Exploring correlation between hydrobiological indicators of aeration tanks and the concentration of phosphates in purified wastewaters

The results of measuring chemical and hydrobiological indices of wastewater in real conditions of the sewage treatment plant of DP “Chernihivvodokanal» (Ukraine) were analyzed, and coefficients of correlation between phosphates concentration after biological purification of wastewater and the hydrobiological indices were calculated. It was established that the informativeness of indices as for the quality of the process of water purification from phosphates decreases in the series: the number of the hydrobiont species CSW – silt volume – the silt index – silt dose; correlation coefficients vary from К cor. =–0,39381 to К cor. =–0,0485. Using the method of fluctuation smoothing with the help of SMA – simple moving average – we identified the trend: the influence of season on the number of hydrobionts and phosphates concentration in wastewater. A change in phosphates concentration in the wastewater purified by biological way occurs mainly simultaneously in antiphase to the change in the number of hydrobiont species, characteristic for satisfactory performance of silt. The use of obtained data allows giving preference in the analysis of the course of the process to one or several indices that would contribute to operational control of purification process.