In this chapter, an introduction to the drinking water treatment plants is given and focuses on the necessity of the water for human beings and for the survival of living organisms, so it emphasizes that besides protecting our environment, we have to protect and save our water sources very carefully. It discusses also that safe and clean water supplement is a great problem for the world and drinking water treatment plants are used to purify the water therefore high quality, safe and sufficient drinking water is essential for our daily life for drinking and food preparation and the water treatment plants are used to remove particles and organisms that lead to diseases and protect the public’s welfare so the supplement of pure drinkable water to the environment, people and living organisms is very important; in addition, treatment plants purification also provide drinking water that is pleasant to the senses: taste, sight and smell and provide safe, reliable drinking water to the communities they serve.
It is emphasized that to provide drinking water to the public is one of the most important tasks of communities and the design of water supply systems has to follow the rules of engineering sciences and needs technical knowledge and practical experience and water is treated differently in different communities depending on the quality of the water which enters the treatment plant.
It is shown that the Drinking Water Directive concerns the quality of water intended for human consumption. Its objective is to protect human health from adverse effects of any contamination of water intended for human consumption by ensuring that it is wholesome and clean. In order to ensure that drinking water is safe for human consumption, the Drinking Water Directive sets out minimum water quality requirements and it identifies microbiological and chemical parameters that could pose a risk to human health when concentrations exceed certain thresholds where the analysis confirms that the Drinking Water Directive contributes to high quality drinking water across the EU, as demonstrated by the high compliance levels with the drinking water quality standards.
The sanitation and hygiene practices are of vital importance for human and environmental health. Annually about 5 million people die from waterborne diseases which arise from contamination of drinking water systems with the urine and faeces of infected animal or people. The only way to break the continued transmission is to improve the people’s hygienic behavior and to provide them with certain basic needs: drinking water, washing and bathing facilities and sanitation. Several types of water contamination can be observed. There are few chemical constituents of water that can lead to acute health problems except through massive accidental contamination of a supply. Among compounds found in water that accumulate in the environment and the human body, the principal ones are: nitrate, fluoride, toxic metals (lead, cadmium, arsenic, aluminium, etc.), bromate and trihalomethanes, pesticides, persistant organic pollutants or POPs (PAHs, PCBs), metals (As, Pb, Cu), hormonal disrupters. The radiological health risk associated with the presence of naturally occurring radionuclides in drinking water should also be taken into consideration. However, one of the most important risks associated with unpurified water is related with the microbial contaminations and transmission of waterborne diseases. Water-related diseases can be classified into 4 major categories: water-borne, water-washed, water-based, and water-related vector-borne. Regular sanitary risk assessment helps to identify these threats to public health and several sanitary standards were introduced, which recorded observable sanitary hazards of water resources, including sources of pollution and technical conditions of the water supply and distribution systems.
Apart from water-related disease microorganisms could also provoke a biocorrosion or microbial influenced/induced corrosion (MIC). This phenomenon is caused by or enhanced by bacteria or other microorganisms and is a result from their action on an underlying substratum, which is a metal or metal alloy like stainless steel. Biocorrosion is a major reason for electrochemical/mechanical damage of water supply and distribution devices. The microorganisms triggering MIC include bacteria, fungi and algae. They are presented either as individual species or can form biofilms, composed by synergistic communities (consortia). MIC problems have been found in piping systems, storage tanks, cooling towers, and aquatic structures. Water damage is typically classified into one of the three categories: Category 1 Water - "Clean Water; Category 2 Water - "Grey Water"; and Category 3 Water - "Black Water". In general, the most effective ways to prevent a material from failing is proper and accurate design, routine and appropriate maintenance, and frequent inspection of the material for defects and abnormalities.
Water has two closely linked dimensions: quantity and quality. Water quality is an important concept related to all aspects of ecosystems and human well-being such as the health of a community, food to be produced, economic activities, ecosystem health and biodiversity. Water quality refers to the condition of the water, including chemical, physical, and biological characteristics. It is usually relative to the requirements of beneficiary use of water to any human need or purposes. It is important to know that different beneficial uses have different needs and thus, there is no single measure that constitutes good water quality. Depending on the beneficiary use, we use guidelines, and standards must be met accordingly.
Water quality guidelines and standards provide basic scientific information about water quality parameters and ecologically relevant toxicological threshold values to protect specific water uses. The most common standards used to assess water quality are related to health of ecosystems, safety of human contact and drinking water. Drinking Water Regulations are health-related standards that establish the Maximum Contaminant Levels. Drinking water should not present a risk of infection, or contain unacceptable concentrations of chemicals hazardous to health and should be aesthetically acceptable to consumer. The control of the feacal pollution depends on being able to access the risk from any water source and to apply suitable treatment to eliminate the identified risks.
In order to describe and access water quality we need to have parameters that can be measured. Measurements of these parameters can be used to determine and monitor changes in water quality, and determine whether it is suitable for the health of the natural environment and the required uses.
Physical measurements are all useful in analysing how pollutants are transported and mixed in the water environment, and can be related to habitat requirements for fish and other aquatic wildlife. With chemical measurements we measure concentrations of wide range of chemicals and chemical properties. With bacteriological analysis we measure the hygienic quality of water. The bacteriological quality of a water body is very important especially when we use the water body for drinking purposes.
Any source of water to meet basic requirements for a public water supply needs some form of treatment. In general, water to be used for public water supply;
Should contain no disease-producing organisms.
Should be colorless and clear.
Should be good-tasting, free from odors and preferably cool.
Should be non-corrosive.
Should be free from gases, such as hydrogen sulfide and staining minerals, such as iron and manganese.
All water sources contain different inorganic and organic substances that must be removed during water treatment to produce water that is fit for domestic use and any other usage. Many treatment processes (sometimes called unit processes and unit operations) are linked together to form a treatment plant in order to produce water of the desired quality. To achieve this goal, a variety of treatment processes are utilized employing various physical and chemical phenomena to remove or reduce the undesirable constituents from the water. Unit operations, which are physical, chemical and mechanical, should be taken into consideration for producing clean drinking water. Physical and chemical processes are aeration, adsorption, membrane processes, ion exchange, coagulation and flocculation, chemical oxidation and water softening while sedimentation and filtration are mechanical processes. Aeration is a unit process of the water treatment using scrubbing action and oxidation to remove or modify constituents of the water. Adsorption is a phase transfer process that is described as enrichment of chemical species from a fluid phase on the surface of a liquid or a solid for removal of a wide range of further organic micropollutants. Membrane processes are used for desalination, softening and particle, color, microbial and natural organic materials removal fouling water’s taste and taint its clarity and other purposes. Ion exchange processes are widely used in water and wastewater treatment to remove unwanted ions from a raw water by transferring them to a solid material. Coagulation and flocculation processes are employed to separate suspended solids portion from water whenever their natural subsidence rates are too slow to provide effective clarification. Chemical oxidation processes involve the transfer of electrons from an oxidizing reagent to the chemical species being oxidized. Water softening is the process for removal of calcium, magnesium, and certain other metal cations in hard water. The sedimentation process removes many particles that include clay and silt based turbidity, natural organic matter, and other associated impurities. Filtration that is a unit operation of separating solids from fluids to remove the particulates suspended in water by passing the water through a layer of porous material.
The larger part of pathogenic microorganisms in drinking water is removed by means of water treatment techniques, such as coagulation, flocculation, settling and filtration. As a final treatment step for increasing the drinking water safety, disinfection is applied. Most European countries applied drinking water disinfection since the end of the nineteenth century or the beginning of the twentieth century. The most widely applied disinfectant is the chlorine. During the process of disinfection both harmful and harmless microorganisms were killed. Disinfection commonly causes disruption of microbial cell wall, or changes in cell permeability, protoplasm or enzyme activity (because of a structural change in enzymes). All these disturbances in cell activity lead to reduction or termination of propagation of microorganisms and their elimination from the system. The effectiveness of disinfection is measured by the CT parameter. The last represent a function of the contact time between disinfectant and microorganism and the concentration of disinfectant. Several factors influence the process of water disinfection and determination of CT: the type and the age of the microorganisms; water nature; temperature. In this respect the European Union has issued in 1998 a directive (98/83/EC) that established minimum standards for water intended for human consumption. This document includes disinfectants and disinfecting by-products limits similar to those recommended by WHO. In the Directive a total of 48 microbiological, chemical and indicator parameters are encompassed and are subjected to regular monitoring and testing. In 1998 the Biocidal Products Directive was also implemented (BPR, Regulation (EU) 528/2012), which repealed the Biocidal Products Directive (Directive 98/8/EC). The last one concerns the placing on the market and use of biocidal products, which are used to protect humans, animals, materials or articles against harmful organisms like pests or bacteria, by the action of the active substances contained in the biocidal product.
In this chapter, basic facts about water supply are discussed and it is shown that distribution system is a network of pipelines that distribute water to the consumers and they are designed to adequately satisfy the water requirement for a combination of, Domestic, Commercial, Industrial and Firefighting purposes. Distribution systems branch pattern is shown and the most commonly used hydraulic analysis are discussed.
The types of pipes are shown, large diameter main pipes which supply water to entire towns, smaller branch lines that supply a street or group of buildings, or small diameter pipes located within individual buildings are explained. It is expressed that in well planned and designed water distribution networks, water is generally treated before distribution and sometimes chlorinated, in order to prevent recontamination on the way to the end user.
It is explained how to obtain water and by protecting drinking water at the source, the risk is minimized from contamination and reduce the level of treatment required before it is supplied to the community.
Reservoirs, dams are discussed, the usages of these establishments are explained, it is declared that the demand for water is steadily increasing throughout the world so precautions must be taken in order to prevent the loss of water and besides in order to accommodate the variations in the hydrologic cycle, dams and reservoirs are needed to store water and then this provides more consistent supplies during shortages.
Selecting the appropriate treatment process is a critical step in providing safe, reliable, good quality drinking water at a cost-effective price. Water treatment process selection is a complex task. Circumstances are likely to be different for each water utility and perhaps may be different for each source used by one utility. The fundamental concept of acquiring the best quality of source water, which is economically feasible, is an important factor in making decisions about source selection and treatment. Water utilities and their engineers need to consider use of alternative sources when a new treatment plant or a major capacity expansion to an existing plant is being evaluated, or when a different and more costly approach to treatment is under study. The design of treatment facilities will be determined by feasibility studies, considering all engineering, economic, energy and environmental factors. All legitimate alternatives should be identified and evaluated by life cycle cost analyses. The interaction of various processes on treated water quality must be considered in the regulatory context and in the broader context of water quality. The source of raw water can be an attactive target for an adversary. Whether it is a lake, river, or well field, many sources are remote can offer an attacker numerous opportunities to attempt a contamination or physical attack. Process reliability is an important consideration and in some cases could be a key aspect in deciding which process to select. Site constraints may be crucial in process selection, especially in pre treatment when alternative clarification processes are available, some of which require only a small fraction of the space needed for a conventional settling basin. Source water quality should be well established when a treatment plant is planned, so that good decisions on treatment processes can be made. After treatment processes are selected, designed, and on-line, the water utility must be able to operate them successfully to attain the desired water quality. Cost considerations usually one of the key factors in process selection. Environmental compatibility issues cover a broad spectrum of concerns that include residual waste management, the fraction of source water wasted in treatment processes, and energy requirements for treatment. Treatment processes should be selected to enhance water stability. The basis for selecting treatment process alternatives is established by the characteristics of the raw water and finished water quality goals. Surface and ground water treatment can be accomplished by a variety of process trains, depending on source water quality. For analysis purposes, the issues to be addressed into the “SHTEFIE (S- Social, H- Health, T- Technological, E- Economic, F- Financial, I- Institutional and E- Environmental)” criteria can be grouped as a tool to help with analysis of development programmes. New approaches to siting and designing critical system components, including water treatment plants, are evolving to reduce its vulnerability.
While water treatment plants produce safe drinking water, they inevitably produce waste products, as well. In the treatment process of drinking water resources, the contaminants that are unhealthy or undesirable for consumption are removed in water treatment plants. The generated waste products are named as ‘residuals’ and may be organic and inorganic compounds in liquid, solid, and gaseous forms depending on quality of the water resources, drinking water production rate, efficiency of the drinking water treatment system, the amount of treatment chemicals used, and type of water resource treated. Residuals commonly generated from coagulation/filtration, precipitative softening plant, membrane separation, ion exchange and granular activated carbon units. The residuals volume at water treatment plants mostly alter seasonally or monthly.
Common pollutants found in water treatment plant residuals have potential environmental impacts on the receiving environment therefore; they should be handled within the water treatment plant.
The hazardous level of materials in waste generated from water treatment process generally depends on the volume of the material extracted from raw water, and the attention needs to be paid to the lowest acceptable presence of a substance per volume of treatment. This lowest level is mostly defined by local/international laws-regulations and standards. To comply with the legal requirements and to avoid health and environmental impacts, knowledge of the lowest acceptable levels of substances in treatment waste has the utmost importance.
Pollution prevention (e.g., process modifications) and waste reduction (e.g., resource recovery) opportunities in water treatment plants are the preliminary steps in residual management, which aims the reduction of the generation of residuals. Residuals generated in a plant are treated in the same plant. After treatment, dewatered residual regarding the conditions are disposed according to the legislations in force.
This chapter revolves around the relationships that the people of the Netherlands have formed with, and around water. Water and physical safety are narrowly related, but over and above that immediate connection, the historical and cultural experiences with water are very important for how the Dutch people handle it, treat it, and even innovate around it. The aim of this chapter is not only to recount the history of one particular countries’ relationship with water, but to frame water management historically and culturally and thus give a more extended meaning to how the Netherlands interacts with, and around water. The relation to drinking water treatment might not be immediately apparent, but the following exploration of the Dutch dependence on water, and of the interdependent factors providing the country with access to safe drinking water today, will hopefully reveal it.
This chapter will start with some information about the physical context of the Netherlands and its geography. Next, its environmental history will be described, which will clearly demonstrate the country’s ambivalent relationship with its watery environment and how it deals with it, both institutionally and through a model of negotiation. The high degree of interdependence of the Netherlands with surrounding countries for the accessibility of safe drinking water will be discussed, and how the Dutch people do their water management according to the ‘polder model’. Finally, a recent innovative water treatment process developed in the Netherlands is highlighted.
A large variety of professional groups are involved in the drinking water supply system (e.g. Civil Engineers, Ms. Environmental Engineers, Chemical Engineer, Town and traffic Planner etc.). These professionals will all have to learn about the structure and maintenance of drinking water supply systems and learn to deal with important aspects of centralised, urban, decentralised and rural supply systems (e.g. aspects related to distribution and treatment). The types of treatment are dependent on the source, size and changing supply of such an extended system, and thus a system approach is required. Innovative Educational arrangements, like multidisciplinary case studies, supported by technology enhanced learning (TEL) environments, can contribute to teaching this subject matter in a more integrated fashion. TEL environments, in addition, afford learning across distances and over time.
Since each water system comprises several interconnected components, which are co-dependent for water quality and quantity, and thus cannot be seen in isolation from each other, collaborative study around cases which demonstrate this interconnection is a necessity. The understanding of this interconnectedness is the basis for any management of the water system. All parties in this locally and often transnationally interconnected system ideally are to be aware of the complexities and dependencies in the drinking water supply system, so that all water-related interests can be optimally served.
Technology enhanced learning (TEL) can enable new ways of learning and collaboration for professionals involved in the Drinking Water Supply system. Innovative solutions like Open Educational Resources and Massive Open Online Courses (MOOCs) offer opportunities to meet the needs and challenges in increasing globalised and interconnected systems like the international water management.
In this chapter an integrated approach, based on learning within interdisciplinary teams is developed. Interdisciplinary teams can learn how to develop their own innovative solutions for drinking water supply challenges, which could be applied to local situations. They can co-develop scenarios to simulate and predict the performance and operation of water supply system components.
In addition, this chapter will describe an example of how to apply synchronous and asynchronous social media, and Open Educational Resources (OER), in solution engineering around case studies. Furthermore it will provide some references to online available MOOCs, among others the PURE-H2O MOOC that was developed based on the chapters of this book.
This chapter provides a foundation to the understanding of key concepts and theories used in water economics. In accordance with this approach, firstly explained from an economic perspective conception of water and different characteristics from other goods. Then it considered demand and supply of water used for domestic purposes. Unique characteristics of water affect the water supply and demand and hence conditions in the domestic water market equilibrium. Therefore, focused on how supply and demand effect the prices in the water economy and generally, why prices do not reflect market prices. It then goes on to describe the key issues related to the economic efficiency of water market.
The chapter starts by looking at the evolution of economic and financial aspects of drinking water and water treatment plants. Then examines the economic and financial procedures of drinking water. Accordingly, this chapter defining includes strategic content and assessment of environmental impacts for the water treatment plants. The demand analysis of the drinking water treatment plants discussed in detail under the economic and financial procedures. Includes, main parameters of demand projections and how to asses and different approaches to the evaluation of the demand. Then addressed estimation cost of water for drinking water treatment plant provides a selection of the various classification systems. Finally, the chapter presents an overview of treatment and sanitation costs for the infrastructure services.
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