Algerian Journal of Environmental Science and Technology Avril edition. Vol.1. N o 2. (2015) ISSN : 2437-1114 www.aljest.webs.com ALJEST Copyright © 2015, Algerian Journal of Environmental Science and Technology, All rights reserved Evaluation of trace metals in sewage sludge from a wastewater treatment plant with perspective of valorisation F. Benoudjit*, M. Hachemi Unité de Recherche Matériaux, Procédés, Environnement (URMPE). Université de M’Hamed Bougara, 35000-Boumerdès. Algérie *Corresponding author: ffouzzia@yahoo.fr ARTICLE INFO ABSTRACT/RESUME Article History: Received : 11/05/2015 Accepted : 15/06/2015 The increasing quantities of sewage sludge from wastewater treatment plants are a great source of worry especially concerning their impact on the environment. Managing such sludge is the basis for a successful general sanitation scheme. The present work subject matter is the evaluation of pollutants present in the sewage sludge recovered from urban wastewater treatment plant of the town of Boumerdès, Algeria, which is treated wastewater from three (03) towns: Boumerdes – Corso – Tidjelabine. For this study, we followed the evolution of some physical and chemical parameters such as the concentration of trace metals which we have analysed mineralogically through the use of X-ray fluorescence and then compared to the French standard NF U 44-041. The NF U 44-041 standard concerns the reuse of sewage sludge as fertilizer in land application. Several sewage sludge samples have been analysed in the present work. The analysis of the sewage sludge physical properties has revealed a low percentage of dry matter (total solids) and a high percentage of organic matter. The chemical characterization of the sludge helped to evaluate their pH and polluting power. Overall the pH level of the sludge was approaching neutrality and their concentration in trace metals was below the thresholds defined by the NF U 44-041 standard. Thus, municipal sewage sludge does not represent any danger to the environment that thus can safely be used in agriculture. Key Words: Sewage sludge, X-ray fluorescence trace metals I. Introduction The Algerian National Office of Sanitation (i.e. l’Office National d’Assainissement ONA) is a national public company with industrial and commercial character created in april 2001 under the Ministry of Water Resources of Algeria. The missions of this company are: management, operation and maintenance of wastewater treatment infrastructures [1]. The treatment of wastewater in the wastewater treatment plants (WWTP) generally leads to the formation of large quantity of sludge. Due to constant growth of the sewage sludge (SS), it deserves a special consideration. Sludge management, valorization and elimination, were problematic as well as the other waste [2]. The agricultural use is the most attractive solution to recycling sludge as fertilizer. Knowledge of heavy metal content in the sludge are the most important factors in selecting the disposal alternatives [3]. Therefore, it is important to evaluate the rates of various pollutants in sewage sludge against the limits defined by the adopted standards. With the objective of identifying valorisation perspective for the sludge as fertilizer, the present paper presents an analysis completed on the low charge residual activated SS from the WWTP of Boumerdès which 9