Pre-treatments anaerobic Palm Oil Mill Effluent (POME) for microalgae treatment

Abstract

Background/Objectives: Pre-treatments Palm Oil Mill Effluent (POME) by coagulation process and adsorption have been done to enhance light penetration during culturing microalgae process for POME anaerobic treatment. Methods/Statistical Analysis: Coagulation process was done by using rice starch and tapioca starch and the adsorption process was done using activated carbon from Palm Kernel Shell (PKS). In this pre-treatments study, several parameter for pretreatments study (dosages, pH, stirring speed, particles sizes) were done in order to optimize the suitable method for POME treatment using microalgae. In microalgae treatment, optimum pre-treatment condition of POME was used for culturing Scenedesmus dimorphus, Chlorella vulgaris and Dunaliella salina. Findings: Pre-treatment by coagulation process using rice starch and tapioca starch as a coagulant showed optimum levels for dosages, the pH of anaerobic POME, settling time and slow stirring speed is 2.5g/L, pH 3, 60 min and 10 rpm and 2.5 g/L, pH 3, 80 min and 10rpm, respectively. While, pre-treatment by adsorption process using activated carbon Palm Kernel Shell (PKS) shows optimum levels for dosages, the pH of anaerobic POME, reaction time and the size of the activated palm kernel shell is 25g, pH 5, 120 hours and 0.5mm, respectively. Adsorption process was fixed at the optimum reduction in turbidity, COD and suspended solids at 83.33, 83.91 and 92.30%, respectively, which are higher than the coagulation process using tapioca and rice starch. In microalgae treatment, Scenedesmus dimorphus and Chlorella vulgaris were suitable for culturing microalgae in synthetic and anaerobic POME as growth medium with rate growth of microalgae are 0.1721 and 0.1699/day, respectively.