FISHERY WASTE EFFLUENTS: A SUGGESTED SYSTEM FOR 

 DETERMINING AND CALCULATING POLLUTANT PARAMETERS 



Jeff Collins and Richard D. Tenney 1 



ABSTRACT 



An improved and simplified system to test for pollutants in shrimp waste effluents is presented. In 

 addition, two methods were developed to calculate both protein and oil and grease content. The first 

 method is based on establishing empirical regressions of protein or oil and grease on total residue. The 

 second and preferred method, a simultaneous equation, is independent of these correlations but 

 dependent on the total residue and chemical oxygen demand (COD) of the waste effluent obtained 

 through routine analyses. The COD value was found to depend upon the amount of potassium di- 

 chromate remaining at the completion of the 2-h reflux period. The dichromate can vary from to 6.25 

 meq excess and between 2 and 5 meq, the COD will vary 4.2% . A table of factors is given to correct the 

 COD to 3.5 meq excess. Coefficients of COD were determined on a number of preparations of protein 

 and oil and grease from shrimp waste effluent and from fish and shellfish. These coefficients (1.338 mg 

 COD/mg protein and 2.678 mg COD/mg oil and grease) were required for the simultaneous equation. 

 The simple analytical tests and mathematical treatment used in this system would be less expensive 

 to the industry and would result in a more accurate and comprehensive evaluation of the waste load 

 than currently obtainable by methods specified in the monitoring regulations. 



An improved testing program for fishery waste ef- 

 fluents has been suggested (Collins and Tenney 

 1976) in which the total residue (TR) and the 

 chemical oxygen demand of the filterable residue 

 (CODfr) were to be determined by analysis and 

 used to calculate other parameters from equations 

 previously established for a particular plant and 

 process. It was also suggested that the protein and 

 oil and grease (O&G) content could probably be 

 calculated from COD and TR data to give more 

 accurate values than by direct analyses. 



The purpose of this study was to test the validity 

 of such a testing-calculating system on waste ef- 

 fluents from a shrimp plant in Kodiak, Alaska. A 

 further purpose was to derive equations whereby 

 O&G and protein could be calculated from COD 

 and TR data. 



EXPERIMENTAL 



Grab samples were taken at specific times dur- 

 ing the shrimp production periods to obtain a 

 range in values that would be useful for subse- 

 quent mathematical treatment. Waste effluents 

 were taken from the underflow of a Bauer Hydra- 



sieve 2 (1 mm, 0.04 inch) in a plant processing 

 shrimp with combined Model A and PCA peelers. 

 The methods of analysis and the method of cal- 

 culating data are similar to those reported previ- 

 ously (Collins and Tenney 1976). The test for 

 filterable residue (FR) was modified, however, to 

 give sufficient filtrate (900 ml) for duplicate 

 macro-Kjeldahl, COD, FR, and ash analyses. 

 About 1,000-ml effluent, after settling 30 min, 

 was decanted through a plug of glass wool in a 

 powder funnel positioned over a 600-ml coarse 

 sintered glass funnel containing GF/A glass filter 

 paper and Vi inch of dry base-acid-water washed 

 ASTM standard Ottawa sand (C-190). The suction 

 flask was evacuated briefly several times during 

 filtration and clamped off to prevent plugging of 

 the filter and evaporation. We have found that use 

 of continuous evacuation causes rapid plugging of 

 the glass filter paper and, additionally, could 

 cause considerable errors through evaporation. 



As will be discussed later, the precision of the 

 residue and ash analyses is particularly impor- 

 tant. Consequently, considerable attention was 

 given these analyses to obtain good precision as 

 well as convenience in conducting the analyses. 

 The major steps of the procedure follow: 



'Northwest and Alaska Fisheries Center, National Marine 

 Fisheries Service, NOAA, P.O. Box 1638, Kodiak, AK 99615. 



Manuscript accepted October 1976. 

 FISHERY BULLETIN: VOL. 75, NO. 2. 1977. 



2 Reference to trade names does not imply endorsement by the 

 National Marine Fisheries Service, NOAA. 



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