Submitted to: Poultry Science
Publication Type: Abstract Only
Publication Acceptance Date: 5/19/2004
Publication Date: 7/25/2004
Citation: Northcutt, J.K., Musgrove, M.T., Jones, D.R. 2004. Chemical analyses of commercial shell egg wash water collected from three different operations [abstract]. Poultry Science. 83(suppl.1):12.
Technical Abstract: A study was conducted to evaluate water from three different commercial in-line shell egg processing facilities (Plants X, Y and Z). During each of three visits, water samples were collected from the tap, washer 1 (W1) and washer 2 (W2). Samples were evaluated for chemical oxygen demand (COD), total Kjeldahl nitrogen (TKN), total suspended solids (TSS), total dissolved solids (TDS), pH, temperature, chlorine and soluble iron. Values for COD, TKN, pH, temperature and chlorine varied significantly among the facilities (P < 0.05). In addition, water sample (tap, W1 or W2) had a significant effect on COD, TKN, TSS, TDS, pH, temperature, chlorine and soluble iron (P < 0.05). COD values for both W1 and W2 followed the order of: Plant Z > Plant X > Plant Y. Water from the egg washers had COD values that ranged from a high of 7300 mg/L (W1, Plant Z) to a low of 1765 mg/L (W2, Plant Y). TKN values for the egg wash water ranged from 302 mg/L (W1, Plant Z) to 81 mg/L (W2, Plant Y). Highest values for TSS and TDS occurred in W1 (601 mg/L and 5287 mg/L, respectively) as compared to W2 (401 mg/L and 3087 mg/L, respectively). Water collected from both egg washers in Plant Z (pH 11.4, W1; pH 11.2, W2) and W1 in Plant X (pH 10.6) had the highest pH values. The pH for W1 in Plant X was statistically similar to the pH for W1 and W2 in Plant Y (pH 10.3, W1 and W2) and W2 in Plant X (pH 10.0). No difference was found in the pH of the tap water samples which averaged from pH 6.1 to 6.7. Egg wash water temperature ranged from 44.1 ' 0.1'C to 39.7 ' 0.3'C, and was generally highest in W2 samples from all three plants. Chlorine levels in the egg wash water for Plant Y (0.89 mg/L, W1; 0.91 mg/L, W2) were significantly lower (P < 0.05) than wash water values for Plant X (2.72 mg/L, W1; 2.62 mg/L, W2) or Plant Z (4.5 mg/L, W1; 2.35 mg/L, W2). Chlorine levels in the tap water were similar among the facilities and ranged from 0 to 0.15 mg/L (P < 0.05). Average values of soluble iron (ferrous) in the egg wash water were 0.29 ' 0.02 mg/L to 1.60 ' 0.29 mg/L; however, iron levels were found to be above the 2.0 mg/L guideline in W1 for Plant X during one of the sample collections. Data provided by the present study may be useful for identifying process deficiencies and minimizing organic and inorganic discharge loads in the waste stream.