Considerații privind reactivitatea incarcarii organice naturale fata de clor din surse subterane tratatei sistem biologic pentru biooxidare ioni amoniu

Abstract

The presence of inorganic compounds containing oxidable nitrogen within groundwater sources at various,high concentration levels, especially in the case of NH+4 (NH+4 ≤ 8 mg/l), is asking for the replacement of classical oxidation technology using “break point” chlorination, due to non-conformities generated by high consumptions of chlorogenic agents (tens mg Cl2/l) upon the quality of treated water (acid pH, high ratio of residual bound chlorine, trihalomethans above the maximum admissible concentration). Biochemical oxidation using a bio-filter system in specific operating conditions (media type, temperature, oxygen demand, inorganic carbon and phosphorus sources, biological contact time, etc.) is representing a feasible technological alternative. Taking into account that carbon source used within the biochemical process is inorganic, the dissolved natural organic matters (NOM- humic matters) can react with the chlorine used in the final stage of biological effluent treatment. In the conditions of advanced removal of NH+ 4, oxidation to NO- 3, the chlorine dosages needed for effluent‟s finishing, disinfection are reduced. Experimental tests have as objectives to set up the chlorine dosage (Cl2 = 0,5 † 0,8 mg/l) that assures the disinfection of effluents resulted from biological nitrification step and a minimum ratio of residual bound chlorine, as well as the assessment of trihalomethanes formation potential in case of dissolved organic load, DOC ≤ 1,8 mg C/l (weight rations Cl2 / DOC = 1 † 8).