Abstract. Corrosion damages of metal structures of wastewater treatment facilities affect the work process parameters and operation safety. The analysis of the factors causing corrosion of metal elements and the assessment of corrosion resistance of the steel grades St08ps, St3sp and St5sp during the treatment stages, including the chlorine treatment, were conducted based on the data obtained from the Rostov-on-Don aeration plant. The article search techniques to determine the corrosiveness of water towards the metal structures. It is established that in this case it is advantageous to use redox indicator systems (rH2), which is calculated on the basis of field measurements of redox potential (ORP) of water. Based on the conducted studies, the correlation dependence for determining the corrosion rate of the steel grades St08ps and St5sp was suggested and statistically assessed for the aeration plant structures.

The paper presents the results of studies on increasing the efficiency of wastewater treatment from nitrogen compounds during the re-engineering of sludge bioreactors with the use of contact carriers for biomass immobilization. To assess the contribution of the indicative species of microorganisms involved in the processes of nitrification and denitrification, an analysis of the indices of species diversity by functional zones was carried out. The results of the operation of the bioreactor are given when using reticulate contact carriers in the form of partitions to separate the functional zones. It was noted that the oxidation-reduction potential of the bioreactor in nitrogen increased 1.7 times after re-engineering.

Проанализированы причины критических ситуаций на очистных сооружениях коммунального водоотведения. Проведено обследование локальных очистных сооружений микрорайона в критической ситуации отказа и определены проблемы, обусловленные сбросом либо недоочищенных, либо полностью неочищенных сточных вод в водоём. Для восстановления функционирования очистных сооружений разработан оптимальный технологический режим с учетом изменения подачи воздуха, ввода биопрепаратов, добавления пероксида водорода и использования светодиодов в аэробной части сооружений. The causes of critical situations in sewage treatment plants for municipal water disposal are analyzed. A survey of local treatment facilities of the microdistrict in a critical failure situation was carried out and problems were identifi ed, caused by the discharge of either under-treated or completely untreated sewage into the reservoir. To restore the functioning of treatment facilities an optimal technological regime has been developed, taking into account changes in air supply, introduction of biologics, addition of hydrogen peroxide and the use of LEDs in the aerobic part of structures.