Microalgae for tertiary treatment of palm oil mill effluent (pome)- effect of light penetration and kinetic study / Tan See Ying

Faculty of Chemical & Natural Resources Engineering

Project paper (Bachelor of Chemical Engineering (Biotechnology)) -- Universiti Malaysia Pahang – 2013

Bibliography : p. 47-50

Microalgae was found to have a high potential to reduce biochemical oxygen demand (BOD) level and colour of black-coloured wastewater, Palm Oil Mill Effluent (POME) in palm oil industry. The major factor that will influent the effectiveness of microalgae in tertiary treatment of POME was light penetration. This thesis presents the effect of light penetration and kinetic study in tertiary treatment of Palm Oil Mill Effluent (POME) by utilizing microalgae. 10% v/v of microalgae was cultured in 10 % v/v to 100 % v/v autoclaved and centrifuged POME in 250 ml conical flask. Sampling was done at the beginning and the end of seven days to observe the microalgae growth under light irradiance of 6000 Lux. Kinetic study was then carried out on the sample with the highest growth rate to observe growth profile of microalgae mix culture within seven days at interval of 24 hours. The BOD and colour of initial sample (autoclaved and centrifuged POME without microalgae) and final sample (at t = 7 days) was determined by applying dilution method (Standard Method 5210B) and ADMI weighted ordinate method respectively. Results revealed that microalgae experienced the highest growth rate at 30 % v/v POME. The minimum light penetration was approximately 2000 Lux corresponding to the light penetrated in 30 %v/v of POME. The microalgae cultured in 30 % v/v of POME had the highest specific growth rate (1.39 d-1) and biomass productivity (0.61 g/L.d). The ratio of POME concentration and the respective growth profile of microalgae led to the similar removal efficiency of BOD. While the low decolourisation yield (colour removal efficiency less than 20%) proved that microalgae was not effective in removing coloured compound