Surfactants are organic chemicals with wide applications as detergents. Linear alkyl benzene sulfonate (LAS) is an anionic surfactant most commonly used. Discharge of raw or treated wastewater containing this chemical into the environment causes major public health problems. In this study, 64 samples were taken from the effluent of Yazd Wastewater Treatment Plant over a period of one year. The samples were analyzed according to standard methods. The results obtained from the samples taken in different seasons showed that the highest efficiency of anionic surfactant removal was achieved in the summer in the secondary facultative stabilization pond. The least efficiency was observed in the autumn in samples from the anaerobic stabilization pond. It was also found that treated wastewater discharged into surface waters, reused for agricultural irrigation, or discharged into absorbent wells had significant differences with Pvalue
