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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.

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Since the reforms in China after 1979, great changes have taken place in the retailing sector, although from the Western point of view it still remains underdeveloped. There is little literature devoted to retailing in China, and an introduction is given here to the retailing sector and the retailing reforms that have occurred during the last decade. The study also provides evidence of some trends which probably will arouse researchers and foreign investors to explore this untapped area.

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