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31 Algal toxins removal from Cyanobacteria Blooms in Drinking Water: Microcystin LR as case study Dr. Sara Azerrad (Shamir Research Institute), Dr. Assaf Lowenthal (Atlantium) Ex p e r i me n t p r o v e s t h a t UV-oxidation systems are capable of cost-effectively removing environmental contaminants Blue-green alga (cyanobacteria) are the most common blooms found in eutrophicated surface water. The released algal toxin (such as microcystin) has caused animal poisoning in many parts of the world and may present risks to human health through drinking and recreational activity, particularly due to its hepatotoxic effect. Therefore, the occurrence of cyanobacteria and their toxins in water bodies used to produce drinking water poses a technical challenge forwater utilitymanagers. Theaimof these research is to test the technical feasibility for removal of microcystin LR used asmodel cyanobacteria toxin in surface water by direct photolysis in medium-pressure lamps (MP). These lamps produced a wide range of wavelengths which can promote direct photolysis of different compounds. The results obtained will be compared with experiments using low-pressure lamp as well as with advanced oxidation processes (AOP) with hydrogen peroxide. Various technologies havebeen tested formicrocystin removal. Such as ozone, granular activated carbon as well as advanced oxidation processes using UV, (monochromatic) low-pressure lamp (LP), with hydrogen peroxide. The proposed technology will allow inline water treatment avoiding the use of chemicals or adsorbents commonly used for microcystin removal. Furthermore, the contribution of nitrates, commonly found in surface water, in the removal of microcystin was also studied. Experiments were performed in a medium- pressure mercury UV lamp housed in a Figure 1: Removal of Microcystin medium- pressure and low-pressure lamps in Kinneret Lake water.