Process solutions to increase the efficiency of wastewater treatment with a low concentration of organic matter

Summary

Through the example of the Moscow wastewater treatment facilities, the ways of improving the efficiency of treatment of low-concentrated wastewater in terms of organic matter are considered: the acidification of raw sludge, addition of an external organic substrate, use of technologies independent of the concentration of organic substances. In the presence of refluxes containing nitrogen and phosphorus, the use of organic matter-independent technologies is promising to reduce the nitrogen and phosphorus load on the main biological treatment line. Process solutions that improve the efficiency of nitrogen and phosphorus removal from low-concentrated wastewater in terms of organic matter at the Liuberetsky and Kurianovsky treatment facilities are as follows: acidification of raw sludge to increase the concentration of readily available organic matter; local treatment of refluxes from the sludge treatment facilities to reduce the nitrogen and phosphorus load on the biological treatment using the Anammox process and obtaining a mineral fertilizer – struvite (magnesium ammonium phosphate). At the small-scale wastewater treatment facilities of New Moscow, the addition of yeast condensate as an additional organic matter provides for increasing the BOD₅/N_total ratio from 3.2 to 4.3, which under these conditions is sufficient for the successful denitrification and biological dephosphorization processes. This made it possible to ensure the standard level of removing nitrogen of nitrates and phosphorus of phosphates and, as a result, reduce the consumption of the chemical (ferric chloride).

Key words

wastewater treatment , removal of nitrogen and phosphorus , best available techniques , return flows , nutrients removal , struvite , Anammox technology , low concentration of organics in wastewater