ANALYSIS OF LONG-CHAIN FATTY ACIDS IN GREY WASTEWATER WITH IN-VIAL DERIVATISATION

摘要

The presence and levels of long-chain fatty acids (C_6-C_(20)) in grey wastewater from bathrooms have been investigated. The acids were purified and concentrated by solid-phase extraction on strong anion exchange discs, in-vial derivatised to their corresponding methyl ester and subsequently analysed by GC-MS. The method was able to quantify the acids at concentration < 1μg/L with a recovery of 31-97%. The levels of fatty acids were found in the range of < 0.5 to 27 100 μg/L and the highest levels were found for the saturated lauric (C_(12)), palmitic (C_(16)) and stearic (C_(18)) acids. The treatment efficiency of a local treatment plant was evaluated by comparing concentrations of fatty acids at the inlet and the outlet. It was found that the treatability decreases with increasing chain length for the saturated acids (19-100% degradation) whereas the corresponding mono unsaturated acids were more easily degraded.