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Against the trend prevalent during the 1990s and 2000s, large-scale infrastructural projects have made a comeback in the water sector. Although sometimes framed as part of a broader sustainable transition, the return of big infrastructure is a much more complicated story in which finance has played a crucial role. In the following article, we explore this encounter between finance and water infrastructure using the case of Britain's first experiment in desalination technologies, the Thames Water Desalination Plant (TWDP). On the surface, the plant appears to be a classic example of the successes of normative industrial ecology, in which sustainability challenges have been met with forward-thinking green innovations. However, the TWDP is utterly dependent on a byzantine financial model, which has shaped Thames Water's investment strategy over the last decade. This article returns to the fundamental question of whether London ever needed a desalination plant in the first place. Deploying an urban political ecology approach, we demonstrate how the plant is simultaneously an iconic illustration of ecological modernization and a fragile example of an infrastructure-heavy solution to the demands of financialization. Understanding the development of the TWDP requires a focus on the scalar interactions between flows of finance, waste, energy and water that are woven through the hydrosocial cycle of London. Contra la tendencia prevaleciente durante los años 1990 y 2000, los proyectos de infraestructura a gran escala han vuelto a aparecer en el sector del agua. Aunque a veces se enmarca como parte de una transición sostenible más amplia, el retorno de la gran infraestructura es una historia mucho más complicada en la que las finanzas han desempeñado un papel crucial. En el siguiente artículo exploramos este encuentro entre las finanzas y la infraestructura del agua utilizando el caso del primer experimento de Gran Bretaña en tecnologías de desalinización, la Planta de Desalinización de Agua del Thames (TWDP). En la superficie, la planta parece ser un ejemplo clásico de los éxitos de la ecología industrial normativa, en la cual los desafíos de sostenibilidad se han encontrado con innovaciones ecológicas progresistas. Sin embargo, el TWDP es completamente dependiente de un modelo financiero bizantino, que ha dado forma a la estrategia de inversión de Thames Water en la última década. Este artículo vuelve a la cuestión fundamental de si Londres alguna vez necesitó una planta de desalinización en primer lugar. Implementando un enfoque de ecología política urbana, demostramos cómo la planta es a la vez una ilustración icónica de la modernización ecológica y un ejemplo frágil de una solución de infraestructura pesada a las demandas de financiarización. Comprender el desarrollo del TWDP requiere un enfoque en las interacciones escalares entre los flujos de financiamiento, desperdicio, energía y agua que se tejen a través del ciclo hidrosocial de Londres. Contra la tendència prevalent durant els anys 1990 i 2000, els projectes d'infraestructura a gran escala han tornat a aparèixer en el sector de l'aigua. Encara que de vegades s'emmarca com a part d'una transició sostenible més àmplia, el retorn de la gran infraestructura és una història molt més complicada en què les finances han tingut un paper crucial. En el següent article explorem aquesta trobada entre les finances i la infraestructura de l'aigua utilitzant el cas del primer experiment de la Gran Bretanya en tecnologies de dessalinització, la Planta de Dessalinització d'Aigua del Thames (TWDP). A la superfície, la planta sembla ser un exemple clàssic dels èxits de l'ecologia industrial normativa, en la qual els desafiaments de sostenibilitat s'han trobat amb innovacions ecològiques progressistes. No obstant això, el TWDP és completament depenent d'un model financer bizantí, que ha donat forma a l'estratègia d'inversió de Thames Water en l'última dècada. Aquest article torna a la qüestió fonamental de si Londres alguna vegada va necessitar una planta de dessalinització en primer lloc. Implementant un enfocament d'ecologia política urbana, vam demostrar com la planta és alhora una il·lustració icònica de la modernització ecològica i un exemple fràgil d'una solució d'infraestructura pesada a les demandes de financiarització. Comprendre el desenvolupament del TWDP requereix un enfocament en les interaccions escalessis entre els fluxos de finançament, malbaratament, energia i aigua que es teixeixen a través del cicle hidrosocial de Londres.

High pulsed electric field (PEF) can be used effectively in drinking water purification, by applying it across the water sample to be treated. Application of sufficient high PEF guarantees killing of harmful germs and bacteria in the drinking water. In this paper, a new multi-module high voltage pulse generator is proposed. Each module is based on DC-DC boost converter in conjunction with capacitor-diode voltage multiplier (CDVM), with closed loop control on its output voltage. The modules are fed from isolated low voltage DC sources, and their synchronized pulsed output voltages are connected in series to increase the total pulsed output voltage. The main advantages of the proposed approach are modularity, scalability, redundancy, and employment of relatively low/medium voltage semiconductor devices to generate a high output voltage (i.e. no need for series connected switches). The proposed approach is validated by simulation study assuming different operating conditions. 2016 IEEE. Scopus

This paper describes a versatile, and simple synthetic route for the preparation of a range of reduced graphene oxide (RGO)-metal/metal oxide composites and their application in water purification. The inherent reduction ability of RGO has been utilized to produce the composite structure from the respective precursor ions. Various spectroscopic and microscopic techniques were employed to characterize the as-synthesized composites. The data reveal that the RGO-composites are formed through a redox-like reaction between RGO and the metal precursor. RGO is progressively oxidized primarily to graphene oxide (GO) and the formed metal nanoparticles are anchored onto the carbon sheets. Metal ion scavenging applications of RGO-MnO2 and RGO-Ag were demonstrated by taking Hg(II) as the model pollutant. RGO and the composites give a high distribution coefficient (Kd), greater than 10Lg-1 for Hg(II) uptake. The Kd values for the composites are found to be about an order of magnitude higher compared to parent RGO and GO for this application. A methodology was developed to immobilize RGO-composites on river sand (RS) using chitosan as the binder. The as-supported composites are found to be efficient adsorbent candidates for field application. � 2010 Elsevier B.V.

This paper provides perspectives on patterns of public-private partnerships in infrastructure across time and space. Public-private partnerships are a new term for old concepts. Much infrastructure started under private auspices. Then many governments nationalized the ventures. Governments often push infrastructure providers to keep prices low. In emerging markets, the price of water covers maybe 30 percent of costs on average, that of electricity some 80 percent of costs. This renders public infrastructure ventures dependent on subsidies. When governments run into fiscal troubles, they often look again for public-private partnerships, and price increases. As a result, public-private partnerships keep making a comeback in most countries, but are not always loved. Waves of interest in public-private partnerships sweep different countries at different times. Overall, in emerging markets today, public-private partnerships account for some 20 percent of infrastructure investments, with wide variations across countries and from year to year. There is no “killer” rationale for public-private partnerships. They can help raise financing when governments face borrowing constraints. They can be more efficient when sound incentives are applied. Existing evaluations suggest public-private partnerships tend to perform often a bit better than public provision. Yet, well-run governments can do as well. Public-private partnerships provide mechanisms to improve the governance of infrastructure ventures where governments are flawed. Once the fiscal troubles are over, the politics of pricing assert themselves again. Tight pricing erodes the profitability of public-private partnerships and the wheel of privatization and nationalization keeps turning, as it has since modern infrastructure services were invented.

Ultrasonic concentration meters have widely been used at water purification, sewage treatment and waste water treatment plants to sort and transfer high concentration sludges and to control the amount of chemical dosage. When an unusual substance is contained in the sludge, however, the attenuation of ultrasonic waves could be increased or not be transmitted to the receiver. In this case, the value measured by a concentration meter is higher than the actual density value or vibration. As well, it is difficult to automate the residuals treatment process according to the various problems such as sludge attachment or sensor failure. An ultrasonic multi-beam concentration sensor was considered to solve these problems, but an abnormal concentration value of a specific ultrasonic beam degrades the accuracy of the entire measurement in case of using a conventional arithmetic mean for all measurement values, so this paper proposes a method to improve the accuracy of the sludge concentration determination by choosing reliable sensor values and applying a neuro-fuzzy learning algorithm. The newly developed meter is proven to render useful results from a variety of experiments on a real water treatment plant.

Las plantas de potabilización producen agua de buena calidad a partir de agua cruda captada de cualquier fuente, pero en su proceso de tratamiento generan efluentes contaminantes que son desechados sin algún tratamiento en una fuente superficial de agua, dichos efluentes tienen un impacto negativo en la fuente receptora y en la población aguas abajo del punto de descarga. En este trabajo de grado se hacen los estudios necesarios para el tratamiento de estos efluentes en la planta de potabilización Los Cuervos ubicada en el municipio de Chinchiná Caldas y con base en los resultados obtenidos se hace el diseño de las estructuras civiles, equipos y maquinaria necesaria para la mitigación del impacto de estos residuos en la fuente receptora. Los efluentes de las plantas de potabilización son conocidos como lodos livianos (aguas de lavado de los filtros) y lodos gruesos (lodos producidos por los sedimentadores de las plantas), los cuales se tratarán como agua de recirculación y tratamiento de concentración y secado respectivamente Abstract : The water treatment plants produce good quality water from raw water collected from any source, but their treatment processes generates pollutants effluents, and are disposed without any treatment in a surface water source, such effluents have a negative impact on the source receiving and population downstream of the discharge point. In this paper grade studies needed to treat this effluent water treatment plant Los Cuervos in the municipality of Caldas Chinchiná and based on the results of the design of civil structures, equipment and machinery required is made to mitigate the impact of these wastes on the receiving source. The effluent treatment plants are known as light sludge (wash water filters) and heavy sludge (sludge produced by settlers from plants), which are treated as water recirculation and treatment concentration and drying respectively Maestría

Current paper’s main contribution includes hydrodynamic modeling and morphological analysis of lake Bolonha which, along with lake Água Preta, makes up the Utinga watershed in Belém, Pará State, Brazil. Bathymetry of lake Bolonha was undertaken by digitalizing the data provided by COSANPA (the local Sanitation and Water Supply Company) dating back to 1983, and from a 2007 field study. Both bathymetries produced two terrain elevation models which were used for morphological analysis and hydrodynamic simulations. The morphological analysis showed that between 1983 and 2007, no significant relief changes occurred on the bottom of lake Bolonha, except for the formation of the outflow channels between the interconnecting channel and Bolonha Water Treatment Plant (WTP). The hydrodynamic model was able to simulate depths and velocities. The velocities, ranging between 1.8 and 9.0 cm s-1, showed a subtle current between the outlet of the canal connecting the lakes Bolonha and Água Preta and the water intakes of the Bolonha and São Braz WTPs. This fact demonstrated that lake Bolonha reservoir is a passage for waters from lake Água Preta.

In this paper, two practical case studies for upgrading two wastewater treatment plants (WWTPs) using the general model BNRM1 (Biological Nutrient Removal Model No. 1) are presented. In the first case study, the Tarragona WWTP was upgraded by reducing the phosphorus load to the anaerobic digester in order to minimize the precipitation problems. Phosphorus load reduction was accomplished by mixing the primary sludge and the secondary sludge and by elutriating the mixed sludge. In the second case study, the Alcantarilla WWTP, the nutrient removal was enhanced by maintaining a relatively low dissolved oxygen concentration in Stage A to maintain the acidogenic bacteria activity. The VFA produced in Stage A favour the denitrification process and biological phosphorus removal in Stage B. These case studies demonstrate the benefits of using the general model BNRM1 to simulate settling processes and biological processes related to both anaerobic and aerobic bacteria in the same process unit., The authors would like to express their gratitude to the Ministry of Science and Education (Spain) for their financial support (CTM2005-06919-C03.). Financial support from Entitat Publica de Sanejament d'Aigues Residuals de la Comunitat Valenciana and Depuracion de Aguas del Mediterraneo is also gratefully acknowledged.

This paper describes a green method for the synthesis of graphenic material from cane sugar, a common disaccharide. A suitable methodology was introduced to immobilize this material on sand without the need of any binder, resulting in a composite, referred to as graphene sand composite (GSC). Raman spectroscopy confirmed that the material is indeed graphenic in nature, having G and D bands at 1597 and 1338 cm -1, respectively. It effectively removes contaminants from water. Here, we use rhodamine 6G (R6G) as a model dye and chloropyrifos (CP) as a model pesticide to demonstrate this application. The spectroscopic and microscopic analyses coupled with adsorption experiments revealed that physical adsorption plays a dominant role in the adsorption process. Isotherm data in batch experiments show an adsorption capacity of 55 mg/g for R6G and 48 mg/g for CP, which are superior to that of activated carbon. The adsorbent can be easily regenerated using a suitable eluent. This quick and cost-effective technique for the into a commercial water filter with appropriate engineering. � 2012 American Chemical Society.

The basins of Piracicaba, Capivari and Jundiaí has a territory of 15,304 square kilometers, about 5.2 million inhabitants, 7% of gross national product. However, the scarcity of water resources threatens all this prosperity. The uses of water have led to conflicts because of its multiple and diverse purposes, which require different quantities and qualities. It is against this background that becomes fundamental to understand the current situation of water supply and waste management from the treatment process. The mobilization of society, awareness of public officials and increase the availability of financial resources for the sanitation sector have provided the municipalities to increase their rates of water treatment, through the construction of new structures and technological innovations, however, has aroused another focus attention to the urgent need for the systemic management of waste from water treatment plants, especially the generation, treatment and disposal of sludge and its actual and potential environmental impacts. This research has made diagnosis of generation under the quantitative aspect of the sludge generated in the 89 water treatment plants operating in 58 cities, and identify some experiences about the management. Through various methodological tools, such as the use of questionnaires for data collection to obtain primary data, the paper presents and discusses information about the current generation of waste, existing experiences regarding the disposal and treatment, and the challenges issue requires to be addressed. The results pointed that 9013.20 tons of monthly dry solids are generated, with prominence the one that 70% of plants in operation don't possess any of measurement of the muds system. The realities, front to the service of the effective legislations, training lack and the managers systemic administration and operators on the theme as well as the need of the integration of the sectorial politics with the operation of the systems of water supply that are the great challenges to be overcome. As bacias hidrográficas dos Rios Piracicaba, Capivari e Jundiaí possuem um território de 15.304 Km², cerca de 5,2 milhões de habitantes, 7% do Produto Interno Bruto Nacional. No entanto, a escassez dos recursos hídricos ameaça toda essa prosperidade. Os usos da água têm gerado conflitos em razão de sua multiplicidade e finalidades diversas, as quais demandam quantidades e qualidades diferentes. É diante desse panorama que se torna fundamental o conhecimento do cenário atual do abastecimento de água e a gestão dos resíduos oriundos do processo de tratamento. A mobilização da sociedade, a conscientização dos gestores públicos e o aumento da disponibilidade de recursos financeiros para o setor de saneamento têm proporcionado que os municípios aumentem os seus índices de tratamento de água, através da construção de novas estruturas e inovações tecnológicas, entretanto, tem despertado a atenção para outro foco, a premente necessidade da gestão sistêmica dos resíduos oriundos das estações de tratamento de água, com destaque a geração, tratamento e disposição dos lodos e seus potenciais e efetivos impactos ambientais. Este trabalho procurou diagnosticar a geração sob o aspecto quantitativo dos lodos gerados em 89 ETAs em operação nos 58 municípios paulistas integrantes da UGRHI n.° 5, além de identificar algumas experiências quanto ao gerenciamento. Através de diversos instrumentos metodológicos, como a utilização de questionários de coleta de dados para obtenção de dados primários, a adoção de métodos teóricos, visitas técnicas, o trabalho apresenta e discute as informações acerca da geração atual desses resíduos, as experiências existentes quanto à destinação final e tratamento, além dos desafios que a temática exige a serem enfrentados. Os resultados apontaram que são gerados 9013,20 toneladas de sólidos secos mensais, com destaque a que 70% das ETAs em operação não possuem sistema algum de medição dos lodos. As realidades, frente ao atendimento das legislações vigentes, carência de capacitação e gestão sistêmica dos gestores e operadores sobre a temática bem como a necessidade da integração das políticas setoriais com a operação dos sistemas de abastecimento de água que se demonstraram como grandes os desafios a serem superados.

Performance assessment of water supply and wastewater services is nowadays a major issue. Over the past six years, LNEC has been developing performance assessment systems (PASs) for water treatment plants (WTPs) and wastewater treatment plants (WWTPs). In 2009, a national field test was launched, 'PASt21', coordinated by LNEC and involving 27 plants (10 WTP and 17 WWTP). This paper presents the second generation of the PI system for the overall performance assessment of WTPs and WWTPs and the PI results obtained with the data available for 2006-2009. It was concluded that all indicators of the systems are relevant, and the results show the ability of the proposed PI systems to assess the overall performance of a given treatment plant. The aggregated results are very important for the continuous improvement of the plant performance through benchmarking and targets’ periodic reassessment. 3 7 16p DHA/NES 2011 14 a 16 Março

This paper presents a computer tool called DSC (Simulation based Controllers Design) that enables an easy design of control systems and strategies applied to wastewater treatment plants. Although the control systems are developed and evaluated by simulation, this tool aims to facilitate the direct implementation of the designed control system to the PC of the full-scale WWTP (wastewater treatment plants). The designed control system can be programmed in a dedicated control application and can be connected to either the simulation software or the SCADA of the plant. To this end, the developed DSC incorporates an OPC server (OLE for process control) which facilitates an open-standard communication protocol for different industrial process applications. The potential capabilities of the DSC tool are illustrated through the example of a full-scale application. An aeration control system applied to a nutrient removing WWTP was designed, tuned and evaluated with the DSC tool before its implementation in the full scale plant. The control parameters obtained by simulation were suitable for the full scale plant with only few modifications to improve the control performance. With the DSC tool, the control systems performance can be easily evaluated by simulation. Once developed and tuned by simulation, the control systems can be directly applied to the full-scale WWTP. © IWA Publishing 2011.

The electrochemical treatment of wastewaters from textile industry is a promising technique for substances which are resistant to biodegradation. This paper deals with the electrochemical decolourisation/degradation of synthetic solutions containing a reactive dye, C.I. Reactive Orange 4. Oxidation, reduction and oxido-reduction processes were evaluated using Ti/SnO 2-Sb-Pt and stainless steel electrodes as anode and cathode, respectively. Electrolyses were performed at galvanostatic conditions in a filter press reactor. Decolourisation and degradation were followed by means of total organic carbon (TOC), chemical oxygen demand (COD) measurements and high performance liquid chromatography (HPLC). A higher mineralisation rate for oxidation was found whilst oxido-reduction process gave more oxidised species. The kinetics of decolourisation was of pseudo-first order in all cases. The reduction process was the slowest process to decolourise. Gas chromatography-mass spectrometry (GC-MS) was employed to investigate the main intermediate compounds, confirming the presence of 2-amino-1, 5-naphthalenedisulphonic acid (2A15NDS) in solution. When this compound was generated, it was gradually degraded during the oxidation and oxido-reduction processes indicating the feasibility and durability of Ti/SnO 2-Sb-Pt electrodes. However, during the electrochemical reduction process, this compound was continuously generated but it was not degraded. © 2011 Elsevier B.V., The authors would like to acknowledge the Spanish Ministry of Science and Innovation (MICINN) and European Union (FEDER funds) for the financial support (CTM2007-66570-C02-02 and CTM2010-18842-C02-02). A. I. del Rio thanks the Spanish Ministry of Science and Innovation (MICINN) for her F.P.I. grant awarding. J. Molina is grateful to the Conselleria d'Educacio (Generalitat Valenciana) for his FPI grant awarding.

In this paper,we evaluate the application of a sensitivity analysis to help fine-tuning a fuzzy controller for a biological nitrogen and phosphorus removal (BNPR) plant. TheMorris Screeningmethod is proposed and evaluated as a prior step to obtain the parameter significance ranking. First, an iterative procedure has been performed in order to find out the proper repetition number of the elementary effects (r) of the method. The optimal repetition number found in this study (r = 60) is in direct contrast to previous applications of the Morris method, which usually use low repetition number, e.g. r = 10 ~ 20. Working with a non-proper repetition number (r) could lead to Type I error (identifying a not-important factor as significant (false positive)) aswell as Type II error (identifying an important factor as not significant (false negative)), hence emphasizing the importance of finding the optimal repetition number for each study in question. With the proper r found, the Morris Screening helped identify the parameter significance ranking, thereby facilitating the calibration of fuzzy controllers,which containmany parameters that need to be adjusted for different wastewater treatment plant (WWTP) applications. © IWA Publishing 2011.

The present paper deals with the photocatalytic transformation of HHCB (1,3.4.6,7,8-hexahydro-4,6,6,7.8,8-hexamethylcyclopent[gamma]+2-benzopyran, trade name Galaxolide), under simulated solar irradiation using titanium dioxide as a photocatalyst. The investigation has involved a study of HHCB decomposition under a variety of experimental conditions, the identification of intermediate compounds, as well as the assessment of mineralization. A fully nested experimental design was applied to study the effect of various matrices (i.e. distilled water, surface water and wastewater) as well as the initial HHCB concentration on the variation of the photocatalytic efficiency. GC/MS and LC/MS were brought to bear in assessing the temporal course of the photocatalyzed process. A first pathway involves the hydroxylation, that is confined to the benzopyran moiety. Another route proceeds through the detachment of the hexamethylpentacycle moiety, with the formation of the ketoderivative. A parallel transformation involves benzopyran moiety with the ring cleavage. All the identified transformation products are degraded themselves until 2 h of irradiation, while complete mineralization is achieved until 8 h. (C) 2010 Elsevier B.V. All rights reserved. Applied Catalysis B-Environmental

6 páginas, 3 figuras, 2 tablas.-- Proceedings of the 44th IEEE Conference on Decision and Control, and the European Control Conference 2005 Seville, Spain, Dec. 12-15 (2005)., The problem of integrated design and control optimization of process plants is discussed in this paper. We consider it as a nonlinear programming problem subject to differential-algebraic constraints. This class of problems is frequently (i) non-convex and (ii) "costly" (i.e. computationally expensive to evaluate). Thus, on the one hand, local optimization techniques usually fail to locate the global solution and, on the second hand, most global optimization methods require many simulations of the model, resulting in unaffordable computation times. As an alternative, one may consider global optimization methods which employ surrogate-based approaches to reduce computation times, and which require no knowledge of the problem structure. A challenging Wastewater Treatment Plant benchmark model (see [1] and references therein) is used to evaluate the performance of these techniques. Numerical experiments with different optimization solvers indicate that the proposed benchmark optimization problem is indeed non-convex, and that we can achieve an improvement of the controller performance compared to the best tuned controller settings available in the literature. Moreover, these results show that surrogate-based methods may indeed reduce computation times while, at the same time ensuring convergence to the best known solutions.