title: Nano-TiO2 enhanced photofermentative hydrogen produced from the dark fermentation liquid of waste activated sludge.
abstract: After anaerobic dark fermentation of waste activated sludge (WAS) for hydrogen production, there are a large number of organic compounds including protein, polysaccharide, and volatile fatty acids left in the dark fermentation liquid, which can be further bioconverted to hydrogen by photofermentation techniquea. In this study, the enhancement of photofermentative hydrogen produced from WAS dark fermentation liquid by using nano-TiO2 is reported. First, high concentration of NH(4)(+)-N in the dark fermentation liquid was observed to inhibit the photofermentative hydrogen production, and its removal was essential. Then the effect of nano-TiO2 on photofermentative hydrogen generation was investigated, and the addition of 100 mg/L nano-TiO2 increased hydrogen by 46.1%. Finally, the mechanisms for nano-TiO2 improving hydrogen production were investigated. It was found that nano-TiO2 improved the decomposition of protein and polysaccharide to small-molecule organic compounds and promoted the growth of photosynthetic bacteria and the activity of nitrogenase but decreased the H2-uptake hydrogenase activity.
authors.affiliation: State Key Laboratory of Pollution Control and Resources Reuse, School of Environmental Science and Engineering, Tongji University , 1239 Siping Road, Shanghai 200092, China.
authors.forename: Yuxiao
authors.initials: Y
authors.lastname: Zhao
authors.forename: Yinguang
authors.initials: Y
authors.lastname: Chen
mesh_terms: D019342:Acetic Acid / Q000737:chemistry; D003624:Darkness; D005285:Fermentation / Q000187:drug effects* / Q000528:radiation effects; D006859:Hydrogen / Q000378:metabolism*; D008027:Light; D053758:Nanoparticles / Q000737:chemistry*; D009584:Nitrogen / Q000302:isolation & purification; D009930:Organic Chemicals / Q000032:analysis; D011134:Polysaccharides / Q000737:chemistry; D011506:Proteins / Q000737:chemistry; D000644:Quaternary Ammonium Compounds / Q000302:isolation & purification; D012241:Rhodopseudomonas / Q000187:drug effects / Q000254:growth & development / Q000528:radiation effects; D012722:Sewage / Q000032:analysis* / Q000382:microbiology; D014025:Titanium / Q000494:pharmacology*; D014865:Waste Disposal, Fluid; D014866:Waste Products / Q000032:analysis*
chemical_list: D009930:Organic Chemicals; D011134:Polysaccharides; D011506:Proteins; D000644:Quaternary Ammonium Compounds; D012722:Sewage; D014866:Waste Products; C009495:titanium dioxide; D006859:Hydrogen; D014025:Titanium; D009584:Nitrogen; D019342:Acetic Acid