Impacts of pH, temperature and pretreatment method on biohydrogen production from organic wastes by sewage microflora

Abstract

Biohydrogen production could be generated from organic wastes: food and beverage processing wastewater, restaurant food waste and raw starch waste. Fermentative hydrogen production from food and beverage processing wastewater by sewage microflora was optimized in terms of pH (4.5-7.0), mesophilic condition (35 ± 2°C) and thermophilic condition (50 ± 2°C). Low initial pH (6.5) and mesophilic condition favored hydrogen production (0.28 L/L) indicating that such parameters along with the wastewater characteristics were crucial to dark-fermentative hydrogen production. Pretreatment methods (methanogenic inhibitor, sterilization, sonication and acidification) on restaurant food waste and raw starch waste to enhance biohydrogen production were also investigated in this study. Maximum hydrogen yields of 3.48 and 2.18 ml H 2 /g COD were observed on sterilization of pretreated restaurant food and raw starch wastes, respectively.

Effects of pre-treatment technologies on dark fermentative biohydrogen production: A review

“…The resulting effects of these changes are that a higher proportion of readily digestible substrates is accessible for enzymatic hydrolysis (Jeon et al, 2013) and subsequently, this improves biogas production from AD (Simonetti et al, 2010;Bougrier et al, 2006;Xie et al, 2005) and bioethanol production from fermentation processes (Nikolíc et al, 2010;Velmurugan and Muthukumar, 2011;Pejin et al, 2012). Additionally, ultrasound has also been investigated for its potential to enhance dark fermentative biohydrogen production following substrates pre-treatment Gadhe et al, 2014aGadhe et al, , 2014bNguyen et al, 2010a) although Wang et al (2003b) and Wongthanate et al (2014) reported decreased H 2 yield after sonication. Abdelhalim et al (2012) reported an increase in H 2 production after sonication under a pH of 5 while at a pH of 6, the authors reported a decrease in H 2 production relative to the control.…”

“…Besides pre-treating inoculum, BESA/BES has also been employed for substrate pre-treatment to increase solubilisation of organic matter while also suppressing any methanogenic bacteria present in the substrate samples, thereby improving biohydrogen production through enhanced DF (Wang et al, 2003b). Wongthanate et al (2014) added 1 M BES to restaurant food and raw starch wastes prior to DF and reported lower H 2 production relative to the untreated substrates. Similarly, Wang et al (2003b) studied the potential of adding 1 M BES to wastewater sludge prior to fermentation with Clostridium bifermentans and reported that although the COD soluble /COD total ratio of the sludge increased after pre-treatment (enhanced solubilisation), the H 2 yield decreased relative to the untreated sludge.…”

Biohydrogen Production from Food and Beverage Processing Wastewater by Enriching Hydrogen-Producing Bacteria from Sludge Compost

“…A batch reactor of 500 mL of serum bottle was added with 20 mL of sludge, 50 mL of nutrient solution and 250 mL of wastewater. The mixed liquor was purged with nitrogen gas for 1 min to ensure an anaerobic condition prior to each run and clogged with a silicone rubber stopper to avoid the gas leakage from the bottle (Wongthanate et al, 2014). The experiment was conducted to produce the hydrogen gas from food and beverage processing wastewater by anaerobic microflora enriched from starch and rice noodle sludge (SSR) or coconut milk sludge (SC).…”

“…The experiment was conducted to produce the hydrogen gas from food and beverage processing wastewater by anaerobic microflora enriched from starch and rice noodle sludge (SSR) or coconut milk sludge (SC). All reactors were operated at initial pH of 6.5 under mesophilic (35±2ºC) condition (Wongthanate et al, 2014). They were placed in a shaking water bath with speed 120±1 (rpm).…”

“…Besides, it is able to operate with various waste streams and bacterial cultures. Particularly, fermentative processes that utilize free carbon available in large volume discharges of agro-industrial wastewater and food and beverage processing wastewater containing carbohydrates can recover available energy and purify the effluent (Wei et al, 2010;Wongthanate et al, 2014). The high carbohydrate wastewaters will be the most useful for industrial production of hydrogen (Van Ginkel et al, 2005).…”