scholarly journals Effects of volatile fatty acids in biohydrogen effluent on biohythane production from palm oil mill effluent under thermophilic condition

2017 ◽  
Vol 29 ◽  
pp. 78-85 ◽  
Author(s):  
Chonticha Mamimin ◽  
Poonsuk Prasertsan ◽  
Prawit Kongjan ◽  
Sompong O-Thong
2015 ◽  
Vol 72 (11) ◽  
pp. 1889-1895 ◽  
Author(s):  
Tjandra Setiadi ◽  
Martha Aznury ◽  
Azis Trianto ◽  
Adi Pancoro

The highest volatile fatty acids (VFAs) concentration from palm oil mill effluent (POME) treated by anaerobic fermentation was achieved for a 1-day process when the main acids used were acetic, propionic and butyric acids. Polyhydroxyalkanoate (PHA) production with VFAs from POME as precursors in the fed-batch mode has advantages over batch mode, both in terms of its productivity and 3HV (3-hydroxyvalerate) composition in the produced polymer. With the fed batch, the productivity increased to 343% and contained more 3HV than those of the batch. The structures of the PHA were identified by different methods and they supported each other; the resulting products consisted of functional groups of 3HB (3-hydroxybutyrate) and 3HV.


2019 ◽  
Vol 10 (1) ◽  
pp. 4740-4746

Polyhydroxyalkanoates (PHA) are storage granules of most bacteria which can be used as biodegradable plastics but the production cost of PHA is twice than petrochemical based synthetic polymers because of substrate cost. The use of alternative renewable and cheap carbon sources are the best option, one such is palm oil mill effluent (POME). POME contains carbon source like volatile fatty acids and other organic components which can be utilised by microorganisms to accumulate PHA. The use of subinhibitory concentration of antibiotics like clindamycin may have an influence on PHA accumulation. In this study, 31 organisms were isolated from POME spillage area and subjected to PHA production. Seven organisms were found to accumulate PHA, which was confirmed by Nile blue staining method, the accumulated PHA was extracted and characterized using HPLC. All the organisms were found to produced poly hydroxy butyrate (PHB). Amongst all the seven isolates, two organisms namely Bacillus sp and Pseudomonas aeruginosa were found to accumulate more PHA. Both the organisms were subjected to produce PHA in POME and clindamycin containing media. PHA production condition was optimized using RSM.


2015 ◽  
Vol 63 (1) ◽  
pp. 92-100 ◽  
Author(s):  
Mohd Rafais Mohd Razaif-Mazinah ◽  
Mohamad Suffian Mohamad Annuar ◽  
Yusrizam Sharifuddin

2019 ◽  
Vol 8 (1) ◽  
pp. 14-21
Author(s):  
Sri Ismiyati Damayanti ◽  
Dian Fitriani Astiti ◽  
Chandra Wahyu Purnomo ◽  
Sarto Sarto ◽  
Wiratni Budhijanto

Two-stage anaerobic fluidized bed is an innovation in anaerobic digestion technology intended to handle liquid waste with high organic loading and complex substrate. The process is based on separation between acidogenic/acetogenic and methanogenic processes. The first stage is anaerobic process to convert substrate (represented as soluble chemical oxygen demand/sCOD) into volatile fatty acids (VFA). The second stage is methanogenic process to convert VFA into biogas. This study aimed to separate acidogenic/acetogenic and methanogenic processes by means of limited injection of air (micro-aeration) and inoculum selection. Micro-aeration was introduced in acidogenic/acetogenic stage because the relevant microbes were facultative so that the obligate anaerobic methanogens will be suppressed. On the other hand, the methanogenic reactor was kept completely anaerobic to ensure methanogenic dominance over acidogenic/acetogenic ones. Two sources of inoculums were used in this study, i.e. anaerobically digested biodiesel waste and anaerobically digested cow manure. Both inoculums were taken from active biogas reactor treating biodiesel waste and cow manure, respectively. Experiments were run in batch reactors treating palm oil mill effluent (POME) as the substrate for the acidogenic/acetogenic reactor. After the reaction in the first stage reached the minimum substrate concentration, the content of the reactor was used as the substrate for the methanogenic reactor as the second stage. Routine measurements were taken for sCOD and VFA concentrations, biogas production, and methane concentration in the biogas. Results confirmed that micro-aeration maintained good performance of acidogenic/acetogenic process, which was indicated by peaks in VFA accumulation, while suppressing methanogenic activities as no methane produced in this stage. Digested biodiesel waste was superior inoculum to be compared to digested cow manure with respect to sCOD removal. In the methanogenic stage, digested biodiesel waste also performed better as inoculum as it led to higher VFA conversion, higher biogas production rate, and higher methane content in the biogas. 


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