removal of sodium dodecylbenzene sulfonate by moving bed biofilm reactor, using synthetic media

background detergents and difficulties of their presence in the water and wastewater cause various problems such as foam production, anomalies in the growth of algae, and accumulation and dispersion in aqueous environments. objectives the aim of this study was to examine and compare the moving bed biofilm reactor with another reactor without media (carries) for anionic surfactants removal. materials and methods in this study, the media was from the 2h company with specific surface of 535 m2/m3 and the experiment reactor was made of a 4-mm plexiglass. the experiment was conducted by using two reactor, as one of them was without media, with exactly similar conditions to compare their operations. the standard method (mbas) was used to measure the anionic surfactant. the concentrations of the examined anionic surfactant were 50, 100, 200, 300, and 400 mg/l in hydraulic retention times (hrts) of 72, 24 and 8 hours. results the removal percentage for both reactors at 50 mg/l concentration of pollutant was same, but after gradually increasing the pollutant concentration and decreasing the hrt, the media-containing reactor had significant efficiency in comparison with the other one. the optimum condition in this experiment was obtained at hrt of about 24 hours and 200 mg/l pollutant concentration with 99.2% removal. conclusions regarding the anionic surfactant standard in iran which is 1.5 mg/l for surface water discharge, using this process is suitable for treating municipal wastewater and industrial wastewater, containing 100-200 mg/l pollutant. however, for the industries that produce detergents, discharging more than 200 mg/l surfactants to the wastewater, using supplementary treatments for achieving the discharge standard are required.