An Effect Of The Oxidative Pretreatment
An effect of the oxidative pretreatment
of surfactants on the biosorption on the granular activated carbon
V.V. Goncharuk, V.F. Vakulenko, N.A. Klimenko
A.V. Dumansky Institute of Colloid Chemistry and Chemistry of Water, Ukrainian National Academy of Sciences,
Vernadsky avenue 42, 03680 Kyiv, Ukraine
At present ozone is often applied prior to the biological granular activated carbon filter to improve the removal of organic pollutants from natural waters and wastewaters. In this approach, ozone is used to convert the refractory organic matter to the compounds having lower molecular weight, which are more accessible to microorganisms. These biodegradable byproducts just generated may be then removed effectively due to the biological activity of a film in the activated carbon column. Such a partial oxidation is more cost-effective than the complete destruction of the target compounds.
Several authors reported that surfactants of alkylbenzenesulfonate (ABS) type are not completely destroyed by ozonation. Ozone in its molecular state reacts with ABS too slowly, and the doses of oxidant needed to provide the necessary removal degree are high enough. Our study showed that the limitations associated with the low removal rate might be avoided if the combined O3/UV process replaces ozonation.
Sodium dodecylbenzenesulfonate (NaDBS) and nonylphenolethoxylate (OP-10) were chosen as typical persistent pollutants. In our work, we focused our attention at the investigation of the destruction kinetics of NaDBS and OP-10, an analysis of the ozonolysis byproducts of surfactants, and varying ratio of such parameters as COD, TOC and BOD5. The data we reached are useful to determine preferable destruction levels of surfactants by O3/UV pretreatment to provide the most effective biosorption process.
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