Isolation, Screening and Identification of Diatoms from Kermanshah Oil Refinery Wastewater Treatment Systems

There are many oil refineries in Iran, so waste water should be treated. Algal remediation is one of the best methods. The class of Bacillariophyta (diatoms) has distinct ecological preferences and tolerances, making them useful indicators of contemporary ecological conditions. Isolation and selection of microorganisms is the first step in bioremediation. Palmer assessed the tolerance of algal species to organic pollution, and incorporated the data into an organic pollution index for rating water quality. Biovolume is used as a measure of relative algal biomass. The present work was conducted to isolate and select the tolerance diatoms from Kermanshah Oil Refinery wastewater treatment systems. This helped to improve diatoms community of Iran and prepare a list of tolerance diatom in bioremediation. Wastewater samples were collected aseptically at six points in and transferred to the laboratory. The serial diluted were prepared in BG broth, and then samples were cultured into Bristol agar and BG agar with chloramphenicol. Finally they were cultured in NA to assurance that there are no bacteria. The brown diatoms colonies were cultured in new plates. The samples were observed through microscope, and keys were used to classify them. Also biovolume according to geometric shapes (um3) were calculated. There was no bacterial growth after 48 hours thus this method is an applied method in order to isolate diatoms. A variety of classes were observed such as Navicula, Nitzschia and Frustulia. Analysis of the biovolume revealed that the species of Fragilaria capucina has the maximum biovolume.Discussion and This research revealed that the diatoms diversity in Kermanshah Oil Refinery wastewater treatment systems is low due to the high rate of organic pollution according to Palmer index. Also Pinnularia, Fragilaria can be used in the list of tolerance diatoms.