Palm Oil Mills Effluent Treatment Through Vermifiltration Employing Eudrilus eugeniae
Loading...
Date
2016-08
Authors
Azuar, Siti Azahani
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
The performance of vermifiltration or worm aided filtration systems employing Eudrilus eugeniae in treating palm oil mill effluents (POME) was studied. Palm oil mill effluent (POME) is considered the most harmful waste for the environment if discharged untreated. The raw palm oil mill effluent (POME) is an acidic non toxic and thick brownish liquid that contains high solids, high BOD and COD values. In Malaysia, high generation of POME from crude palm oil production is currently treated using conventional method known as ponding system, which is space inefficient. As an attempt to resolve the long-standing dilemma, recent and alternative method such as vermifiltration is being studied and introduced to wastewater treatment. Vermifiltration is a filtration process where solids are separated from liquid aided by earthworms. In this research, four experiments were conducted to select the best conditions for vermifiltration system. The first experiment was to compare performance of filter using different filter medium (100% of palm pressed fibre, 100% of construction sand and 100% of garden soil) in 0.0009 m3 volume of filter medium. The second experiment was to compare performance of filter with different height of vermibed (vermibed height; 5 cm, 10 cm and 15 cm) in 0.0009 m3 volume of filter medium. The third experiment was to compare performance of filter using different worm loadings (10 worms/L, 20 worms/L, 30 worms/L, 40 worms/L and 50 worms/L) in 0.0009 m3 volume of filter medium. The final experiment, larger scale of vermifilter system with 0.0045 m3
volume of filter medium was setup and the performance of a vermifilter (VF) containing the earthworms, Eudrilus eugeniae and a control filter (CF), without earthworms were compared using the mixture of sand and garden soil as filter medium. Vermibed with height 15 cm and worms loading 40 worms/L were selected respectively as the best depth of vermibed and worm loadings for vermifilter system with readings showed the highest reduction in COD (89.9 %), TSS (92 %) and turbidity (84%). The research was conducted at laboratory scale. All type of filters was set as triplicates. The POME pH increased from acidic to neutral. It was observed that vermifilter in larger scale phase shows the highest reduction rate of BOD, COD, TSS and turbidity by 92%, 90%, 95% and 86% respectively compared to control filter in larger scale phase by 55%, 45%, 65% and 52% respectively. In addition, the germination analysis for vermifiltered POME in vermifiltration system was done. The result of germination test showed germination percentage higher than 50% only for 1% and 3% concentration of vermifiltered POME, so these dilutions indicates the maturity of the compost and are safe to be used as nutrient solutions in soil-less culture on plants. Vermifiltration technology can therefore be applied as an environmentally friendly technique, has potential to treat POME and exhibit potential in cultivation purposes.
Description
Keywords
Vermifiltration is a filtration process where solids are separated from liquid , aided by earthworms.