Chapter 5 : Biochemical Oxygen Demand (BOD)

Introduction: Desalination using seawater reverse osmosis (SWRO) technology is an important option available to water-scarce coastal regions. Worldwide sea water desalination is a very effective and economical way of producing potable water for drinking and industries. Reverse osmosis plants to convert sea water to potable drinking water and for other usages have been prevalent throughout the world for more than 4 decades. Design and operation of seawater reverse osmosis plants strongly depend on the raw seawater quality to be treated. The performance of desalination reverse osmosis (RO) systems relies upon the production of high quality pre treated water, and the selection of the best pre treatment technology depends on the raw seawater quality and its variations. Number of full-scale experiences has shown that pre treatment is the key for this application of reverse osmosis technology. It is why during these last years, an import effort has been done to identify and to characterise the diverse organic and mineral components present in the seawater in a view to optimise the seawater pre-treatment and to develop advanced analytical methods for feed water characterization, appropriate fouling indicators and prediction tools. This Chapter describes firstly a comprehensive approach to characterize raw seawater samples through analytical tools which allow the knowledge of the characterization of seawater from many aspects: (a) inorganic content, (b) natural organic matter, (c) enumeration of micro-organisms and phytoplankton. Secondly, this Chapter describes the effect of each of these parameters on the fouling of the reverse osmosis membrane. Finally, this chapter describes the different possible pre treatments available to reduce or remove the elements or substances up-stream reverse osmosis stage.

Big data analysis for water supply and sanitation is important for ensuring urban viability. Our research is devoted to studying the methodology for analyzing big data of the water supply and sanitation systems. Based on a review of scientific publications and their analysis, a model for analyzing large data was proposed. It comprises information sources, data collection and storage platforms with indication of parameters for the programming model, runtime and storage environment, as well as data analysis and processing.

In this study water quality was indicated in terms of Water Quality Index that was determined through summarizing multiple parameters of water test results. This index offers a useful representation of the overall quality of water for public or any intended use as well as indicating pollution, which are useful in water quality management and decision making. The application of Water Quality Index (WQI) with ten physicochemical water quality parameters was performed to evaluate the quality of Euphrates River water for drinking usage. This was done by subjecting the water samples collected from seven stations within Al-Anbar province during the period 2004-2010 to comprehensive physicochemical analysis.

Surging population, energy demands, and climate change will push us, ever more urgently, to find new approaches to meet growing water demands. Most often, this will involve harvesting lower quality or impaired water supplies (e.g., seawater or brackish groundwater) as a source for drinking water. Recently desalination using membrane-based processes (e.g., reverse osmosis [RO], electrodialysis [ED], and nanofiltration [NF]) has shown promise for providing additional sources of fresh water across the United States. However, the current membrane separation processes are commonly energy intensive and produce large volumes of concentrated brine which poses unique challenges. Particularly in land-locked urban center brine disposal often relyes on surface water discharge or deep-well injection which pose economic and practical difficulties for wide-spread adoption of such technologies. Thus, there is an urgent need for energy-efficient desalination technologies that reduce the amount of concentrate produced, or identify cost-effective solutions for concentrate management.