2.2 Pre-treatment Technologies of Anaerobic Fermentation
35
acid, alkali, and CHCl 3 displayed the most intensive protein-like peaks at the Ex/Em
wavelengths of 220/300 nm. In both Regions I and II, the protein-like peaks exhibited
lower intensity and number in the other pre-treatment methods. Particularly in the
drying pre-treatment, the peaks of the by-product-like materials and tyrosine-like
were centred on the Ex/Em wavelength pairs of 220/305, 270/300 and 270/305 nm.
Whereas, no humic acid-like matter peak was observed.
It can be learnt from the above results the control bioreactor was found to show
complicated microbial community, in addition to diverse fluorescence peaks. In the
sludge treatments with acid, alkali, and CHCl 3 , microorganic activity was suppressed,
resulting in incomplete metabolism, strong peaks of biodegradable protein-like materials, and a lower characteristic DOM peak in the 3D fluorescence spectrum. The
bacteria consuming hydrogen were inhibited in the BES and drying pre-treatments
which while improved activity of bacteria producing hydrogen, giving rise to adequate substrate metabolism. Hence, the drying of the PADRs led to the rapid and
complete consumption of the biodegradable DOM, along with the lowest content of
organic material hard to be degraded. Therefore, drying is the optimal pre-treatment
method for PADRs. Additionally, it is demonstrated in the research on the EEM spectra of DOM that the substrate metabolism generated some biodegradable protein-like
materials and lower non-biodegradable materials. These substances themselves were
potential for methane production through anaerobic digestion (Jia et al. 2013).
2.3 Research on High-Efficient Anaerobic Fermentation
Technology for Organic Wastes
2.3.1 High-Efficient Anaerobic Fermentation Technology
of Kitchen Wastes
Based on hydrothermal pre-treatment technology of kitchen wastes, the coupling
technologies and equipment of high-efficient hydrothermal pre-treatment and anaerobic fermentation of kitchen wastes were developed (Fig. 2.16). This study deeply
discussed the influences of different conditions of hydrothermal pre-treatment on
transformation characteristics of organic wastes and the performance of combined
hydrogen and methane production. Furthermore, this research elaborated the change
laws of metabolic intermediates in combined production via anaerobic fermentation,
succession of microbial community, and response relation of functional protein and
analysed metabolic mechanism of combined hydrogen and methane production of
organic wastes. Based on the functional regulation level of protein, the optimisation
and regulation strategies of the process for improving hydrogen production efficiency
and stable operation were proposed. This solves the difficulties, such as long starting
time, low biogas production efficiency and unstable operation in the actual operation.
35
acid, alkali, and CHCl 3 displayed the most intensive protein-like peaks at the Ex/Em
wavelengths of 220/300 nm. In both Regions I and II, the protein-like peaks exhibited
lower intensity and number in the other pre-treatment methods. Particularly in the
drying pre-treatment, the peaks of the by-product-like materials and tyrosine-like
were centred on the Ex/Em wavelength pairs of 220/305, 270/300 and 270/305 nm.
Whereas, no humic acid-like matter peak was observed.
It can be learnt from the above results the control bioreactor was found to show
complicated microbial community, in addition to diverse fluorescence peaks. In the
sludge treatments with acid, alkali, and CHCl 3 , microorganic activity was suppressed,
resulting in incomplete metabolism, strong peaks of biodegradable protein-like materials, and a lower characteristic DOM peak in the 3D fluorescence spectrum. The
bacteria consuming hydrogen were inhibited in the BES and drying pre-treatments
which while improved activity of bacteria producing hydrogen, giving rise to adequate substrate metabolism. Hence, the drying of the PADRs led to the rapid and
complete consumption of the biodegradable DOM, along with the lowest content of
organic material hard to be degraded. Therefore, drying is the optimal pre-treatment
method for PADRs. Additionally, it is demonstrated in the research on the EEM spectra of DOM that the substrate metabolism generated some biodegradable protein-like
materials and lower non-biodegradable materials. These substances themselves were
potential for methane production through anaerobic digestion (Jia et al. 2013).
2.3 Research on High-Efficient Anaerobic Fermentation
Technology for Organic Wastes
2.3.1 High-Efficient Anaerobic Fermentation Technology
of Kitchen Wastes
Based on hydrothermal pre-treatment technology of kitchen wastes, the coupling
technologies and equipment of high-efficient hydrothermal pre-treatment and anaerobic fermentation of kitchen wastes were developed (Fig. 2.16). This study deeply
discussed the influences of different conditions of hydrothermal pre-treatment on
transformation characteristics of organic wastes and the performance of combined
hydrogen and methane production. Furthermore, this research elaborated the change
laws of metabolic intermediates in combined production via anaerobic fermentation,
succession of microbial community, and response relation of functional protein and
analysed metabolic mechanism of combined hydrogen and methane production of
organic wastes. Based on the functional regulation level of protein, the optimisation
and regulation strategies of the process for improving hydrogen production efficiency
and stable operation were proposed. This solves the difficulties, such as long starting
time, low biogas production efficiency and unstable operation in the actual operation.