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Absent anoxic activity of PAO I on nitrate under different long-term operational conditions
Published in Francisco Javier Rubio Rincon, Effect of Sulphide on Enhanced Biological Phosphorus Removal, 2017
Enhanced Biological Phosphorus Removal (EBPR) is a worldwide applied process used to remove phosphorus in wastewater treatment plants (WWTP) (Henze et al., 2008). EBPR is carried out by microorganisms broadly known as polyphosphate accumulating organisms (PAOs) that are capable of storing phosphorus beyond their growth requirements as poly-phosphate (Poly-P) (Comeau et al., 1986; Mino et al., 1987). PAOs have different metabolic processes depending on the availability of electron acceptors. Under anaerobic conditions, PAOs store volatile fatty acids (VFA) (e.g. acetate, propionate) as poly-hydroxyβ-alkanoates (PHA) at the expense of poly-P hydrolysis and glycogen degradation. Thereafter, when an electron acceptor is available (e.g. oxygen, nitrate, nitrite), PAOs consume the stored PHA to replenish their Poly-P and glycogen storage pools, for biomass synthesis and maintenance purposes (Comeau et al., 1986; Wentzel et al., 1986; Smolders et al., 1994a, 1994b; Kuba et al., 1996b).
New Insights of Bacteriophages: Potential Tool for Wastewater Treatment
Published in Rouf Ahmad Bhat, Moonisa Aslam Dervash, Khalid Rehman Hakeem, Khalid Zaffar Masoodi, Environmental Biotechnology, 2022
Saima Hamid, Mohammad Yaseen Mir
Enhanced biological phosphorus removal (EBPR) is a commonly used wastewater management method for the absorption of phosphorus and carbon. It works when the intracellular deposition of phosphate through polyphosphate-accumulating species (PAO) (Gu et al., 2008). PAO’s metabolism is unusual because of its anaerobic carbon absorption combined with the high-energy release from accumulated intracellular polyphosphate in a phosphate stream. During the tricarboxylic acid process, the deposited carbon is then used aerobically to produce biomass while part is used for excess absorption of external phosphates and the regeneration of intracellular polyphosphate reserves (Mino et al., 1998).
Organics, Salts, Metals, and Nutrient Removal
Published in David H.F. Liu, Béla G. Lipták, Wastewater Treatment, 2020
R. David Holbrook, Sun-Nan Hong, Derk T.A. Huibers, Francis X. McGarvey, Chakra J. Santhanam
With given influent wastewater characteristics, an EBPR system designed for a higher F/M ratio generally achieves a higher degree of phosphorus removal. A system operating with a higher F/M ratio produces a larger amount of cell mass (sludge) to incorporate phosphorus. Since sludge production and wasting are responsible for net phosphorus removal, this parameter is key to successful biological phosphorus removal.
Long-term exposure to zinc oxide nanoparticles improves PAOs function in enhanced biological phosphorus removal
Published in Environmental Technology, 2023
Haining Huang, Lei Dong, Yang Wu, Shuyang Zhou, Xiong Zheng, Yinguang Chen
In the past decades, enhanced biological phosphorus removal (EBPR) has been considered as an economic and environmentally friendly process, widely applied for phosphorus removal to prevent eutrophication in wastewater [1,2]. As a modified activated sludge process, the performance of EBPR relies on enriched heterotrophic bacteria like phosphorus accumulating organisms (PAOs) and glycogen accumulating organisms (GAOs) [3,4]. In the anaerobic phase, PAOs and GAOs both can take up carbon sources like volatile fatty acids (VFAs) and store them as polyhydroxyalkanoates (PHAs), with glycogen degradation to supply the necessary energy/reducing power. Whereas in aerobic conditions, they are both able to oxidize PHAs for bacterial growth and glycogen replenishment [4,5]. During the transformations of PHAs and glycogen, net phosphorus removal is achieved only by PAOs. However, GAOs, coexisting with PAOs, usually compete for the often-limited substrates, disturbing the biological phosphorus removal efficiency [4,6]. Clearly, the competition between PAOs and GAOs plays a crucial role in EBPR systems.
Recovery of phosphorus from wastewater: A review based on current phosphorous removal technologies
Published in Critical Reviews in Environmental Science and Technology, 2023
Yulin Zheng, Yongshan Wan, Yue Zhang, Jinsheng Huang, Yicheng Yang, Daniel C. W. Tsang, Hailong Wang, Hao Chen, Bin Gao
Although various biological P treatment processes have been applied to improve the performances of the conventional activated sludge process, EBPR process can only achieve an up to 70% removal efficiency for N and P in real wastewater at the pilot/full scale (Hasan et al., 2021; Wu et al., 2020). There is probably no ideal single EBPR system for efficient and simultaneous removal of organics, P and N from low to medium strength wastewater. Chemical precipitation along the EBPR process or post-treatment with physiochemical P removal processes would provide more accurate control on the effluent concentration of nutrients. Furthermore, conventional biological P removal process would not be considered as the technology to achieve direct P recovery (Ye et al., 2017). Recovering and reusing P directly from the sewage sludge still remain a great challenge due to low efficiency, high cost and secondary contamination risks associated with pathogens, heavy metals, persistent organic pollutants, and other micropollutants (Liu et al., 2021).
Greywater treatment in SBR-SND reactor - optimization of hydraulic retention time, volumetric exchange ratio and sludge retention time
Published in Environmental Technology, 2022
Kumari Priyanka, Manaswini Behera, Neelancherry Remya
Biological processes have reported very low phosphate removal [9]. Enhanced biological phosphorus removal (EBPR) is a potential approach for biological phosphorus removal from wastewater. The phosphorus removal using EBPR process could be accomplished by alternating anaerobic, aerobic and anoxic conditions in modified SBRs [10,11]. Phosphate (PO43--P) removal could be improved by combining biodegradation and adsorption processes, which are not studied for greywater treatment. Hence, combining adsorption with SBR is needed to improve phosphorus removal efficiency. Considerable research was conducted on integrating biodegradation and adsorption processes, including coal slag activated sludge-SBR, powdered activated carbon-SBR and granular activated carbon-SBR [12,13]. However, these adsorbents have several limitations to the practical applicability, such as high initial cost. As a result, new approaches have been investigated for developing low-cost adsorbents. Previous literature has reported good phosphate sorption capacity using agricultural waste materials (apple peel, peanut peel, sawdust, rice husk, corncob and wheat straw)[14–16]. However, few studies [17] with combined biodegradation and adsorbents were conducted for phosphate removal in SBR.