Composition and Distribution of Extracellular Polymeric Substances in Aerobic Flocs and Granular Sludge

Extracellular polymeric substances (EPS) were quantified in flocculent and aerobic granular sludge developed in two sequencing batch reactors with the same shear force but different settling times. Several EPS extraction methods were compared to investigate how different methods affect EPS chemical characterization, and fluorescent stains were used to visualize EPS in intact samples and 20-µm cryosections. Reactor 1 (operated with a 10-min settle) enriched predominantly flocculent sludge with a sludge volume index (SVI) of 120 ± 12 ml g–1, and reactor 2 (2-min settle time) formed compact aerobic granules with an SVI of 50 ± 2 ml g–1. EPS extraction by using a cation-exchange resin showed that proteins were more dominant than polysaccharides in all samples, and the protein content was 50% more in granular EPS than flocculent EPS. NaOH and heat extraction produced a higher protein and polysaccharide content from cell lysis. In situ EPS staining of granules showed that cells and polysaccharides were localized to the outer edge of granules, whereas the center was comprised mostly of proteins. These observations confirm the chemical extraction data and indicate that granule formation and stability are dependent on a noncellular, protein core. The comparison of EPS methods explains how significant cell lysis and contamination by dead biomass leads to different and opposing conclusions

Microbial populations associated with fixed- and floating-bed reactors during a two-stage anaerobic process

Microbial populations associated with methanogenic fixed- or floating-bed bioreactors used for anaerobic digestion of lignocellulosic waste were investigated. Fluorescent in situ hybridization (FISH) was used to characterize microorganisms in samples obtained from different heights in the reactors, which were operated in a semi-continuous manner (feeding and mixing once every 2 days). The FISH results showed that Methanosaeta concilii cells were most numerous at the bottom of both reactors. M. concilii cells were more abundant in the fixed-bed reactor (FXBR), which performed better than the floating-bed reactor (FLBR). Species of the Methanosarcina genera (mainly M. barkeri and M. mazei) were also observed in the FLBR but rarely in the FXBR. Methane production in each of the reactors ranged from 0.29 to 0.33 m3 CH4/kgCODrem (chemical oxygen demand removed). The removal of volatile fatty acids (VFA; 70–75 h) in the FXBR was more efficient than in the FLBR. [Int Microbiol 2007; 10(4):245-251

Swirl Flow Bioreactor coupled with Cu-alginate beads: A system for the eradication of Coliform and Escherichia coli from biological effluents.

It is estimated that approximately 1.1 billion people globally drink unsafe water. We previously reported both a novel copper-alginate bead, which quickly reduces pathogen loading in waste streams and the incorporation of these beads into a novel swirl flow bioreactor (SFB), of low capital and running costs and of simple construction from commercially available plumbing pipes and fittings. The purpose of the present study was to trial this system for pathogen reduction in waste streams from an operating Dewats system in Hinjewadi, Pune, India and in both simulated and real waste streams in Seattle, Washington, USA. The trials in India, showed a complete inactivation of coliforms in the discharged effluent (Mean Log removal Value (MLRV) = 3.51), accompanied by a total inactivation of E. coli with a MLRV of 1.95. The secondary clarifier effluent also showed a 4.38 MLRV in viable coliforms during treatment. However, the system was slightly less effective in reducing E. coli viability, with a MLRV of 1.80. The trials in Seattle also demonstrated the efficacy of the system in the reduction of viable bacteria, with a LRV of 5.67 observed of viable Raoultella terrigena cells (100%)

Model evaluation and optimisation of nutrient removal potential for sequencing batch reactors

Performance of sequencing batch reactors for simultaneous nitrogen and phosphorus removal is evaluated by means of model simulation, using the activated sludge model, ASM2d, involving anoxic phosphorus uptake, recently proposed by the IAWQ Task group. The evaluation includes all major process configurations with different aerobic, anoxic, anaerobic sequences, and fill conditions. Basic relationships between modelling and design based on overall process stoichiometry are established for the interpretation of nutrient profiles associated with different operation modes. A similar approach is also used for the assessment of the effect of major operating parameters on system performance. WaterSA Vol.28(4) 2002: 423-43

Eco-Industrial Networking: ein neues umweltpolitisches Konzept für den Industriesektor Indiens

Die ökologische und ökonomische Entwicklung Indiens zeichnet sich durch gegenläufige Tendenzen aus. Einerseits lässt sich in Indien eine wachsende Umweltkrise beobachten, die schon bedrohliche Ausmaße erreicht hat. Andererseits weist Indien in den beiden letzten Jahrzehnten ein relativ hohes Wirtschaftswachstum mit über 5% auf. Seit Beginn der 90er Jahre war die wirtschaftliche Entwicklung in Indien durch den eingeleiteten Reformprozess, d.h. durch die Liberalisierungspolitik, mit hohen Erwartungen verknüpft. Bedeutende Wirtschaftsexperten erwarteten, dass Indien zu einem neuen Tiger, bzw. zu einem asiatischen wirtschaftlichen "Miracle" aufsteigen werde. Die Wachstumsraten des Bruttoinlandsproduktes stiegen Mitte der 90er Jahre auf über 7% pro Jahr an und schienen insofern die Hoffnungen zu bestätigen

Eco-Industrial Networking: Ein neues umweltpolitisches Konzept für den Industriesektor Indiens

Die ökologische und ökonomische Entwicklung Indiens zeichnet sich durch gegenläufige Tendenzen aus. Einerseits lässt sich in Indien eine wachsende Umweltkrise beobachten, die schon bedrohliche Ausmaße erreicht hat. Andererseits weist Indien in den beiden letzten Jahrzehnten ein relativ hohes Wirtschaftswachstum mit über 5% auf. Seit Beginn der 90er Jahre war die wirtschaftliche Entwicklung in Indien durch den eingeleiteten Reformprozess, d.h. durch die Liberalisierungspolitik, mit hohen Erwartungen verknüpft. Bedeutende Wirtschaftsexperten erwarteten, dass Indien zu einem neuen Tiger, bzw. zu einem asiatischen wirtschaftlichen „Miracle“ aufsteigen werde. Die Wachstumsraten des Bruttoinlandsproduktes stiegen Mitte der 90er Jahre auf über 7% pro Jahr an und schienen insofern die Hoffnungen zu bestätigen

Performance Improvement of a Sequencing Batch Reactor for Treating Tannery Wastewaters

[EN] Tannery wastewater has a high environmental impact due to its low biodegradability. Sequencing batch reactors (SBRs) are an established method for treating highly polluted wastewater. To minimize the hydraulic retention time (HRT) of the SBRs, various HRT values were tested and the best value was chosen according to the removal efficiency of the soluble chemical oxygen demand (COD). A series of experiments was then carried out with two cationic polyelectrolytes added to the system in two different modes to improve the effluent quality. Both modes were evaluated in terms of the soluble COD, suspended solid concentration, and turbidity of the final effluent. The results showed that reducing the HRT to two days did not diminish the COD removal efficiencies.This work was supported by the Universitat Politecnica de Valencia (Project Ref.: PAID-06-10-2269).Balaguer-Arnandis, E.; Cuartas Uribe, BE.; Bes-Piá, M.; Mendoza Roca, JA.; Galiana Aleixandre, MV. (2017). Performance Improvement of a Sequencing Batch Reactor for Treating Tannery Wastewaters. Chemical Engineering & Technology. 40(9):1666-1673. https://doi.org/10.1002/ceat.201600410S1666167340

The TUM Senior Excellence Faculty of the Technical University of Munich – A 15-year success story

The article presents the unique and highly interdisciplinary initiative "TUM Senior Excellence Faculty (SEF)" of the Technical University of Munich (TUM). At TUM, selected outstanding professors are awarded the honorary title "TUM Emeritus of Excellence (EoE)" on retirement. The EoE sustain their commitment to their alma mater and support essential tasks of the university. Here, we provide deeper insight into the idea of the SEF and its responsibility to society and outline the mission, concept, organization, and activities of individual EoE. We offer a glimpse at their work by example of their interdisciplinary group initiative TUM Forum Sustainability. Finally, we argue that this strategic project should serve as a model for other universities

Growth of Leuconostoc mesenteroides NRRL-B523 in an alkaline medium: Suboptimal pH growth inhibition of a lactic acid bacterium

Bacterial profile modification (BPM), a form of tertiary oil recovery, diverts water from the water-flooded high-permeability zone into the oil-bearing low-permeability zone. During field use, exopolymer-producing bacteria plug the high-permeability zone only in the immediate vicinity of the injection point (the near-well bore region). For effective BPM the plug must penetrate far into the formation. Slowing the specific growth rate, lengthening the lag phase, and slowing the polymerization rate are techniques that can prolong the onset of biopolymer gelation and extend the depth of the biological plug. In batch experiments, the growth of Leuconostoc mesenteroides NRRL-B523 was inhibited by the synergistic effects of high substrate loading and an alkaline pH. Exponential growth was delayed up to 190 h. It was observed that cell division was significantly retarded until the medium pH, reduced by the acid byproducts of fermentation, reached a critical value of 6.79 ± 0.06. A mathematical model was developed to describe the relationship between specific growth rate, lag time, and medium pH. © 2004 Wiley Periodicals, Inc.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/34343/1/20315_ftp.pd