Treatment and Reuse of Effluents from Palm Oil, Pulp, and Paper Mills as a Combined Substrate by Using Purple Nonsulfur Bacteria

Abstract

The growth of Rhodobacter sphaeroides NCIMB8253 was investigated under photoanaerobic conditions with different concentrations of palm oil mill effluent in a dual effluent growth medium. The influence of pulp and paper mill effluent as an alternative diluting agent on the bacterial growth was also investigated. During this study, it was determined that the use of pulp and paper mill effluent as a diluting agent promoted bacterial growth compared with the use of raw palm oil mill effluent medium alone. The cell growth data for all experimental sets were well-fitted to the logistic and modified Gompertz models. The results revealed that 25% (v/v) palm oil mill effluent medium with pulp and paper mill effluent as a diluting agent, namely G5 medium, can be applied as a suitable growth medium. A maximum colony-forming-units (CFU) number of 360 × 10 8 CFU/mL was achieved in G5, which was higher than that for raw palm oil mill effluent and comparable with that for water-diluted palm oil mill effluent medium. Furthermore, chemical oxygen demand level (COD total and COD soluble ) reductions were observed in all treatments.

Photo-fermentational hydrogen production of Rhodobacter sp. KKU-PS1 isolated from an UASB reactor

“…CQK 01 to produce hydrogen Electronic Journal of Biotechnology 18 (2015) 221-230 [17]. PNSB are widely distributed in aquatic and wastewater environments [18,19,20]. They can be isolated from the environment using conventional enrichment techniques.…”

Improvement of Biohydrogen Production through Combined Reuses of Palm Oil Mill Effluent Together with Pulp and Paper Mill Effluent in Photofermentation

“…Hence, an introduction of PPME as a diluting agent in this study was necessary to promote photo-biohydrogen production by increasing the visibility of substrate and improving the light penetration into the system. Budiman et al 19 also reported that a combination of POME and PPME as single substrate could be applied as a suitable growth medium for R. sphaeroides because of the enhanced light penetration and faster adaptation in the diluted media. 19 Furthermore, the introduction of PPME (a low nitrogen source) helped increase the C/N ratio of photofermentation substrate (Table 1).…”

“…Budiman et al 19 also reported that a combination of POME and PPME as single substrate could be applied as a suitable growth medium for R. sphaeroides because of the enhanced light penetration and faster adaptation in the diluted media. 19 Furthermore, the introduction of PPME (a low nitrogen source) helped increase the C/N ratio of photofermentation substrate (Table 1). It was reported that high C/N ratio promoted the production of biohydrogen by allowing PNS bacteria to dispose their excess energy and reducing power through production of hydrogen.…”

“…12 Besides, Budiman et al 19 reported that a concentration of 25% (v/v) POME was the best to be reused as a growth medium for R. sphaeroides due to the presence of adequate nutrients and light penetration. However, Budiman et al 19 did not further investigate if the diluted POME could be reused as a substrate in biohydrogen production through photofermentation process. During photofermentation, natural or artificial illumination is supplied to support the bacterial growth and initiate biohydrogen production.…”

“…biological degradation. The physical and chemical characteristics of both effluents are summarized in Table 1 19 before the bacteria were transferred into photo-biohydrogen production medium. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 …”