scholarly journals Storage of aerobic granular sludge embedded in agar and its reactivation by real wastewater

2018 ◽  
Vol 16 (6) ◽  
pp. 958-969 ◽  
Author(s):  
Yuanyuan Cheng ◽  
Xinpeng Xuan ◽  
Linan Zhang ◽  
Jue Zhao ◽  
Bei Long
Keyword(s):  
Suspended Solids ◽  
Extracellular Polymeric Substances ◽  
Granular Sludge ◽  
Aerobic Granular Sludge ◽  
Utilization Rate ◽  
Oxygen Utilization ◽  
Mixed Liquor ◽  
Offensive Odour ◽  
Real Wastewater ◽  
Oxygen Utilization Rate

Abstract Aerobic granular sludge (AGS) was preserved using an agar embedding method to maintain its stability. No obvious damage was imposed on the granular appearance during 30 days of cold and dry storage, but the granular microstructure had an uneven surface with a large number of holes. The results were consistent with the extinction of microbial communities and the monitored consumption of extracellular polymeric substances, in which granular specific oxygen utilization rate and mixed liquor volatile suspended solids/mixed liquor suspended solids ratio, respectively, decreased by 72.4% and 62.5% during storage. A mass conversation calculation indicated that the loss of granular mass was 1.6393 g. An offensive odour was smelled during storage, and the results indicated that a material transformation and mitigation were involved between AGS and the gas phase. Although the granular structure was destroyed to a certain extent, no obvious damage was imposed on the granular skeleton during storage. After it was aerated again after a feeding with real wastewater, the residual skeleton served as a carrier for the rapid proliferation of microorganisms, and good granular properties were obtained after 11 days of reactivation.

scholarly journals The treatment of solvent recovery raffinate by aerobic granular sludge in a pilot-scale sequencing batch reactor

2015 ◽  
Vol 13 (3) ◽  
pp. 746-757 ◽  
Author(s):  
Bei Long ◽  
Chang-zhu Yang ◽  
Wen-hong Pu ◽  
Jia-kuan Yang ◽  
Guo-sheng Jiang ◽  
...  
Keyword(s):  
Suspended Solids ◽  
Sequencing Batch Reactor ◽  
Batch Reactor ◽  
Granular Sludge ◽  
Pilot Scale ◽  
Volume Index ◽  
Aerobic Granular Sludge ◽  
Average Particle ◽  
Solvent Recovery ◽  
Mixed Liquor

Mature aerobic granular sludge (AGS) was inoculated for the start-up of a pilot-scale sequencing batch reactor for the treatment of high concentration solvent recovery raffinate (SRR). The proportion of simulated wastewater (SW) (w/w) in the influent gradually decreased to zero during the operation, while volume of SRR gradually increased from zero to 10.84 L. AGS was successfully domesticated after 48 days, which maintained its structure during the operation. The domesticated AGS was orange, irregular, smooth and compact. Sludge volume index (SVI), SV30/SV5, mixed liquor volatile suspended solids/mixed liquor suspended solids (MLVSS/MLSS), extracellular polymeric substances, proteins/polysaccharides, average particle size, granulation rate, specific oxygen utilization rates (SOUR)H and (SOUR)N of AGS were about 38 mL/g, 0.97, 0.52, 39.73 mg/g MLVSS, 1.17, 1.51 mm, 96.66%, 47.40 mg O2/h g volatile suspended solids (VSS) and 8.96 mg O2/h g VSS, respectively. Good removal effect was achieved by the reactor. Finally, the removal rates of chemical oxygen demand (COD), total inorganic nitrogen (TIN), NH4+-N and total phosphorus (TP) were more than 98%, 96%, 97% and 97%, respectively. The result indicated gradually increasing the proportion of real wastewater in influent was a useful domestication method, and the feasibility of AGS for treatment of high C/N ratio industrial wastewater.

Performance of aerobic granular sludge at variable circulation rate in anaerobic–aerobic conditions

2014 ◽  
Vol 69 (11) ◽  
pp. 2252-2257 ◽  
Author(s):  
Hasnida Harun ◽  
Aznah Nor Anuar ◽  
Zaini Ujang ◽  
Noor Hasyimah Rosman ◽  
Inawati Othman
Keyword(s):  
Municipal Wastewater ◽  
Granular Sludge ◽  
Ammonia Removal ◽  
Soy Sauce ◽  
Volume Index ◽  
Aerobic Granular Sludge ◽  
Circulation Rate ◽  
Anaerobic Conditions ◽  
Aerobic Conditions ◽  
Mixed Liquor

Aerobic granular sludge (AGS) has been applied to treat a broad range of industrial and municipal wastewater. AGS can be developed in a sequencing batch reactor (SBR) with alternating anaerobic–aerobic conditions. To provide anaerobic conditions, the mixed liquor is allowed to circulate in the reactor without air supply. The circulation flow rate of mixed liquor in anaerobic condition is the most important parameter of operation in the anaerobic-AGS processes. Therefore, this study investigates the effect of circulation rate on the performance of the SBR with AGS. Two identical reactors namely R1 and R2 were operated using fermented soy sauce wastewater at circulation rate of 14.4 and 36.0 l/h, respectively. During the anaerobic conditions, the wastewater was pumped out from the upper part of the reactor and circulated back into the bottom of the reactor for 230 min. A compact and dense AGS was observed in both reactors with a similar diameter of 2.0 mm in average, although different circulation rates were adopted. The best reactor performance was achieved in R2 with chemical oxygen demand removal rate of 89%, 90% total phosphorus removal, 79% ammonia removal, 10.1 g/l of mixed liquor suspended solids and a sludge volume index of 25 ml/g.

Important limitations in the modeling of activated sludge: biased calibration of the hydrolysis process

2002 ◽  
Vol 45 (12) ◽  
pp. 23-36 ◽  
Author(s):  
G. Insel ◽  
Ö. Karahan Gül ◽  
D. Orhon ◽  
P.A. Vanrolleghem ◽  
M. Henze
Keyword(s):  
Activated Sludge ◽  
Hydrolysis Rate ◽  
Utilization Rate ◽  
Oxygen Utilization ◽  
Experimental Assessment ◽  
Experimental Database ◽  
Hydrolysis Process ◽  
Biochemical Mechanisms ◽  
Oxygen Utilization Rate ◽  
Activated Sludge Models

The merit of activated sludge models depends on the accuracy and reliability of the information they contain on the wastewater to be treated and the biochemical mechanisms involved. In most advanced calibration studies, respirometry i.e. the measurement of the oxygen utilization rate, (OUR), provides the majority of the required experimental database. However, currently used procedures still involve a number of basic and practical problems. Model evaluation of the OUR data may generate a distorted image of the processes involved. Hydrolysis is the most important, yet the most vulnerable process as far as the experimental assessment of accurate kinetic parameters is concerned. This study intends to provide an overview of major experimental limitations in the modeling of activated sludge, with emphasis on the appropriate experimental design for the assessment of the hydrolysis rate.

Correct manipulation method of MBR operating parameters in membrane fouling studies

2013 ◽  
Vol 68 (10) ◽  
pp. 2301-2308 ◽  
Author(s):  
N. Kayaalp ◽  
C. Kinaci
Keyword(s):  
Retention Time ◽  
Membrane Fouling ◽  
Organic Loading Rate ◽  
Utilization Rate ◽  
Operating Parameters ◽  
Oxygen Utilization ◽  
Membrane Area ◽  
Membrane Flux ◽  
Oxygen Utilization Rate ◽  
Common Application

In this study, various parameter manipulation methods, variable sludge retention time (SRT)–variable mixed liquor suspended solids (MLSS) concentration, constant SRT–variable MLSS concentration and variable SRT–constant MLSS concentration, were compared based on the interrelationships among the following membrane bioreactor operating parameters: SRT, food to microorganisms (biomass) (F/M) ratio, MLSS concentration, volumetric organic loading rate (OLR) and membrane flux. Although it is the most applied method, concurrent change of SRT (or F/M ratio) and MLSS concentration is not a good parameter manipulation method because it causes unnecessary changes in many other parameters such as viscosity, oxygen transfer efficiency and oxygen utilization rate. The method of constant SRT–variable MLSS concentration has similar disadvantages to the method of variable SRT–variable MLSS concentration. The best alternative parameter manipulation method to study membrane fouling is the method of variable SRT–constant MLSS concentration because this method eliminates unnecessary changes in other parameters. In addition, while changing OLR or hydraulic retention time (HRT), contrary to the common application, membrane flux should be kept constant because any change in flux overrides changes in other parameters. Accordingly, required changes in OLR or HRT should be made by adjusting membrane area rather than membrane flux.

Sign in / Sign up

Export Citation Format

Share Document