Microextended X-ray Absorption Fine Structure Studies of Cadmium Speciation within Single Municipal Solid Waste Fly Ash Particles

The local chemical structure of trace amounts of cadmium within microvolumes of highly inhomogeneous municipal solid waste fly ash particles was successfully monitored by means of μ-EXAFS. A new quantification procedure was developed for the evaluation of the μ-EXAFS data sets obtained from each individual particle based on a reverse Monte Carlo simulation. Evidence has been presented for the existence of cadmium silicate and cadmium chloride, with the cadmium silicate being the dominant form, and it has been demonstrated that the cadmium exists in both crystalline and amorphous states within the microspots analyzed.