Internal vs. External (Alternative) Carbon Sources for Denitrification and EBPR Accomplished by a Full-Scale Process Biomass

Abstract

The efficiencies of denitrification and enhanced biological phosphorus removal (EBPR) in biological nutrient removal (BNR) activated sludge systems are strongly dependent on the availability of appropriate carbon sources. The aim of this study was to determine the immediate effects of dosing different carbon sources on the denitrification capability and EBPR interactions of a full-scale process biomass from the "Wschod" WWTP in Gdansk (Poland). The settled wastewater (without pretreatment and after coagulation-flocculation) as well as acetic acid, ethanol and by-products from a distillery were tested in three kinds of batch experiments, such as the "conventional" nitrate utilization rate (NUR) measurements, NUR measurements during anoxic P uptake and aerobic respirometric measurements. The removal of colloidal and particulate fractions by coagulation-flocculation resulted in the reduced process rates: up to 30 and 25%, respectively, for the NUR1 and NUR2 during the "conventional" NUR measurements, and up to 60% for the NUR during the anoxic PUR test. In the "conventional" batch experiments, the observed NURs with fusel oil (2.5-2.7 g N/(kg VSS·h) were higher in comparison with pure ethanol. The addition of fusel oil at the beginning of the anoxic phase (preceded by an anaerobic phase) did not appear to affect adversely the parallel P uptake rates and the observed NURs (3.5-4.3 g N/(kg VSS·h)) were comparable to the other examined carbon sources.

A distillery by-product as an external carbon source for enhancing denitrification in mainstream and sidestream treatment processes

“…NURs observed during the two-phase batch tests with the different carbon sources (two measurements) in comparison with the previous study(Makinia et al 2009) Carbon source NUR in the anoxic phase of the two-phase batch test, g N/(kg VSS·h)…”

Advanced Supervisory Control System Implemented at Full-Scale WWTP—A Case Study of Optimization and Energy Balance Improvement

“…The value of Y H was only changed minorly from 0.63 g COD/g COD (default) to 0.65 g COD/g COD, but in the case of Y PO4 , a more significant adjustment was needed. The Y PO4 coefficient was adjusted to 0.32 g P/g COD, which was 25% lower than the ASM2d default value (0.4 g P/g COD), however, it was still within the range reviewed in the literature, e.g., Makinia et al [45,46] for MMCS (0.27 to 0.43 g P/g COD).…”

“…By comparing both studies, lower values of Y PO4 were observed probably because of the glycogen-accumulating organism's (GAOs) presence in the AS system. In the anaerobic P release tests at the Wschod WWTP with mixed liquor [1,45,46], there was no significant acetate utilization after the polyphosphate depletion in the PAO biomass. The sensitive analysis of GAO showed a very low value of <0.01, which, according to the ranking and particulate forms, did not have a significant role at the plant, so there was no need to model their metabolism in this study.…”