Despite of the advantages of anaerobic processes fortreating slaughterhouse and similar wastewaters, thereare still technical problems, particularly long periods forstaring-up and stabilization of the reactor due to the highconcentration highconcentration of toxic compounds present in wastewater andthe low concentration of nutrients with respect to the highconcentration of carbon, organic matter that is measured asCOD. Nutrients and trace metals provide suitable biochemicalresources for the optimum growth of microorganisms. It isimportant to note that if the wastewater to be treated doesnot have one or more of the important nutrients and traceelements, then the biological treatment process is severelyaffected; this is because of the inability of microbial cell togrow at optimum rate and to produce new cells (Johns, 1995;Khanal, 2008; Padilla-Gasca et al., 2011).