| Summary: | 碩士 === 逢甲大學 === 綠色能源科技碩士學位學程 === 103 === To produce a stable and high yield operation for textile wastewater hydrogen production, combining with aerobic thermophilic sludge treatment to investigate the feasibility of sludge reduction or hydrogen-energy recovery in high loading rate biohydrogen system is the main point of this study. Microbial fuel cells (MFC) was used to substitute methanation of acid-containing wastewater. The effects of homemade MFC carbon anode on achieving the environmental protection and energy development were also assessed.
In continuous flow biohydrogen production, the conditions tested were by pH5.5 and 6.0, HRT 12h, 8h and 6h, substrate co-fermentation and acid pretreatment. The results show that textile wastewater after phosphate acid pre-treatment (pH2.0) for 12 hours, at pH value to 5.0 with nutrients addition, the biosystem can be applied to two wastewater sources with stable hydrogen production for 21 days at 37 ℃ and pH6.0. The results were HPR 35.3 L/L/d, HY 29.1 mmole/g-hexose, and total sugar removal 92%.
The hydrogen production sludge was digested at 60 (± 5) ℃ and ORP 0~10 mV, pH value and alkalinity were reduced gradually during digestion. The highest concentrations of SCOD and VFA, activity of thermophilic bacteria, were determined at two days sludge digestion times. When digestion time was extended to three days, it gave the best VSS reduction rate 68.8%.
Sludge digestion effluent from 1~5 days operation was used as a substrate for hygrogen production by batch experiment. Fermentation reaction was more significant in 1 to 2 days digestion times ; the concentration of soluble total sugar was decreasing along with digestion times. H2 concentration was about 30 to 33%. However, when substrate digestion time was longer than 3 days, hydrolysis was greater than hydrogen production.
Acidic wastewater from hydrogen production and sludge aerobic thermophilic sludge treatment was used to test MFC. The single chamber MFC with homemade carbon brush anode had the highest VFA removal of 93%. In double chamber, VFA removal was quite low since the fermentaion was working at the samtime in the same space. Scanning homemade carbon brush anode with cyclic voltammetry that mixing 1 mg electronic carbon into 1 mL cyclohexanone thinner had best production efficiency. MFC with homemade brush anode could hold up active sluge easier.
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