Production of organic acids from tomato solid waste
1994
Yuwadi Nakhaphadungrat | Phonphan Loetthawisin | Khruawan Khluansungnoen (Srinakharinwirot University. Prasarnmit Campus, Bangkok (Thailand). Faculty of Science)
It was found that the organic content, in term of mgCOD/litre, and the volatile fatty acid content in the filtered liquor when using 20 g/litre tomato solid waste suspension are higher than those of using 10 g/litre tomato solid waste suspension. The organic destruction, both in terms of percentages of total solid and total volatile solid, in the filtered liguor when using 20 g/litre tomato solid waste suspension is lower than that of using 10 g/litre one. Moreover, it was also demonstrated that as the solid retention time increases, the organic content, the volatile fatty acid content, pH, alkalinity and the organic destruction increase. The intermidiates found in the filtered liquor were acetic acid, propionic acid, butyric acid, valeric acid and ethanol. The experiments were carried out by using semicontinuous feeding of 10 g/litre tomato solid waste suspension with various solid retention times of 3, 5 and 10 days and at various temperatures, i.e. room temperature, 40 deg C, 45 deg C, 50 deg C and 55 deg C. The results demonstrated that ethanol, acetic acid, propionic acid, butyric acid and valeric acid were found as inmtermidiates, but ethanol and valeric acid were not producted at 50 deg C and 55 deg C. At various solid retention times studied the intermidiates were produced in the order of acetic acidbutyric acidethanolpropionic acid and valeric acid. However, the organic content of 1911 mgCOD/litre and the maximum yield of acetic acid (12.31 mM in average) were found together with butyric acid (5.51 mM in average) at 5 day-soliod retention time and 40 deg C.
显示更多 [+] 显示较少 [-]