Several microorganisms growing in aquatic environments are able to adhere, multiply and development on solid surfaces in interacting and organized, 3D structures name bioflims. Many problems in drinking water network, such as corrosion, obstruction, increased resistance to biocides or contaminants and persistance of pathogenic species are due to the existance of biofilms. One the other hand, arsenic (As) in natural waters is a serious global problem due to its adverse impact on human health.