The construction and testing of the portable Hg2+ ultrasonic calibrator for the control of mercury speciation systems

During fuel combustion mercury, as Hg-0 and Hg2+ forms, is emitted to the atmosphere. Effective reduction of mercury emission requires applying speciation systems for emission control and research. An important part of all mercury determination and speciation systems are the calibrators. Calibrators are responsible for the accuracy of mercury determination and, in consequence, the effective reduction of mercury emission. The aim of the work was to construct a portable HgCl2 calibrator. The purpose of the device was the control of mercury speciation systems for continuous measurements and study of HgCl2 sorption. As a result of previously conducted research, the portable Hg2+ ultrasonic calibrator was designed, constructed and tested. The ultrasonic calibrator generates a stable stream of HgCl2 (RSD=2.8% for C-Hg=28 mu g/m3). The correlation between theoretical and reading concentration of HgCl2 was R-2=0.9983. The average recovery of HgCl2 was 95%. The advantages of the ultrasonic Hg2+ calibrator are: high accuracy and selectivity, low pressure of HgCl2 stream and very low cost of production. The calibrator was successfully tested, both in the laboratory and in the power plant, during a preliminary study on HgCl2 sorption on a fly ash filter. (C) 2015 Elsevier B.V. All rights reserved.