Bioassay and dose measurement in UV disinfection

Bioassay and dose measurement in UV disinfection.

A bioassay method was developed to measure the average intensity within a UV disinfection reactor. The survival of spores of Bacillus subtilis was determined as a function of UV dose to prepare a standard curve. Spores were added to unknown systems, and the survival rate was used to determine the average intensity. A modification was used for flow-through reactors by which spores were injected ...

Disinfection Efficiency and Dose Measurement of Polychromatic UV Light

Impact of Particle Aggregated Microbes on UV Disinfection. II: Proper Absorbance Measurement for UV Fluence

Ultraviolet UV absorbance measurements are subject to significant error using a standard spectrophotometer when particles or aggregates that scatter light are present. True UV absorbance for highly turbid waters should be measured using integrating sphere IS spectrophotometry that allows the collection of reflected and transmitted radiation simultaneously. This is especially important when the ...

Modelling the Kinetic of UV Water Disinfection

Ultraviolet disinfection is an attractive tool for treating water and eliminating pathogens with safe and available technology especially in developing countries where waterborne diseases cause the death of thousands of people every year. Even though UV is an easy tool to perform disinfection, concerns over the potential of microorganism reactivation constitute an issue for its development. In ...

Cryptosporidium Occurrence in Wastewaters and Control Using UV Disinfection

This paper summarizes the conclusions of two recently completed projects that examined the occurrence of the protozoan pathogen Cryptosporidium in wastewater streams, and the efficacy of ultraviolet (UV) light for treatment of wastewaters to control Cryptosporidium. A 15-month survey of Cryptosporidium oocyst occurrence was conducted at ten US wastewater treatment plants. Cryptosporidium oocyst...