title: Quantitative evaluation on the characteristics of activated sludge granules and flocs using a fuzzy entropy-based approach.
abstract: Activated sludge granules and flocs have their inherent advantages and disadvantages for wastewater treatment due to their different characteristics. So far quantitative information on their evaluation is still lacking. This work provides a quantitative and comparative evaluation on the characteristics and pollutant removal capacity of granules and flocs by using a new methodology through integrating fuzzy analytic hierarchy process, accelerating genetic algorithm and entropy weight method. Evaluation results show a higher overall score of granules, indicating that granules had more favorable characteristics than flocs. Although large sized granules might suffer from more mass transfer limitation and is prone to operating instability, they also enable a higher level of biomass retention, greater settling velocity and lower sludge volume index compared to flocs. Thus, optimized control of granule size is essential for achieving good pollutant removal performance and simultaneously sustaining long-term stable operation of granule-based reactors. This new integrated approach is effective to quantify and differentiate the characteristics of activated sludge granules and flocs. The evaluation results also provide useful information for the application of activated sludge granules in full-scale wastewater treatment plants.
authors.affiliation: Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing 210098, China.|CAS Key Laboratory of Urban Pollutant Conversion, Department of Chemistry, University of Science &Technology of China, Hefei 230026, China.
authors.forename: Fang
authors.initials: F
authors.lastname: Fang
authors.affiliation: Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing 210098, China.
authors.forename: Li-Li
authors.initials: LL
authors.lastname: Qiao
authors.affiliation: CAS Key Laboratory of Urban Pollutant Conversion, Department of Chemistry, University of Science &Technology of China, Hefei 230026, China.
authors.forename: Bing-Jie
authors.initials: BJ
authors.lastname: Ni
authors.affiliation: Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing 210098, China.
authors.forename: Jia-Shun
authors.initials: JS
authors.lastname: Cao
authors.affiliation: CAS Key Laboratory of Urban Pollutant Conversion, Department of Chemistry, University of Science &Technology of China, Hefei 230026, China.
authors.forename: Han-Qing
authors.initials: HQ
authors.lastname: Yu