Assessment of the Active Sludge Microorganisms Population During Wastewater Treatment in a Micro-Pilot Plant

Knowledge of the impact of chemicals on the environment is important for assessing the risks that chemicals can generate in ecosystems. With the help of pilot-scale micro-tests, it was possible to evaluate the biological sludge in terms of its chemical and biological composition, information that can be applied on an industrial scale in treatment plants. The important parameters analyzed in the evaluation of the biodegradability of wastewater were pH, chemical composition (NH₄⁺, NO₃^-, NO₂^-, and PO₄^3-), dry substance (DS), inorganic substance (IS), and organic substance (OS), and the biological oxygen demand (BOD)/chemical oxygen consumption (COD) ratio. The examination revealed the presence of free active ciliates <i>Aspidisca polystyla</i>, <i>Lyndonotus setigerum</i>, <i>Vorticella microstoma</i>, fixed by <i>Zooglee</i>, <i>Paramecium</i> sp., <i>Opercularia</i>, <i>Colpoda colpidium</i>, <i>Euplotes</i>, <i>Didinum nasutum</i>, <i>Stentor</i>, and <i>Acineta tuberosa,</i> metazoa <i>Rotifers</i>, filamentous algae, <i>Nostoc</i> and <i>Anabena</i>, and bacteria <i>Bacillus subtilis</i>, <i>Nocardia</i>, and <i>Microccocus luteus.</i> The novelty of this study lies in the fact that we carried out a study to evaluate the population of microorganisms starting from the premise that the probability of biodegradation of substances is directly proportional to the number of microorganisms existing in the environment and their enzymatic equipment.