Filamentous bacteria existence in aerobic granular reactors

“The final publication is available at Springer via http://dx.doi.org/10.1007/s00449-014-1327-x”Filamentous bacteria are associated to biomass settling problems in wastewater treatment plants. In systems based on aerobic granular biomass they have been proposed to contribute to the initial biomass aggregation process. However, their development on mature aerobic granular systems has not been sufficiently studied. In the present research work, filamentous bacteria were studied for the first time after long-term operation (up to 300 days) of aerobic granular systems. Chloroflexi and Sphaerotilus natans have been observed in a reactor fed with synthetic wastewater. These filamentous bacteria could only come from the inoculated sludge. Thiothrix and Chloroflexi bacteria were observed in aerobic granular biomass treating wastewater from a fish canning industry. Meganema perideroedes was detected in a reactor treating wastewater from a plant processing marine products. As a conclusion,the source of filamentous bacteria in these mature aerobic granular systems fed with industrial effluents was the incoming wastewaterThis work was funded by the Spanish Government through NOVEDAR Consolider (CSD2007-00055) and PLASTICWATER (CTQ2011-22675) projects. The authors belong to the Galician Competitive Research Group GRC 2013-032, programme co-funded by FEDER.S

Stability of aerobic granular biomass treating the effluent from a seafood industry

This is the pre-print previous reviewed version of the following article: Val del Rio, A., Figueroa, M., Mosquera-Corral, A., Campos, J. L., & Mendez, R. (2013). Stability of Aerobic Granular Biomass Treating the Effluent from A Seafood Industry. International Journal of Environmental Research, 7(2), 265-276, which has been published in final form at https://ijer.ut.ac.ir/article_606_0.html. This article may be used for non-commercial purposesThe aerobic granular systems represent a good alternative to substitute the conventional activated sludge process in the treatment of industrial effluents due to the lower surface requirements. In this work the effluent from a seafood industry, characterized by a high variability and the presence of residual amounts of coagulant and flocculant reagents, was used to study the development of aerobic granular biomass and its stability. In a first stage with OLRs between 2 and 5 kg CODS/m3∙d the development of aerobic granular biomass was promoted with good physical properties: SVI of 35 mL/g TSS, density of 60 g VSS/Lgranule and average diameter of 2.8 mm. In a second stage the continuous change in the OLR applied from 3 to 13 kg CODS/m3∙d, to simulate the real conditions of the industry, showed that the removal of organic matter was not affected (90%) but the aerobic granules disintegrated. The maximum OLR treated in the system without granules disintegration was around 4.4 kg CODS/m3∙d. The nitrogen removal was 30% (for biomass assimilation) and the maximum ammonia removal was around 65% and depending on the solids retention time, the free ammonia concentration and the average granule diameterThis work was funded by the Spanish Government (TOGRANSYS CTQ2008-06792-C02-01, NOVEDAR_Consolider CSD2007-00055), Xunta de Galicia (project coordinated by Espina y Delfin S.L. PGIDIT06TAM004) and Ministry of Education of Spain (FPU AP2006-01478). Authors want to thank Mar Orge, Mónica Dosil and Miriam Vieites for their support in the analytical techniquesS

Effect of Coagulant-Flocculant Reagents on Aerobic Granular Biomass

This is the post-print reviewed version of the following article: Val del Río, A., Morales, N., Figueroa, M., Mosquera-Corral, A., Campos, J.L., Méndez, R. 2012. Effect of coagulant-flocculant reagents on aerobic granular biomass. Journal of Chemical Technology and Biotechnology, 87(7), 908-913, which has been published in final form at http://onlinelibrary.wiley.com/doi/10.1002/jctb.3698/full. This article may be used for non-commercial purposesBACKGROUND: Technologies based on aerobic granular biomass are presented as a new alternative for its application to the wastewater treatment due to its advantages in comparison with the conventional activated sludge ones. However the properties of the aerobic granules can be influenced by the presence of residual amounts of coagulant-flocculant reagents, frequently used as pre-treatment before the biological process. In this work the effect of these compounds on aerobic granular biomass development was tested. RESULTS: The presence of coagulant-flocculant reagents led to a worse biomass retention capacity with a lower VSS concentration compared to a control reactor (4.5 vs. 7.9 g VSS/L) and with a higher SVI (70 vs. 40 mL/g TSS) and diameter (5.0 vs. 2.3 mm). These reagents also caused a decrease in the maximum oxygen consumption rate, but the removal efficiencies of organic matter (90%) and nitrogen (60%) achieved were similar than the control reactor. CONCLUSION: The continuous presence of residual levels of coagulant-flocculant reagents from the pre-treatment unit negatively affected the formation process and the physical properties of the aerobic granules, however the removal of organic matter and nitrogen were not affectedThis work was funded by the Spanish Government (TOGRANSYS CTQ2008-06792-C02-01, NOVEDAR_Consolider CSD2007-00055) and Ministry of Education of Spain (FPU AP2006-01478).S

Bacterial community dynamics in long‐term operation of a pilot plant using aerobic granular sludge to treat pig slurry

This is a Post-print version of the articleAerobic granular sludge represents an interesting approach for simultaneous organic matter and nitrogen removal in wastewater treatment plants. However, the information about microbial communities in aerobic granular systems dealing with industrial wastewater like pig slurry is limited. Herein, bacterial diversity and dynamics were assessed in a pilot scale plant using aerobic granular sludge for organic matter and nitrogen elimination from swine slurry during more than 300 days. Results indicated that bacterial composition evolved throughout the operational period from flocculent activated sludge, used as inoculum, to mature aerobic granules. Bacterial diversity increased at the beginning of the granulation process and then declined due to the application of transient organic matter and nitrogen loads. The operational conditions of the pilot plant and the degree of granulation determined the microbial community of the aerobic granules. Brachymonas, Zoogloea and Thauera were attributed with structural function as they are able to produce extracellular polymeric substances to maintain the granular structure. Nitrogen removal was justified by partial nitrification (Nitrosomonas) and denitrification (Thauera and Zoogloea), while Comamonas was identified as the main organic matter oxidizing bacteria. Overall, clear links between bacterial dynamics and composition with process performance were found and will help to predict their biological functions in wastewater ecosystems improving the future control of the processThis work has been financed by FISHPOL (CTQ2014-55021-R) and GRANDSEA (CTM2014-55397-JIN) projects from the Spanish Government and co-funded by FEDER. The authors belong to the Galician Competitive Research Group GRC 2013-032, programme co-funded by FEDER, and CRETUS (AGRUP2015/02)S

Aerobic granular systems for biological treatment of industrial wastewater: operation and characterization of microbial populations

The new regulations and policies, both at a State and European Community level, are the more and more exigent regarding the concentrations of pollutants in the generated effluents at industrial and urban level. This fact, together with the reduction of the available surfaces for their management, is promoting the development of new more effective and compact systems and technologies for wastewater treatment where the simultaneous organic matter and nutrients removal, like nitrogen and phosphorus, can be performed. The use of sequencing batch reactors (SBR) with aerobic granular biomass applied for the biological wastewater treatment in aerobic conditions is presented as an alternative to the conventional activated sludge processes. These reactors are operated in sequential cycles that comprise filling, reaction, settling and withdrawal phases that are characterised by the short length of the filling and settling ones aiming to the development of biomass in the shape of granules in aerobic conditions. These systems allow the treatment of higher loading rates than the activated sludge systems because higher biomass concentrations can be achieved. On the other hand, the excellent settling properties of aerobic granules and their low biomass productivity allow doing without the big and expensive secondary settlers and moreover smaller footprint is required for its implantation. Another advantage of these granular systems is that organic matter and nitrogen removal can be simultaneously carried out in the same unit by means of simultaneous nitrification and denitrification processes (SND). In this way not only the improvement of the quality of the generated effluents but also a reduction of the implementation and sludge management costs are attained. First studies focused on aerobic granulation were developed at laboratory scale reactors using synthetic media in order to better understand all the variables that affected the granulation process. In this way the settling time, the hydrodynamic shear and stress forces, the type of substrate, the organic matter (COD) and nitrogen concentrations, the dissolved oxygen concentration in the bulk liquid or the presence of possible inhibitory substances were identified to be among the key factors affecting the operation of these systems