Modeling and optimization in anaerobic bioconversion of complex substrates to acetic and butyric acids

✍ Scribed by Seokhwan Hwang; Conly L. Hansen

• Publisher: John Wiley and Sons
• Year: 1997
• Tongue: English
• Weight: 312 KB
• Volume: 54
• Category: Article
• ISSN: 0006-3592
• DOI: 10.1002/(sici)1097-0290(19970605)54:5<451::aid-bit5>3.0.co;2-d

✦ Synopsis

Cheese-processing wastewater was biologi-groups: acidogenic and methanogenic bacteria (Grady cally treated to produce short-chain organic acids in laborand Lim, 1980).

atory scale continuously stirred tank reactors. A constant

The two groups of microorganisms differ widely in inoculum system was used to mimimize the experimental their physiology, biokinetics, and growth environment.

error due to the use of inconsistent inoculum. The inocu-Several research groups have claimed that optimization lum system was operated with dilute cheese-processing of each phase would enhance the overall rate of waste wastewater with 5000 mg soluble chemical oxygen demand/L at pH 6.5 and 35ЊC at 0.5 days hydraulic retenstabilization if the biphasic ecosystem could be maintion time. Response surface methodology was successtained in separate digesters in series: one for acid profully applied to determine the optimum physiological conduction and one for methane production (Bull et al., ditions where the maximum rates of acetic and butyric 1983; Cohen et al., 1979;; Ghosh and Klass, acid production occurred. These were pH 7.01 at 36.2ЊC

1978; . However, very few reports and pH 7.26 at 36.2ЊC, respectively. The lack of overall predictability for butyric acid production meant that the show that two-phase processes have advantages over response surface was much more complicated than that single-phase processes of acetic acid; therefore, a small change in pH or tempera-

1988).

ture could cause large variations in the response of bu-Designing a maximum efficiency, two-phase process tyric acid production.