Bioenergy from anaerobic degradation of lipids in palm oil mill effluent

Innovative pretreatment strategies for biogas production

“…Alkaline treatment breaks the intramolecular bonds between the lignin, hemicellulose, and cellulose and disrupts the lignin structure (Hsu, 1996). Lime (Ca(OH) 2 ) pretreatment in the presence of water (9 ml/g dry biomass) was investigated for 2 h on switchgrass at 100-120 °C with 0.1 g Ca(OH) 2 …”

Early warning indicators for process failure due to organic overloading by rapeseed oil in one-stage continuously stirred tank reactor, sewage sludge and waste digesters

“…Therefore, fullscale biogas reactors are still regarded as "black boxes" and are often operated at suboptimal organic loading rates (OLRs) to prevent process failures. Hence, one-stage continuously stirred tank reactors in commercial waste treatment plants are typically operated at OLRs of 1 to 4.5 kg VS m -3 d -1 (Bischofsberger et al 2005, Ahmad et al 2011, FNR 2005. Developing a comprehensive understanding of this process is the key to optimize the reliability of the plant performance and the economy.…”

Palm Oil Mill Effluent Treatment Process Evaluation and Fate of Priority Components in an Open and Closed Digestion System

“…Biological treatment systems are chiefly designed for the removal of organic carbon by activated sludge microorganisms. Therefore, removal of organics by these systems may be regarded as a side benefit, minimizing the amount of carbon emission and sludge disposal and producing biogas and methane 9,20 .…”

“…Fatty acid accumulation inhibits biogas production as reported in earlier studies; however, up to a certain level of VFA accumulation (2,000-3,000 mgl -1 ), biogas production is not disturbed [30]. Because of this, the biogas production rate in both tanks was almost low, but it was continued because of the low concentration of VFA in the organic matter 31 found low biogas yield and organic matter removal because of the accumulation of inhibiting substances, such as volatile fatty acids 32 reported that COD removal was greater than VFA removal at the same pH and initial concentrations 20 . Furthermore, VFA removal efficiency is affected not only by VFA species and concentration but also by other conditions, such as operating parameters and physical, chemical, and biological factors 33 .…”

“…B i o d e gra d a t i o n i s a m e t a b o l i s mindependent consumption of organic to living cells, nonliving biomass, or microbial extracellular polymers 17,18 . Specific metabolic pathways resulting in bio-precipitation of organic molecules or their mechanisms of degradation have been provided elsewhere 19,20 . Moreover, surface exposure of organic-binding microbes improves organic-binding properties of microorganisms based on degradation and microbial metabolic activities 21 .…”