Estimating the Percentage of Hexagonal Chromium for Cement Factories in Libya

Hexavalent chromium (Cr⁶⁺) is a highly toxic heavy metal in cement which has serious effect on the health of workers and consumers. The purpose of the study was to make the estimation of amount or percentage of Cr⁶⁺ in cement sample from five cement factories of Libyan cement industries. Measurements of 40 samples of cement (by 40 samples) in the diphenylcarbazide mode using a total of 40 samples were made by UV-Vis spectrophotometry. The range of Cr⁶⁺ concentrations was 0.85 to 6.72 mg/kg with a mean of (3.45 ± 1.62) mg/kg. However, European Union acceptable limit levels for 2 mg/kg were exceeded by the highest contaminated cement factory which was the Al Fataih Cement Factory (5.87 ± 1.13 mg/kg) and 37.5 percent of these factories (15 of 40) exceeded the European Union accepted limit. It was determined by a one way ANOVA test (F = 14.62, p < 0.001) of Cr⁶⁺ concentrations between factories that there were significant differences (p < 0.001). Additionally, Cr⁶⁺ levels were also correlated with kiln temperature (r = 0.78, p < 0.001) and thus higher production temperatures were considered to have contributed to condensation. Of these samples, 62.5% conformed to safety standards, but the other 37.5% in excess of regulatory limits, which pose a health hazard. Libyan cement factories must therefore take additional steps to limit Cr⁶⁺ contamination.