DE2557937A1 - PROCESS TO REDUCE POLLUTION IN A WASTE STREAM FROM A MULTI-STAGE CELLULOSE BLEACHING PROCESS - Google Patents

Description

<983921/22>

Hooker Chemicals & Plastics Corp., Niagara Falls, N.Y. 14302,

United States

Process for reducing the impurities in a waste stream from a multi-stage cellulose bleaching process

ren

The invention relates to a method for reducing contaminants from a waste stream by controlling and Separation of the color bodies, COD, BOD and other organic compounds from the inorganic chloride impurities in the aqueous waste effluent from a cellulose pulp bleaching process, in which a chlorination stage (D.) or a mixed (D / C) stage is carried out one after the other, This is followed by an extraction (E) or oxygen stage (0), in which the conditions for the D or D / C stage are selected in this way that the pulp product obtained thereby has a low content of inorganic chloride and organically bound Contains chlorides and that the waste effluent therefrom has poor organic distribution compared to that Waste effluent of the subsequent E or O stage, and in which the waste effluent through an active bed or an active

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Layer is conducted under conditions in which the color bodies COD, BOD and other organic materials can be selectively removed therefrom without having any significant effect on the inorganic chloride content. at In the process according to the invention, the conditions in the E or O stage are selected so that the waste effluent of which shows a high distribution of organic substances, but a low distribution of inorganic chloride, compared with the waste effluent from the D or D / C stage. At least a portion of the E or Level 0 waste effluent becomes intermittent with the D or D / C stage waste effluent through an active layer under such conditions sufficient to elute the color bodies, COD, BOD and other organic materials therefrom.

Effluents from industrial waste streams pose cleaning problems which are very different from the problems of urban waste treatment. The waste stream this process is unique to every industrial process and requires special treatment or special rectification. The pH of acidic or alkaline waste materials must be controlled, which is of ecological importance and can easily be achieved by direct chemical treatment for industrial waste streams. However, the removal, solubilization or passivation of specific impurities poses a problem, that is more difficult to resolve, and is often a combination of physical, biochemical, and chemical treatments necessary. Particularly complex are the difficulties encountered in preventing color, for the chemical oxidation demand "Chemical Oxidation Demand" (COD), the biological oxidation demand "Biological Oxidation Demand "(BOD) and chloride contamination

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of surface water into which waste streams from pulp mills are discharged. The pollution of surface water Color poses a particularly visible aesthetic problem and possesses marine plants and animal life an adverse effect, since the incidence of light on the surface water will be changed.

The cleaning of pulp mill effluents is a major problem in waste water treatment because the effluents less respond to known water treatment methods that are used today in the cleaning of urban and industrial waste water. In the pulp making process many effluents with intense discoloration are generated, the discoloration mainly on extracted tannins, lignins and their derivatives, which are obtained from the cellulose pulp in the various chemical Treatment stages removed are due. Any change in the actual treatment of the pulp, resulting in an effluent with fewer impurities contains, disadvantages the quality of the pulp product, although the requirements for the waste stream treatment, before the effluent is discharged into surface water, may be reduced. The chemical actually performed The bleaching process can still hardly be changed because of economic considerations in this chemical treatment and yield considerations play a role and since the pulp and paper industries use a bleached product calls for very good properties and therefore is some active program for the elimination of water pollution difficult to perform.

In known multi-stage bleaching sequences in which a chlorination (C), a subsequent chlorination (D_) or mixed

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If chlorine and chlorine dioxide (D / C) are used, the bulk of the impurities consists of chlorides, lignins, tannins and their chlorinated and oxidized derivatives. The term "subsequent chlorination" (D ₀ ) means the treatment with chlorine dioxide which immediately follows the treatment with chlorine. The term "chlorination" (C) means treatment with chlorine without chlorine dioxide and mixtures of chlorine and chlorine dioxide (D / C) means treatment with chlorine and chlorine dioxide at the same time. Each of these contaminants reacts differently to specific contamination control mechanisms and can be detrimental to a process or to the economics of treatment steps designed to treat one or more of the other contaminants. For example, chlorides quickly corrode and damage devices, so that transport of these chlorides with the stream of organic contaminants decreases the useful life of the devices and increases the cost of any treatment to which the stream is subjected. Although the chemical and physical treatment of color bodies in pulp mill effluents is an effective method for their reduction, the economic requirements of such systems are very great and this process is impractical in modern technology, so that in practice pulp mill effluent processes, with a few exceptions, not be carried out. Activated sludge systems, aerated lagoons and seepage filters were used to reduce BOD organic materials to an effectiveness of more than 80 % . However, only between about 10-15 % of the discoloration in the waste water effluent is removed by a pulp bleaching plant. Correspondingly, between 85 and 90 % of the dyed materials from the bleaching plant go through the biochemical one

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Decomposition stage and are released into the surface water.

In the known bleaching sequences, multi-stage bleaching processes are used for the wood pulp and the following treatments are typically carried out with the cellulose pulp: with chlorine (C), a subsequent chlorination (D.) or with mixtures (D / C), followed by an alkaline extraction or an oxygen treatment stage. In practice, further chlorine dioxide stages, alkaline extraction stages, oxygen or peroxide stages can be carried out in the overall process. Two particularly effective multi-stage bleaching processes are usually described as CEDED and D EDED, the letters each signifying: (C) chlorine, (D) successively chlorine dioxide / chlorine, (E) extraction and (D) chlorine dioxide treatment stages. Other effective multi-step bleaching processes include D / CEDED, D ₀ ODED, D / CODED, D ₀ ED, D / CED, D ₀ OD, D / COD, D ₀ EP, D / CEP, D ₀ OP, D / COP, D ₀ EDEP, D / CEDEP, D ₀ ODEP, D / CODEP, D EDEDP, D / CEDEDP, D ODEDP and D / CODEDP, where (P) is the per-

C C

oxide treatment means. It should be emphasized that further Process steps such as washing, etc., if necessary can be performed on the entire bleaching system. The effluents from each of these stages contain different ones Means amounts and concentrations of the contaminants described above and total downstream contamination a very difficult elimination problem. The waste effluents from CE, CO, DE, D "0, D / CE or D / CO included originating from the bleaching process, are only used as mass effluent to this day treated and the modification of the bleaching process or the separation of the dirty effluents themselves received little attention. The chemical and physical processes have so far not been satisfactory

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the results and are economically and technically unsatisfactory.

A particularly great difficulty encountered in treating pulp mill waste streams is that the combined impurities have such different effects on the treatment processes to be carried out, so that it is not possible to develop an economical system with high performance and low maintenance costs. The very corrosive inorganic chlorides in both acid and salt form limit the expected Service life of the devices used strong. Inorganic chloride salts clog and pollute together with organic materials, such as with color bodies, COD, BOD and organic acids the devices so that a constant Cleaning and constant maintenance are required. The presence of all these impurities in one single stream requires, on average, anti-pollution treatment at each stage, creating a Maximizing treatment is prevented.

The applicant has surprisingly found that in a multi-stage bleaching process for cellulose pulp, in a successive or mixed chlorine dioxide and chlorine treatment and a subsequent extraction or oxygen step treatment is carried out, a Process modification can be carried out in such a way that it is possible to remove the impurities in each stream to regulate and essentially separate and that the separated impurities are treated economically and effectively and that a waste effluent flowing from Relatively impurities free is obtained at an economically low cost.

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The invention relates to a process for reducing the impurities in waste streams by controlling and separating color bodies, COD, BOD and other organic materials from the inorganic chloride impurities in the waste stream of a cellulose pulp bleaching process in which the sequence DE, D ₀ O, D / CE or D / CO

C C

is carried out, which is characterized in that the conditions in the D or D / C stage are chosen so that the product thereof has a low content of inorganic chlorides and organically bound chlorides and that the waste effluent thus exhibits low organic distribution. The waste effluent is then sent to a activated layer passed under such conditions that the color bodies, COD, BOD and other organic materials can be selectively removed from the effluent with no significant effect on the inorganic chloride content. In the following E- or O-stage, the conditions are chosen so that the waste effluent therefrom has a high organic distribution but shows a low inorganic chloride distribution. At least a portion of the E or Stage E waste effluent stage 0 is intermittent with stage D or D / C waste effluent through the activated layer under such conditions which are sufficient that the color bodies. COD, BOD and other organic materials made from it removed. The intermittent elution stream of stage E or 0 can then be combined with the base waste effluent of the Level E or 0 can be combined again. The procedure is in the combination of stages D or D / C, E and 0 of bleaching processes useful and consists essentially in maintaining specific conditions at these stages and that certain stages are combined with each other which act on these specific stages, independently of their position in the entire bleaching process. The result of the above system is the division of the impurities

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into two different effluent streams, a waste effluent, the D or D / C stage with the majority of the process inorganic chloride impurities in it and with a substantial amount of colored bodies, COD, BOD and other organic materials in it, and a waste effluent the E or O stage with a strong contamination of colored bodies, COD, BOD and other organic contaminants, but which does not contain a substantial part of inorganic chlorides in it. The pH control of the inorganic Chloride-containing D or D / C streams can be easily performed and are easy and economical an acceptable waste stream, whereas the organic-rich stream recycles, concentrated, incinerated or otherwise disposed of without causing substantial amounts of chloride impurities contains.

The applicant has surprisingly found that the amount of inorganic chloride and organic bound Chloride impurities in the pulp product at the D or the D / C stage can be reduced by using this stage works at a low pH with a high ratio of chlorine dioxide to chlorine. With chlorine dioxide-to-chlorine ratios from about 65:75 to about 95: 5, and preferably from about 75:25 to about 95: 5 and at a pH below about 3.5 there is a substantial decrease in the amount of chloride impurities in instead of the D or D / C pulp product, with the amount of BOD, COD and other organic contaminants in the effluent of which is also considerably reduced. It was also found, surprisingly, that the comparatively Distribution of the organic contamination in the D or D / C effluent is also reduced, so that a substantial

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licher part of the distribution with the pulp together to the subsequent stages is performed. Furthermore, the toxicity and BOD of the effluent are related to the D or D / C stage with the entrained toxicity and the entrained BOD in the pulp product is greatly reduced. Accordingly contains an effluent from such a controlled D or D / C stage has a relatively high distribution of inorganic chloride impurities, compared to the effluent of the E or 0 stage and a relatively low distribution of color bodies, COD, BOD and other organic materials. * Such an effluent with controlled impurities can be from the suspended solids are clarified and then passed through an activated layer in a suitable manner, where the bulk of the color bodies and substantial parts of COD, BOD and other organic materials are in the effluent be held back. The activated layer should be such that the inorganic chlorides, except one a small amount of salt trapped in the layer will pass through the layer without substantial retention. Because the activated layer is exposed to lower levels of organic contamination than previous ones Adsorption systems, the activated layer becomes a longer one Have loading time or service life and thus be more economical to operate. The activated layer can be physical, chemical, ionic, adsorptive or have an absorptive effect. Preferred activated layers include aromatic and aliphatic ion exchange layers, absorptive and adsorptive resin layers. Nonionic macroporous ones are particularly preferred. Resins, including crosslinked polystyrene resins, highly crosslinked hydrophilic acrylic ester copolymers, polyamide resins and phenol-formaldehyde resins. Particularly suitable resins are those described in US Pat. No. 3,652,407 and in Macroreticular Polymeric Adsorbents,

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I & EC Product Research & Development, Volume 12, March 1973. The D or D / C effluent flowing through such an activated layer has passed, then the bulk of the inorganic formed during the process becomes Chlorides, few organically bound chlorides, few color bodies and a significantly reduced COD and BOD compared to the D or D / C effluent that was introduced into the activated layer.

Subsequent oxygen or extraction treatments of the pulp are carried out under such conditions that the Distribution of organic materials is maximized and the distribution of inorganic chlorides in the effluent is minimal is held. The effluent from this subsequent extraction stage then becomes a substantially reduced inorganic one Chloride distribution along with a high distribution of organic acids, COD, BOD and other organic Own materials. The effluent must be basic; H. a pH of about 8 to about 13 »preferred from about 10 to about 13, and most preferably from about 11 to about 13.

When the multi-step bleaching process is carried out, the material in the activated layer is colored with bodies of color, COD, BOD and other organic materials that it is holding back from the D or D / C effluent. Periodically becomes

the D or D / C effluent flow is thereby interrupted and the layer is regenerated by passing at least part of the basic effluent from stages E or 0 da through it. Flushing the system using oxygen or the effluent from the extraction stage elutes the color bodies, COD, BOD and other organic materials from the layer material and concentrated in the extraction or Oxygen stage effluent. The result is two separate effluents

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currents of electricity. One contains the majority of the inorganic chloride ions formed during the process, the other contains the majority of BOD, color bodies, COD and other organic materials. This current, the inorganic one Contains chloride, can easily be neutralized and discarded. Alternatively, the inorganic chloride containing stream before or after it enters the activated layer to remove volatile impurities low molecular weight stripped, preferably by evaporation. The BOD, COD, the color bodies and others Stream containing organic materials can be recycled to a recovery furnace where it is incinerated and where warmth and alkaline values are obtained. A particular advantage of this method is that in the COD, Very few chloride ions are present in a stream containing BOD, color bodies, and other organic materials and thereby the corrosion and other adverse influences on the incinerator and others are used Devices avoided or reduced. Another advantage of the method is that the secondary, local or regional treatment is reduced or eliminated.

The following examples illustrate the invention.

Example 1 - Usual Chlorination

A sample of Wes.tern softwood kraft pulp (western softwood kraft pulp) with a permanganate number of 20.7, a viscosity of 27.6 cP and an unbleached brightness of 26 % is subjected to the usual CE ^ D.EpDp bleaching sequence according to Subject to the conditions of Table 1.

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step

Table 1

Chemical addition in%, related to the pulp close wiit (dried in the oven)

Time (min.)

Temp.

Pulp consistency

(C) chlorine
(E ₁ ) extraction
(D ₁ ) chlorine dioxide
(E ₂ ) extraction
(D ₂ ) chlorine dioxide

6.63

3.0

0.95

0.6

0.41

45

60

180

60

180

25/77 70/158 70/158 70/158 70/158

3 10

10

The final brightness and viscosity of the pulp product are measured and are 88.5% and 15.0 cP, respectively. The waste effluent of each stage is cleared of suspended solids by filtration, analyzed and possessed the in the contents of organic material and chloride given in Table 2.

(C) -. (E ₁ ) Table 2 (E ₂ ) (D ₂ ) All in all 42.4 268 (kg / ton ⁺ ) 6.1 ' 1.4 325.2 93.7 15.6 step 0.5 3.5 121.0 20.3 45.5 (D ₁ ) 3.8 1.4 77.1 colour 6.0 3.7 7.3 1.0 0.3 12.4 Chlorides
(as NaCl) 7.7 COD 6.1 BOD 1.4

The tons are given in the metric system,

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if

Example 2 - Conventional Sequential Chlorination

A sample of western softwood kraft pulp having the same physical properties as in Example 1 becomes one technical D E ^ D ^ EpDp bleaching sequence according to the in Table 3 subjected to conditions specified.

step

(D) chlorine:

Chlorine dioxide one after the other (50:50)

(E ₁ ) extraction (D ₁ ) chlorine dioxide (E ₂ ) extraction (D _n ) chlorine dioxide

Tabel

Chemical addition in%, based on the pulp weight (oven-dried)

Time

Min.

Temp.

Pulp consistency

6, O ⁺ 30th 26.7 / 80 3 2.4 60 71/160 10 0.9 180 71/160 3 0.5 60 71/160 10 0.4 180 71/160 3

⁺ Equivalent of the chlorine addition

The final brightness and viscosity of the pulp product are measured and are 88.7 % and 18.3 cP, respectively. The waste effluent from each stage is the suspended solids by filtration, clarified, analyzed and has the organic matter and chloride content given in Table 4 below.

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colour

Chlorides

(as NaCl) 50.1

COD
BOD

18.5
5.0

$ 1

Table 4 (kg / t)

step
(E ₁ ) (Dj (E ₉ ) (D ₉ )

42.0 171.4 7.0

9.0 7.6 37.2 6.0 4.7 1.0

1.2

3.5 1.4 0.3

All in all

227.6

70.6 67.0 11.7

Example 3

A sample of western softwood kraft pulp with a permanganate number of 20.7, a viscosity of 27.6 cP and a brightness of 26 % is subjected to the DE, .D, .E ₉ D ₉ bleaching sequence corresponding to that given in Table 5 Subject to conditions.

Table 5

) Chlorine dioxide:
After chlorine
each other
(75:25) Chemical addition
in %, based on
the pulp weight
(dried in the oven
net) Time
Min. Temp. Pulps
consi
stence
Q /
/O ... extraction 6, O ⁺ 30th 3o / 86 10 (E) Chlorine dioxide 2.0 60 70/158 10 (D) extraction 0.93 180 70/158 3 (E) Chlorine dioxide 0.5 60 70/158 10 (D) 0.4 180 70/158 3

⁺ Total equivalent chlorine addition

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The final brightness and viscosity of the pulp product are measured and are 88.5% and 16.2 cP, respectively. The waste effluent each stage is cleared of suspended solids by filtration, analyzed and possessed in the following Table 6 indicated contents of organic material and chloride.

(D c> (E ₁ ) Table 6 (E ₂ ) (D ₂ ) All in all 37 ,1 141 (kg / t) 3.5 2.9 188 step 34 , 7 4.9 (D ₁ ) 0.4 3.5 51, colour 17th , 5 41.3 3.5 3.4 1.0 69 chloride 4th 5.5 0.5 0.3 11 (as NaCl) 7.7 COD 6.4 , 2 BOD 0.8 , 6 ,1

The D waste effluent is passed through a laboratory column with a diameter of 2.5 cm, which is connected to a highly cross-linked, hydrophilic, macroporous, adsorbent acrylic ester copolymer resin. A flow rate is used from 10 to 12 shift volumes per hour. Analysis of the effluent from the D flow at 30 layer volumes through the macroporous layer indicates an average content of organic material and Chloride of:

colour 9.6 kg / t chloride 33.9 kg / t (NaCl) COD 9.8 kg / t BOD 3.6 kg / t

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Room

The chloride was easily neutralized with alkali.

The flow of the D effluent through the resin layer is interrupted and part of the material of the E ₁ stage is passed through until the resin is completely regenerated, which is indicated by a constant eluate COD content. The E ^ eluate stream is then combined with the base Ε ,, waste stream and sent to a recovery system where the organic materials are incinerated and where heat and alkalis are recovered.

The total contaminants found in a waste stream during this bleaching sequence are as follows:

Paint 19.5 kg / t

chloride 45 , 5 kg / t (NaCl) COD 21 , 4 kg / t BOD 5 , 2 kg / t

A comparison with the waste effluent from a known system shows the following percentage reduction in impurities:

Known s
CEDED, % Known
D_EDED, % colour 94 91 chloride
(NaCl) ·. 62 36 COD 72 68 BOD 58 56

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A further reduction in the impurities in the waste stream can easily be achieved by countercurrent _{washing, the D 1, E 2} and D ₂ stages, the corresponding waste streams therefrom being combined with the E ₁ and D inflowing wash stream. Overall, a reduction in impurities is obtained in the following order of magnitude:

colour 11.3 kg / t chloride (NaCl) 44.9 kg / t COD 13.9 kg / t BOD 4.6 kg / t

Similarly, pulp can have a D "0D ^ ED _o bleaching sequence

CI c.

according to the conditions given in Table 7.

Table 7

step Addition of cherries
in %, based on
the pulp weight
(in the oven
dries; Time
Min. Temp.
(° C / ° F) Pulps
con
persistence
% (D.) Chlorine
^c oxide:
chlorine
after one
at the
(75:25) 6.0 30th 26.7 / 80 10 (0) oxidation
O ₂ (lOOpsi)
7kg / ciu ² 1.5 30th 127/260 35 (D ₁ ) chlorine dioxide 0.53 180 71/160 3 (E) extraction 0.5 60 71/160 10 (D ₂ ) chlorine dioxide 0.4 180 71/180 3

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The final brightness and viscosity of the pulp product is approximately 88 % and 14 cP. After countercurrent washing, treatment of the D. effluent in an activated acrylic resin bed and incineration of the waste effluent from the oxidation stage, the total impurities are given off in the following magnitudes:

Paint 12 kg / t

Chloride 41.0 kg / t (NaCl)

COD 15.0 kg / t

BOD 5.0 kg / t

Examples 4-9

Various samples of western softwood kraft pulp having a permanganate number of 20.7, a viscosity of 27.6 cP and a brightness of 26 % are subjected to D EDE ₂ Dp bleaching and a subsequent effluent treatment sequence according to the conditions and procedures as in Example 3, except that the material in the activated layer is varied. The organic matter and chloride content of the untreated effluent is given in Table 6. Analysis of the effluent from the D flow through the activated layer of various materials gives the organic content given in Table 8.

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Tabel

(kg / t) layer material

Example 4 Polystyrene

Example 5 Example 6 Example 7

Example 8 Example 9

Acrylic acid resin +)

Phenol formaldehyde resin polystyrene / phenol form di vinyl aldehyde,
Benzene, qua- amine functional ammonality, ionic functional exchange rate, ion exchange

Polyamide resin

colour 18th , 6 9.65 15.9 3.71 COD 11 , 7 9.3 11.2 9.45 BOD —— __ __ 3.72

15.6

15.2 11.4

Differs from the resin of Example 3 in the pore diameter.

cn cn -J co co

- 1 *

Example 10

A sample of western softwood kraft pulp with a permanganate number of 20.7, a viscosity of 27.6 cP and an unbleached brightness of 26.9 becomes a D / C-E ^ D ^ EpDp bleaching sequence subjected according to the conditions of Table 9.

Table 9

Addition of chemicals,

based on the
Pulp weight, %
(dried in the oven
Level net) extraction 6.25 ⁺ Time
Min. Temp. Pulps
consi
stence (D / C) chlorine dioxide /
Chiο r mixture
(75/25) Chlorine dioxide 2.0 30th 32/90 10 (E ₁ ) extraction 0.93 60 71/160 10 (D ₁ ) Chlorine dioxide 0.5 180 71/160 3 (E ₂ ) 0.4 60 71/160 10 (D ₂ ) 180 71/160 3

Equivalent chlorine addition

The final brightness and viscosity of the pulp product are measured and found to be 85.0 % and 14.9 cP, respectively. The effluent from each stage is clarified from the suspended solids by filtration, analyzed and has the contents of organic material and chloride given in Table 10.

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Table 10

(kg / t) level

(D / C) (E ₁ ) (D ₁ ) (E ₂ ) (D ₂ ) All in all colour 23.8 156.6 4.0 3.6 3.0 191.0 Chlo
ride
(NaCl) 35.3 4.8 8.0 0.4 3.5 52.0 COD 14.6 45.0 7.2 4.0 1.5. 72.3 BOD 3.9 6.1 0.9 0.6 0.3 11.8

The effluents are treated using the method and materials of Example 3. Analysis of the D / C eluate stream gives the following values for organic materials and for chloride:

Paint 6.5 kg / t

chloride 34.5 kg / t (NaCl) 9.5 kg / t COD 3.6 kg / t BOD

Analysis of the total contaminants in the waste stream the bleaching sequence is:

colour 17.1 kg / t chloride (NaCl) 46.4 kg / t COD 22.2 kg / t BOD 5.4 kg / t

A further reduction in the impurities in the waste stream can easily be _{brought about by countercurrent washing of the D 1} , E ₂ and D ₂ waste streams, the corresponding waste streams being combined with the E ₁ and D _c incoming wash stream.

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Example 11

The (E ^) effluent from Example 1 is combined with sufficient (C) effluent of the same example are combined to adjust pH below about 3 »0. The effluent, its pH is then passed through a laboratory column with a diameter of 2.5 cm filled with the resin of Example 3 is filled. Analysis of the effluent from the macroporous layer shows an organic content of:

colour 28 kg / t COD 20.5 kg / t BOD 4 kg / t

The total contaminants found in the waste stream from this process are as follows:

colour Example 12 73.3 kg / t Chlorides (NaCl) 121 kg / t COD 46.4 kg / t BOD 8.5 kg / t

The (E ₁ ) effluent from Example 1 is passed through a laboratory column 2.5 cm in diameter packed with the resin from Example 6. Analysis of the effluent from the ion exchange layer indicates an organic and chloride content of:

colour 13th , 4 kg / t kg / t Chlorides kg / t (NaCl) 0, 8th kg / t COD 4, 6th BOD 2, 2

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All of the impurities present in the waste stream of the Procedure to be determined are the following:

colour 70 6 kg / t Chlorides. (NaCl) 120 , 2 kg / t COD 36, 2 kg / t BOD 7.8 kg / t

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Claims (1)

Claims • 1 «Improved cellulose bleaching process for regulation and reducing pollution in the waste stream characterized in that: the cellulose pulp is successively chlorinated in the first stage or treated with a mixture of chlorine dioxide and chlorine, then oxidized or extracted in the second stage and the conditions of the first stage are chosen so that the pulp product of which has a low content of inorganic and organically bound chlorides, and that the waste effluent from the first stage has little color body, chemical oxidation requirement, biological oxidation requirement and that the distribution of other polluting organic materials is low compared to the waste effluent from second stage, one through the waste effluent from the first stage an activated layer for the selective removal of color bodies, COD, BOD and other organic contaminants The second stage is passed without any significant effect on the inorganic chloride content of the waste effluent conditions such that the waste effluent will maintain high levels of dye bodies, chemical oxidation needs, biological oxidation needs and other organic levels Has impurities but has low levels of inorganic chloride impurities compared to that Waste effluent of the first stage, and at least part of the waste effluent of the second stage is intermittent with the waste effluent of the first stage passes through the activated layer, thus the color bodies, COD, BOD and others organic contaminants are removed from it. 70982S / 0887 "2. The method according to claim 1, - characterized in that the sequence of the first and second stage D _c E is. 3. The method according to claim 1, characterized in that the sequence of the first and second Level DO is. 4. The method according to claim 1, characterized in that the sequence of the first and second Level D / CE is. 5. The method according to claim 1, characterized in that the sequence of the first and second Level D / CO is. 6. The method according to claim 1, characterized in that the bleaching process comprises a multi-stage bleaching sequence selected from the group D EDED,
D / CEDED, D ₀ ODED, D / CODED, D _C ED, D / CED, D _C OD, D / COD, D ₀ EP, D / CEP, D ₀ OP, D / COP, D ₀ EDEP, D / CEDEP, D ₀ ODEP, D / CODEP, D _Q EDEDP, D / CEDEDP, D ODEDP and D / CODEDP. 7. The method according to claim 1, characterized in that the first stage with a chlorine dioxide : Chlorine ratio is maintained from about 65:25 to about 95: 5. 8. The method according to claim 7, characterized in that the first stage at a pH below about 3 »5. 9. The method according to claim 1, characterized in that the activated layer is aromatic or aliphatic ion exchange resin layers, absorption or adsorption resin layers can be used. 709826/0887 10. The method according to claim 9, characterized in that a non-ionic macroporous resin layer is used as the resin layer, from the group
which contains: cross-linked polystyrene, acrylic ester copolymer,
Phenol-formaldehyde resin and polyamide resin. 11. The method according to claim 1, characterized in that the extraction and oxidation stage ab · at a pH of about 8 to about 13
is held. 12. The method according to claim 11, characterized in that the pH is from about 9 to about 13 is. 13. The method according to claim 1, characterized in that the effluent of the second stage, which is passed intermittently through the activated layer, with the mother extraction or oxidation waste effluent
is mixed again. 14. The method according to claim 1, characterized in that the waste effluent from the first stage is neutralized before it is passed through the activated layer, and that the resin is an ion exchange resin
is. 15 · The method according to claim 1, characterized in that the waste effluent from the first stage is neutralized after passing through the activated layer. 16. The method according to claim 1, characterized in that at least part of the waste effluent the second stage passed into a recovery furnace 709826/0887 and is burned there, with caustic materials or alkaline materials and calorie values being obtained. 17. The method according to claim 1, characterized in that the stages following the D-, D '"? -, E- and countercurrent washing of the O stage to concentrate the waste contaminant in at least one of the waste effluents of the D, D / C, E and O stages. 18. The method according to claim 16, characterized in that at least part of the burned Waste product is recycled to the pulp process. 19. The method according to claim 16, characterized in that at least part of the chloride, which is introduced into the recovery furnace is removed by treating the precipitator dust. 20. Cellulose bleaching process with successive chlorination or treatment 'with a mixture of "chlorine oxide and Chlorine in the first stage and a subsequent second oxidation or extraction stage, characterized in that the waste stream impurities in the aqueous effluent are controlled and regulated by choosing the conditions of the first stage so that the pulp product thereof has a low content of inorganic and organically bound chlorides, and that the waste effluent from it has a low content of color bodies, chemical oxidation requirements, biological Oxidation requirement and a different organic pollution distribution Compared to the second stage waste effluent, the first stage waste effluent passes through 709826/0887 An activated layer is passed for the selective removal of color bodies, COD, BOD and other organic Contaminants with no significant effect on the inorganic chloride content in the waste effluent, the conditions in the second stage are kept so that the waste effluent therefrom has a high content of color bodies, chemical Oxidation requirement, biological oxidation requirement and other organic pollution, but a low one Inorganic chloride impurity content compared to the first stage effluent and at least a portion of the second stage waste effluent intermittently with the first stage waste effluent through the activated one Layer conducts, for the elution of the color bodies, COD, BOD and other organic impurities from it. 709828/088?