WASTE GASES ARISING IN RENDERING PLANTS FOR ANIMAL AND FISH WASTE

Gases of disagreeable smell and those harmful to the external environm ent and working premises, arising during harmless removal of animal wa ste in rendering plants, have been investigated. The waste gases in th e Department (and equipment) for Raw Material Reception are generated by proteolytic destruction of raw material, which is promoted by tissu e and bacteriological enzymes. in the processing department gases aris e mostly under the influence of high temperatures during processing. D uring these procedures proteins and fats are broken down into ammonia, sulphurated hydrogen, sulphur dioxide, carbon dioxide, carbon monoxid e, acrolein and some other identified gases of a pungent and unpleasan t odour. According to our investigations, in the Department for Raw Ma terial Reception, near the tank for raw materials, the concentrations of ammonia (67,10 ppm), sulphurated hydrogen (19,40 ppm) and sulphur d ioxide ( 11,60 ppm) were above the values for maximum allowable concen trations (M. A. C.) for the tested gases. The sulphur dioxide concentr ation was above the prescribed value for the MAC at all the measuring points in the same department In the Processing Department the highest concentration of ammonia, sulphurated hydrogen, sulphur dioxide, carb on dioxide and acrolein were found in the devices for Brud vapours con densation. In the Department for Grinding and Bagging the obtained con centrations were under the prescribed MAC values. As during rendering some harmful gases are released with concentrations above the MAC, it is absolutely essential to process exclusively fresh raw materials, as well as to maintain adequate hygiene of the unit and to install a sys tem for conveying and purification of waste gases.