5-41

Five- Day Biochemical Oxygen Demand

COD Chemical Oxygen Demand

of Photographic Chemicals

This printing replaces the 12 73 edition COD values have been added, some BOD5 values revised, new chemicals added, and discontinued chemicals deleted The information contained in this publication has been carefully prepared and IS believed to be accurate Any particular use of such information must, however, be the responsibility solely of the user and must be without obligation or liability on the part of Eastman Kodak Company 0 Eastman Kodak Company 1981

Table of Contents Page No

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Testing and Reliability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . BOD ......................... ........... COD .............................. ..................

3 3

Purpose of BOD and COD Measurements . . . .

Sample Calculations

. . .. . . . ..

*

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....... . . ... ... .. .... .

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Table I

BOD5 and COD Values for Individual Chemicals

Table II

BODs and COD Values for Black-and-white Film Processing Chemicals

Table Ill

BOD5 and COD Values for Black-and-white Paper Processing Chemicals

Table IV

........ BOD5 and COD Values for Color Film Processing Chemicals . . . . . . . . . . . . . . . . . . . ...... KODAK Chemicals, Process C-22 . KODAK Tri-Mask Chemicals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . KODAK Chemicals, Process E-4 . . . . . . . . . . . . . . . . . . . . . . . . . . KODAK Chemicals, Process E-6 . ............

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45 6

..

KODAK Chemicals, Process E-GAR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . EA-5 Chemicals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ...... KODAK Chemicals for Motion Picture EKTACHROME Films EKTACHROME Movie Chemicals . ........................ ES-8 Chemicals . . . . . . . . . FLEXICOLOR@Chemicals fo

a a 8 8 9 9 9 9 9 9 10 10 10

................................ ............ . . .. . . .. FLEXICOLORa Chemicals for Process C-41V FLEXICOLORs AR Chemicals . . . . . . . . . . . . . . . . . . . . 10 Table V

BODs and COD Values for Color Paper Processing Chemicals . . . . . . . . . . . EKTAPRINT 2 Chemicals . ................................... EKTAPRINT 3 Chemicals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . EKTAPRINT 300 Chemicals . ... EKTAPRINT R - 5 Chemicals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . EKTAPRINT R-100 Chemicals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

10 10 10 10 10 10

Table VI

BODSand COD Values for Processing Chemicals for KODACHROME Films. .................. KODAK Replenishers, Process K-14 . . . . . . . . .

10 10

Table VI1

BOD5 and COD Values for Litho Plates Processing Chemicals . . . . . . . . . . . KODAK POLYMATIC S, M, W, and L Litho Plates ...... KODAK POLYMATIC P Litho Plate . KODAK PMT@Litho Plates . . .......................... Sundries and Press Chemicals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

11 11 11

BOD5 and COD Values for Misce!!aneons Chemica!s . . . . . . . . . . . . . . . . . . .

!I

Table Vlll

More Information

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cleaner environment. These publications are components of a series known as "Information for a Cleaner Environment from Kodak." The pamphlet you are reading now is part of this series as well as those publications listed on page 12.

Eastman Kodak Company has long been committed in both words and actions to the goal of a cleaner environment. One small step toward this goal has been the preparation of a number of publications on how the photographic-processing industry can contribute toward a

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r

Purpose

of BOD and COD Measurements

Genesee River approximately three miles below the industrial waste-water treatment plant operated by Eastman Kodak Company at Kodak Park in Rochester, New York. It has been determined through tests in our laboratories that the type of seed water used in this area is not important in these analyses because all had similar microorganisms, A Weston and Stack dissolved oxygen analyzer was used to measure the dissolved oxygen content, and was calibrated using the azide modification of the Winkler method. In determining the BOD of a mixture of chemicals such as that found in packaged processing chemicals, the measurement can be made on the composite mixture, or alternatively, on solutions of each individual chemical, and the results totaled. The latter method was chosen here to avoid interference (toxicity) by any of the other chemicals in the mixture. Certain chemicals, when present above a "threshold" concentration, may inhibit the action of microorganisms, thus producing an erroneously low BODS. When these inhibiting chemicals are diluted below their "threshold" levels, as they would be in a municipal wastetreatment plant, the true BOD5 of the remaining ingredients can be measured. Nearly all effluents experience some mixing with other wastes before they are treated. When the treatment plant effluent is discharged to a stream, any residual biodegradable matter would continue to be biodegraded.

Used photographic-processing solutions are generally discharged into a municipal sewer that leads to a waste treatment plant. The regulatory agency may require photographic processors and other users of the sewer to furnish a measure of the waste load that is to be discharged daily. For proper operation, a treatment plant must not be overloaded. The total volume of waste and some measure of its strength is needed. The strength may be measured by the amount of oxygen that is required for the degradation of the waste. The most common measure of the waste load is the Biochemical Oxygen Demand (BOD). This test provides an estimate of the extent to which material degrades biologically during waste treatment or in a stream. Biochemical oxygen demand is dependent upon time and is usually measured over a five-day period. BOD is a measure of the amount of oxygen required to degrade the material. lt may be expressed as a concentration in units of milligrams per litre or as a total quantity per unit of time (for example, pounds per day). Since the BOD is a static test, it does not necessarily parallel what will occur in a biological treatment system. It more closely estimates what will happen in a receiving body of water. However, it is widely used to estimate the load on a waste treatment plant and is probably as reliable as any other available test method. Chemical Oxygen Demand (COD) is a test method that determines the amount of oxygen required to oxidize the chemicals that are measured by a particular test method. COD measures most of the photographic processing chemicals that are measured by BOD, and also measures some chemicals not measured by BOD. The COD numerical value is usually larger than the BOD. However, there is no fixed correlation between the two measurements except in specific cases. A waste effluent is described more completely by reporting both the BOD and the COD. As an aid to the processor, this publication lists both the BOD5 and COD values of most chemicals that can be used in the processing of Kodak photographic materials, including prepared packages of chemicals. Thus, a processor may estimate the total waste load by tabulating the amounts of chemicals used and by summing the BOD5 values individually and the COD values individually,

Example: Let us assume that a photographic solution contains thiosulfate, sulfite, acetate, hydroquinone, and copper. (This is a hypothetical example because copper is not used in photographic-processing solutions.) The thiosulfate, sulfite, acetate, and hydroquinone are all biodegradable and would exhibit definite measurable oxygen demands when measured either as a composite soiution or independently and totaled. Copper, itself, has no oxygen demand. However, when added to the above mixture, it inhibits the growth of bacteria and produces an artificially low BOD5 value. When the solution passes to the drain and eventually to a treatment plant, the effect of the copper becomes negligible and the BOD5 contribution of the remaining materials is the same as it would be if copper were not Dresent.

COD: This rapid test measures that portion of the waste chemicals that is oxidized by dichromate under the test conditions. Unlike the BOD test, the COD is not affected by the presence in a waste of materials that may be toxic to microorganisms. It measures oxjjgeii-demanding materials such as thiosulfate, sulfite, developing agents, etc. The basis for the method is the reaction of the test material with a boiling mixture of dichromate and sulfuric acids. A catalyst is used to provide measurement of some chemicals not otherwise oxidized. An additional reagent is added to avoid the interference of halides. The excess dichromate is titrated and then the calculation is made for the oxygen demand. This test method is also described in Standard Methods for the Examination of Water and Waste-Water, American Public Health Association. The reliability of the test method, using glucose as the test chemical, is 2 8 percent (standard deviation),

Testing and Reliability

BOD: The BOD test is made under laboratory conditions rather than under the conditions actually prevailing in a waste treatment plant or in a stream. The dissolved-oxygen concentration, temperature, time, amount of sunlight, biological population, and agitation may be different. However, the method does give a fair approximation of most waste loads. The test method is described in Standard Methods for tbe Examination of Water and WasteWater, American Public Health Association. The precision of this test method, measured on a synthetic mixture in 34 laboratories with each laboratory using its own seed water, showed a standard deviation of +17 percent. The precision by a single analyst was 2 5 percent. The seed water used in our tests was taken from the

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Example: If 25 gallons of a two-component solution consisting of 200 grams per litre of sodium thiosulfate (pentahydrated) and 40 grams per litre of sodium sulfite (anhydrous) were discarded, how many pounds of BOD5 would be sent to the sewer system? Because this solution has more than one component, the pounds of BOD5 must be determined for each component and added together to find the total of BOD5 going to the sewer.

SAMPLE CALCULATIONS FROM BODS/COD TABLES The following sample calculations should help in estimating the pounds of BOD5 or COD that might be discarded into the sewer through the discharge of photographic waste effluents. The examples are given for BODS values. The same calculations can be applied for COD values.

A.

First, for sodium thiosulfate (pentahydrated),

From Prepared Solutions

25 gallons 0.20 pound of BOD5 per pound of chemical (see Table I) 200 grams per litre x 0.00834 1.668 pounds per gallon G x R x S 25 x 0.20 x 1.668 8.34 pounds of BOD5 for sodium thiosulfate

When BOD5 per gallon of solution is known directly from table. If G = gallons of solution sewered P = BOD5 in pounds per gallon and Q = pounds of BOD5 sewered Then Q = G x P

Second, through a similar calculation, the Qz for sodium sulfite will be determined to be 1.001 pounds of BODS. Because the solution is a combination of the above chemicals, the total BOD5 is obtained by adding the two results from above. Total Q, = Q I Qz

Example: If 25 gallons of KODACHROME First Developer Replenisher, Process K-14, were discarded, what would be the amount of BOD5 sewered? Then G = 25 gallons P = 0.12 pound of BOD5 per gallon (see Table VI) Q = G X P

+

= 8.340 + 1.001

= 25 x 0.12 Q = 3.0 pounds BOD5sewered

Total Q T I 9.341 pounds of BOD5 sewered

C. Example: If 50 litres of Process EA-5 Prehardener and Replenisher were discarded, what would be the amount of BOD5 sewered? Then G = 50 + 3.8 (3.8 L/gal) G = 13.16 gallons P = 0.21 pound of BOD5 per gallon (see Table IV) Q = G x P

For Total Effluent from Processing Operations

The approximate BOD5 of the effluent from all of the processing operations is determined by adding the pounds of BODSfrom all packages and prepared solutions. That total is then divided by the number of gallons of water used by the processing operation during the time under consideration plus the amount of discarded solution.

Q = 13.16 x 0.21 Q = 2.76 pounds of BOD5 sewered

B.

Example: If, during the time that the solutions from Example A and Example B were sewered, 1000 gallons of water were used, what was the BOD5 per gallon sent to the sewer? Q= Total BOD5

From Prepared Solutions

When BOD5 per pound of chemical is known directly from table. If G = gallons of solution R = BOD5 per pound of chemical in solution S = concentration of chemical in pounds per gallon and Q = pounds of BOD5 of chemical ThenQ = G x R x S

Water usage

+ discarded solution

= 3.0 + 9.341 = 12.341 1000 + 25

Q

Remember ihai 3 m u s t be in terms of pounds per gallon. Therefore, if the amount of chemical in solution is known in grams per gallon or grams per litre or ounces per gallon, the following conversion factors must be used in order to convert to pounds per gallon. Grams per gallon, multiply by0.0022 Grams per litre, multiply by 0.00834 Ounces per gallon, multiply by 0.0625

1025

= 0.01204 pound of BOD5 per gallon during interval under consideration

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Table I 0

BOD5

and COD Values far Individual Chemicals

Chemical

Table I (continued)

Pounds

Pounds

per Pound of Chemical BODS COD

per Pound of Chemical BODS COD

Chemical

~~

0 0

Ammonium Hydroxide Ammonium Persulfate (Anhydrous) Ammonium Thiocyanate Ammonium Thiosulfate (58% solution) KODAK Anti-Calcium, No. 1 KODAK Anti-Calcium, No. 3 KODAK Anti-Calcium, No. 4 KODAK Anti-Calcium, No. 5 KODAK Anti-Calcium, No. 6 KODAK Anti-Calcium, No. 7