Development of Novel Turbidity Calibration Standards and Methodologies Using Appropriate Technology

Jonathan Racey, Purdue University

Abstract

The measurement of turbidity is currently conducted using a variety of methodologies for different applications, primarily using calibration standards composed of formazin, a material which can be difficult to obtain, short-lived, and toxic. The discrepancies between the various measurement methods lead to unreliability in sharing meaningful data across applications, and the deficiencies of the primary calibration standard make it difficult to conduct measurements in appropriatetechnology environments. This research focused on examining the current methodologies and synthesizing new materials to use as calibration standards. The selection criteria for these materials were such as to ensure longevity, stability in solution, and ease of creation. Results showed that dilutions of dissolved sodium chloride yielded parabolic regression curves of comparable accuracy to formazin, which could be used for device calibration. These standards can be easily and safely synthesized in appropriate-technology settings. The use of fluorescent materials as calibration standards was also investigated, and the implications of the characteristic curves of turbidity versus solute concentration are discussed.

Degree

M.Sc.

Advisors

Pekny, Purdue University.

Subject Area

Optics|Water Resources Management

COinS