Detergents contain synthetic or organic surface active agents called surfactants, which
are derived from petroleum product precursors. They have the common property of
lowering the surface tensions of water thus allowing dirt or grease adhered to various
articles to be washed off. Linear alkyl benzene sulfonate (LAS) is a most commonly
used anionic surfactant. Discharge of raw or treated wastewater containing this
chemical substance into the environment causes major public health and enviromental
problems. In this study, samples were taken from raw wastewater and effluents of
treatment ponds of Elzaraby waste stabilization ponds over a period of one year. The
treated effluent is either discharged into surface waters or re-used in agricultural
irrigation. The samples were analyzed according to the standard methods. The results
obtained from the samples taken in different seasons showed that the highest overall
removal efficiency of LAS was achieved in summer season (77%), and the least
efficiency was observed in Winter season (55%), while the maximum overall efficiency
of BOD5 was in summer (88%) and minimum efficiency was (73%) in winter season.
The Dissolved oxygen concentrations along the pond series (DO) ranged from 0.18 to
4.8 mg/l.