A methodology for characterising ceramic wastes

Traditional ceramic industries (ceramic tiles, frits, glazes and pigments) generate solid wastes, wastewater and gas emissions that have different characteristics depending on the type of product made. The present study was undertaken to define a series of test methodologies for characterising each type of waste. The approach involved defining the elements to be analysed in each kind of sample, subsequently carrying out the respective test methods for the determinations in terms of type of parameter and sample. In gas emissions, the study addressed fluorine compound analysis. In liquid samples, AAS and ICP‐OES techniques were compared, validating the methods by using reference materials and participating in CALITAX and AQUACHECK intercomparison rounds on wastewater analysis. In solid samples, ICP‐OES and XRF techniques were compared, validating the methods by participating in International Proficiency Tests of Analytical Geochemistry Laboratories (GEOPT‐7, GEOPT‐8 and GEOPT‐9). The selective electrode determination of fluorine in gas emissions yields good results. The study shows that toxicity can be determined in liquid and solid samples by the bioluminescence assay. In liquid samples, good results were found for metal elements analysis by AAS and ICP‐OES, the latter being better. Finally, in solid wastes the ICP‐OES technique has advantages in analysing minor elements compared with XRF, whereas XRF is more suitable for analysing major elements, as it is a faster, more reproducible technique.