Sorption of atrazine, 2,4‐D,nitrobenzene and pentachlorophenol by urban and industrial wastes |
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| Authors: | Q Wu H ‐P Blume L Rexilius M Flschow U Schleuss |
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| Institution: | Q. Wu,H. ‐P. Blume,L. Rexilius,M. Fölschow,U. Schleuss |
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| Abstract: | This study was carried out to investigate the sorption properties of man‐made soil developed from sewage sludge, municipal wastes, brick and mortar debris, harbour sludge, sand fills, fly ash, and wastes from coking plants and coal mines. The composition of organic matter in the samples was analysed, and the sorption isotherms of four reference chemicals (nitrobenzene, atrazine, 2,4‐D, pentachlorophenol) were determined. Fly ash, which contains up to 89% of its carbon as Black Carbon, showed a strong affinity to all four chemicals. For the other waste materials, a strong correlation between the logarithm of the Freundlich adsorption constant, Kf, and the logarithm of organic carbon, Co, was established (r = 0.85–0.96). This holds for the non‐ionic nitrobenzene and also, within a certain pH range depending on the pKa of the compound, for the three ionizable organic compounds (atrazine: pH > 4; 2,4‐D: pH > 5; PCP: pH > 6). At pH near the pKa value the sorption is sensitive to pH. There were no statistically significant differences between the waste materials and the natural soils in the relations between logKf and logCo for either ionic or non‐ionic chemicals. This result suggests that the method devised for estimating the sorption of organic chemicals in natural soils based on their content of organic carbon is equally valuable for the waste materials, with the exception of fly ash which contains a large amount of Black Carbon. |
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