In order to prevent of detergent surfactant contamination to water and soil, or even in well water, decreasing surfactant in a laundry wastewater has been studied by using photodegradation under UV/TiO 2 /H 2 O 2 (photo-Fenton-like) and UV/Fe 2+ /H 2 O 2 (photo-Fenton) processes. Photodegradation processes were performed in a batch system by exposing UV light to the laundry wastewater for a period of time. In both processes, the factors influencing the effectiveness of the photodegradation have

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... been evaluated. The surfactant concentration left in the wastewater was determined by UV/Visible spectrophotometry using methylene blue as a coloring agent. The research results indicated that the surfactant concentration in the laundry wastewater could be decreased significantly by using both UV/TiO 2 /H 2 O 2 and UV/Fe 2+ /H 2 O 2 processes. In both processes, it was observed the dependency of the surfactant photodegradation effectiveness on TiO 2 dose, Fe(II) and H 2 O 2 concentrations, pH and time. From the influencing factors study, the optimal conditions could be obtained. To get the surfactant concentration in the wastewater that fulfills the quality standard regulated by Indonesian Government, two steps of both UV/TiO 2 /H 2 O 2 and UV/Fe 2+ /H 2 O 2 processes were required. It also is clearly confirmed that UV/Fe 2+ /H 2 O 2 (photo-Fenton) process was more effective in the surfactant photodegradation than that of UV/TiO 2 /H 2 O 2 (photo-Fenton-like) process.