Water Treatments Overview

A Report of the Water Supply Committee of the Great Lakes--Upper Mississippi River Board of State and Provincial Public Health and Environmental Managers

This is an introduction to water treatment systems and technology. It is not a design manual or an exhaustive treatise. It is intended for engineers who are not regularly involved in water treatment projects, but who are interested in learning some of the basics involved. Criteria to be followed in determining the necessity for and the extent of treatment are discussed here, as are procedures applicable to the planning of water treatment projects.

The University of Tennessee, Knoxville (UTK) received funding from the Bureau of Reclamation (Reclamation) in September 2013 to investigate a novel salt and organic removal technology. Using microbial electrolysis cell (MEC) technology and salt removal via capacitive deionization (CDI) to remove organic compounds present in produced water was investigated. This project was conducted in collaboration with CAP Holdings Company (CHC), which provided expertise in CDI technology. Converting soluble organic compounds via MEC was coupled to salt removal via CDI, providing a proof of principle for synergistic salt and organic removal. Hydrogen was generated by MEC from organic compounds and used to produce renewable electricity via a polymer electrolyte membrane (PEM) fuel cell , which was then used to power the CDI cell to achieve deionization.

This paper aims at analyzing the drinking water issue in the Mediterranean region, highlighting the principal problems and the appropriate technologies applicable in the different countries. The countries of this area are characterized by a huge variety from social, cultural, economic and environmental point of view. In particular, water distribution is inhomogeneous between the North, East, and South; even the type of water sources and the related quantity and quality problems differ country by country. Potable water comes from brackish and seawater, surface water, groundwater and water reservoirs with each source face different issues. The main problem of brackish and seawater for example is the high salinity and the contamination by disinfection byproducts, in addition to the microbiological and chemical contamination due to human activities that characterize also other surface water sources. Groundwater is also affected by human activity and it is not exempted from salinity because of the water intrusion. Moreover, water reservoirs are often contaminated by seasonal algal blooms. Technologies applied for drinking water treatment vary country by country. The paper presents the main treatment processes associated with the main water pollutants, according to the Mediterranean region. Case studies of drinking water treatment plants are also analyzed, presenting alternative technologies appropriate for specific contexts, among others. The characteristics of each specific context should be carefully analyzed in order to develop the most appropriate technologies; high-end technologies for drinking water treatment may not be applied equally to all countries or communities of the Mediterranean region.