Differential overload simulation of condensate and housekeeping rendering wastewater for nutrient removal.

Abstract

The meat rendering process transforms waste from the meat industry to valuable materials as animal feed supplements. During the rendering process, large amounts of condensate and housekeeping wastewater (CWW and HKWW), solids and greenhouse gases are released into the environment imposing a huge pollution threat. Rendering condensate wastewater also causes many issues that commonly affect biological treatment processes such as pH inhibition, nutrient deficit and temperature. Therefore, the main objective of this work was to simulate the nutrient removal from a sequencing batch reactor (SBR) through the differential nitrogen overload of CWW. With aid of simulation, results found that the current SBR system does not remove carbon and nitrogen as much as other biological systems. This is due to low biodegradation of chemical oxygen demand (COD), the high content of inert particulate carbon (XI), identified in the fractionation of HKWW, and the toxic and inhibitory effect of ammonium present in CWW. When the system is overloaded with nitrogen from CWW there is little removal of biochemical oxygen demand (BOD), ordinary heterotrophic organisms (OHO) outnumber autotrophic nitrifying organisms (ANO) and ammonium toxicity occurs, all contributing to a failure to remove nutrients.