@article{scholars733,
         journal = {Renewable Energy},
           pages = {1245--1251},
            year = {2009},
           title = {Effects of process factors on biological activity of granular sludge grown in an UASFF bioreactor},
          number = {5},
            note = {cited By 14},
          volume = {34},
             doi = {10.1016/j.renene.2008.10.013},
            issn = {09601481},
          author = {Zinatizadeh, A. A. L. and Younesi, H. and Bonakdari, H. and Pirsaheb, M. and Pazouki, M. and Najafpour, G. D. and Hasnain Isa, M.},
        abstract = {Control and operation of a hybrid granular sludge reactor are mainly related to biological behavior of the granules under different process conditions. In this study, a 1-l digester was used to examine biological activity of the granules grown in a hybrid anaerobic reactor (AHR). The biogas production process was modeled and analyzed with three-process variables viz., influent COD (3000, 6500 and 10,000 mg COD/l), biomass concentration (2000, 4000 and 6000 mg VSS/l) and initial alkalinity (200, 1100 and 2000 mg CaCO3/l). Experiments were conducted based on a central composite face-centered design (CCFD) and analyzed using response surface methodology (RSM). In order to carry out a comprehensive analysis of the biogas production process, the indicative parameters viz., specific methanogenic activity (SMA), bicarbonate alkalinity produced-to-COD removed ratio, and COD removal were studied as the response. The maximum SMA was modeled to be 0.99 g CH4-COD/g VSS d under CODin, initial bicarbonate alkalinity (BA) and biomass concentrations of 10,000 mg COD/l, 2000 mg CaCO3/l and 2000 mg VSS/l, respectively, while the observed value was 1.039 g CH4-COD/g VSS d. The maximum COD removal was achieved at the condition when the influent COD was within the range of 4250-5250 mg/l and initial BA was more than 1100 mg CaCO3/l. Initial BA and CODin played an important role in the production of bicarbonate alkalinity during the digestion process. {\^A}{\copyright} 2008 Elsevier Ltd. All rights reserved.},
        keywords = {Anaerobic digestion; Bioactivity; Biogas; Biological materials; Biomass; Bioreactors; Granular materials; Granulation; Industrial chemicals; pH; pH effects; Production engineering; Renewable energy resources; Shape memory effect; Spectrum analyzers, Biogas production; Biological activity; Biological behavior; Biomass concentration; Central composite; Chemical oxygen demand (COD) removal; Comprehensive analysis; Digestion process; Granular sludge; Process conditions; Process factors; Process variables; Response surface methodology (RSA); Sludge reactors; UASFF bioreactor, Sludge digestion, alkalinity; bicarbonate; bioactivity; biogas; biomass; bioreactor; calcium carbonate; chemical oxygen demand; experimental study; gas production; pollutant removal; sludge},
             url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-58649083454&doi=10.1016\%2fj.renene.2008.10.013&partnerID=40&md5=8c6e18670a9593e4d89269f0e0cdacc7}
}