page 285 |
Previous | 1 of 10 | Next |
|
|
Loading content ...
Section 11. AGRICULTURAL WASTES RECOVERY OF PROTEIN FROM SLAUGHTERHOUSE EFFLUENTS BY DOUBLE ADJUSTMENT OF pH R. N. Cooper. Section Leader J. M. Russell, Chemist Meat Industry Research Institute of New Zealand (Inc.) Hamilton, New Zealand J. L. Adam. Engineer Ruakura Agricultural Research Station Hamilton, New Zealand The effluent from a slaughterhouse characteristically contains high concentrations of fat and organic nitrogen. Primary treatment of slaughterhouse effluents removes only 20% of the organic nitrogen [ 1 ], reflecting the large proportion that is soluble. Further treatment can therefore be effected only by biological or chemical methods. Chemical treatment of slaughterhouse effluents has been studied for a long time. However, attention has only recently been focused on recovering potentially valuable protein- aceous material from these effluents. All recovery techniques acidify the effluent to a pH between 3 and 5, and these techniques often use protein precipitants such as lignosulfonic acid [2-6] or sodium hexametaphosphate [71 to recover soluble blood proteins. These techniques also destabilize other colloidal material and break fat emulsions, enabling proteins, other colloids and fats to be separated from the liquid phase by gravity sedimentation or dissolved air flotation. Aluminum (8) and ferric ions [9] have also been used to purify slaughterhouse effluents, but the recovered material is contaminated with the metals which may preclude its use as an animal feed supplement. The use of sodium hexametaphosphate in conjunction with acidification has been studied extensively in New Zealand. However, the high cost of this and other protein precipitants has led to the development of an alternative technique-the double pH adjustment process [10,11). In this process the effluent pH is reduced to approximately 3 by the addition of sulfuric acid and then neutralized with either sodium or calcium hydroxide to a pH between 6 and 9. This chapter reports experiments on the mechanisms of double pH adjustment. It also describes the performance of a 1 20-m3 /hr double pH adjustment plant of the type described by Stephenson [111 and reports the results of pig-feeding trials using dried material recovered from this plant. EXPERIMENTAL Materials Fresh blood, collected from a mutton slaughter area, was immediately diluted to 0.1- 1% with water to allow hemolysis to occur. Slaughterhouse effluent, obtained from a large New Zealand slaughterhouse, was allowed to settle for 1 hour and the middle fraction was used for subsequent experimental work. Hemoglobin (Calbiochem Bclhring Corp., U.S.), was dissolved in distilled water to make a 0.1 2% solution. Analytical Methods Effluents were analyzed for COD, TKN, NH3N. fat, TSS. TS. VS and total and inorganic phosphorus (TP and IP) by the procedures described in Standard Methods [12]. Carbo- 285
Object Description
Purdue Identification Number | ETRIWC198233 |
Title | Recovery of protein from slaughterhouse effluents by double adjustment of pH |
Author |
Cooper, R. N. Russell, J. M. Adam, J. L. |
Date of Original | 1982 |
Conference Title | Proceedings of the 37th Industrial Waste Conference |
Extent of Original | p. 285-294 |
Collection Title | Engineering Technical Reports Collection, Purdue University |
Repository | Purdue University LIbraries |
Rights Statement | Digital object copyright Purdue University. All rights reserved. |
Language | eng |
Type (DCMI) | text |
Format | JP2 |
Date Digitized | 2009-07-14 |
Capture Device | Fujitsu fi-5650C |
Capture Details | ScandAll 21 |
Resolution | 300 ppi |
Color Depth | 8 bit |
Description
Title | page 285 |
Collection Title | Engineering Technical Reports Collection, Purdue University |
Repository | Purdue University Libraries |
Rights Statement | Digital copyright Purdue University. All rights reserved. |
Language | eng |
Type (DCMI) | text |
Format | JP2 |
Capture Device | Fujitsu fi-5650C |
Capture Details | ScandAll 21 |
Transcript | Section 11. AGRICULTURAL WASTES RECOVERY OF PROTEIN FROM SLAUGHTERHOUSE EFFLUENTS BY DOUBLE ADJUSTMENT OF pH R. N. Cooper. Section Leader J. M. Russell, Chemist Meat Industry Research Institute of New Zealand (Inc.) Hamilton, New Zealand J. L. Adam. Engineer Ruakura Agricultural Research Station Hamilton, New Zealand The effluent from a slaughterhouse characteristically contains high concentrations of fat and organic nitrogen. Primary treatment of slaughterhouse effluents removes only 20% of the organic nitrogen [ 1 ], reflecting the large proportion that is soluble. Further treatment can therefore be effected only by biological or chemical methods. Chemical treatment of slaughterhouse effluents has been studied for a long time. However, attention has only recently been focused on recovering potentially valuable protein- aceous material from these effluents. All recovery techniques acidify the effluent to a pH between 3 and 5, and these techniques often use protein precipitants such as lignosulfonic acid [2-6] or sodium hexametaphosphate [71 to recover soluble blood proteins. These techniques also destabilize other colloidal material and break fat emulsions, enabling proteins, other colloids and fats to be separated from the liquid phase by gravity sedimentation or dissolved air flotation. Aluminum (8) and ferric ions [9] have also been used to purify slaughterhouse effluents, but the recovered material is contaminated with the metals which may preclude its use as an animal feed supplement. The use of sodium hexametaphosphate in conjunction with acidification has been studied extensively in New Zealand. However, the high cost of this and other protein precipitants has led to the development of an alternative technique-the double pH adjustment process [10,11). In this process the effluent pH is reduced to approximately 3 by the addition of sulfuric acid and then neutralized with either sodium or calcium hydroxide to a pH between 6 and 9. This chapter reports experiments on the mechanisms of double pH adjustment. It also describes the performance of a 1 20-m3 /hr double pH adjustment plant of the type described by Stephenson [111 and reports the results of pig-feeding trials using dried material recovered from this plant. EXPERIMENTAL Materials Fresh blood, collected from a mutton slaughter area, was immediately diluted to 0.1- 1% with water to allow hemolysis to occur. Slaughterhouse effluent, obtained from a large New Zealand slaughterhouse, was allowed to settle for 1 hour and the middle fraction was used for subsequent experimental work. Hemoglobin (Calbiochem Bclhring Corp., U.S.), was dissolved in distilled water to make a 0.1 2% solution. Analytical Methods Effluents were analyzed for COD, TKN, NH3N. fat, TSS. TS. VS and total and inorganic phosphorus (TP and IP) by the procedures described in Standard Methods [12]. Carbo- 285 |
Resolution | 300 ppi |
Color Depth | 8 bit |
Tags
Comments
Post a Comment for page 285