The role of biodegradable particulate and colloidal organic compounds in biological nutrient removal activated sludge systems

Abstract

The efficiency of denitrification and enhanced biological phosphorus removal in biological nutrient removal activated sludge systems is strongly dependent on the availability of appropriate carbon sources. Due to high costs of commercial compounds (such as methanol, ethanol, acetic acid, etc.) and acclimation periods (usually) required, the effective use of internal substrates is preferred. The aim of this study was to determine the effects of slowly biodegradable compounds (particulate and colloidal), as internal carbon sources, on denitrification, phosphate release/uptake and oxygen utilization for a full-scale process mixed liquor from two large wastewater treatment plants located in northern Poland. Since it is difficult to distinguish the effect of slowly biodegradable substrate in a direct way, a novel procedure was developed and implemented. Four types of one-and two-phase laboratory batch experiments were carried out in two parallel reactors with the settled wastewater without pre-treatment (reactor 1) and pre-treated with coagulation-flocculation (reactor 2). The removal of colloidal and particulate fractions resulted in the reduced process rates (except for phosphate release). The average reductions ranged from 13 % for the oxygen utilization rate during the second phase of a two-phase experiment (anaerobic/aerobic), up to 35 % for the nitrate utilization rate (NUR) during the second phase of a conventional NUR measurement.

Computer Simulation in Predicting Biochemical Processes and Energy Balance at WWTPs

“…Sample results and model predictions of batch experiments are presented in Figure 2 a-b [4,6]. Set of the process stoichiometric and kinetic parameters in ASM2d was used as a base point of further process calibration in newly developed comprehensive model Mantis2 for simulation study of "virtual" plant layout in GPS-x (Figure 2c).…”

“…Continual feedback between the model and real-time measurements (e.g. NH 4 -N and NO 3 -N and PO 4 -P behavior) from "Wschód" WWTP were additionally used to confirm initial modeling results. It was shown that a "well" calibrated model within an assessment study could be used to evaluate process capacities, operational changes, upgrades and/or process changes.…”

“…volume of 4.0 dm3), control system and computer. This batch experiments results were obtained by Drewnowski and Makinia [4] at a large (600,000 PE) BNR "Wschód" WWTP in Gdansk (Poland) provided the experimental database for comparison of the model predictions as well as additional 96-hour measurement campaign in the full-scale MUCT bioreactor at this plant presented earlier by Swinarski et al [3] was integrated to calibration/validation process. During that time only full-scale MUCT bioreactor was simulated using base model ASM2d.…”

Simultaneous removal of nutrients in a novel anaerobic–anoxic/aerobic sequencing reactor: removal of nutrients in a novel reactor

“…Phosphate adsorption above cellular capacity by PAOs is possible in enhanced biological phosphorus removal (EBPR). EBPR places the PAOs in alternating anaerobic and aerobic conditions (Zhou et al 2012;Drewnowski and Makinia 2014). Simultaneous removal of total phosphate (TP) and total nitrogen (TN) consumes organic matter.…”

The effects of carbon/phosphorus ratio on polyphosphate- and glycogen-accumulating organisms in aerobic granular sludge

“…The efficiency of EBPR is strongly dependent on the availability of appropriate carbon sources (Drewnowski and Makinia 2014). COD/P ratio affects the structure of bacterial communities involved in EBPR; however, majority of studies on PAO-GAO selection have been carried out on flocculent activated sludge as reviewed by Oehmen et al (2007).…”