Extraction solvent's effect on biogas production from mixtures of date seed and wastewater sludge

Abstract

The objective of this study was to evaluate the impact of extraction solvent on biogas production from mixtures of date (Phoenix dactylifera) seed and wastewater treatment sludge. Date palm seed is a locally produced waste which is used in different useful purposes. Date seed is rich in proteins, carbohydrates and lipids and have the potential for biogas enhancement. In this study, three extraction solvents, hexane, ethyl acetate and Ethanol:water (1:1), were used on two types of date seeds (locally known as Khalas and Khudari). Date seed powder of size 0.425 - 0.6 mm after extraction was mixed with wastewater treatment sludge at dry date seed/dry sludge solids ratios of 0%, 10%, 20%, 40%, 60%, and 80%. The study showed a direct relationship between biogas production and ratio of date seeds/wastewater sludge in the mixture. Furthermore, the results confirmed that the quantity of biogas produced from samples containing raw date seed was almost same as the quantity produced from samples containing date seed after extraction. The results revealed that the used extraction solvents had no effect on biogas production.