Article
Agricultural Engineering
Wenyu Li, Yongzhen Peng, Ruitao Gao, Qiong Zhang, Xiyao Li, Chengkun Kao, Jianwei Li
Summary: This study investigates the impact of low salinity levels on a double-anammox system in treating municipal wastewater, finding that a salinity of 1.0% led to a nitrogen removal efficiency of 81.2%, with a significant contribution of 76.5% from anammox. Low salinity was also found to promote nitritation and denitratation, enhancing the overall nitrogen removal efficiency. The enrichment of specific microbial populations, such as Ca. Brocadia and Nitrosomonas, further supported the effectiveness of the double-anammox process in treating saline wastewater.
BIORESOURCE TECHNOLOGY
(2022)
Article
Agricultural Engineering
XiaoTong Wang, Hong Yang, JiaWei Wang
Summary: A two-stage partial nitritation/anammox process based on microbial encapsulation (PN/A-E) was established and thoroughly studied. The nitrogen removal efficiency of PN/A-E was compared to anammox granular sludge (AnGS) under high and low ammonia nitrogen conditions, as well as after reactivation from a long-term shutdown. The results showed that PN/A-E had a stable performance even under high ammonia nitrogen, and the nitrite accumulation rate reached 95.2 +/- 0.7%. The total nitrogen removal rate of encapsulated anammox bacteria was twice that of AnGS, and it exhibited better resilience to external interference. PN/A-E also demonstrated good reactivation performance with a final effluent total nitrogen of 10.0 +/- 1.4 mg·L-1 at a hydraulic retention time of 2.18 h. The immobilized fillers facilitated the growth of ammonia-oxidizing bacteria under restricted conditions and promoted the dominance of functional bacteria and stability of microbial community under low ammonia nitrogen. This study provides a positive method for achieving reliable PN/A process.
BIORESOURCE TECHNOLOGY
(2023)
Article
Chemistry, Multidisciplinary
Umesh Ghimire, Veera Gnaneswar Gude, Renotta Smith, John P. Brooks, Dewayne Deng
Summary: The nitritation-anammox biocathode microbial desalination cell showed high efficiency in nitrogen and salinity removal, with low energy consumption and high net energy output.
ACS SUSTAINABLE CHEMISTRY & ENGINEERING
(2021)
Review
Engineering, Environmental
Peng Wu, Junjiang Chen, Vijay Kumar Garlapati, Xingxing Zhang, Francis Wani Victor Jenario, Xiang Li, Wenru Liu, Chongjun Chen, Tejraj M. Aminabhavi, Xiaonong Zhang
Summary: This study presents a comprehensive review of the anammox process, the advancements in nitritation and denitratation processes, and proposes a novel wastewater treatment method for efficient nitrogen removal.
CHEMICAL ENGINEERING JOURNAL
(2022)
Article
Engineering, Environmental
Wenyu Li, Qiong Zhang, Jianwei Li, Ruitao Gao, Chengkun Kao, Xiyao Li, Yongzhen Peng
Summary: Nitrogen removal from saline municipal wastewater has become an area of interest, leading to the development of the energy-efficient technique of anaerobic ammonium oxidation (anammox) for advanced nitrogen removal. This study investigated the long-term salt adaptation and evolution mechanisms of an anammox-based process under different salinities. The results showed that the anammox bacteria had strong adaptability to salinity, with contribution levels of over 85% even at high salinity levels. Metagenomic sequencing revealed that the production of multiple nitrite substrates by specific bacteria ensured a high anammox contribution. This study provides valuable insights for the improved application of anammox-based processes in saline wastewater treatment.
CHEMICAL ENGINEERING JOURNAL
(2023)
Article
Biotechnology & Applied Microbiology
Weihua Zhao, Yanyan Wang, Meng Bai
Summary: The enhancement of nitrogen removal was achieved through the nitritation/anammox process in an anaerobic/oxic/anoxic (AOA) system with integrated fixed biofilm activated sludge. Nitritation was initially accomplished by inhibiting ammonia residues using free nitrous acid (FNA), and anaerobic ammonia oxidizing bacteria (AnAOB) were subsequently introduced into the system to enable nitritation coupled with anaerobic ammonia oxidation (anammox). The results demonstrated that the nitritation/anammox pathway significantly enhanced nitrogen removal efficiency to 88.9%. Microbial analysis revealed the enrichment of ammonia oxidizing bacterium (AOB) Nitrosomonas on the biofilm (5.98%) and in the activated sludge (2.40%), while the AnAOB Candidatus Brocadia was detected on the biofilm at a proportion of 0.27%. The successful achievement and maintenance of nitritation/anammox were attributed to the accumulation of functional bacteria.
BIOPROCESS AND BIOSYSTEMS ENGINEERING
(2023)
Article
Biotechnology & Applied Microbiology
Kuo Zhang, Xinjue Li, Shou-Qing Ni, Sitong Liu
Summary: The study investigated the impact of different carrier materials on nitritation performance, finding that the Sepiolite nonwoven composite carrier significantly inhibits nitrite-oxidizing bacteria, improving the efficiency of the nitritation process and holding significant importance for mainstream wastewater treatment.
FRONTIERS IN BIOENGINEERING AND BIOTECHNOLOGY
(2022)
Article
Agricultural Engineering
Hao Jiang, Pei Yang, Zhong Wang, Shang Ren, Jingang Qiu, Haoran Liang, Yongzhen Peng, Xiyao Li, Qiong Zhang
Summary: The study utilized a novel PnA/PdA SBBR to achieve efficient nitrogen removal from landfill leachate, by increasing DO and continuous carbon source feeding. The combined partial nitrification and partial denitrification processes synergized to significantly enhance nitrogen removal efficiency. Ammonia oxidation bacteria and Anammox bacteria showed comparable activities during aerobic period, while organic carbon redirection from complete denitrification to partial denitrification occurred during anoxic period.
BIORESOURCE TECHNOLOGY
(2021)
Review
Agricultural Engineering
Yujie Chen, Guangze Guo, Yu -You Li
Summary: This review introduces the application of anaerobic ammonia oxidation (anammox) process in nitrogen removal and summarizes methods to improve nitrogen removal rate. Recently developed integrated systems aim to enhance nitrogen removal rate and efficiency, providing new insights for achieving efficient nitrogen removal.
BIORESOURCE TECHNOLOGY
(2022)
Article
Agricultural Engineering
Enzhe Yang, Jing Chen, Ziyi Jiang, Zhengyu Deng, Zhi Tu, Hong Wang, Sha Wu, Zhe Kong, Eli Hendrik Sanjaya, Hong Chen
Summary: This study successfully recovered a deteriorated PNA system using a unique recovery strategy and explored the mechanism of recovery. The results showed that high nitrogen loading rate and hydraulic shear force can induce sludge granulation in the reactor, leading to recovery of microbial community structure and rapid restoration of nitrogen removal performance.
BIORESOURCE TECHNOLOGY
(2022)
Article
Engineering, Environmental
Qiongpeng Dan, Rui Du, Tong Wang, Tiantian Sun, Honggui Han, Xiaorong Zhu, Xiyao Li, Qiong Zhang, Yongzhen Peng
Summary: A hybrid system of anammox combined with heterotrophic endogenous metabolisms was developed in a single-stage bioreactor to treat real domestic wastewater. Nitrogen removal was achieved at a low carbon to nitrogen ratio and maintained under an extremely low ratio. The coexistence and enrichment of different bacteria contributed to the co-metabolism of carbon, nitrogen, and phosphorus.
CHEMICAL ENGINEERING JOURNAL
(2023)
Article
Engineering, Environmental
Wenyu Li, Xiyao Li, Jianwei Li, Ruitao Gao, Chengkun Kao, Qiong Zhang, Xiaohang Hou, Yongzhen Peng
Summary: This study evaluated the stability of a step-feed bioreactor dominated by denitratation/anammox (PD/A) for treating municipal wastewater with decreased temperature. By operating at low temperature, the nitrogen removal efficiency (NRE) was improved, and the contribution of anammox increased. The study also identified the key microbial populations responsible for denitrification and anammox in the system. This research provides an optimistic prospect for promoting anammox in mainstream applications at low temperature.
RESOURCES CONSERVATION AND RECYCLING
(2023)
Article
Environmental Sciences
Pian-Pian Xu, Jia Meng, Xianhui Li, Jiuling Li, Kai Sun, Bing-Feng Liu, Min Zheng
Summary: This study explores the potential of using heterotrophic denitrification to remove residual nitrate in the nitritation-anammox process for nitrogen removal from wastewater. By monitoring a laboratory microaerobic reactor, it was found that high-level nitrogen removal can be achieved through the nitritation-anammox pathway in low-carbon wastewater treatment, with complete nitrate depletion possible by controlling oxygen supply. The study also identified a complex microbial community including nitrifiers, denitrifiers, and anammox bacteria in the reactor biomass.
JOURNAL OF ENVIRONMENTAL MANAGEMENT
(2021)
Article
Engineering, Environmental
Feng Zhou, Wan-Zi Xiao, Kai-Yuan Zhou, Jin-Long Zhuang, Xu Zhang, Yong-Di Liu, Bing-Jie Ni, James P. Shapleigh, Min Zhou, Xi-Zi Luo, Wei Li
Summary: This study developed a novel one-stage nitrogen removal method that integrates partial nitrification, anammox, and denitratation for the treatment of low C/N wastewater. The expression of key genes for nitritation, anammox, and denitratation increased as reactor performance improved. Analysis of the metagenome revealed the dominant genera of ammonium-oxidizing bacteria, anammox bacteria, and denitratation bacteria. Mass balance confirmed that anammox was the dominant nitrogen removal pathway.
CHEMICAL ENGINEERING JOURNAL
(2022)
Article
Agricultural Engineering
Shenhua Yang, Yongzhen Peng, Shujun Zhang, Xiaoyu Han, Jialin Li, Liang Zhang
Summary: This study analyzed and compared the biofilm structure, performance, and nitrogen removal pathways of microporous and macroporous carriers from a full-scale partial nitritation/anammox reactor. Microporous carriers had thicker biofilms, higher biomass, and nitrogen removal efficiency due to the integration of denitrifying and anammox bacteria, while macroporous carriers had thinner biofilms, lower microbial richness, but strong network correlation among genera.
BIORESOURCE TECHNOLOGY
(2021)