Improving the biochemical composition of Jatropha curcas L. leaves and seed cakes by irrigation with sewage water and sewage sludge

: This study aims to elevate the physiological biochemical composition of Jatropha curcas L. via irrigation by the nutrient rich treated sewage water or sewage water + sludge. At the same time, it might be considered as a steppingstone for the solution of the huge amount of sewage water that lost daily at the Drinking and Sewage Water Treatment Station in Al-Gabal Al-Asfar, Cairo, Egypt. Jatropha curcas is one of the best candidates of biodiesel production since its seeds contain oil which is practically participating in biodiesel production. In addition, its seed cake (a waste by-product produced after oil extraction) contains considerable percentages of cellulose, hemicellulose, and starch. The results cleared that, irrigation by sewage water and sewage water + sludge have been increased the levels of photosynthetic pigments (chlorophyll (a), chlorophyll (b) and carotenoids) and antioxidant enzymes [super oxide dismutase (SOD), catalase (CAT), poly phenol oxidase (PPO) and peroxidase (POX)] in the plant leaves. proline, and lignin in addition to total phenols have been increased in leaves and seed cakes of Jatropha curcas plants under irrigation by either sewage water or sewage water + sludge.