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HYDROGEN SULFIDE, PHOSPHATE, COOPER, CHROMIUM, SELENIUM & ARSENIC REMOVAL MEDIA FILTERSORB HSR® Granular Ferric Hydroxide Based Removal Media WATCH FILTRATION TECHNOL OGY Leading Manufacturer of Filtration Medias for Water Technology ® FILTERSORB Hydrogen Sulfide, Arsenic and Phosphates Removal in Drinking Water Introduction Hydrogen sulfide is a colorless gas with an offensive stench and is said to smell like rotten eggs. The gas can be detected at a level of 2 parts per billion. It is very erosive in a wet state and become Sox when it is oxidized. Physical Properties of H2S Hydrogen sulfide has a structure similar to that of water. This is where the similarity ends, however. Sulfur is not nearly as electronegative as oxygen so that hydrogen sulfide is not nearly as polar as water. Because of this, comparatively weak intermolecular forces exist for H2S and the melting and boiling points are much lower than they are in water. Hydrogen sulfide and water boil at - 60.7 °C and +100.0 °C, respectively. General Information Filtersorb HSR Using a patented process, ferric hydroxide can now be produced in a granular form. Various bead diameters can be made by combination of crushing and sieving procedures. This gives access to a great variety of new applications of ferric (III) hydroxide. The Filter media, containing iron hydroxide Fe(OH)3 has an amorphous structure. The ferric ions content in the filtering media is about 40% by weigh. Because of its chemical activity, ferric (III) hydroxide is quite appropriate to bind arsenate, phosphate or sulfide ions in aqueous media. Due to internal high pH of media it has an additional effect of the reaction with H2S and can reach oxidation capacity up to 20% by its dry weight. Operation Principles Arsenic and Phosphate removal In a first step arsenate or phosphate ions in aqueous solutions were adsorptively bounded to the surface of Filtersorb HSR. Second step is a chemical conversion to stable ferric arsenate or ferric phosphate to the surface of Filtersorb HSR. Fe(OH)3 + H3PO4 > FePO4 + 3 H2O Fe(OH)3 + H3AsO4 > FeAsO4 + 3 H2O Hydrogen Sulfide removal Sulfide ions formed from hydrogen sulfide in water are removed in a similar way under precipitation of hardly soluble ferric sulfide. 2 Fe(OH)3 + 3 H2S > Fe2S3 + 6 H2O watch water technology Hydrogen Sulfide, Arsenic and Phosphates Removal in Drinking Water Filtersorb HSR Chemical formula and composition: Amorphous Fe(OH)3 Mineralogical composition: Up to 40% of Ferric Ions from its weight Physico-Mechanical properties: Bulk weight 640 kg/m3 2 Free board down flow 50-75% Bed depth up flow 50-100% Specific surface 270 m /g Free board up flow 10-50% Colour dark brown Service flow rate 10-20 m/h Mesh size 0,5-2,0 mm, 2,0-4,0 mm Back wash flow rate 25-30 m/h 4+ Total adsorbtion capacity as P Total adsorption capacity as As 5+ 15 g/kg 12 g/kg Operation condition and exchange capacity: Oxidation capacity as H2S up to 20% of its dry weight Bed depth down flow pH 5-9 450-850 mm Application: • Water treatment: Filtersorb HSR media is applicable in a wide range of water treatment processes, from large-scale municipal systems to small-scale residential treatment units. Regardless of the system size, there are operational design parameters that must be considered to ensure effective, trouble free performance of the Filtersorb HSR media. Groundwater or surface water is simply pumped in down flow mode through a single or multiple fixed bed pressure vessel containing the Filtersorb HSR media, but it can be also used successfully in up flow filtration. In down flow filtration is recommended to use oxygen dosing for better oxidation. It is also being used in systems to remove Chromium, Cooper, Selenium. The multiple pressure vessel design is either assembled in Parallel Flow or Series flow. Flow to each vessel is measured and totalized to record the volume of water treated. Pressure differential through each vessel is also monitored. Periodic backwashing is typically performed at start-up and after each pressure drop of 0,5-1,0 Bar thereafter depending on usage and water quality. • Elimination of Arsenic from drinking water • Binding of Phosphates from rivers and lakes • Oxydation of Hydrogen Sulfide in water • Treatment of contaminated ground water • Filter beds for the separation of phosphates compounds In wet lands • “Reactive barriers” for the confinement of contamination In depositions • Binding of nutritive substances in aquarium or garden pond treatment watch water technology