Speaker: Prof. David Sedlak, Department of Civil and Environmental Engineering, University of California, Berkeley, USA
Place: Forum Chriesbach, FC-C20
In response to water scarcity, environmental engineers are focusing their attention on the development of advanced water treatment systems that are capable of converting municipal wastewater effluent into drinking water. In California, Singapore and several other places where the safety of the process has been subjected to close scrutiny, reverse osmosis (RO) treatment followed by exposure to ultraviolent (UV) light in the presence of hydrogen peroxide (H2O2) is being used. These two treatment processes individually are capable of controlling many of the chemical and microbial contaminants in wastewater; however, a few chemicals may still be present after treatment at concentrations that affect water quality. To avoid the expense associated with managing the concentrate produced by RO, environmental engineers in other locations are employing treatment processes that rely upon other types of physical barriers (e.g., ozonation followed by biological filtration, or activated carbon filtration) as part of potable water reuse projects. These processes allow a larger number of chemical contaminants to pass through the treatment process. In locations where wastewater effluent accounts for a significant fraction of the drinking water supply (i.e., de facto reuse scenarios), natural treatment systems (e.g., riverbank filtration, constructed wetlands) are being used to remove chemical contaminants. For some contaminants, natural treatment systems are relatively ineffective. To protect public health, researcher need to confront the challenge of designing systems that provide adequate health protection without creating expensive and complicated systems that will not be built by water system planners.