2 8 2011 8 ENVIRONMENTAL SCIENCE Vol 2 No 8 Aug 2011 710055 SBR 18 2 27 d 79% 8% 6% COD SOUR 1 29 1 26 X70 1 A 0250-01 2011 08-25-05 Air Drying Process of Granules and Characteristics of Their Structure LI Zhi-huaZHANG Yu-rong WANG Xiao-chang Key Laboratory of Northwest Water ResourcesEnvironment and EcologyMinistry of EducationSchool of Environmental and Municipal EngineeringXi'an University of Architecture and TechnologyXi'an 710055China Abstract Filamentous granules were cultivated using a sequencing batch reactor The yellowish bacteria dominated granulesblack fungi dominated granules and Microthrix parvicella dominated white smooth granules occurred in the reactor on the day 182 and 27 respectively Distribution of surface related free water and capillary water were analysis using air drying method It was found that the surface related free water in the black and white filamentous granules was 79% and 8% respectivelyand that in the conventional bacteria granules were 6% suggesting that the surface area opening ratio of surface and porosity decreased in the order of white black and yellowish granules According to the air drying rate in different phases of granules it can be inferred that the white and black filamentous granules could rapidly exchange the substrates on the surface and consequently prone to be big and loosewhich discourages the stability of granules Additionallythe section image showed that filamentous granules were more porous than the black bacteria granules Filamentous granules exhibited encouraging COD and nitrogen removal efficiencies The black and white filamentous granules showed higher bioactivity with the oxygen up-take rate SOUR of 1 29 and 1 26 fold of the conventional yellowish granules Key words filamentous microorganisms granulation air drying rate wastewater treatment 1 2 1 COD 0 5 1 1 g / L d 5 cm 2 L 5% A 2 / O ph 9 16 mg / L SBR ph = 0 5 2010-09-08 2010-11-07 510780 09JS027 PCSIRT IRT085 1976 ~ E-mail lizhihua@ gmail com
25 2 h 5 min 226 NIS-Elements AR 0 min min 5 min 1 2 L / min COD NH + -N 1 L 7 25 ± 1 2 2 1 COD 600 2 1 mg / LNH + -N 60 mg / LTP 0 mg / L ph 6 8 1 2 1 N90i 6 7 d 200 2 ml = 1 - W dry / W wet W wet 500 W dry 105 1 120 g /0 1 mg 0 5 h HR-120-20 OCT 18 d 2 d d MICROM HM 500 O 50 selective pressure μm Table 1 1 1 Mean diametersettling velocity and density of different granules / mm / m h - 1 / g ml - 1 0 69 ± 0 18 n = 500 2 57 ± 7 98 n = 150 1 008 0 0 1 ± 0 10 n = 1 26 ± 1 98 n = 20 52 7 ± 15 n = 20 1 006 0 52 ± 0 06 n = 7 2 05 ± 1 1 n = 11 0 28 ± 8 58 n = 11 1 002 1 0 55 ± 0 1 n = 12 1 n 2 2 96% 85% 8 2 9 10 1 2 105 2 h
8 255 2 Ⅰ Ⅱ 20 ~ 0 210 ~ 260 225 ~ 285 min 2 2 Ⅲ 1 1 2 b Fig 1 1 Microscopic observation of different granules after cryosection Fig 2 2 Air-drying characteristics of different granules Table 2 2 1 Air-drying phases and the composition of free and capillary water of different granules / min / % Ⅰ Ⅱ Ⅲ 0 ~ 100 100 ~ 0 0 ~ 90 79 16 95 96 0 ~ 60 60 ~ 10 10 ~ 280 8 11 9 96 0 ~ 100 100 ~ 225 225 ~ 0 6 1 78 85 1
256 2 15 EPS EPS EPS COD NH + -N 11 EPS 0 095 g 0 108 g 0 01 g PBS 100 ml 10 EPS min 5 ml EPS 12 NO - -N60 mg / L 0 5 EPS EPS h EPS 60 min COD 70% COD EPS 105 2 h COD 2 NH + -N SOUR 79% 8% 1 2 COD NH + -N SOUR 1 1 Fig Pollutant removal characteristics of different granules
8 257 SOUR 1 29 1 26 1 granular sludgej 19-26 79% 8% 6% J 128-1287 9 2006 0-10 1997 1 52-59 2 COD 20071 5 1022-100 SOUR 1 29 1 26 1 1Flores-Alsina XComas JRodriguez-Roda I et al Including J 20100 56-62 the effects of filamentous bulking sludge during the simulation of 2 J wastewater treatment plants using a risk assessment modelj 200929 9-7 Water Research2009 18 527-58 Li ZZhang TLi Net al Granulation of filamentous microorganisms in a sequencing batch reactor with saline wastewaterj Journal of Environmental Sciences201022 1 62-67 Yang SLi XYu H Formation and characterisation of fungal and bacterial granules under different feeding alkalinity and ph conditionsj Process Biochemistry2008 1 8-1 5 Liu YLiu Q S Causes and control of filamentous growth in aerobic granular sludge sequencing batch reactors J Biotechnology Advances20062 1 115-127 6 Etterer TWilderer P A Generation and properties of aerobic Water Science and Technology2001 7 M 2002 8 2008 28 7 J J 11Li X YYang S F Influence of loosely bound extracellular polymeric substances EPS on the flocculationsedimentation and dewaterability of activated sludgej Water Research 12McSwain B SIrvine R LHausner Met al Composition and distribution of extracellular polymeric substances in aerobic flocs and granular sludge J Applied and Environmental Microbiology200571 2 1051-1057 1 J 20082 21 9-12 15Malaviya PRathore V Bioremediation of pulp and paper mill effluent by a novel fungal consortium isolated from polluted soil J Bioresource Technology200798 18 67-651