Drinking water Technology, Eawag, developed a method by which hazard maps could be produced for geogenic toxic substances in groundwater. This provides an efficient way of determining which wells should be tested. Parameters for drinking water quality typically fall within three categories: Physical and chemical parameters include heavy metals, trace organic compounds, total suspended solids (TSS), and turbidity. Microbiological parameters include Coliform bacteria, "E. coli", and specific pathogenic species of bacteria (such as cholera-causing "Vibrio cholerae"), viruses, and protozoan parasites. Chemical parameters tend to pose more of a chronic health risk through buildup of heavy metals although some components like nitrates/nitrites and
Quantum yield Quantum yield The quantum yield (Φ) of a radiation-induced process is the number of times a specific event occurs per photon absorbed by the system. The "event" is typically a kind of chemical reaction. The quantum yield for the decomposition of a reactant molecule in a decomposition reaction is defined as: Quantum yield can also be defined for other events, such as fluorescence: Here, quantum yield is the emission efficiency of a given fluorophore. Quantum yield is used in modeling photosynthesis: In a chemical photodegradation process, when a molecule dissociates after absorbing a light quantum, the quantum yield is the