Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
583738 | Journal of Hazardous Materials | 2008 | 7 Pages |
Abstract
This study deals with evaluation of organic matter from Mexico City waste sanitary landfill leachate of Bordo Poniente (including domestic and industrial) by ozonation after a coagulation treatment with Fe2(SO4)3 (2.5Â g/L at pH 4-5). The content of humic substances after the coagulation treatment decreases up to 70%. Then leachate obtained from a solid with initial CODÂ =Â 1511Â mg/L and the pH 8.5 was treated by ozone. The aqueous samples by a UV-vis and HPLC technique were analyzed. The partial identification of the initial composition of the organic matter as well as of intermediates and final products was carried out after the extraction of the initial and ozonated leachate with benzene, chloroform:methanol (2:1) and hexane. Then the extracts with a gas chromatograph with mass detector and FID were analyzed. In the HPLC results we identify malonic and oxalic acids. The initial concentrations of these acids were 19Â mg/L and 214Â mg/L, respectively. The oxalic acid is formatted and accumulated in ozonation. The obtained results show that the color disappears (visually) at 100% during 5Â min of ozonation. The organic substances, extracted with chloroform-methanol, may be destructed during 15Â min of ozonation; the organic matter, extracted with benzene, destructs completely by ozone during 5Â min, and the organic compounds extracted with hexane have a low ozonation rate. The toxic compounds presented in leachate decompose completely during 15Â min of ozonation. The ozonation rate constants for each group of organics (as observed constants) were calculated applying simplified mathematical model and the recurrent least square method using the program MATLAB 6.5.
Related Topics
Physical Sciences and Engineering
Chemical Engineering
Chemical Health and Safety
Authors
Tatyana Poznyak, G. Luis Bautista, Isaac ChaÃrez, R. Ivan Córdova, L. Elvira RÃos,