Qualitative Analysis Of Heavy Metals In Flue Gas By Laser-Induced Breakdown Spectroscopy

Nowadays, there are more and more pollutants in industrial combustion flue gas, including kinds of toxic heavy metals, they are harm to the environment. It's very important how to detect heavy metal in flue gas rapidly and accurately, and it is one of the most necessary data for evaluation of its impact on environmental pollution and control heavy metal emissions.The traditional technologies of the heavy metals analysis are almost off-line and spent long time, they couldn't meet the requirement of analyzing heavy metals in the flue gas. Laser-Induced Breakdown Spectroscopy (LIBS) is a rising atomic emission spectroscopy, it has been researched as an element analysis technique in many fields because of its advantages of remote distance, in-situ and multi-element analytical capability.The principle of LIBS, the quantitative calibration models, the advantages and shortcomings of LIBS in analysis of heavy metals in the flue gas was introduced at first, and then the LIBS mechanisms used for analysis heavy metals in the flue gas were introduced in detail.Prepared 21 experiment samples, choose the optimum experimental condition parameters of LIBS for heavy metals analysis, including delay time and laser energy intensity. Analyzed heavy metals in simples use internal reference method, the calibration curves of the heavy metals including the Pb and Cd were constructed, the relative deviation were below 10%, and the limits of detection (LOD) of Pb and Cd were in the range of 30-60 mg/kg .Detected gas-solid and flue gas with the flue gas detection bench, analyze the spectrum of Na, K, O and H in flue gas and Ca in CaCO3. Analyze heavy metal in coal combustion flue gas, detected characteristic spectrum of Cr, Ti, Fe, Hg, Ni, Pb, Ba, Mn, Mo and Cd.Finally, the results of the whole research works were summarized and the directions for the further studies were suggested.