Fate of linear alkylbenzene sulfonates in wastewater treatment plants, Jordan

The linear alkylbenzene sulfonates (LAS) are used extensively as surfactants, and commercially consisted of a mixture of homologues and isomers. This work represents an UV-HPLC methodology for determination of homologues, isomers and sum of LAS concentration in wastewater. The different LAS homologues (Cm-C13) were separated and their total concentration was determined within 15 min using a Waters Spherisorb(r) 5 .tm particle size ODS2 (4.6x250 mm) analytical column, with gradient elution of a mixture of NaClO4 and acetonitrile. LAS concentration was determined for influenting untreated wastewater and treated wastewater effluent from four sites in Al-Karak province, Jordan. The concentration levels of LAS ranged from 4.7 mg/L to 12.1 mg/L, and from 0.3 mg/L to 4.6 mg/ L, for influents and effluents, respectively. However, complete mineralization of LAS was observed to be aerobic, when using an activated sludge wastewater treatment plant. Meanwhile, the results indicated that concentrations of LAS homologues (C10-C13) for effluent wastewater varied, and were dependent on the type of treatment.