Abstract: In this study, physico-chemical variables, monitored before and during composting of different mixtures with different ratios were combined to obtain an overall statistical evaluation of the composting process. The study shows that there was statistically a clear positive relationship between Organic Matter (OM) and several parameters such as C and C/N. However, negative but well correlation between detergent and heavy metals as well as negative correlation between OM and heavy metals were also observed suggesting that there is an interaction between them. On the other hand, the data obtained showed important variations of detergent and some heavy metal contents (Fe and Cu) in the composting site. The obtained data provided valuable information concerning changes and relationship between several toxicants and composting parameters. However, further analytical research on the distribution of detergent degradation products and their cumulative effects on sludge composts are needed along.