The Effect of Iron Salt on Anaerobic Digestion and Phosphate Release to Sludge Liquor Gele ies druskos taka anaerobinio dumblo pūdymo procesui ir fosfat i siskyrimui dumblo vanden

Iron salts are used at wastewater treatment plants (WWTPs) for several reasons: for removing chemical phosphorus, preventing from struvite formation and reducing the content of hydrogen sulfide (H2S) in biogas. Anaerobic digestion is a common scheme for sludge treatment due to producing biogas that could be used as biofuel. Laboratory analysis has been carried out using anaerobic digestion model W8 (Armfield Ltd, UK) to investigate any possible effect of adding FeCl3 on the anaerobic digestion of primary sludge (PS) and waste activated sludge (WAS) mixture as well as on releasing phosphates to digested sludge liquor. The obtained results showed that FeCl3 negatively impacted the anaerobic digestion process by reducing the volume of produced biogas. Fe-dosed sludge (max) produced 30% less biogas. Biogas production from un-dosed and Fe-dosed sludge (min) was similar to the average of 1.20 L/gVSfed. Biogas composition was not measured during the conducted experiments. Phosphorus content in sludge liquor increased at an average of 38% when digesting sludge without ferric chloride dosing. On the contrary, phosphate content in sludge liquor from digested Fe-dosed sludge decreased by approx. 80%. Nuotek valymo renginiuose gele ies druskos naudojamos cheminiam fosforui alinti, sieros vandeniliui biodujose ma inti ir struvito nuogul formavimosi prevencijai. Tyrimai atlikti laboratorin mis s lygomis naudojant anaerobinio pūdymo model W8 (Armfield Ltd., Did ioji Britanija) ir pūdant pirminio perteklinio dumblo mi in , kur buvo dedama gele ies druskos, siekiant nustatyti gele ies druskos naudojimo efekt anarobinio pūdymo procesui ir fosfat i siskyrimui dumblo vanden . Rezultatai parod , kad pūdant dumbl be gele ies druskos ir dedant gele ies druskos minimali doz , susidar vidutini kai vienodi kiekiai bioduj (mL/gBSMtiekiam.), bet pūdom dumbl dedant maksimali gele ies doz , bioduj i eiga vidutini kai suma jo 30 %. pūdom dumbl nededant gele ies chlorido, fosfat koncentracija dumblo vandenyje vidutini kai padid jo 38 %. Ir prie ingai, gele ies chlorido doz s fosfat koncentracij pūdyto dumblo vandenyje suma ino 80 %. Straipsnis angl kalba