Bio-hydrogen production from food waste and sewage sludge in the presence of aged refuse excavated from refuse landfill

Abstract

a b s t r a c tIn this work, the aged refuse (AR) excavated from a typical refuse landfill with over 10 years of placement was used for the enhancement of bio-hydrogen production from food wastes. Firstly, the food wastes taken from a university dining hall were inoculated with sewage sludge (SL) pre-treated by 15 min heating at 80 1C. It was found that below 0.4% of hydrogen concentration could be detected in the biogas produced due to its severe acidification properties. However, the addition of AR (50% in weight) can considerably increase the hydrogen concentration in the biogas to over 26.6% with pH ascending from 4.36 to 5.81, in comparison with 4-6% using activated carbon as additive with pH descending from 4.43 to 3.91. Meanwhile, it was also found that the hydrogen content in the biogas decreased drastically to 3.3% when the AR was sterilized by heating at 160 1C for 2 h and then used as additive for biohydrogen production from food wastes, indicating that the AR may chiefly function as a microbial inoculum instead of a porous material like activated carbon. Statistical analysis showed that the ultimate hydrogen production potential (H p ), hydrogen production rate (R max ) and lag-phase time (l) were found to be 193.85 mL/gVS, 94.35 mL/(h gVS), 15.28 h, respectively, in the presence of 50% AR, and the optimal mixing ratios were 100:50 (wet weight) for food wastes to AR and 100:30 (dry weight) for food wastes to sewage SL, respectively.

Aged Refuse Characterization as Resource for Wastewater Treatment and Landfill Remediation

“…Table 1 shows perfect exchangeable adsorptive properties for the AR with available specific surface area of 3.376 m 2 g-1. The texture grading of the screened AR shows that the AR media is similar to loamy clay with an average moisture content of 29.5% which is close to values obtained from similar studies [20,30]. This percentage of moisture will also provide the required oxygen for aerobic microorganisms to grow and when there is lack of oxygen the anaerobic microorganisms take place.…”

Optimization of hydrogen production from organic fraction of municipal solid waste (OFMSW) dry anaerobic digestion with analysis of microbial community

“…However, Ming et al . found that the addition of aged refuse excavated from a typical refuse landfill to food waste + sewage sludge considerably increased the hydrogen content in the biogas composition from 0.4 to 26.6%. The pH value was dropped from 6.7 ± 0.23 (feedstock) to 4.72 ± 0.4 (digestate) for all experiments (Figure c).…”

“…H 2 content remained unaffected at a value of 68-72% during the whole experimental period, which is substantially higher than those reported by Tawfik et al [45] for co-digestion of kitchen; wastewater with OFMSW. However, Ming et al [48] found that the addition of aged refuse excavated from a typical refuse landfill to food waste + sewage sludge considerably increased the (Figure 7c). The addition of sodium bicarbonate maintained a final pH above 4.72, which is the optimum value for H 2 production process.…”

Hydrogen production conditions from food waste by dark fermentation with Clostridium beijerinckii KCTC 1785

“…Hydrogen is a clean energy source with a high-energy yield (122 kJ/g), producing only water when it burns [1]. Although steam reforming, thermal cracking of natural gas, and electrolysis of water are well-known methods of hydrogen production, they are cost and energy intensive.…”