2018 Volume 16 Issue 1 Pages 18-29
Consumption of detergents containing linear alkyl benzene sulfonate (LAS) and fluorescent whitening agents (FWAs) is increasing rapidly in Asian countries. A respirometric oxygen uptake method was conducted to examine the aerobic biodegradability of some of the commercially available laundry and dishwashing detergents of India, Japan, Indonesia, and Thailand. Indian detergents and Japanese detergents showed 95–100% of LAS removal. However, the three-dimensional fluorescent spectra results indicated the presence of residual metabolites such as sulfophenyl carbonate. Indonesian detergents and Thai detergents showed less LAS removal, but the progress of benzene ring cleavage of LAS in these detergents was observed from the test results. The FWAs were observed mainly in laundry detergents. The removal of FWAs during biodegradation test was observed to be between 12.4 and 78.8%. The complex changes in oxygen uptake curve during the test period suggested the presence of various organic compounds in the detergents. The tested detergents were classified into three clusters based on the relationship between the total organic carbon and the fluorescence (220/290 nm) removals. The diverse biodegradation results among the tested detergents from different Asian countries suggested the effects of various ingredients present in the detergents.
