Research of the effectiveness of tertiary treatment of wastewater

Abstract

As cities grow and expand, pollution and wastewater volumes also increase, surpassing the treatment capacity of wastewater treatment plants and directly impacting the ecological status of rivers. The primary and secondary treatment stages in wastewater treatment plants are becoming increasingly burdened. Additionally, stricter regulations on treated wastewater pollution levels are being introduced. Due to these reasons, the tertiary wastewater treatment stage is becoming more relevant. The study was conducted in a municipal wastewater treatment plant. The research examined the removal efficiency of a tertiary treatment unit for different pollutants under varying reagent dosing conditions, which were divided into two stages: when the reagent dose for phosphorus removal was lower than required and when it was dosed optimally. The study determined that in the first stage, the average removal efficiency was as follows: total phosphorus – 28%, phosphate phosphorus – 20%, BOD₇ – 66%, Tn – 9.3%, and suspended solids (SS) – 83%. In the second stage, the removal efficiency of total phosphorus and phosphate phosphorus reached 30%, BOD₇ – 36%, Tn – 4.3%, and SS – 68%.