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intake on the selection and design of the pretreatment system. The chapter encom- passes practical pretreatment experience with desalination plants using both open intakes and subsurface intakes and contains guidance of how to select intake configura- tion that minimizes downstream pretreat- ment requirements for the site-specific conditions of a given desalination project. The chapter analyzes the key advantages and challenges associated with the use open and subsurface intakes and the trade-off be- tween the use of costlier intakes and less complex pretreatment systems and vice versa.
Chapter 5 focuses on the type and configuration of the most commonly used screening equipment applied for removal of course particulate materials (large debris, algae, jellyfish, etc.) from the saline source water. The chapter addresses the criteria for selection of bar, band, and drum screens as well as microscreens, and cartridge filters.
Chapter 6 is dedicated to systems for addition of chemicals to the saline source water, which allow to condition this water prior to its further pretreatment or direct application for RO-system processing. Source- water conditioning is of critical importance for the efficient and cost-effective sedimen- tation, and filtration of the particulate and organic compounds contained in the water as well as for prevention of formation of scale on the RO-membrane surface. This chapter de- scribes the purpose and dosing of commonly applied source-water conditioning chemicals such as coagulants, flocculants, scale in- hibitors, biocides, acids, and bases.
Chapter 7 presents alternative pretreat- ment technologies that are commonly applied for removal of relatively large sus- pended solids contained in the source water. The chapter contains key design criteria used for sizing of lamella settlers and dissolved air
flotation (DAF) clarifiers and provides con- struction cost curves for these facilities.
Chapter 8 is dedicated to the most commonly used type of technology for removal of find solids from the source wateregranular media filtration. It discusses alternative types of filters used in desalina- tion plants and their area of application and performance. The chapter incorporates con- struction cost curves for gravity and pressure-driven granular media filtration systems.
Chapter 9 discusses the use of MF and UF membranes for pretreatment of saline source water. The chapter presents key consider- ations associated with the selection, plan- ning, and cost estimating of membrane pretreatment systems for seawater desalina- tion plants. This chapter incorporates design examples for submerged and pressure- driven membrane pretreatment facilities.
Chapter 10 provides a comparative anal- ysis of the key advantages and disadvan- tages of granular media and membrane pretreatment filters in terms of: the effect of source water quality and temperature on their performance; surface area re- quirements; quantity and quality of the generated residuals; chemical and power uses; and overall water production costs.
Chapter 11 features a methodology for identifying the type and configuration of the most suitable seawater pretreatment system for the site-specific conditions of a given desalination project. The selection method- ology is based on the analysis of the source water quality collected by the desalination plant intake and is built upon the industry- wide practical experience with the imple- mentation of alternative technologies and configurations over the past 20 years.
Chapter 12 delineates how to access the impact of the pretreatment system on the selection of the most-suitable configuration
PREFACE ix