A Biological Waste Water Monitor Study Using Differential Laser Light Scattering from Bacteria.
Abstract
A ninety-minute bioassay of selected toxicants (monomethylhydrazine, dimethylhydrazine, nitrosodimethylamine, JP4, and JP8) in water has been confirmed. The method consists of measuring the differential light scattering (DLS) patterns of exponential phase bacterial suspensions in water containing the selected toxicant relative to a toxicant-free control suspension. The suspensions are illuminated by a fine laser beam and the light scattered as a function of angle with respect to the incident beam is recorded (the DLS pattern). Relative to the bacteria in the control, toxicant-free, suspension, bacteria affected by the toxicants may change their shape, average size, size distribution, and/or number density. Any such changes will in general result in a changed DLS pattern relative to that of the control. The measurement of such differences forms the basis for the present bioassay technique. The bacterial suspensions are usually prepared from a bacterial chemostat source driven by paristaltic pumps of a Technicon manifold. Throughout an 8 hour sampling period cultures will generally not vary by more than 20% in number density and negligibly in morphology. Within the ninety minute assay period, number density variations are less than 5%.
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 01, 1979
- Accession Number
- ADA078527
Entities
People
- Philip J. Wyatt