2.3. Anaerobic batch digestions
The anaerobic batch digestions were carried out at 35 C in
250 mL glass bottles, closed with rubber seals. The inoculum was
obtained from sludge digester operating at 35 C. For each flask
containing 100 mL inoculum, 8 g untreated water hyacinth were
added together with 2 g pretreated water hyacinth samples.
2.4. Structure characterization of the regenerated water hyacinth
samples
XRD analysis of the regenerated water hyacinth samples were
conducted with a X-ray diffractometer (D8 Advance, Bruker Inc.,
Germany) operated at 40 kV and 50 mA with Ni-filtered Cu-Ka
radiation. The surface properties of were observed by a scanning
electron microscopy (S-3700N, Hitachi Ltd., Japan) equipped with
an alpha ray spectrometer (Quantax, Bruker Inc., Germany).
2.5. Recovery of pretreatment solvent
Pretreatment solvent was recovered by separated from an aqueous
biphasic system (ABS). After pretreatment and regeneration of