Potential applicability of Jatropha curcas leaves in bioethanol production and their composites with polymer in wastewater treatment

Abstract

Among the biggest issues facing the world now are fuel shortages and water contamination. Therefore, the goal of the current study was directed to produce bioethanol from Jatropha curcas leaves and use the residual wastes in the form of composite sheets for crystal violet (CV) removal. The leaves were collected from Jatropha curcas, irrigated by various irrigation sources; sewage-water (A), sewage-water-sludge (B), and tap water (C). The acid hydrolysis (4% H2SO4) of these leaves demonstrated that the hydrolysis of the Jatropha curcas leaves (A) produced higher values of total reducing sugars (≈ 21 g/l) than other leaves (B &C). Moreover, the bioethanol concentrations obtained from the fermentation of this hydrolysate (A) at the bioreactor scale using Candida tropicalis and Saccharomyces cerevisiae (≈10 and 7 ml/l, respectively) were relatively increased compared to the flask level (≈7 and 5 ml/l, respectively). Afterwards, the unhydrolyzed wastes were dried, grinded, and embedded in polyvinyl chloride (PVC) polymer forming sheets. The sheets were characterized using FT-IR, SEM, swelling, and porosity. The highest CV removal percent of 95.39%, after optimization, was achieved at 100 ppm crystal violet concentration using 2.5 g/l from PVC-A composite sheet after 180-min contact time.