Digester acid-phase

C, application of this equation indicated that optimum conversion of glucose can be achieved at 0 s of 4 h and 4 days in the acid- and methane-phase reactors. For cellulosics and activated biosolids, the corresponding ffs are much higher, about 1 to 2 days for acid-phase digestion and 5 to 8 days for methane-phase digestion. 

The relationship of the acid and methane phases to the scheme in Fig. 12.1 raises several interesting questions, such as where the acetogenic bacteria are located and whether methane is formed exclusively from acetate or from both carbon dioxide reduction and acetate in the methane-phase reactor. The experimental data useful in answering these questions include the observations that for a glucose-fed, two-phase digestion system, more than 96% of the products from the acid-phase reactor were carbon dioxide, hydrogen, acetate. 

Maharaj, I., Elefsiniotis, P. (2001). The role ofHRT and low temperature on the acid-phase anaerobic digestion of municipal and industrial wastewaters. Bioresource Technology 76 191-197. 

No alkali was used for digester pH control. The acid-phase feeds for Runs A3C/M3C and A7C/M7C were pretreated for 24 hr with 2.561 of 1 wt % NaOH solution in a total volume of 48 f under ambient conditions. The product gases from each phase were collected together for these two runs. 

TabI V. THERMOPHILIC (BEX) ACID-PHASE AND MESOPHILIC OB C) METHANE-PHASE DIGESTION OF PRETREATED HYACINTH-QRASS-MSW-SLUDOE BLEND... 

FAAS >75 pgr Acid digestion/solid-phase preconcentration... 

The 4mL acid phase then is drained into a 10 ml Teflon or quartz beaker, and the 100 mL separatory funnel is rinsed twice with ImL of Tmol/LHNOj. The total extract of about 6mL is evaporated slowly to dryness on a ceramic hot-plate (see Fig. 12-1), and the residue is digested with two or three sequential volumes of 0.25 mL concentrated HNO3. The residue then is dissolved in 1.000 mL of 0.1 mol/LHN03 and is ready for ETAAS analysis. 

Miniaturized columns have provided a decisive advantage in speed. Uracil, phenol, and benzyl alcohol were separated in 20 seconds by CEC in an 18 mm column with a propyl reversed phase.29 A19 cm electrophoretic channel was etched into a glass wafer, filled with a y-cyclodextrin buffer, and used to resolve chiral amino acids from a meteorite in 4 minutes.30 A 6 cm channel equipped with a syringe pump to automate sample derivatization was used to separate amino acids modified with fluorescein isothiocyanate.31 Nanovials have been used to perform tryptic digests on the 15 nL scale for subsequent separation on capillary Electrophoresis.32 A microcolumn has also been used to generate fractions representing time-points of digestion from a 40 pL sample.33 A disposable nanoelectrospray emitter has been... 

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