Article
Environmental Sciences
Simon Mills, Anna Christine Trego, John Ward, Juan Castilla-Archilla, Johannes Hertel, Ines Thiele, Piet N. L. Lens, Umer Zeeshan Ijaz, Gavin Collins
Summary: This study utilized laboratory-scale bioreactors to investigate the formation, maturation, disintegration, and re-formation of new granules. The findings highlighted distinct morphological features of granule sizes and biofilm development stages, which are important for maximizing bioreactor performance.
JOURNAL OF ENVIRONMENTAL MANAGEMENT
(2021)
Article
Environmental Sciences
Yahua Wang, Ying Meng, Fubo Luan
Summary: This study achieved high loading start-up and rapid loading increase in an up-flow anaerobic sludge bed reactor using anammox granules. The loading rapidly reached 38.0 kg-N m(-3) day(-1) within 44 days. The study also provides a potential strategy for obtaining superior anammox granules with robust removal efficiency.
WATER AIR AND SOIL POLLUTION
(2023)
Article
Microbiology
Simon Mills, Anna Christine Trego, Piet N. L. Lens, Umer Zeeshan Ijaz, Gavin Collins
Summary: This study investigated the microbial ecology of granule formation in high-rate, up-flow anaerobic bioreactors and proposed an ecological granulation model. By analyzing the microbial communities actively undergoing growth, breakage, and reformation within the granules, important ecological roles influencing granule formation and stability were identified, leading to the development of a stepwise ecological model for granulation.
MICROBIOLOGY SPECTRUM
(2021)
Article
Agricultural Engineering
Huan Li, Teng Cai, Yijing Gao, Qicai Dai, Xinyu Liu, Xue Chen, Xueqin Lu, Guangyin Zhen
Summary: An upflow blanket filter (UBF) reactor with porous fixed cylinder carriers was used to investigate the formation mechanism of anammox granules. The UBF achieved the highest nitrogen removal efficiency of 93.19 +/- 3.39% at a nitrogen loading rate of 3.6 kg-N/m3/d and HRT of 2 h. Tryptophan-like proteins were found to be vital for granule formation, and the analysis of 16s rRNA revealed the important role of SBR1031 in cell aggregation. The anammox granules developed a two-layered spatial structure consisting of an outer-layer of ammonia oxidizing bacteria and an inner-core of anaerobic ammonia oxidizing bacteria. Introduction of porous fixed cylinder carriers effectively prevented biomass loss and flotation.
BIORESOURCE TECHNOLOGY
(2023)
Article
Green & Sustainable Science & Technology
Xiang Li, Yan Yuan, Yong Huang
Summary: Partial nitrification (PN)-Anammox is considered the optimal nitrogen removal process for municipal sewage, but NOB growth under low temperature and low-ammonium conditions leads to excessive NO3--N production. The cyclic utilization of Fe2+/Fe3+ in Feammox and NDAFO processes can achieve continuous conversion of NH4+-N and NO3--N without sludge mineralization. Coupling Feammox and NDAFO with Anammox enhances the conversion of NH4+-N to N-2.
JOURNAL OF CLEANER PRODUCTION
(2021)
Review
Engineering, Environmental
Kaiyao Hu, Wenxuan Li, Yaning Wang, Bo Wang, Hao Mu, Shuang Ren, Kexin Zeng, Hongjuan Zhu, Jinming Liang, Ya'e Wang, Juqiang Xiao
Summary: Wastewater with a low carbon to nitrogen ratio (C/N) contains insufficient organic carbon sources, resulting in incomplete removal of nitrogen (N) and phosphorus (P) during denitrification and anaerobic phosphorus release processes. N and P pollutants in water bodies pose a serious threat to sustainable development, human health, and water ecosystems. Therefore, the development of energy-saving, efficient, and sustainable N and P removal technologies is of great significance.
JOURNAL OF WATER PROCESS ENGINEERING
(2023)
Article
Agronomy
Ambar Cerda, Macarena Gonzalez, Carolina Rodriguez, Jennyfer Serrano, Eduardo Leiva
Summary: The excessive deposition of ammonium in the environment has negative impacts on biodiversity and ecosystem eutrophication. Anthropogenic sources are responsible for the majority of terrestrial reactive nitrogen, contributing to 45% of the total annual production on Earth. The Feammox process, a biological method that anaerobically metabolizes ammonium, coupled with hollow fiber membrane bioreactors (HFMBs), shows promise for the removal of ammonium from agriculturally derived wastewater. This study evaluated the formation of Feammox bacterial biofilms and demonstrated their efficiency in ammonium removal, providing valuable insights for scaling up the HFMBs process.
Review
Engineering, Environmental
Jia Li, Zhiwei Wang, Yayi Wang
Summary: Membrane aerated biofilm reactors (MABRs) are an energy-efficient technology for biological nitrogen removal (BNR), which can bring wastewater treatment plants (WWTPs) closer to carbon neutrality. MABRs use gas-permeable hydrophobic membranes to supply oxygen and serve as carriers for biofilm attachment. This review summarizes the characteristics and advantages of MABRs, as well as their application in coupling with novel BNR processes. It also discusses the potential of MABRs in upgrading existing WWTPs and the integration of PN/A process into MABRs.
CHEMICAL ENGINEERING JOURNAL
(2023)
Article
Agricultural Engineering
Buddhima Siriweera, Muhammad Siddiqui, Xu Zou, Guanghao Chen, Di Wu
Summary: This study explored the feasibility of coupling thiosulfate-driven denitrification (TDD) with partial nitrification and anammox (PNA) in a single membrane-aerated biofilm reactor (MABR) unit for the treatment of ammonium-containing wastewater. The MABR-1 and MABR-2 based on the TDD-PNA process achieved satisfactory total nitrogen removal efficiencies of 63% and 76%, with maximum oxygen utilisation efficiencies of up to 66% and 80% and nitrogen removal fluxes of 1.3 and 4.7 gN/(m(2)center dot d), respectively. The predictions from the AQUASIM-model validated the integrated bioprocess. These lab scale findings confirmed the applicability of MABR technology for simultaneous sulfur and nitrogen removal, showing promise for pilot-scale application.
BIORESOURCE TECHNOLOGY
(2023)
Article
Engineering, Environmental
Rahil Fofana, Michael Parsons, Megan Bachmann, Kimberly Jones, Jeseth Delgado Vela, Benay Akyon, Wenjun Liu, Stephanie Klaus, Christine deBarbadillo, Charles Bott, Haydee De Clippeleir
Summary: Partial denitrification-anammox (PdNA) technology has the potential to improve nitrogen removal efficiency and reduce costs. The study found that methanol is the preferred carbon source due to its higher PdNA efficiency and rate. However, achieving low effluent total nitrogen limits in PdNA filters primarily depends on the appropriate ratio of ammonium to NOx in the upstream activated sludge.
ENVIRONMENTAL SCIENCE-WATER RESEARCH & TECHNOLOGY
(2023)
Article
Environmental Sciences
Carlos R. Chan-Pacheco, Edgardo Valenzuela, Francisco J. Cervantes, Guillermo Quijano
Summary: This study comprehensively reviews recent biotechnologies related to nitrogen removal processes, including various nitrogen removal processes and the application of new technologies. These technologies can play an important role in wastewater treatment and gas emission control, with the potential to reduce greenhouse gas emissions and improve air quality.
SCIENCE OF THE TOTAL ENVIRONMENT
(2021)
Article
Environmental Sciences
S. Nivedhita, P. Shyni Jasmin, M. Sarvajith, Y. V. Nancharaiah
Summary: The formation, performance, and microbial community structure of aerobic granular sludge (AGS) were investigated in the presence and absence of oxytetracycline (OTC). The results showed that the addition of OTC promoted the formation of well-settling AGS, but decreased the removal rates of nitrogen and phosphorus. This study is important for understanding the impact of antibiotics on AGS and designing treatment methods for antibiotic-laden wastewaters.
Article
Agricultural Engineering
Chenchen Huan, Zhiying Yan, Jiang Sun, Yang Liu, Yong Zeng, Wei Qin, Yapeng Cheng, Xueping Tian, Zhouliang Tan, Qingyang Lyu
Summary: A strain of Paracoccus denitrificans named HY-1 with excellent capacity of heterotrophic nitrifying aerobic denitrification was isolated from activated sludge. HY-1 was capable of removing NH4+, NO2-, and NO3-, and also could perform denitrification under anaerobic conditions. The study found that HY-1 required less energy investment at a carbon-nitrogen ratio of 1.
BIORESOURCE TECHNOLOGY
(2022)
Article
Environmental Sciences
Mohd Rayaz, Mohd Aamir Khan, Abid Ali Khan, Fehmeeda Khatoon
Summary: The study investigated the optimal operating conditions for the formation of granules in an A/O/A cyclic mode aerobic granular biomass reactor (AGBR) for the treatment of anaerobic effluent. The results showed that the short aeration time, comprising 50% of the total cycle time, was the most effective phase for achieving high removal of organics and nutrients.
WASTE AND BIOMASS VALORIZATION
(2023)
Article
Engineering, Chemical
Meibo He, Tze Chiang Albert Ng, Shujuan Huang, Boyan Xu, How Yong Ng
Summary: This study proposes the use of poly (acrylic acid) hydrogel as a post-treatment method for AnMBRs to remove and recover NH4+-N, thus promoting the circular economy and the adoption of AnMBR technology. The results show that PAA hydrogels have excellent adsorption capacities for NH4+-N and can be regenerated multiple times with minimal decline in adsorption capacity. The use of a strategic recirculation of HCl solution as an eluent also shows promise in concentrating NH4+-N as resources. Economically, the PAA hydrogel-based adsorption/desorption process coupled with eluent recirculation is cost-effective for removing and recovering NH4+-N from AnMBR effluent. Overall, this study has the potential to expand the application of AnMBRs and contribute to innovations in sustainable wastewater treatment.
SEPARATION AND PURIFICATION TECHNOLOGY
(2022)
