Burgess, A. C., Palmer, G. T., Lowe, D. J., & Cooke, P. J. (2003). Progressing the science of effluent treatment using Lasersizer diffraction analysis - a pilot study. In L. Currie & J. Hanly (Eds.), ASPAC (Australasian Soil and Plant Analysis Council Inc.) and FLRC (Fertilizer and Lime Research Centre) - A Combined Workshop: Incorporating the ASPAC Biennial Conference and the 17th Annual FLRC Workshop (Vol. Tools for Nutrient and Pollutant Management: Applications to agriculture and environmental quality, pp. 249–252). Conference held at Palmerston North: Fertilizer and Lime Research Centre, Massey University, Palmerston North, New Zealand.
Permanent Research Commons link: http://hdl.handle.net/10289/10204
Disinfection of waste water with ultraviolet (UV) light is a common procedure in many sewage treatment plants because it is used to inactivate coliform bacteria in the effluent. The number of coliform bacteria in a given sample is used as a proxy to indicate the presence of targeted pathogenic organisms. Typically the coliform bacteria exist in a particle-associated state which results in their being shielded from the UV light (Darby et al., 1999). Such particles are documented in the size range 20 to 80 μm, and therefore measurement of the size distribution in a sample could be used to indicate the degree of shielding. UV treatment is less effective for particles larger than about 40 μm in size (Table 1). Our pilot study used the laser diffraction technique to generate particle-size distributions of samples of effluent. By quantifying the amount of bacteria-shielding particles using this technique we were able to estimate the general efficacy of the UV sterilization process. The surface weighted mean diameter statistic was taken as a numerical measure of the bacteriashielding particle size distribution.
Fertilizer and Lime Research Centre, Massey University, Palmerston North, New Zealand
Paper presented at the 17th Annual FLRC Workshop, Massey University, 02-03 December 2003. Used with permission.