Study And Design On Portable And Fast Monitoring Instrument Of Biological Toxicity

With the development of commercial process, the number of toxic andharmful substances increases rapidly, which has done great harm to people'sliving environment. And it's urgent to develop toxicity identificationtechniques to test environmental pollutants.Making use of light-emitting phenomenon of bacterial cell, combininglight-emitting bacteria toxicity measurement techniques with modernoptoelectronic detecting techniques, a portable emergent toxicity detector isdesigned in the paper.Taking vibrio, luminous and iso-short rod-shaped bacteria, the paperanalyzes their luminous spectra, presents luminescence mechanism andlight-emitting intensity characterizations, determines dependence of relativeluminosity of light-emitting bacterial on total concentration of toxic gradientsin environmental substances. At the same time, relation of reference mercurychloride concentration on emergent toxic level of environmental pollutants isdetermined.After fundamentals working principles and characterized parameters ofelectrophotonic detector are reviewed, and cooling principles as well asadvantages of cooling semiconductor are analyzed, optoelectrical detectingmethod based on luminous intensity is determined.Considering interference of color environmental pollutants containingsuspended substances on light intensity of light-emitting bacteria, the paperpresents basic principles of beam path compensation, establishes interferencecorrection method, and measurement accuracy is greatly improved. Thenhardware and software parts of portable emergent toxic detector withphotomultiplier as electrophotonic detector are designed.Finally, measuring method of the designed detector are given, and testingexperiments on stability, repeatability and accuracy of the detector are carriedout. Obtained results are compared with organism light-emitting luminometerin the laboratory and compared results are satisfactory.Compared with traditional emergent toxic detecting techniques, theproposed method which combines techniques of light-emitting bacteria toxicdetecting method and photoelectric detecting method to determine emergenttoxic level of environmental pollutants is easy to carry out with high accuracy,shortens greatly experiment during, and reduces operating error.