Abstract:
This research studied leaching behaviors of heavy metals from drinking water containers made of Portland cement from co-incineration process. The modified version of EA NEN 7375, a standard leaching test, was applied to examine various factors affecting heavy metals leachability. The leaching results were compared to drinking water standards to assess the contamination level of heavy metals in leachants. Moreover, the cement paste samples with the same properties as the drinking water containers were analyzed using X-ray Diffraction Spectrometer (XRD) and Fourier Transform Infra-Red Spectrophotometer (FT-IR) to consider the change of bond and compound in matrix after leaching tests. The experimental results indicated that initial concentration of heavy metals in cement paste, type, and amount of the leachants play crucial roles on metal leachability. The studies showed that at Liquid/Surface ratio of 8, cumulative concentration of metals at the water-solid interface was substantially high. Besides, the leachates from various leachants showed that Manganese did not mobilize in tap water while Boron leached substantially in a closed system with synthetic acid rain as a leachant. Various Leaching phenomena of heavy metals were observed. After surface wash off phenomenon Alumimium showed the obvious dissolution at the final state of the study, while Chromium showed solely surface wash off at the beginning state. For the leaching in open system, Co[subscript2] affected in decreasing pH and conductivity and the precipitate has formed. Under this condition, most of heavy metals, except Vanadium, became less mobilized. Cadmium and Lead were found the concentration higher than the standards of drinking water under all conditions for all leachants. Analyzing cement paste and precipitate with XRD and FTIR, the precipitate was found to be CaCO[subscript3]. Heavy metals were not detected by XRD and FTIR because of their relatively small amounts in cement.