Partial Nitrification and Enhanced Biological Phosphorus Removal in a Sequencing Batch Reactor Treating High-Strength Wastewater

Abstract

Complex and high levels of various pollutants in high-strength wastewaters hinder efficient and stable biological nutrient removal. In this study, the changes in pollutant removal performance and microbial community structure in a laboratory-scale anaerobic/aerobic sequencing batch reactor (SBR) treating simulated pre-fermented high-strength wastewater were investigated under different influent loading conditions. The results showed that when the influent chemical oxygen demand (COD), total nitrogen (TN), and orthophosphate (PO43−-P) concentrations in the SBR increased to 983, 56, and 20 mg/L, respectively, the COD removal efficiency was maintained above 85%, the TN removal efficiency was 64.5%, and the PO43−-P removal efficiency increased from 78.3% to 97.5%. Partial nitrification with simultaneous accumulation of ammonia (NH4+-N) and nitrite (NO2−-N) was observed, which may be related to the effect of high influent load on ammonia- and nitrite-oxidising bacteria. The biological phosphorus removal activity was higher when propionate was used as the carbon source instead of acetate. The relative abundance of glycogen accumulating organisms (GAOs) increased significantly with the increase in organic load, while Tetrasphaera was the consistently dominant polyphosphate accumulating organism (PAO) in the reactor. Under high organic loading conditions, there was no significant PAO–GAO competition in the reactor, thus the phosphorus removal performance was not affected.

Impact of Dissolved Oxygen on the Performance and Microbial Dynamics in Side-Stream Activated Sludge Hydrolysis Process

“…In the A 2 O reactor, the main genera were Acinetobacter (0.5%−28.7%), Lelliottia (0.3%−25.7%), and Competibacter (5.4%−19.3%), while Acinetobacter (12.0%−45.0%), Thiothrix (1.3%−23.2%) and Cloacibacterium (1.6%−9.3%) exhibited the highest abundance in SSH reactor. These dominant genera were commonly detected in previous BNR studies [8,46,57,58]. Competibacter, Thiothrix, and Cloacibacterium were known GAO, denitrifier and fermentative bacterium, respectively [59].…”

Integrated Anaerobic–Aerobic Moving Bed Biofilm Reactor and Biochar Adsorption for the Efficient Removal of Organic Matter and Nutrients from Brazilian Landfill Leachate

“…This behavior may be due to the influence of the high concentrations of COD and NH 4 -N in phases II and III, which, as found in the literature, are competitive against biological phosphorous removal. In fact, high organic loads favor the growth of non-polyphosphate-accumulating organisms and lead to polyphosphate-accumulating organisms being screened out of the system [56,57]. Our study found that the integrated anaerobic-aerobic MBBR and biochar adsorption method was highly effective in removing TP from landfill leachate, with a total maximum removal rate of 99.9%.…”