The Effect of Benzene, Toluene, and o-Xylene on COD Removal in an Aerobic Fluidized Bed Reactor Utilizing Acetic Acid as the Main Carbon Source

2001 ◽  
Vol 18 (6) ◽  
pp. 337-345 ◽  
Author(s):  
Ayşegül Pala
2014 ◽  
Vol 625 ◽  
pp. 616-619
Author(s):  
Ali Norizan ◽  
Yoshimitsu Uemura ◽  
Hafizah Ahmad Afif ◽  
Noridah Osman ◽  
Wissam N. Omar ◽  
...  

This study investigates the effect of pyrolysis temperature on the yields of char, organic compounds, water and gas. Fast pyrolysis was carried out in a fluidized bed reactor of 108 mm in internal diameter operated at 400, 450, 500 and 550 °C with nitrogen gas with flow rate of 25 L(NTP)/min. In specific the effect of temperature on the yields of known and unknown organics in bio-oil is discussed. For higher total organics, 500 oC was favorable. But higher phenol and acetic acid yields, 450 oC was preferable. The major organics include acetic acid, phenol and furfural. The minor ones include 2-methylphenol, 4-methylphenol, 4-methylnaphthalene, benzene, toluene and THF.


2014 ◽  
Vol 625 ◽  
pp. 608-611
Author(s):  
Yoshimitsu Uemura ◽  
Ali Norizan ◽  
Hafizah Ahmad Afif ◽  
Norridah Osman ◽  
Wissam N. Omar ◽  
...  

This study investigates the effect of biomass size on the yields of char, liquid (organic compounds and water) and gas for fast pyrolysis of palm kernel shell (PKS). Fast pyrolysis was carried out in a fluidized bed reactor of 108 mm in internal diameter operated at 450 °C using three different sizes of palm kernel shell (0.325, 0.75 and 1.5 mm). In specific the effect of biomass size on the yields of known and unknown organics in bio-oil was mainly investigated. The major organics include acetic acid, phenol and furfural. The minor ones include 2-methylphenol, 4-methylphenol, 2-methylnaphthalene, benzene, toluene and tetrahydrofurane (THF). Smaller biomass sizes were favorable for higher bio-oil yields.


1976 ◽  
Vol 22 (9) ◽  
pp. 1312-1319 ◽  
Author(s):  
L. van den Berg ◽  
G. B. Patel ◽  
D. S. Clark ◽  
C. P. Lentz

A stable enrichment culture converting acetic acid to methane was successfully obtained from a pear waste digester, using a synthetic substrate solution with acetic acid as the main carbon source. This enrichment culture converted up to 10 mmol of acetic acid per litre per day at 35 °C and did not use hydrogen or formic acid in appreciable amounts as substrate for methane production instead of or in addition to, acetic acid. The rate of conversion of acetic acid to methane was maximum at temperatures of 40–45 °C, at a pH of 6.5 to 7.1, and was adversely affected by exposure to air, reducing agents, and high salt concentrations. The rate of conversion was independent of acetic acid concentration between 0.2 and 100 mM, but dropped markedly at concentrations below 0.2 mM.


1972 ◽  
Vol 129 (2) ◽  
pp. 263-272 ◽  
Author(s):  
A. G. Dickerson

Evidence suggests that sucrose is the main carbon source for growth of Claviceps spp. in the parasitic condition. The sucrose acts as substrate for an active β-fructofuranosidase, produced by the fungus, which in the first instance converts the disaccharide into glucose and an oligofructoside. In this way, 50% of the glucose, supplied as sucrose, is made available to the parasite for assimilation. Subsequent action of the enzyme on both sucrose and the oligofructoside leads to the release of more glucose and the formation of additional oligosaccharides. The structures of the main oligosaccharides formed have been elucidated and the interactions of each compound studied. In experiments with purified enzyme in vitro the interaction of the oligosaccharides is rapid but in culture they are assimilated only slowly; in each case some free fructose is liberated. Free fructose is not assimilated in the presence of glucose and, further, inhibits growth at concentrations which might be expected to occur in the parasitic condition. A dual role has been suggested for the enzyme, with sucrose as substrate, in which glucose is made available to the growing parasite, while at the same time transfer of the fructose to form oligosaccharides prevents it from accumulating at inhibitory concentrations. Ultimately, when glucose becomes limiting, the fungus will adapt to fructose assimilation.


2016 ◽  
Vol 73 (10) ◽  
pp. 2446-2452 ◽  
Author(s):  
B. Düppenbecker ◽  
P. Cornel

This study focuses on the anaerobic treatment of sulfate-containing municipal wastewater at 20 °C with a fluidized bed reactor. Mean influent chemical oxygen demand (COD) and sulfate concentrations were 481 and 96 mg/l. The response of the COD removal efficiency to increasing organic loading rates (OLR) was investigated. Average total COD removal was 61% at OLR between 2.7 and 13.7 kg COD/(m³·d) and did not distinctly depend on the OLR. To assess the removal efficiency in more detail the COD in- and output mass flows were balanced. The results showed that only 11–12% of the input COD was recovered as gaseous methane. About 12–13% of the input COD remained in the effluent as dissolved methane. Furthermore, a distinct amount of 12–19% of the input COD remained in the reactor as settled sludge and was not further biologically degraded. Due to the reduction by sulfate-reducing bacteria, 13–14% of the input COD was degraded. Further adverse impacts of the influent sulfate on the anaerobic treatment process are discussed as well.


2012 ◽  
Vol 35 (6) ◽  
pp. 897-906 ◽  
Author(s):  
M. Sousa ◽  
V. M. M. Melo ◽  
S. Rodrigues ◽  
H. B. Sant’ana ◽  
L. R. B. Gonçalves

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