cools and drains from the system 0

It was reported that the gas phase contained 1.5 ppm of ammonia and 0.04 ppn of nitrogen oxides, the remainder consisting of nitrogen, oxygen and carbon dioxide, and no sulfur oxides, hydrogen sulfide and cyano-hydrochloric acid being present.

The properties of the waste water mixture and the treated water are shown in Table 3.

Example 17 «

Lien treats wastewater in the same way as in example. 5 III, but uses titanium oxide as a support instead of α-aluminum oxide «

The gas phase contained nitrogen, oxygen, carbon dioxide, 0.8 ppm of ammonia and 0.02 ppm of nitrogen oxides, but no sulfur oxides, hydrogen sulfide and hydrogen cyanide. The status of the treated water is shown in Table 3e.

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Comparative example II »

The same wastewater as in Example III is treated at the same temperature and pressure and with the same catalyst as in Example III without addition of sodium hydroxide solution to the reaction vessel to obtain treated water of the same quality as in Example III. then supply air at the following greatly changed speeds *

Spatial rate of wastewater: 0.95 hours - ^, (based on an empty column).

10 Feed rate of wastewater: 5 »20 ton / m2 * hour (same I as in pre-fed lil).

! Spatial air feed rate: 133 hours based on an empty column, under standard conditions. It was found that the amount of catalyst required in this comparative example was about 182 in comparison. with the amount of catalyst required in Example III, which was set at 100 * In this comparative example, therefore, a very much larger amount of catalyst is needed than in Example III. the method is therefore much less expensive than that in example III.

20 | The pH of the treated water was only about 2.8, while the dissolved aluminum concentration was 25 mg / l.

The process of the invention is carried out in the manner illustrated in FIG. 2 for the treatment of a coke oven gas water containing phenol, ammonium thiocyanate, ammonium thiosulfate, ammonium nitrite, ammonium nitrate, ammonium carbonate and ammonia and combined with waste water which comes from the purification of coke oven gas and hydrogen cyanide, hydrogen sulphide, ammonia and a very small amount of naphthalene, in a ratio of two parts of the first waste water to part of the last * A particulate catalyst of dimensions 0 is mixed 15 to 0.3 mm consisting of 5 wt. Ruthenium deposited on α-aluminum oxide with the combined waste water to obtain a slurry containing 10 wt.% Of the catalyst. The slurry pH is adjusted to 10.5 with a calcium hydroxide solution and passed into a 7909090-22 cylindrical stainless steel reactor at a spacing of 1.51 hours, based on an empty column, that is, with a feed rate of 4 53 tons / m2, hour. Air is introduced into the reactor at a spatial rate of 57 8 hours based on an empty column, under standard conditions.

The interior of the reactor is maintained at a temperature of 250 ° C and a pressure of 60 kg / cm 2 G, while a 40% aqueous sodium hydroxide solution is introduced into the reactor in such an amount that the portion of the water, that the reactor fills, is kept at least 8.5 of its length from the bottom at a pH of at least 8.5 and the water from the wet oxidation has a pH of about 7-8. The liquid-gas mixture obtained by the catalytic wet oxidation reaction is continuously discharged from an upper part of the reactor, it is cooled immediately and it is passed into a liquid-gas separator, in which the mixture is separated into a liquid and a gas. The pressure of the separated gas is brought to atmospheric pressure and it is discharged into the atmosphere. The pressure of the liquid phase is brought to atmospheric pressure, this phase is passed into a liquid-solid separator and a separation is effected between the catalyst and the treated water to recover the catalyst. The separated gas phase contains 5 PPm of ammonia and 0, 05 PP® nitrogen oxides, while the remainder consisted of nitrogen, oxygen and carbon dioxide and no sulfur oxides or hydrogen sulfide were present, 25 The status of the combined wastewater and treated water is shown in Table C,

Example VI,

Waste water is treated in the same manner as in Example V, but zdLrone oxide is used as the support instead of α-alumina.

The gas phase was found to contain 2.1 ppm ammonia and 0.08 ppm nitrogen oxides, the remainder consisting of nitrogen, oxygen and carbon dioxide, and no sulfur oxides, hydrogen sulfide and cyanohydroic acid present, The status of the treated water has been reported in table C, 7909090 - 23- -1-1-1- “” - I i ill I 03 O ® ® {| , § i ai ai Q η σ \ σ \ -Λ I! ï! i? Q 1 · Ησ \ · Ηα · \ Ε— 1

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Examples VII to XX «

Waste water is treated in the same manner as in Example III, but in each example the catalyst shown in Table D is used. Label D also mentions the removal efficiency of the chemically oxidizable substances and the ammonia in each example, as well as the pH of the treated water and the observed concentration of dissolved carrier.

The gas phase was found to contain up to 5.0 ppm ammonia and up to 1.0 ppm nitrogen oxides, the remainder consisting of nitrogen, oxygen and carbon dioxide, but no sulfur oxides, hydrogen sulfide and hydrogen cyanide were present. 7909090 t-25-ii > i $ j 1 Φ ü 1 I Ή Λ l

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I.len treats wastewater in the same manner as in Example III, but uses in each example the catalyst listed in Table E, Label E also lists the percentage removal of the chemically oxidizable substances and the percentage removal of ammonia in each example, as well as pH of the treated water. It was found that no carrier was dissolved,

The gas phase contained up to 2.5 ppm ammonia and up to 0.5 PP® nitrogen oxides, the remainder consisting of nitrogen, oxygen and carbon dioxide, and no sulfur oxides, hydrogen sulfide and hydrogen cyanide were present,> 1! «I t 1 790909a - 28-

Tab el Ξ_

Example! Catalyst Removal Removal pH of the chem. oxidation of ammonia-treated bare substances ($) water ($) XXI 1.0 $ Ir-TiO 99 At least 6.2 99 XXII 0.3 $ Pt-TiO At least »7.1 99 XXIII 1.0 $ lu-TiO2 99 98 7.2 XXIV 0.5 $ Pd-TiO Tenminsta At least 6.9 99 99 XXV 1.0 $ Hh-Zr02 95 95 6.9 XXVI 5.0 $ Pe-Ti02 97 97 7.5 XXVII 5.0 $ Ni-Ti02 92 98 6.2 XXVIII 5.0 $ W-Ti02 91 95 6.3 XXIX 5.0 $ Cu-Ti02 99 95 6.8 XXX 5.0 $ Co-Ti02 97 98 6.3 y XXXI 5.0 $ Fe2 O3-TiC2 92 95 6.9 XXXII 5.0 $ Pe203-TiC2 92 91 7.1 XXXIII 2.0 $ Pd-TiO ^ At least 7.2 99 99 XXXIV 2.0 $ Pt-TiO2 "*" 7.1 XXXV 2.0 $ RuCl2- ZiC2 91 96 7.5 XXXVI 5.0 $ Co0-Ti02 91 95 7.5 - - "" - J - ..—! 7909090 - 29-

I Examples | XXX7II to XLI

They carry out the method of the invention; in the manner illustrated in FIG. 1 i.

i; Eenβη subjects a gas water from a coke oven to a pH of 9 95 to wet oxidation in the same manner as in Example 1, but controls the pH of the water set to sodium hydroxide. solution at 10.5 and then treat the water with application; of the for each example in table? listed temperature, pressure and catalyst.

Table F also lists the percentage of ammonia removed in each example.

"Table F

; Example Temp. Pressure Ammonia removal (ji) 15 ^ ° G '(k & / cs2 &) 2jiPd-aAlo0 T 1 $ Pt-aAlo0, 2 5 2 5; XXXVII 100 10 90 93 XXXVIII 150 -20 95 98 'XXXIX 200 50 At least 20' 99 99 XL 250 45 ""; XLI 280 75 "

i Examples XLII to XLV

They carry out the method of the invention on the method shown in FIG. explained manner.

To a mixture of 8.2 g of a coke oven gas water and waste water of a sulfur recovery desulfurization waste sulfur mixture, first add a sodium hydroxide solution to the pi listed in Table G using 50 sodium hydroxide solution and subject it to the mixture. then wet oxidation in the same manner as in Example III. Table G also lists the percentage of ammonia removed in each example as well as the pi of the treated water.

i i 1_ ♦ - ---- - --------- 7 9 0 S 0 9 o - 30-

Table_G

----.----- 7 --------------------- p --------------- 1- ----------------! !

Example pH of the waste- Removed pH of the treated water mixture ammonia (for) divided water 5 XLII 8.5 95 7.5 XLIII 9.0 At least 7.9 99 XLIV 10.0 "7.5 XLV 11.0" 7.8 io —--------------------------------------------- ----- 1 --------------------

Example XLVI,

The method of the invention is carried out in the same manner as explained in Fig. 4, but does not use the humidifier 9.

A coke oven gas water is brought to a pH of 11.0 using a sodium hydroxide solution and then passed into a lower portion of a reactor at a spatial rate of 0.99 hours based on an empty column Be feeding speed of the water is 5.45 ton / m 2 hour. 20 air with two grams / lm3 hydrogen sulphide, 4 g / Hm3 ammonia and 0.1 g / Nm3 cyanohydroic acid is introduced into the lower part of the reactor at a spatial speed of 44.4 hours based on an empty column, under standard conditions. The reactor contains a catalyst in the form of spheres with a diameter of approximately 6 mm consisting of 2.0 wof Wofo palladium deposited on α-aluminum oxide.

The interior of the reactor is maintained at a temperature of 250 ° C and a pressure of 55 kg / cm 2 G, while a 48% aqueous sodium hydroxide solution is introduced into the reactor in such an amount that the portion of the water that the reactor fills over 50 to 80 ° / o of its length from the bottom is always kept at a pH of at least 8.5 and the water from the wet oxidation has a pH of about Jr6. The liquid-gas mixture from the catalytic reaction is continuously discharged from an upper part of the reactor and passed into a liquid-gas-55 separator. The gas phase obtained after 4,000 hours from the start of the operation contained 3 .5 ppm ammonia and 0.05 ppm nitrogen oxides, the remainder consisting of nitrogen, oxygen and carbon dioxide, but none | sulfur oxides, hydrogen sulfide and hydrogen cyanide were present »i Table E shows the quality of the treated water after 4,000 hours j '5 | from the start of treatment * I Table 5 | I Composition Composition Disposal i gas water (ppm) treated water (fjiter (ppm) 10 y, ---------------------------- ---------------------------------------- I Chemically oxidizable 4 * 000 10 At least I substances 99; Total NH_ 5o000 2.5 At least i * 99 15; Nitrate and nitrite 60 0.8 98.7 nitrogen TOD 16,000 20 At least 99! TC 2,200 175 92.0 20; T0C 1,500 15 99 i TN 4 * 700 At least

. QQ

: Concentration dissolved '<dissolved Al - 1.2 i # —-------------------------------- s-- --------------------------------— 25 Example XLVII.

The process of the invention is carried out in the same manner as illustrated in fig. 2, but does not use the humidifier 9.

A coke oven gas water having a 30 ρΞ of 9.2 is mixed with a particulate catalyst of from 0.15 to 0.3 mm in size consisting of 5 ruthenium deposited on titanium oxide to form a slurry which is a spatial speed of 1.51 hours ”^ based on an empty column and a feed rate I of 4.53 tons / m2, hours in a cylindrical stainless steel reactor 35 | They direct air with 5 g / Nm 3 hydrogen sulphide into the reactor with 7909090 o-32- a spatial velocity of 72.4 hours based on an empty column, under standard conditions.

The interior of the reactor is maintained at a temperature of 250 ° C and a pressure of 60 kg / cm 2 G, while an aqueous sodium hydroxide solution is introduced into the reactor in an amount such that the water in the reactor a pH of at least 8.5 is maintained and the water after the wet oxidation has a pH of about 6.5. The liquid-gas mixture from the catalytic wet oxidation reaction is continuously discharged from an upper part of the reactor, it is cooled indirectly and it is passed into a liquid-gas separator, in which the mixture is separated into a liquid and a gas. The pressure of the separated gas is brought to atmospheric pressure and it is discharged into the atmosphere. The pressure of the liquid phase is brought to atmospheric pressure, this phase is passed into a liquid-solid separator and the catalyst is separated from the treated water to recover the catalyst. The separated gas phase contains 1.0 ppm of ammonia and 0.02 ppm nitrogen oxides, while the remainder consisted of nitrogen, oxygen and carbon dioxide and no sulfur oxides or hydrogen sulfide were present, The quality of the wastewater and the treated water is shown in Table I,

Table I »

Composition Composition Removal

gas water (ppm) treated water (fQ

ter (ppm) 25 --------------------------------------------- - ----------------------------

Chemical oxidants 4,000 6,9 At least bare substances 99

Total NH, 5th 000 0.5 At least

3 OQ

Nitrate and nitrite nitrogen 300 0.3 At least 5 99 TOD 16,000 20 At least 99 TC 2,200 120 94.5 T0C 1,500 15 99 35 TN 4,700 19 At least 99 7909090 “33 -

Paragon XIVIII »

Serste staircase

One passes a raw coke oven gas into the lower portion of an absorption tower, while industrial water is sprayed from the top of the tower and contacted with the gas under the conditions listed in Table J »Table K reports the extent , i 5 in which the harmful components of the gas are absorbed by the talker »Table L shows the composition of the water at the | discharge of the absorption tower»

10 I Table J

; Spatial speed of the gas $ 1231 hours

Water supply speed: 64 to »hours; Spatial speed of the water ï 10.5 hours ^

Temperature in the tower: 40 ° C »

15 Table K

i

Supply Drain Absorption (¢); _______ ifAüïi) _______________ (z / EbH ____________________________________ i BH. 8.0 0.04 99.9 5 20: HOST 1.56 0.015 99.0! E2S 4.50 0.68 84.9 y _____ - ^ ^ - ^ ___-.%.

; Table L

25 * Concentration (mg / l) 6 y KH 933 j HCIT 18l I E2S 448

Second stage

One brings a mixture of 1 part by weight of the first stage waste water, a part by weight of a coke oven gas water and 0.1 part by weight waste water from a wet desulfurization of the sulfur recovery with pH of L -——---: - 7909090 -34- about 10.5 using a sodium hydroxide solution and then feeding it into the bottom part of a stainless steel cylindrical reactor at a spatial rate of 0.74 hours based on an empty column and a feed rate of 2.59 t / m2 "hour, 5 Air is introduced into a lower part of the reactor at a spatial speed of 51" 4 hours "·", based on an empty column, under standard conditions The reactor contains a catalyst in the form of spheres with a diameter of 5 mm and consisting of 2.0 wt.% Ruthenium applied to a titanium oxide support. The interior of the reactor is kept at a temperature of 250 ° C and a pressure of 45 kg / cm2 G, while a 48 ^ The aqueous sodium hydroxide solution in the reactor results in an amount such that the portion of the water in the reactor is maintained at a pH of at least 8.5 at 80 degrees from its bottom at all times from the bottom and the water of the wet oxidation has a PI of about J.2. The liquid-gas mixture from the catalytic wet oxidation reaction is continuously discharged from an upper part of the reactor and passed into a liquid-gas separator. The separated gas phase and the liquid phase are immediately cooled separately to about 30 ° C, The gas phase is then discharged from the system, while the liquid phase is still led to the third stage under pressure9

The gas phase contained 0.5 ppm of ammonia and 0.03 PPm of nitrogen oxides, the remainder consisting of nitrogen, oxygen and carbon dioxide, and no sulfur oxides, hydrogen sulfide, and hydrogen cyanide were present.

The composition of the waste water mixture and the water treated in the second stage are shown in table M «7909090 -35-

Γ ~ "" - I

i Table LI

31: Waste water mixture In the second stage treated "_ ___ ___ (mg / l) _ waste water (mg / l) 5; :; h- 3373 2.5! HCI? HO track I EgS 297 track! COD * 12850 34 y TOO 1224 20 IQ I TOD 2II42 IO6; τι * 3267 5.0

! 30, 1162, 1796O

a

: Ha * 37OC 8700! * chemically oxidizable substances.

Third stage them continuously leads the 7th ater of the second stage. under pressure (about 45 kg / cm) through a reverse osmosis device with a reactant inlet with a desalting efficiency of 95 to 973.

20; One hundred parts of the water fed into the reverse osmosis device provides 70 parts of purified water and 30 parts of concentrate, adding an additional amount of industrial water; the purified water and use the mixture as the absorbent for the first stage. Them recover sodium sulfate with a purity of at least 99% conventional 7% ice from the concentrate.

Table N lists the composition of the purified water: and the concentrate obtained from the second stage water, the data of which are given in the right column of Table M.

ï

L

1: »- - .....____ ______ 7902090 -36- 4

Tabjj

Purified water Concentrate _______________________________________ i5 & / i2 ________________ 5 M 0.1 8.1 HCN rail track

HpS track track COD * 1.5 276.5 TOC 4 57.3 10 TOD 5 342 T1T 0.5 15.5 S0 ~~ 260 59 260

Ra + 350 28183 15 oxidisable chemicals.

First stage

The coke oven gas is purified in the same manner as in the first step of Example XLYIII. The conditions of contact of the liquid with the gas are shown in Table 0, the absorption efficiency in Table P and the composition of the water at the discharge from the absorption tower in Table Qe

Table 0

Spatial velocity of the gas: 611 hours ^ 25 Feeding speed of the water: 4 t / m2.hr

Spatial speed of the water i 1.0 hours

Temperature in the tower: 3 ° 0C.

Table P

30 Supply (g / Nm3) Discharge (g / Nm3) Absorption ($) • »ttt ^ o„ At least ETII ^ 6.82 track ^ Η0Ν 1.35 0.02? 98 h2s 5.00 0.80 84 35 C10Hg 1.23 0.21 82.9 7909090 - 37- ί ---—-----------) Table 4 I Concentration (ng / l) j 5 BH, 4092 HCl 794 I H23 2520 I gioh8 612! "" * "" * "~" "10 j Second stage 1: They first bring the waste water from the first stage with a j.

I sodium hydroxide solution at a pH of about 9 * 5 and then passes it into the bottom part of a reactor at a spatial rate of 1.4 hours based on an empty column and a feed rate of 3.45 t / m2.hr. Air is passed into a lower part of the reactor at a space velocity of 67.4 hours, based on an empty column, under standard conditions. The reactor contains a catalyst in the form of spheres with a diameter of 5 µm, consisting of 2.0 wt.% Palladium deposited on a titanium oxide support. (The interior of the reactor is maintained at a temperature of 270 DEG C. and a pressure of 65 kg / cm 2 G, while passing a 48% aqueous sodium hydroxide solution into the reactor in such an amount that it part of the water in the reactor is kept continuously at a pH of at least 25 ° 8.5 over 8Qp of its length from the bottom and the water has a pH of about 6.5 after the wet oxidation. the liquid-gas mixture from the catalytic wet oxidation reaction continuously discharges from an upper part of the reactor and passes it into a liquid-gas separator.

Indirectly cools the separated gas phase and liquid phase to about room temperature.

The gas phase contained 0.2 ppm of ammonia and 0.01 ppm of nitrogen oxide, while the residue consisted of nitrogen, oxygen and carbon dioxide, and no sulfur oxides, hydrogen sulfide and cyanohydroic acid were present. Czars * 35 I The composition of the waste water before and after the wet 7903090 • - 38 oxidation treatment is listed in Table R „

Table R

Before treatment After treatment 5 __________________________isiZil_______________________________ MHj 4092 4 HCN 794 track h2s 2520 5 C10Hg 612 track 10 Na + 3580 3580 S04 "" nothing observed 7110

Third stage

The second stage of the second stage is continuously fed under pressure 15 (about 65 kg / cm 2) through a reverse osmosis device with an acetate membrane with a desalting efficiency of 95 to 98 grams.

One hundred parts of the water fed into the reverse osmosis device i yield 85 parts of purified water and 15 parts of concentrate. An additional amount of industrial water is added to the purified water and the mixture is used as the absorbent for the first stage. Sodium sulfate is recovered the usual way from the concentrate »

Table S lists the composition of the purified water and the concentrate obtained from the second stage water, the data of which are given in the right column of Table R.

Table_S

Purified water Concentrate ________________________ (5 l / l) ___________________ iSfZil_______________ 30 Ni ^ 0.06 26.3 HCN trace trace k2s 0.05 33.1 C1QHg trace trace

Na + 72 2346Ο 35 so4 ~ 70 47000 7909090 - 39- ï y ΐ Examples It / n LZZ.

I "" "" I lien treats wastewater in the same way as in Example XL7III, but. for each example, use the catalyst shown in Table I. In Table T, also, in the second stage, each l 5 | example variable amount of ammonia and chemically soluble | substances listed, The gas phase contained up to 4.5ppm & ammonia and up to 0.8ppm; nitrogen oxides, the remainder being nitrogen, oxygen and

L

| carbon dioxide and no sulfur oxides, hydrogen sulfide and hydrogen cyanide was present, Table I? {I Example Catalyst Removed Removed chem.

ammonia oxidisable substances (#) (#) 15 ------------------------------ L ------- --------- K -----------------— L 1.0 # Ir-Al 0.98 At least, p 99 ί LI 0.3 # Pt -TiO At least At least! 99 99 20 \ Lil 1.0 # Au-Al92 99; LUI 0.8 #? D-Ti0 At least At least ί 99 99 99; 117 1.5 # Th-Al2o3 93 95! D&C 5.0 #? E-Alo0z 92 95 2 p 25! 171 5.0 iri-Al203 90 90 I 1711 5.0 # Ώ-Α1203 91 95 I LYIII 5.0 # Ou-Al.Q, 93 At least 2 3 95 LIX 5.0 # Co-Al. 0, 98 2 3 30 LX 2.0 # Hu carbon At least "LXI 2.0 # Ru-ZrOg 3 \

Example LXII.

The method of the invention is carried out on them in FIG explained way, 7903090 - 40-

First_trag

A crude furnace gas is introduced into a lower portion of an absorption tower, while an aqueous solution of ammonia at a concentration of 1 g / l is sprayed from the top of the tower »

The conditions under which the contact between the liquid and the gas take place are given in Table II, the absorption efficiency in Table Y and the composition of the water and the discharge from the absorption tower in Table II.

Spatial velocity of the gas: 662 hours

Water feed rate s 10.6 t / m2 / hr

Spatial speed of the water: 2.6 hours

Temperature in the tower · 25 ° C »

Table Y

Supply Discharge Absorption (g / lm3) (g / ïTm3 (jo) 20 7.50 0.83 89 RCN 1.55 0.05 97 H0S 4.75 0.04 At least 2 99 C10ï8 1.52 0.23 85 25 ------------- 4 ----------------------------------- 1 ------------------

Table W

—-—-—-— ----------—-------—

Concentration (mg / l) 30 RI ^ 2667.5 HCR 370 ï1S 1175 ° 10H8 320 35 7909090 - 41-

Second stage 1 brings a mixture of 1 part of the first stage waste water and 0.2 parts by weight of a coke oven gas water to a pH of about 11. A particulate catalyst of size 0 is mixed. 15 to 0.3 mm and consisting of 5 wt.% Ruthenium deposited on a titanium oxide support with the slurry mixture containing the catalyst at a concentration of 10% by weight. The slurry is introduced into a bottom portion of the cylindrical stainless steel reactor at a spacing speed of 1.51 hours based on an empty column and a feed rate of 4.55 t / m 2, hours. Air is introduced into the reactor at a room speed of 62 hours based on an empty column under standard conditions. The interior of the reactor is maintained at a temperature of 250 ° C and a pressure of 60 kg / cm 2, while a 48% aqueous sodium hydroxide solution in the reactor is fed in an amount such that the portion of the water in the reactor is 80 DEG from its bottom at a pE of at least 8 Is maintained and the water after the wet oxidation has a pH of about 20.5. 30 ° C and passes it into a liquid-gas separator, in which the mixture is separated into a liquid and a gas. The pressure of the separated gas is brought to atmospheric pressure and it is discharged into the atmosphere. The liquid phase is pressurized (60 kg / cm 2) into a liquid-solid separator in which the catalyst is separated from the treated water to recover the catalyst. The separated liquid phase is passed to the third stage while maintaining a controlled pressure of 50 kg / cm2. 3rd gas phase contains 1.0 ppm of ammonia and 0.02 ppm of nitrogen oxides, the remainder consisting of nitrogen, oxygen and carbon dioxide. and no sulfur oxides, hydrogen sulfide and hydrogen cyanide was present, 3rd composition of the wastewater mixture and the treatment water is reported in Table X, »7909090-42-

Table_X

Waste water mixture Treated in the second stage (msZi water_ (mg / l) _________________ 5 KH, 280 6 1.5 HOT 517 track H2S IOO4 track GOD 4125 8.5 TOC 727 12 10 TOD 8820 20 TIT 2490 3 »5 so“ 200 4995

After + 24ΟΟ 24ΟΟ 15 Table X shows that the water treated in the second stage has been cleaned in such a way that it can be discharged into the sea »

Third stage The water obtained in the second stage and separated from the catalyst is passed continuously under pressure (about 50 kg / cm 2). a reverse osmosis device with an acetate membrane with a; desalting efficiency from 95 to S8fi. J Hundreds of parts in reverse osmosis plant i! supplied water supply 85 parts of purified water and 15 parts of concentrate. The purified water can be used as part of the water used for the absorption in the first stage or as water J for industrial purposes. on ge! usual way out of the concentrate »

Table Y lists the composition of the purified water and the concentrate obtained from the second stage liquid, the data of which are listed in the right column of Table X: 7909090.

Purified 77ater Concentrate _____________________ (mg / l) ____________________ iïfZil _______________

-43 -Table J

5 liEj 0.04 9.75 Ιί & ί track track I ïï2S track track j 1Γ a + 56 15680 I S04 "~ 59 33000 10 I ---------------------- ----------------------------------------------! ii !! fti iijii * 7909090

Claims (3)

160 Process according to claims 1-4, characterized in that the wet oxidation of the waste water is carried out in a reactor of the type with a fluidized 17, Process according to claims 1-4, characterized in that the oxygen-containing gas is supplied in an amount of about 1.05 to about 1.2 times the required theoretical amount of oxygen. 18. Process according to claims 1-4, characterized in that the reaction is carried out at a temperature of about 200 to about 300 ° C, tj! ? ί i i ί i j ΤΊΠΠΠΓΤβ--