http://espace.library.uq.edu.au/ The University of Queensland en Fez http://blogs.law.harvard.edu/tech/rss http://espace.library.uq.edu.au/view/UQ:273483 Electroactive microbial biofilms and the microorganisms embedded therein are not only of crucial fundamental interest because they play an important role in redox cycles that occur in nature, they are also attracting increasing attention as key component of microbial bioelectrochemcial systems (BES). In these systems, interconversion of chemical and electrical energy and the associated exchange of electrons between living microbial cells and solid electrodes take place. The fascinating prospects and promise of BES technology have considerably increased the research on electroactive microbial biofilms over recent years. As a consequence, the research community is truly multifaceted, with backgrounds and interests ranging from molecular biology, via chemistry, to engineering. One of the most-important and most-widespread applied electrochemical techniques is cyclic voltammetry (CV). This Focus Review illustrates the power of this electrochemical technique and the versatility of the information that can be gained by its application for the electrochemical freshman. This Review will also pinpoint hurdles in using this technique, especially for the non-electrochemist, and the limitations of present models for data analysis. Because it aims to be a basic introduction, this Review will not discuss the latest intricacies in the field. 2012-04-30T20:56:42Z Harnisch, Falk og Freguia, Stefano http://espace.library.uq.edu.au/view/UQ:160637 There is a need for alternative catalysts for oxygen reduction in the cathodic compartment of a microbial fuel cell (MFC). In this study, we show that a bipolar membrane combined with ferric iron reduction on a graphite electrode is an efficient cathode system in MFCs. A flat plate MFC with graphite felt electrodes, a volume of 1.2 L and a projected surface area of 290 cm2 was operated in continuous mode. Ferric iron was reduced to ferrous iron in the cathodic compartment according to Fe3+ + e- → Fe2+ (E0 = +0.77 V vs NHE, normal hydrogen electrode). This reversible electron transfer reaction considerably reduced the cathode overpotential. The low catholyte pH required to keep ferric iron soluble was maintained by using a bipolar membrane instead of the commonly used cation exchange membrane. For the MFC with cathodic ferric iron reduction, the maximum power density was 0.86 W/m2 at a current density of 4.5 A/m2. The Coulombic efficiency and energy recovery were 80−95% and 18−29% respectively. 2009-01-14T00:00:00Z ter Heijne, Annemiek og Hamelers, Hubertus V. M. og de Wilde, Vinnie og Rozendal, Rene A. og Buisman, Cees J. N. http://espace.library.uq.edu.au/view/UQ:127749 2008-02-18T00:00:00Z Burow, Luke C. og Kong, Yunhong og Nielsen, Jeppe L. og Blackall, Linda L. og Nielsen, Peter H. http://espace.library.uq.edu.au/view/UQ:164669 Tag für Tag befreit uns ein sanfter Druck auf die Spültaste von dem stinkenden gelb-braunen Süppchen, das wir „Unser Abwasser“ nennen. Wasser aus Duschen, Spül- und Wachmaschinen kommt hinzu. Auf seinem Weg durch kilometerlange, unterirdisch verlegte Rohrleitungen vereinigt sich dieses „Unser Abwasser“ mit Abläufen aus Gewerbebetrieben und Industrieanlagen. So entsteht schließlich eine heterogene Mischung aus gelösten und partikulären Substanzen organischer und anorganischer Natur. Dieses Stoffgemisch zu entwirren und aus dem Abwasser wieder abzuscheiden, ist die Aufgabe der Kläranlage. Es entsteht so aber nicht nur gereinigtes Abwasser, sondern auch das Konzentrat dessen, was zuvor im Abwasser enthalten war, Klärschlamm nämlich. Über dessen Entsorgungsmöglichkeiten reden sich bereits Generationen von Ingenieuren, Landwirten, Umweltschützern und Kommunalpolitikern die Köpfe heiß. Ist die Technik der Abwasserbehandlung, wie sie sich über die zurückliegenden 150 Jahre hinweg in den Industriestaaten entwickelt hat, eigentlich noch zeitgemäß? 2009-02-17T00:00:00Z Wilderer P.A. http://espace.library.uq.edu.au/view/UQ:203276 2010-04-16T00:00:00Z Nguyen, Tung og Nobi, Nur og Soliman, Alfred og Sharma, Keshab http://espace.library.uq.edu.au/view/UQ:267405 Heavy metal content of infiltration inlet sediment, arterial road dust, housing area road dust and infiltration area soil was investigated. Heavy metals content in infiltration inlet sediment was almost equal to relevant survey results of foreign countries. Based on evaluation results of pollution by urban traffic activities with use of enrichment factor, traffic activities were pointed out as main pollution source of Pb, Zn, Cu, Cd, Cr and Ni. Cluster analysis of heavy metal composition was conducted for grouping above dusts and soils. Based on results of principal component analysis, main component 1 as urban traffic pollution and main component 2 as other non-artificial pollution were grasped. Through above analysis, pollution characteristics was clarified. 2012-02-10T00:00:00Z Murakami, M. og Nakajima, F. og Furumai, H. og Aryal, R. K. http://espace.library.uq.edu.au/view/UQ:119247 The oxidation of acetate to hydrogen, and the subsequent conversion of hydrogen and carbon dioxide to methane, has been regarded largely as a niche mechanism occurring at high temperatures or under inhibitory conditions. In this study, 13 anaerobic reactors and sediment from a temperate anaerobic lake were surveyed for their dominant methanogenic population by using fluorescent in situ hybridization and for the degree of acetate oxidation relative to aceticlastic conversion by using radiolabeled [2-C-14]acetate in batch incubations. When Methanosaetaceae were not present, acetate oxidation was the dominant methanogenic pathway. Acetielastic conversion was observed only in the presence of Methanosaetaceae. 2007-10-17T00:00:00Z Karakashev, D og Batstone, DJ og Trably, E og Angelidaki, I http://espace.library.uq.edu.au/view/UQ:178702 Nitrogen removal via nitrite (the nitrite pathway) is beneficial for carbon-limited biological wastewater treatment plants. However, partial nitrification to nitrite has proven difficult in continuous processes treating domestic wastewater. The nitrite pathway is achieved in this study in a pilot-scale continuous pre-denitrification plant (V = 300 L) treating domestic wastewater by controlling the dissolved oxygen (DO) concentration at 0.4–0.7 mg/L. It is demonstrated that the nitrite pathway could be repeatedly and reliably achieved, with over 95% of the oxidized nitrogen compounds at the end of the aerobic zone being nitrite. The nitrite pathway improved the total nitrogen (TN) removal by about 20% in comparison to the nitrate pathway, and also reduced aeration costs by 24%. FISH analysis showed that the nitrite oxidizing bacteria (NOB) population gradually reduced at low DO levels, and reached negligible levels when stable nitrite pathway was established. It is hypothesized that NOB was washed out due to its relatively lower affinity with oxygen. A lag phase was observed in the establishment of the nitrite pathway. Several sludge ages were required for the onset of the nitrite pathway after the application of low DO levels. However, nitrite accumulation increased rapidly after that. A similar lag phase was observed for the upset of the nitrite pathway when a DO concentration of 2–3 mg/L was applied. The nitrite pathway negatively impacted on the sludge settleability. A strong correlation between the sludge volume index and the degree of nitrite accumulation was observed. 2009-06-23T00:00:00Z Ma, Yong og Peng, Yongzhen og Wang, Shuying og Yuan, Zhiguo og Wang, Xiaolian http://espace.library.uq.edu.au/view/UQ:176147 2009-04-16T00:00:00Z Romain Lemaire og Marcelino, M. og Yuan, Zhiguo http://espace.library.uq.edu.au/view/UQ:160832 A coupled solar photocatalytic-biological pilot plant system has been employed to enhance the biodegradability and complete mineralization of a biorecalcitrant industrial compound, α-methylphenylglycine, dissolved in distilled water and simulated seawater at 500 mg L−1. The pollutant was completely degraded by a solar photo-Fenton treatment in a 75-L pilot plant made up of four compound parabolic collector (CPC) units. The catalyst concentration employed was 2 and 20 mg L−1 of Fe2+ and the H2O2 concentration was kept in the range of 200–500 mg L−1. A Zahn–Wellens (Z–W) test applied to photo-treated samples demonstrated that intermediates produced within a short time of starting the photo-Fenton process were biodegradable. Consequently, the photocatalytic and biological processes were combined. Biodegradable compounds generated during the preliminary oxidative process were biologically mineralized in a 170-L aerobic immobilised biomass reactor (IBR), filled with 90–95 L propylene Pall® Ring supports colonized by activated sludge. Almost total mineralization (90% overall total organic carbon removed) was attained in the combined treatment system (for both distilled and seawater experiments). Moreover, nitrification and denitrification phenomena were also observed. 2009-01-15T00:00:00Z Oller, I. og Malato, S. og Sanchez-Perez, J. A. og Gernjak, W. og Maldonado, M. I. og Pérez-Estrada, L. A. og Pulgarín, C. og Ross, J.R.H http://espace.library.uq.edu.au/view/UQ:178705 A comparative study on the use of methanol as a supplementary carbon source to enhance denitrification in primary and secondary anoxic zones is reported. Three lab-scale sequencing batch reactors (SBR) were operated to achieve nitrogen and carbon removal from domestic wastewater. Methanol was added to the primary anoxic period of the first SBR, and to the secondary anoxic period of the second SBR. No methanol was added to the third SBR, which served as a control. The extent of improvement on the denitrification performance was found to be dependent on the reactor configuration. Addition to the secondary anoxic period is more effective when very low effluent nitrate levels are to be achieved and hence requires a relatively large amount of methanol. Adding a small amount of methanol to the secondary anoxic period may cause nitrite accumulation, which does not improve overall nitrogen removal. In the latter case, methanol should be added to the primary anoxic period. The addition of methanol can also improve biological phosphorus removal by creating anaerobic conditions and increasing the availability of organic carbon in wastewater for polyphosphate accumulating organisms. This potentially provides a cost-effective approach to phosphorus removal from wastewater with a low carbon content. New fluorescence in situ hybridisation (FISH) probes targeting methanol-utilising denitrifiers were designed using stable isotope probing. Microbial structure analysis of the sludges using the new and existing FISH probes clearly showed that the addition of methanol stimulated the growth of specific methanol-utilizing denitrifiers, which improved the capability of sludge to use methanol and ethanol for denitrification, but reduced its capability to use wastewater COD for denitrification. Unlike acetate, long-term application of methanol has no negative impact on the settling properties of the sludge. 2009-06-23T00:00:00Z Ginige, Maneesha P. og Bowyer, Jocelyn C. og Foley, Leah og Keller, Jurg og Yuan, Zhiguo http://espace.library.uq.edu.au/view/UQ:160928 The degradation of gallic acid and imidacloprid with supported Millennium PC500 and Degussa P25 TiO2 is reported. TiO2 particles were immobilized using a titanium sol-solution and direct deposition on glass supports. The film characterization was done by x-ray diffraction, scanning electron microscopy, and atomic force microscopy, and degradation of organic compounds was monitored by high-performance liquid chromatography, total organic carbon analyzer, and ion chromatography. The experiments were performed under sunlight in compound parabolic collector plants with flat supports inside the glass tubes. Photocatalytic activity of the films was compared and identified. Although sol-gel coatings had better mechanical properties, mineralization was observed to be approximately five times slower than paste-deposited films. Photoactivity of the films decreased with silver deposition due to the nature of the organic compounds. The rate constants were calculated to be between 2×10–1 and 6×10–2 mg m2/kJ for organic compounds, and 6×10–2 and 6×10–3 for total organic carbon. 2009-01-16T00:00:00Z Kus, Mahmut og Gernjak, Wolfgang og Fernadez Ibanez, Pilar og Rodriguez Malato, Sixto og Blanco Galvez, Julian og Icli, Siddik http://espace.library.uq.edu.au/view/UQ:138309 2008-05-13T00:00:00Z Rodriguez, J. og Batstone, D. J. og Yuan, Z. og Rabaey, K. http://espace.library.uq.edu.au/view/UQ:86508 Regular monitoring of wastewater characteristics is undertaken on most wastewater treatment plants. The data acquired during this process are usually filed and forgotten. However, systematic analysis of these data can provide useful insights into plant behaviour. Conventional graphical techniques are inadequate to give a good overall picture of how wastewater characteristics vary, with time and along the lagoon system. An approach based on the use of contour plots was devised that largely overcomes this problem. Superimposition of contour plots for different parameters can be used to gain a qualitative understanding of the nature and strength of relationships between the parameters. This is illustrated in an analysis of monitoring data for lagoon 115 East at the Western Treatment Plant, near Melbourne, Australia. In this illustrative analysis, relationships between ammonia removal rates and parameters such as chlorophyll a level and temperature are explored using a contour plot superimposition approach. It is concluded that this approach can help improve our understanding, not only of lagoon systems, but of other wastewater treatment systems as well. 2007-08-19T00:00:00Z Hurse, T. J. og Connor, M. A. http://espace.library.uq.edu.au/view/UQ:141593 Most wastewater treatment plants regularly monitor plant performance. Analysis of the resulting data can provide valuable insights into plant behaviour. A useful first step in the systematic analysis of such data is to depict them graphically. The resulting plots help identify the more obvious relationships between measured wastewater characteristics. They also help in locating anomalous data points. In the case of multi-pond wastewater treatment lagoons, finding an informative way of depicting the monitoring data is difficult. This is because the required data plots need to show not only how measured characteristics vary with time but also how they vary along the pond chain. Conventional 2-D time-series plots are inadequate for this task if the lagoon comprises more than a few ponds, or if the amount of accumulated data is large. An alternative, contour plot based approach was developed that overcomes the problems with conventional 2-D plots. The procedure for producing such plots is described and factors affecting their accuracy discussed. A major advantage of the contour plot approach is that contour plots for different parameters can be superimposed. By examining these superimposed plots, one can learn much about the way different parameters are related. A procedure is described that enables the interrelatedness of any given pair of parameters to be systematically characterised. The effectiveness of the contour plot approach is illustrated using data obtained over a 9-year period for an 11 (later 10) pond lagoon at the Western Treatment plant in Melbourne, Australia. (C) 2000 Elsevier Science Ltd. All rights reserved. 2008-06-10T00:00:00Z Hurse, T. J. og Connor, M. A. http://espace.library.uq.edu.au/view/UQ:298206 2013-04-23T15:28:00Z Wang, Qilin og Ye, Liu og Jiang, Guangming og Yuan, Zhiguo http://espace.library.uq.edu.au/view/UQ:187843 2009-11-25T00:00:00Z Malato, S. og Blanco, J. og Maldonado, M.,I. og Alarcón, D. og Fernández, P. og Oller, I. og Gernjak, W. http://espace.library.uq.edu.au/view/UQ:187839 2009-11-25T00:00:00Z Malato, S. og Blanco, J. og Maldonado, M.,I. og Alarcón, D. og Fernández, P. og Oller, I. og Gernjak, W. http://espace.library.uq.edu.au/view/UQ:187836 2009-11-25T00:00:00Z Maldonado, M.,I. og Malato, S. og Blanco, J. og Alarcón, D. og Fernández, P. og Oller, I. og Gernjak, W. http://espace.library.uq.edu.au/view/UQ:187844 2009-11-25T00:00:00Z Oller, I. og Malato, S. og Sánchez-Pérez, J. A. og Blanco, J. og Maldonado, M. I. og Gernjak W. og Pérez-Estrada L. http://espace.library.uq.edu.au/view/UQ:187830 2009-11-25T00:00:00Z Maldonado, M. I. og Malato, S. og Blanco, J. og Alarcón, D. og Fernández, P. og Oller, I. og Gernjak, W. http://espace.library.uq.edu.au/view/UQ:187845 2009-11-25T00:00:00Z Maldonado, M. I. og Malato, S. og Fernández P. og Gernjak W. og Oller, I. og Pérez-Estrada L. og Blanco, J. og Alarcón, D. http://espace.library.uq.edu.au/view/UQ:161416 2009-01-21T00:00:00Z Cook, Andrew E. og le Roes, Marilize og Meyers, Paul R. http://espace.library.uq.edu.au/view/UQ:141710 This paper presents a technique which enables on-line monitoring of activated sludge flocculation. The usefulness of this technique is demonstrated by investigating the effect of shear on steady-state floc sizes. The technique is based on a method developed to investigate flocculation of inorganic particles. Samples of activated sludge are sonicated for 3 min at 50 W to produce the necessary primary particles to observe flocculation. The samples are then stirred in a batch mixing vessel and sized on-line using a Malvern Mastersizer/E. The dynamics of flocculation were found to be reproducible and follow the principles of inorganic shear induced flocculation. The median flee size was found to increase until an equilibrium between the rates of aggregation and breakage was reached. At this point, a steady-state floc size was maintained. The effect of shear on the steady-state flee size was quantified using the experimental technique. The change in floc size-with shear followed a power law relationship. This relationship was used to investigate the breakage mechanisms. (C) 2000 Elsevier Science Ltd. All rights reserved. 2008-06-10T00:00:00Z Biggs, C. A. og Lant, P. A. http://espace.library.uq.edu.au/view/UQ:164583 2009-02-16T00:00:00Z Possemiers, Sam og Heyerick, Arne og Robbens, Veerle og De Keukeleire, Dennis og Verstraete, Willy http://espace.library.uq.edu.au/view/UQ:164272 This paper investigates limestone and iron slag filters as an upgrade option for phosphorus removal from wastewater treatment ponds. A review of ‘active’ filter technology and the results from laboratory and field research using packed columns of the different media is presented. It is shown that both limestone and iron slag can remove phosphorus but highlights that different types of limestone give markedly different performance. Filter performance appears to be improved by increasing temperature and by the presence of algae, presumably because of its tendency to elevate pH. Performance is related to hydraulic retention time (HRT), but this relationship is not linear, particularly at low HRTs. Importantly for future research, the results from field-testing with pond effluent show significant differences compared to those obtained when using a synthetic feed in the laboratory. For the iron slag filter, higher performance was observed in the field (72% in field vs. 27% in laboratory, at a 12 hour-HRT), while the opposite was observed for the limestone (64% in laboratory vs. 18% in field, at a 12-hour HRT). 2009-02-13T00:00:00Z Shilton, A. og Pratt, S. og Drizo, A. og Mahmood, B. og Banker, S. og Billings, L. og Glenny, S. og Luo, D. http://espace.library.uq.edu.au/view/UQ:61850 Fault detection and isolation (FDI) are important steps in the monitoring and supervision of industrial processes. Biological wastewater treatment (WWT) plants are difficult to model, and hence to monitor, because of the complexity of the biological reactions and because plant influent and disturbances are highly variable and/or unmeasured. Multivariate statistical models have been developed for a wide variety of situations over the past few decades, proving successful in many applications. In this paper we develop a new monitoring algorithm based on Principal Components Analysis (PCA). It can be seen equivalently as making Multiscale PCA (MSPCA) adaptive, or as a multiscale decomposition of adaptive PCA. Adaptive Multiscale PCA (AdMSPCA) exploits the changing multivariate relationships between variables at different time-scales. Adaptation of scale PCA models over time permits them to follow the evolution of the process, inputs or disturbances. Performance of AdMSPCA and adaptive PCA on a real WWT data set is compared and contrasted. The most significant difference observed was the ability of AdMSPCA to adapt to a much wider range of changes. This was mainly due to the flexibility afforded by allowing each scale model to adapt whenever it did not signal an abnormal event at that scale. Relative detection speeds were examined only summarily, but seemed to depend on the characteristics of the faults/disturbances. The results of the algorithms were similar for sudden changes, but AdMSPCA appeared more sensitive to slower changes. 2007-08-14T00:00:00Z Lennox, J. og Rosen, C. http://espace.library.uq.edu.au/view/UQ:61339 Due to the socio-economic inhomogeneity of communities in developing countries, the selection of sanitation systems is a complex task. To assist planners and communities in assessing the suitability of alternatives, the decision support system SANEX™ was developed. SANEX™ evaluates alternatives in two steps. First, Conjunctive Elimination, based on 20 mainly technical criteria, is used to screen feasible alternatives. Subsequently, a model derived from Multiattribute Utility Technique (MAUT) uses technical, socio-cultural and institutional criteria to compare the remaining alternatives with regard to their implementability and sustainability. This paper presents the SANEX™ algorithm, examples of its application in practice, and results obtained from field testing. 2007-08-14T00:00:00Z Loetscher, Thomas og Keller, Jurg http://espace.library.uq.edu.au/view/UQ:257282 2011-10-19T00:00:00Z Basakcilardan-Kabakci, Sibel og Thompson, Andrew og Cartmell, Elise og Le Corre, Kristell http://espace.library.uq.edu.au/view/UQ:162822 Adsorption of arsenate (As(V)) and arsenite (As(III)) to two commercially available titanium dioxide (TiO2) suspensions, Hombikat UV100 and Degussa P25, was investigated as a function of pH and initial concentration of adsorbate ions. The BET surface area and zeta potential values of TiO2 were also measured to understand the difference in adsorption behavior of two suspensions. Both As(V) and As(III) adsorb more onto Hombikat UV100 particles than Degussa P25 particles. Adsorption of As(V) onto TiO2 suspensions was more than As(III) at pH 4 while the adsorption capacity of As(III) was more at pH 9. The electrostatic factors between surface charge of TiO2 particles and arsenic species were used to explain adsorption behavior of As(V) and As(III) at different pH. The Langmuir and Freundlich isotherm equations were used to interpret the nature of adsorption of arsenic onto TiO2 suspensions. The usefulness of adsorption data in removing arsenic in water is briefly discussed. 2009-02-04T00:00:00Z Dutta, Paritam K. og Ray, Ajay K. og Sharma, Virender K. og Millero, Frank J. http://espace.library.uq.edu.au/view/UQ:239682 This work investigates the removal of nitrobenzene (NB), a model pollutant from water, by combining adsorption onto zeolites and regeneration with ozone. The adsorption equilibrium isotherms of NB onto zeolites enabled the best adsorbent to be selected and zeolites with a high Si/Al ratio were the most efficient. The adsorption capacity depended on the Si/Al ratio and on the pore size. In a sequential process coupling adsorption and oxidation by ozone, NB was completely removed from water and the initial adsorption capacity of the zeolite was totally restored. Although no catalytic effect was noticed, the adsorption produced locally high concentrations, thus enhancing the oxidation rate for NB. 2011-04-04T00:00:00Z Reungoat, J. og Pic, J. S. og Manero, M. H. og Debellefontaine, H. http://espace.library.uq.edu.au/view/UQ:164521 2009-02-16T00:00:00Z Lissens, Geert og Verstraete, Willy og Albrecht, Tobias og Brunner, Gerd og Creuly, Catherine og Seon, Jerome og Dussap, Gilles og Lasseur, Christophe http://espace.library.uq.edu.au/view/UQ:203500 2010-04-19T00:00:00Z Radjenović, Jelena og Petrović, Mira og Barceló, Damià http://espace.library.uq.edu.au/view/UQ:160776 Two advanced oxidation processes (AOPs), ozonation and photo-Fenton, combined with a pilot aerobic biological reactor at field scale were employed for the treatment of industrial non-biodegradable saline wastewater (TOC around 200 mg L-1) containing a biorecalcitrant compound, a-methylphenylglycine (MPG), at a concentration of 500 mg L-1. Ozonation experiments were performed in a 50-L reactor with constant inlet ozone of 21.9 g m-3. Solar photo-Fenton tests were carried out in a 75-L pilot plant made up of four compound parabolic collector (CPC) units. The catalyst concentration employed in this system was 20 mg L-1 of Fe2 + and the H2O2 concentration was kept in the range of 200–500 mg L-1. Complete degradation of MPG was attained after 1,020 min of ozone treatment, while only 195 min were required for photo-Fenton. Samples from different stages of both AOPs were taken for Zahn–Wellens biocompatibility tests. Biodegradability enhancement of the industrial saline wastewater was confirmed (>70% biodegradability). Biodegradable compounds generated during the preliminary oxidative processes were biologically mineralised in a 170-L aerobic immobilised biomass reactor (IBR). The global efficiency of both AOP/biological combined systems was 90% removal of an initial TOC of over 500 mg L-1 2009-01-15T00:00:00Z Oller, I. og Malato, S. og Sánchez-Pérez , J. A. og Maldonado, M. I. og Gernjak, W. og Pérez-Estrada, L. A. http://espace.library.uq.edu.au/view/UQ:145156 We introduce an Australian collaborative research and development project aimed at implementing advanced process control strategies to biological nutrient removal wastewater treatment plants. We show why process control is a key technology for the future of this industry and present several control 'tools' which we have developed. (C) 1999 IAWQ Published by Elsevier Science Ltd. All rights reserved. 2008-06-10T00:00:00Z Islam, K. A. og Newell, B. og Lant, P. http://espace.library.uq.edu.au/view/UQ:256478 2011-10-17T00:00:00Z Reungoat, Julien http://espace.library.uq.edu.au/view/UQ:164482 2009-02-16T00:00:00Z Rudder, J. D. og Wiele, T. V. D. og Dhooge, W. og Comhaire, F. og Verstraete, W. http://espace.library.uq.edu.au/view/UQ:132897 The enhanced biological phosphorus removal (EBPR) process has been implemented in many wastewater treatment plants worldwide. While the EBPR process is indeed capable of efficient phosphorus (P) removal performance, disturbances and prolonged periods of insufficient P removal have been observed at full-scale plants on numerous occasions under conditions that are seemingly favourable for EBPR. Recent studies in this field have utilised a wide range of approaches to address this problem, from studying the microorganisms that are primarily responsible for or detrimental to this process, to determining their biochemical pathways and developing mathematical models that facilitate better prediction of process performance. The overall goal of each of these studies is to obtain a more detailed insight into how the EBPR process works, where the best way of achieving this objective is through linking together the information obtained using these different approaches. This review paper critically assesses the recent advances that have been achieved in this field, particularly relating to the areas of EBPR microbiology, biochemistry, process operation and process modelling. Potential areas for future research are also proposed. Although previous research in this field has undoubtedly improved our level of understanding, it is clear that much remains to be learned about the process, as many unanswered questions still remain. One of the challenges appears to be the integration of the existing and growing scientific knowledge base with the observations and applications in practice, which this paper hopes to partially achieve. (C) 2007 Elsevier Ltd. All rights reserved. 2008-03-26T00:00:00Z Oehmen, A. M. og Lemos, P.C. og Carvalho, G. og Yuan, Z. og Keller, J. og Blackall, L. L. og Reis, M. A. M. http://espace.library.uq.edu.au/view/UQ:267315 2012-02-09T12:34:47Z Watts, Shane og de Kruek, Merle og Pijuan, Maite og Di Iaconi, Claudio og Ried, Achim og Rossetti, Simona og Del Moro, Guido og Mansini, Annalisa og De Sanctis, Marco og Giesen, Andreas og Pronk, Mario og Vanloosdrecht, Mark M. C. og Keller, Jurg http://espace.library.uq.edu.au/view/UQ:139020 2008-05-30T00:00:00Z Yilmaz, G. og Lemaire, R. og Keller, J. og Yuan, Z. http://espace.library.uq.edu.au/view/UQ:196364 2010-02-23T00:00:00Z Watts, S. R. og Millan, L. og Read, P. og Keller, J. http://espace.library.uq.edu.au/view/UQ:164629 Aerobic granular sludge was successfully cultivated in a lab-scale SBR-system treating malting wastewater with a high content of particulate organic matter (0.9 gTSS/L). At an organic loading rate (CODtotal) of 3.4 kg/(m3.d) an average removal efficiency of 50% in CODtotal and 80% in CODdissolved was achieved. Fractionation of the COD by means of particle size showed that particles with a diameter less than 25-50 mm could be removed at 80% efficiency, whereas particles bigger than 50 mm were only removed at 40% efficiency. Tracer experiments revealed a dense sessile protozoa population covering the granules. The protozoa appeared to be responsible for primary particle uptake from the wastewater. 2009-02-17T00:00:00Z Schwarzenbeck, N. og Erley, R. og Wilderer, P. http://espace.library.uq.edu.au/view/UQ:278644 2012-08-06T10:56:20Z Ni, Bing-Jie og Yu, Han-Qing http://espace.library.uq.edu.au/view/UQ:141717 The ability of heterotrophic bacteria in a nitrite-oxidising bioreactor to respire with nitrate as an electron acceptor was examined. Approximately 70% of 1000 heterotrophic isolates were able to express a nitrate reductase. A detailed survey of 15 isolates showed that five expressed the azide-insensitive nitrate reductase encoded by the napA gene. A two-round PCR amplification of the napA gene using degenerate PCR primers and DNA sequence analysis of these products confirmed the presence of this gene in the positive isolates. Partial 16S rDNA products and napA products were amplified from the biomass in the bioreactor and denaturing gradient gel electrophoresis of these products identified 21 distinct ribotypes and 12 distinct napA sequences. The results show that the ability to respire with nitrate as an electron acceptor under aerobic conditions is widespread among the heterotrophic population of this bioreactor. (C) 2000 Federation of European Microbiological Societies. Published by Elsevier Science B.V. All rights reserved. 2008-06-10T00:00:00Z McDevitt, C. og Burrell, P. og Blackall, L. L. og McEwan, A. G. http://espace.library.uq.edu.au/view/UQ:161129 The main processes involved in enhanced biological phosphorus removal (EBPR) under anaerobic and subsequently aerobic conditions are widely described in the literature. Polyphosphate accumulating organisms (PAO) are the organisms responsible for this process. However, the mechanisms of PAO are not fully established yet under conditions that differ from the classical anaerobic/aerobic conditions. In this work, we made a comparison between the behavior of PAO under classical EBPR conditions and its behavior when consuming substrate under only aerobic conditions. In addition, oxygen uptake rate (OUR) was measured in the set of experiments under aerobic conditions to improve the characterization of the process. A kinetic and stoichiometric model based on Activated Sludge Model No.2 (ASM2) and including glycogen economy (AnOx model), calibrated for classical anaerobic/aerobic conditions, was not able to describe the experimental data since it underestimated the acetate consumption, the PHB storage, and the OUR. Two different hypotheses for describing the experimental measurements were proposed and modeled. Both hypotheses considered that PAO, under aerobic conditions, uptake acetate coupled to PHB storage, glycogen degradation, and phosphorus release as in anaerobic conditions. Moreover, the first hypothesis (PAO-hypothesis) considered that PAO were able to store acetate as PHB linked to oxygen consumption and the second one (OHO hypothesis) considered that this storage was due to ordinary heterotrophic organisms (OHO). Both hypotheses were evaluated by simulation extending the AnOx model with additional equations. The main differences observed were the predictions for PHB degradation during the famine phase and the OUR profile during both feast and famine phases. The OHO hypothesis described the experimental profiles more accurately than the PAO hypothesis. 2009-01-19T00:00:00Z Guisasola, Albert og Pijuan, Maite og Baeza, Juan A. og Carrera, Julián og Casas, Carles og Lafuente, Javier http://espace.library.uq.edu.au/view/UQ:161134 The mechanisms of polyphosphate accumulating organisms (PAO) are not fully established yet under conditions that differ from the classical anaerobic/aerobic conditions. Recently, some research in the field of biological phosphorus removal has been focused on studying systems where the electron donor (substrate) and the electron acceptor (nitrate or oxygen) are present simultaneously. The aim of this study was to assess the influence of the levels of intracellular storage compounds in the net phosphorus removal process occurring under continuous aerobic conditions. An enhanced biological phosphorus removal (EBPR) system was enriched in a sequencing batch reactor working under alternating anaerobic/aerobic conditions and the percentage of “Candidatus Accumulibacter phosphatis” (the PAO in this study) was 45%. Three different batch experiments were performed to obtain a better insight of this process: one under standard anaerobic–aerobic conditions and two experiments under strictly aerobic conditions. One of the aerobic experiments was developed with the EBPR biomass withdrawn at the end of the anaerobic period and the other one with biomass withdrawn at the end of the aerobic period of the standard process. Although net phosphorus removal was achieved in both aerobic experiments, the ratios of phosphorus released and glycogen degraded versus acetate taken up were higher when the sludge was withdrawn at the end of the aerobic period, where higher levels of polyphosphate and glycogen were present in the biomass. 2009-01-19T00:00:00Z Pijuan, M. og Guisasola, A. og Baeza, J.A. og Carrera, J. og Casas, C. og Lafuente, J. http://espace.library.uq.edu.au/view/UQ:285441 Aerobic sludge granules are suspended biofilms with the potential to reduce the cost and footprint of secondary wastewater treatment. Attempts to answer how and why they form leads to a consideration of the role of their extracellular polymeric substances (EPS) in determining their physical and microbiological properties. The exopolysaccharide components of this matrix, in particular, have received attention as putative structural, gel-forming agents. Two quite different exopolysaccharides have been proposed as the gel-forming constituents, with their gel properties clearly different from those of activated sludge EPS. This review aims to address the question of whether more than one gel-forming exopolysaccharide exist in granules. Based on the available structural data, it seems likely that they are different gel-forming polymers and their differences are not artifacts of the analytical methods used. Nonetheless, both proposed structural gel polymers are extracted and purified based on procedures selecting for anionic polar polysaccharides soluble at high pH, and both contain hexuronic acids. Granulation does not result from EPS synthesis by any single microbial population, nor from production of a single exopolysaccharide. Future studies using solvents suitable for recalcitrant polysaccharides are likely to reveal important structural roles for other polysaccharides. It is hoped that this article will serve as a guide for subsequent studies into understanding the roles of exopolysaccharides in aerobic granular sludge. 2012-11-15T15:05:51Z Seviour, Thomas og Yuan, Zhiguo og van Loosdrecht, Mark C. M. og Lin, Yuemei http://espace.library.uq.edu.au/view/UQ:95739 2007-08-23T00:00:00Z Rosen, C. og Larson, M. og Jeppsson, V. og Yuan, Z. http://espace.library.uq.edu.au/view/UQ:61856 In this paper an approach to extreme event control in wastewater treatment plant operation by use of automatic supervisory control is discussed. The framework presented is based on the fact that different operational conditions manifest themselves as clusters in a multivariate measurement space. These clusters are identified and linked to specific and corresponding events by use of principal component analysis and fuzzy c-means clustering. A reduced system model is assigned to each type of extreme event and used to calculate appropriate local controller set points. In earlier work we have shown that this approach is applicable to wastewater treatment control using look-up tables to determine current set points. In this work we focus on the automatic determination of appropriate set points by use of steady state and dynamic predictions. The performance of a relatively simple steady-state supervisory controller is compared with that of a model predictive supervisory controller. Also, a look-up table approach is included in the comparison, as it provides a simple and robust alternative to the steady-state and model predictive controllers, The methodology is illustrated in a simulation study. 2007-08-14T00:00:00Z Rosen, C. og Larsson, M. og Jeppsson, U. og Yuan, Z. http://espace.library.uq.edu.au/view/UQ:257286 2011-10-19T00:00:00Z Le Corre, Kristell S. og Valsami-Jones, Eugenia og Hobbs, Phil og Jefferson, Bruce og Parsons, Simon A.