[The formation of trihalomethanes precursor in anionic surfactant biodegradation].
Trihalomethanes (THMs) formed by chlorination of precursor substances in raw water, are found in drinking water. They are found at concentration levels higher than those of other organic contaminants. In the present study, the relationship between the formation of THM precursors and anionic surfectants biodegradation was investigated. Three anionic surfectants (LAS, AS and soap), dissolved in river
Biodegradation of α-Olefin Sulfonates (AOS) and Other Surfactants
To follow the progress of biodegradation of anionic surfactants, the methylene blue method is the most widely employed for quantitative analysis. But, there is unaccountably the case in which the activity to methylene blue disappeared even before surfactant has not yet completely been biodegraded into inorganic compounds. And so, we examined the biodegradability of several surfactants by measuring the residual carbonaceous materials in comparison with the colorimetric analysis.Sodium α-olefin sulfonates (AOS) and other ten anionic and three nonionic surfactants were taken as test materials. In the shake culture test method, it was found that surfactants containing straight alkyl chain such as AOS, alcohol sulfate and soap were degraded in shorter period necessary for the disappearance of the carbonaceous materials during biodegradation. However, surfactants having benzene ring or ethoxylate chain in their molecules were slow in decrease of the concentration of organic carbon during biodegradation, and there was a large discrepancy between the biodegradation rates obtained by colorimetric analysis and measurement of organic carbon.
The use of ultra-violet absorbance for monitoring the total organic carbon content of water and wastewater
The correlation between ultra-violet absorbance at 254 nm (A254 nm) and total organic carbon (TOC) content has been determined for a variety of treated and untreated water samples. These samples ranged from municipal secondary sewage effluent to raw and processed river water. 
 
High correlation coefficients were obtained for water samples which contained sufficient organic carbon to permit accurate TOC determinations. Predictably, systems with low TOC levels yielded lower correlation coefficients. However, even with the lower correlation coefficients, absorbance measurements can still be used to monitor a process stream for its organic carbon content if interferences from turbidity do not exceed certain limits.