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Über dieses Buch

Growing populations and rising standards of living exert stress on water supply and the quality of drinking water. In wastewater management, new challenges are caused by new chemicals of concern, including endocrine disrupters, pharmaceuticals, hormones, and personal care products, which often pass through wastewater treatment plants unabated, but may cause serious impacts on receiving aquatic ecosystems. Advanced wastewater treatment leads to production of biosolids, which are processed in various ways, including on-land applications in agriculture. Municipal effluents, combined with increasing withdrawals of water, lead to the worsening of receiving water quality. Expert opinions indicate that the only way to deal with the current urban water management dilemmas is by integrated management and innovative delivery of water services.

This book presents important aspects of Challenges in Management of Urban Water Resources, Challenges in Urban Water Supply, Urban Drainage and Water Bodies, Wastewater Treatment and Security, and Wastewater Treatment and Reuse.

Inhaltsverzeichnis

Frontmatter

CHALLENGES IN MANAGEMENT OF URBAN WATER RESOURCES

Frontmatter

PROTECTION OF WATER RESOURCES IN THE SLOVAK REPUBLIC

Water supply resources are groundwater and surface water bodies currently used or intended for prospective use. Water used from identified water bodies shall meet relevant qualitative objectives and resulting requirements on water quality and quantity according to its purpose of use. Water resources protection should be viewed as a integrated protection of quality and quantity of sustace and ground water, including natural curative springs and minerals waters. For water resources protection the protection zones with limited agricultural use and other activities are designated according to the valid legislation. The paper deals with issues relating to water quality and quantity protection.

JOZEF KRIŠ, MARTIN FAŠKO

THE HUMAN DIMENSIONS OF IWRM: INTERFACES BETWEEN KNOWLEDGES AND AMBITIONS

The challenges of IWRM are multiple and practitioners are only recently starting to come to terms with some of the implications of the theory. In promoting wider consultation and involvement in the management of water resources, IWRM approaches encroach on the worlds of social relations, governance and politics. In this paper, we argue for more investment in understanding how competing knowledges and ambitions might influence the search for effective and just water management arrangements. Through discussion of the nature of the interfaces where such competition takes place and the constraints placed on praxis by theory, we expose a number of challenges for the academic and practitioner communities.

PAUL JEFFREY

SUPPORTING THE SITING OF NEW URBAN DEVELOPMENTS FOR INTEGRATED URBAN WATER RESOURCE MANAGEMENT

Establishing the best location for new urban developments requires a synthesis of a variety of factors that, in view of sustainability principles, need to encompass technical and environmental issues related to urban water as well as broader requirements related to the economic and social characteristics and constraints of the region. The complexity of the problem requires a concise, structured and objective method of data organisation and analysis. Decision support systems (DSS) provide such a framework, aided by the incorporation of multi-criteria analysis. This chapter details the development of a DSS tool, based on a fuzzy inference methodology, able to prioritise areas suitable for new urban areas and to screen out unsuitable sites. The effectiveness of the tool was tested on the Humber sub-region in the UK. Results suggest that the overall suitability evaluation is mostly influenced by the choice of site attributes taken into account and to a lesser degree by analytical processes. It is concluded that the tool is flexible and user friendly and can significantly assist in the assessment and visualisation of the effect of spatial characteristics and user preferences on the siting of new urban developments.

DAVID BUTLER, ANNA KOKKALIDOU, CHRISTOS K. MAKROPOULOS

GIS FOR INTEGRATED WATER RESOURCES MANAGEMENT

GIS and modeling clearly have the potential to make an important contribution to integrated water resources management: indeed, in view of the general scarcity of environmental and health data, some form of modeling is likely to be a prerequisite. Even in the absence of a full understanding of the processes and relationships involved, or of adequate data, the construction of flow diagrams and mind maps can help to develop an appreciation of the issues and help to build consensus amongst the various stakeholders. This paper examines some of the issues involved in using GIS as part of the integrated water resources management process, and illustrates their use with examples from Ukraine.

OLEG UDOVYK

URBAN INFRASTRUCTURE MODELLING

The practical application of a simulation modelling for large size urban drainage systems is subjected to a number of simplifying assumptions, constrains and bottlenecks which require a high level of user abstraction and interpretation on a side of project team and the client. A good technical formulation of project tasks as well as a proper schematisation of a system structure and process is the essential milestone for a successful completion of the project. In the same moment numerical modelling of water supply and water distribution systems has become a standard and an inevitable practice in any serious attempt of evaluating hydraulic, water quality, and economic aspects of these complex systems. Modelling capacity of well-suited models, featuring advanced technologies including linking the models to GIS systems and telemetry systems, accurate fire flow calculations, water quality analysis, and leakage reduction is incomparable with any alternative approach for these purposes. Hydraulic modelling of water supply and water distribution network is used for planning linking-up consumers to the network and evaluating the remaining capacity of the network, modelling of network’s breakdown, modelling of various loading and operational states of the system including fire flow analysis, reconstruction of existing and planning of new pipes, pressure zone optimisation, leakage reduction and others.

KAREL PRYL, ZDENEK SVITAK

INTEGRATED URBAN WATER CYCLE MODELING

New trends are increasingly recognized in the software development business. These trends are following a couple of fundamental terms „integration“ and „openness“ and originate from long term users needs for software tools with integrated functionality and open human interface. The paper is focussing on current experience with software products and basic requirements originating from practical software use. Then a basic concept of “integrated and open” software architecture is introduced and documented on new product MIKE URBAN for integrated modelling of urban water cycle. It is argued in the paper that “integrated and open” architecture meets most of current user needs while bringing to users higher effectiveness and comfort of work.

TOMÁŠ METELKA

WATER RESOURCES POLICY AND MANAGEMENT IN JORDAN

Jordan water resources are very limited, among the lowest in the world on a per capita basis. Water demand at present exceeds the available renewable water resources which have been overexploited to bridge the gap. This gap is expected to widen in the future in all water sectors. This situation can not be maintained without endangering sustainable development. The adoption of a new strategy for water planning is therefore crucial. The strategy should focus on demand management and development of non-conventional water resources. The objective of this paper is to present the water situation in Jordan along with various components of water development and planning, and future water management scenarios.

NIZAR K. AL-HALASAH, BASHAAR Y. AMMARY

URBAN WATER RESOURCES MANAGEMENT IN UKRAINE

Analyzed in the paper are outstanding issue faced by Ukraine in the area of urban water resources management, sanitation and water supply for population and economic needs in Ukraine. Paper is based on results of studies carried out in Ukraine by a number of international organizations, e.g. the World Bank, EBRD, DANCEE at which the author took a part as a local expert.

VOLODYMYR KUZNYETSOV

WATER SUPPLY, URBAN DRAINAGE AND WASTE WATER TREATMENT IN THE ORAVA REGION

solves water supply, wastewater collection and waste water treatment in the whole Orava region, by achieving following goals:

RADOVAN HALOUN

CHALLENGES IN URBAN WATER SUPPLY

Frontmatter

ROBUST DESIGN AND MANAGEMENT OF WATER SYSTEMS: HOW TO COPE WITH RISK AND UNCERTAINTY?

The implications of uncertainty in input data and model parameters are not always understood or considered when designing urban water systems. There is an obvious need to develop design methods that can model uncertainties and produce 'robust' designs. These designs should provide adequate service to customers despite fluctuations in some or all of the design parameters. This paper presents a general methodology for robust design of such systems. The methodology is based on closely integrating reduced Monte- Carlo sampling with multiobjective Genetic Algorithms. An application to the New York Tunnels rehabilitation problem illustrates the effectiveness of the methodology. The results show that the robust design methodology presented here seems to be capable of identifying Pareto optimal fronts for uncertain input variables while achieving significant computational savings when compared to the full MC sampling technique.

DRAGAN SAVIC

AGEING AND RENEWAL OF URBAN WATER INFRASTRUCTURE

A framework for the rehabilitation management of urban water infrastructure is introduced, which distinguishes between a long-term strategic approach on the network level, and a detailed approach for setting short term rehabilitation priorities on the single pipe level. Based on a detailed condition analysis, life time expectancies for water infrastructure pipe types are defined, future rehabilitation needs are calculated, and alternative strategies are systematically compared. Then, priorities for rehabilitation are defined with a set of decision criteria within the framework of the given budget of a calculated strategy by a formalised interactive elimination procedure. Both approaches found their way into the CARE-W and CARE-S decision support systems, which have been developed in research projects under the 5

th

framework programme of the EC.

ROLF BAUR

BENCHMARKING OF WATER SUPPLY SYSTEMS - WATER LOSSES ASSESSMENT

Modern methods of benchmarking are starting to be use for objective evaluation of water supply level, these methods provide relative comparison of attained results of water companies. Possibilities for improvement of companies create by comparison of selected indicators, such way we can define situation of company considering other similar companies. Selection of figure of merits is the most important for benchmarking method to give desired results by comparison of them. Important indicators of evaluation of water supply are not only financial indicators, but technical too, technical indicators characterise technical condition of water pipelines, fault liability and with these related water losses. Water losses are significant factor, which affects inefficient exploitation of quality water sources. Management of water company needs to obtain information about selected indicators to can apply benchmarking methods. For that purpose benchmarking centres are starting to institute in the world. In this report will be presented new approach of evaluation of water losses indicators from point of view operator of water supply. There will be described benchmarking method which can be use for evaluation of water supply systems oriented for water losses. In this article will be presented results of evaluation of water supply systems in Slovakia.

KATARINA TOTHOVA, VANDA DUBOVA, DANICA BARLOKOVA

WATER SUPPLY OF BUCHAREST - PAST, PRESENT, FUTURE: A STUDY CASE

The history of water supply of Bucharest is presented starting with the first drinking water systems with faucets till the actual situation when the water supply in Bucharest is provided by the company “Apa Nova”, controlled by the French Group Veolia Water and by the Municipality Council. The main conditions of the Concession Contract, evolution of few key indicators/levels of services and technical/operational results are presented. The average water consumption per inhabitant, as well as specific consumption in industry is higher than in other countries and this due and to exaggerated losses along the delivery and distribution networks, to waste and to inefficient technologies that were used. The main measures taken in order to improve the situation of the water supply system of Bucharest:

EPSICĂ CHIRU

WATER SUPPLY IN CITIES OF BELARUS: WATER QUALITY AND RISK ASSESSMENT

In the paper different types of water supply systems in cities of Belarus and the quality of drinking water are discussed. Problems associated with intakes from pressure and non-pressure water-bearing horizons and surface water are described. Factors of drinking water pollution, including initial water chemical composition and current condition of water distribution system are analyzed. The peculiarities of groundwater pollution within urban areas, its main contaminants, spatial structure and dynamics are shown on the examples of Svetlogorsk and Polotsk cities. Ecological risk connected with consumption of polluted drinking water is assessed on the basis of concept of reference doze. The interrelated problems of groundwater pollution, safety water supply and food production are shown.

TAMARA KUKHARCHYK, VALERY KHOMICH

RISK ASSESSMENT OF POTABLE WATER USED FROM RIVER INTAKES NEAR RADIATION-DANGEROUS OBJECTS (OBNINSK FOR ILLUSTRATION)

Coupling of natural and anthropogenic factors reduces water quality to the values exceeding sanitary and hygienic standards. Near to radiationdangerous objects a threat is represented with pollution of groundwater technogenic radioisotopes, including tritium. In Russia not enough attention is given specifications under contents tritium and etc. radionuclides in potable water. For an establishment of a degree of influence on the person tritium and chemical pollutants it is convenient to use health risk assessment in its ingress into the human body.

O. MOMOT, B. SYNZYNYS, G. KOZMIN, I. SILIN

URBAN DRAINAGE AND WATER BODIES

Frontmatter

WASTEWATER NETWORK CHALLENGES AND SOLUTIONS

Sewer and storm water systems in cities worldwide suffer from ageing and inappropriate wastewater networks. This challenge has to be met by systematic upgrading and preventive maintenance. It is necessary to analyse the current performance of the wastewater networks, to determine the system bottlenecks that cause system vulnerability on floods in city areas and pollution of receiving waters. The next task is then to use this information for selecting and ranking upgrading projects to improve the situation. CARE-S is a computer based system developed to meet this challenge. It is designed for sewer and storm water network rehabilitation planning.

SVEINUNG SÆGROV, LEIF SIGURD HAFSKJOLD, AXEL KÖNIG, JON RØSTUM, INGRID SELSETH, FRØYDIS SJØVOLD, DENISE AZEVEDO, MASSIMO GADDONI, SANTE MAZZACANE, RÉMI BARBIER, JEAN-PHILIPPE TORTEROTOT, ROLF BAUR, RAIMUND HERZ, STEFAN HOEFT, INGO KROPP, NORA SCHULZ, STEWART BURN, DHAMMENIKA SILVA, ADRIANA CARDOSO, RAFAELA MATOS, DELTA SOUSA DE SILVA, JEANETTE COOKE, ROGER HURLEY, KEVIN TAYLOR, WILL WILLIAMS, VITTORIO DE FEDERICO, TONINO LISERRA, MARCO MAGLIONICO, MAURO PACCHIOLI, RITA UGARELLI, GABRIELE FRENI, PETR HLAVINEK, PETR PRAX, JAROSLAV RACLAVSKY, VLADIMIRA SULCOVA, MARCELL KNOLMAR, CZANAD GERGELEY SZABO, REIDAR KVEINE, YVES LEGAT, CATHY WEREY, JULIETA MARQUES, CARLOS MONTERO, ANGEL VILLANUEVA, JADRANKA MILINA, WOLFGANG SCHILLING, JES VOLLERTSEN

APPLICATION OF DECISION SUPPORT SYSTEM FOR SEWER NETWORK REHABILITATION

Efficient planning requires the planner to be in possession of a substantial amount of background knowledge and experience on the types of encountered problems, current performance and possible effective solutions. The engineer must be aware of the objectives of rehabilitation for each problem, and apply sound judgement using all the tools available in an appropriate manner. This places huge demands on the engineer when many rehabilitation methods are feasible and there are many solutions to improve service delivery to customers (a multivariate problem). The engineer must be guided by a suite of useful analysis tools to help him choose the most cost-effective rehabilitation options.

PETR HLAVINEK, JIRI KUBIK, PETR PRAX, PETRA SIMCIKOVA, VLADIMIRA SULCOVA

IMPLEMENTATION OF FIBER OPTIC CABLES IN SEWAGE SYSTEM

Implementation of optical fibers in the cities causes the involving excavations of city streets. These excavations cause pollution, traffic hold-ups, economic loss, and unsafe conditions to the inhabitants in every city. Even worse, the repair of the streets after excavation rarely left the streets in acceptable condition. These forced mayors to issue moratoriums on new open cut excavations involved in the “Last-Mile” work. The “Last-Mile” is the section of a network that connects from the basement of an end-user building to the city-area network that surrounds a city. The novel idea of leasing space inside of existing sewers by telecommunications companies has a rather interesting appeal in that owners of existing sewers get to generate a new revenue stream and telecommunication companies could install their optical fiber cables at an attractive cost. This paper describe the advantages of building optical fiber networks inside existing sewers, base conditions for this implementation and briefly describe the interactions between the pipe, cable and liquid. The computer simulations was execute with MOUSE model in the Slovakia.

STEFAN STANKO, IVANA MAHRIKOVA

OVERVIEW OF URBAN DRAINAGE IMPACTS ON AQUATIC HABITAT

Urban drainage impacts on aquatic habitat are discussed under five major headings affecting the biological community performance: food (energy) sources, water quality, habitat structure, flow regime, and biotic interactions. Among these factors, perhaps the best understood one is stormwater quality. On the other hand, the changes in the (physical) aquatic habitat structure resulting from urbanization and stormwater discharges are the least understood and require further study. Promising approaches to mitigating the adverse drainage impacts on habitat include preservation of natural drainage features, sustainable development or redevelopment of urban areas, and balanced applications of stormwater management practices.

JIRI MARSALEK

URBAN RUNOFF – CONTAMINATION, PROBLEMS OF TREATMENT AND IMPACT ON RECEIVING WATER

In the paper the results of urban runoff chemical composition study in different seasonal periods and functional zones in Minsk are discussed. Increasing of contaminant concentrations in the receiving water downstream in urban area because of urban runoff impact are shown. The main pollutants (chlorides, natrium, suspended solids, heavy metals and oil products) of urban runoff are revealed. The problems of urban runoff treatment in Minsk are also under consideration.

ALENA AUCHAROVA, VALERY KHOMICH

IMPACT OF ANTHROPOGENIC LOADS ON WATER QUALITY OF RIVERS OF THE UPPER AREAS OF OKA AND DESNA BASINS

The long-term integrated investigations of water quality of rivers at different streams with different anthropogenic loads of the upper areas of Oka and Desna basins on the territory of Kaluga Region testify that downstream from cities a 2-5–km zone with the increased values of determent indices is formed. The research of chemical composition of water and bottom sediments made for streams and water bodies within the cities and adjoining suburbs suggest the increased content of heavy metals resulted from man-made activity. Storm water runoff from the territory of the rivers catchments area is the main contributor to biogenic pollution. It has been determined that most polluted are small rivers running on the territory of large cities and receiving mainly municipal wastes and storm water runoff. Large anthropogenic load is typical for some small rivers with runoff forming on urbanized and economically developed territories.

IRINA SEMENOVA, TAMARA MORSHINA, VENIAMIN SEMYONOV

BIOSORBENTS IN SURFACE WATERS IN SITU TREATMENT AGAINST RADIONUCLIDES

The method of water purification employing biosorbent of natural water reservoir, immobilized onto the fibrous carriers was suggested. The perifiton carriers were used for purification of natural water in Chernobyl zone canal falling into r. Dnieper. The developed onto carriers perifiton sorbs and holds radionuclides, their activity onto the biosorbent to be 3-4 order higher than that into the water. Both total and separate

137

Cs and

90

Sr β-activities, were determined to control radionuclide accumulation. At water/sorbent ratio of 1,2 m

3

/kg water activity was found to be 0,42.10

8

and 3,92.10

6

Bk/m

3

for

137

Cs

90

Sr respectivelly. In this case, the purification degree was 90,5 i 90,2%, respectively. The advantages of the method suggested are ass follows: simple realization, environmental friendly, avoidance of the valuable expenditure and complex expensive equipment to produce the biosorbet, possipility of succesfully purification of large volumes of the radioactive contaminated natural flowing water.

LARYSA N. SPASONOVA, V. TOBILKO, B. KORNILOVICH, P. GVOZDYAK, O. SHEVCHENKO

WASTEWATER TREATMENT AND SECURITY

Frontmatter

ECONOMIC AND TECHNICAL EFFICIENCY OF WASTEWATER PLANTS: A BASIC REQUISITE TO THE FEASIBILITY OF WATER REUSE PROJECTS

The water reuse could be considered essential both from a social and also an environmental and health point of view. In light of the growing importance of water reuse as an alternative source of water resources in many regional areas, the objective of this paper is to analyse the efficiency of wastewater treatment plants. Efficient performance, both in technical and economic terms favours reuse possibilities and, therefore, increases the water supply. An analytical benchmarking methodology based on non-radial measures gives us an efficiency indicator for each input considered in the wastewater treatment process. These indicators, obtained by means of mathematical programming techniques, are used to rank plants’ activity through a Variance Analysis.

F. HERNANDEZ-SANCHO, R. SALA-GARRIDO

JOINT OPTIMISATION OF SEWER SYSTEM AND TREATMENT PLANT CONTROL

Large cities in most of the cases are equipped with combined sewer systems discharging to waste water treatment plants. This is also the case for the City of Vienna. This city has just extended its Main Treatment Plant and has equipped the sewer system with a control system, which will make optimal use of the existing storage capacity, which amounts to about 500.000 m

3

. For the operation of the treatment plant the worst loading situation occurs at the beginning of wet weather conditions. A sophisticated control system influencing the gates in the large trunk sewers and the control system at the treatment plant are aiming at minimizing the pollution discharge to the different receiving rivers and to optimize the treatment plant performance. The basic concept of the control systems is described and first operational results from the extended Main Treatment Plant of Vienna are presented in the paper.

HELMUT KROISS

WASTEWATER TREATMENT IN BELARUS: PURIFICATION EFFICIENCY AND SURFACE WATER POLLUTION RISK

Official statistics were used for an investigation of wastewater disposal structure, for a study of characteristics of pollutants in urban sewage and estimation of anthropogenic (pollutant) load on receiving waters. The capacities of town sewage plants and efficiency of wastewater refinement are examined. It is shown that wastewater discharged without adequate treatment into surface waters has affected water bodies that have created some problems in water resources use. Pollution of receiving waters is analyzed.

OLGA KADATSKAYA

WASTEWATER TREATMENT AND REUSE

Frontmatter

WATER REUSE IN CANADA: OPPORTUNITIES AND CHALLENGES

Reclamation and reuse of various types of wastewater, including stormwater, greywater, and domestic wastewater, represents an important component of the urban water cycle helping close the loop between water supply and wastewater disposal. Safe and scientifically-based water and wastewater reuse has been practised for about a century, and a great wealth of practical experience with such practices has been reported in the literature. Essential elements of water reuse plans include the selection of categories of reuse, selection of water quality criteria for such specific reuses (in accordance with the existing regulations and guidelines), design of the treatment train providing the effluent of the required quality, and examination of overall feasibility. In Canada, water reuse is generally conducted on a small-scale or experimental basis. While no national guidelines exist at this time, a number of provinces have developed guidelines for specific water reuse applications. The current stresses on water supply, caused by growing population and increasing water demands, depletion of water sources, reduced supply reliability caused by climate change, ageing infrastructure and limited funding for its expansion, as well as the promotion of environmental sustainability and needs to reduce wastewater discharges to sensitive receiving waters, will contribute to further growth and expansion of water and wastewater reclamation and reuse.

KIRSTEN EXALL, JIRI MARSALEK, KARL SCHAEFER

INTEGRATED CONCEPTS FOR REUSE OF UPGRADED WASTEWATER – ROLE OF MEMBRANES IN WATER RECYCLING

The AQUAREC project on “Integrated Concepts for Reuse of Upgraded Wastewater” is funded by the European Commission within the 5th Framework Programme as well as in Australia by the Commonwealth Department of Education, Science and Training. The project is coordinated by RWTH Aachen University. The general objective of the AQUAREC project is to provide knowledge to support rational strategies for municipal wastewater reclamation and reuse as a major component of sustainable water management practices.

THOMAS WINTGENS, THOMAS MELIN, DAVIDE BIXIO, CHRIS THOEYE

WATER REUSE FEASIBILITY STUDY IN THE CZECH REPUBLIC

This paper describes the potential for greater wastewater reuse in the Czech Republic. On the basis of a country wide analysis of the water management situation, different regions were identified with particular water stress problems. The first water stressed region was identified on the basis of insufficient surface water quality, where most of the rivers were ranked into the water quality category V. This region is known as industrial area and hence there is a possibility to reuse wastewater for industrial purposes. The second investigated region is in a rain shadow area and can be characterized as water stressed in terms of climatic conditions. This area is in the South of Moravia which is famous for agricultural production, and there is a potential to reuse wastewater for agricultural purposes.

BEATA JANOSOVA, PETR HLAVINEK, JANA MIKLANKOVA, THOMAS WINTGENS

ALTERNATIVE FORMULATIONS FOR THE REUSE OF TREATED WASTEWATER IN MENEMEN PLAIN IRRIGATION SCHEME

this study, it is intended to investigate the possibility and technical viability of using the effluents of Izmir Wastewater Treatment Plant in Menemen plain irrigation. The research verified the fact that the influent of the plant generally demonstrates typical characteristics of domestic wastewater with the exception of elevated values of electrical conductivity and salinity. These high values are mainly attributed not only to salt water intrusion due to failing pipes and improper pipe connections of the interceptor canal but also to highly-concentrated pre-treated discharges of various industries within the city. It has also been observed that these high values are as well reflected in the plant effluent hindering its use in irrigation. Considering the strong demand for the treatment plant effluent by the farmers and irrigation unions, this study intends to find out possible solutions for high conductivity and salinity. The research involves the formulation of alternative techniques and methodologies such that the quality of treated effluents would satisfy the irrigation water quality criteria currently effective in Turkish legislation.

ORHAN GUNDUZ, AYSEN TURKMAN, DENIZ ULAS DOGANLAR

ASSESSMENT OF RAINWATER ROOF HARVESTING SYSTEMS FOR HOUSEHOLD WATER SUPPLY IN JORDAN

The largest environmental challenge that Jordan faces today is water scarcity. This scarcity attributed to climatic conditions, such as aridity and abundance of high solar radiation, and population pressure. Current use already exceeds renewable supply. Many methods have been suggested to increase the sources of water supply, one alternative source is rainwater harvesting. This paper aims at evaluating the importance of rainwater roof harvesting systems for domestic supply in Jordan. General domestic water storage patterns and design considerations of roof water harvesting systems have been addressed. Moreover, it estimates the maximum amount of rainwater, which may be collected in cisterns using roof catchment systems. Finally, recommendations to improve the quality and quantity of harvested rainwater have been provided.

FAYEZ A. ABDULLA, AMANI W. AL-SHAREEF

WASTEWATER REUSE FOR IRRIGATION ON THE DESERT SANDY SOIL OF EGYPT: LONG-TERM EFFECT

In Egypt, the reuse of sewage water on the sandy soil of El-Gabal El-Asfar Farm took place since 1923. The present work discusses the physical and chemical characteristic of this water. Different soil samples that were irrigated by sewage for different increasing periods were collected to investigate the changes in the soil texture as well as accumulation of heavy metals by the soils according to the period of irrigation (7, 12, 23, 40, 50 and 75 years). The overall results revealed that the longer period of irrigation demonstrated higher level of metal accumulation in the soil. The progressive increase of metals in the soil represents serious risk to the cultivated plant (as a food cycle). It is; therefore; recommended to decrease the level of heavy metals in sewage water via further simple wastewater treatment. For this purpose, a laboratory attempts were carried out to decrease the level of metals in the sewage water. Lime, as coagulant, and/or the dried leaves of Water Hyacinth plant were examined. Remarkable elimination of metals was demonstrated. It was also recommended to use the given sewage water for cultivating the woody or Lumber trees (for high economic revenue) to reduce any expected metal hazard in the food chain.

HUSSEIN I. ABDEL-SHAFY, MAMDOUH F. ABDEL-SABOUR

MEMBRANES FOR UNRESTRICTED WATER REUSE

Water reuse is becoming a key component of the water cycle management.The provision of sufficient and safe water supplies for human and environmental needs is a difficult challenge in many parts of the world, especially in arid regions. In order to manage water resources in an efficient and sustainable way, a wide range of tools and techniques are required. Water recycling and reuse is an increasingly important element of sustainable water management strategies in both water poor and water rich regions. Municipal wastewater, which comprises between 60-80% of municipal water consumption, is one of the most reliable sources of water, since municipal water supply is always of high priority. If treated properly, it can replace potable water and used for unrestricted irrigation, including edible crops. Membrane separation processes such as ultrafiltration (UF) and microfiltration (MF) hold the key to better water treatment as tertiary filtration, after existing biological treatment. Careful evaluation of engineering aspects of these filtration technologies will yield design and operation parameters for applications in Europe. A few case studies will be presented. Economic analysis was carried out, for a system that produces a net effluent capacity of 25,000m

3

/day, resulted in a total cost of 8-10 cent per cubic meter. Recently, Membrane Bioreactor Systems (MBR) are becoming an attractive alternative, especially for limited space constrains, taking into advantage their smaller footprint, as compared to conventional wastewater systems. Also, the higher qualities of their effluent, with SDI values lower than 3, indicate the suitability of the process for pretreatment for desalination by Reverse Osmosis, for effluents with high salinity. The concept of Integrated Membrane Systems (IMS) will be elaborated, and case studies will be described.

RAMI MESSALEM

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