2.Recent advances in the structure and function of microbial community in anaerobic granular sludge.
Changjie GUO ; Weigang WANG ; Yayi WANG
Chinese Journal of Biotechnology 2023;39(11):4517-4533
Anaerobic granular sludge (AnGS), a self-immobilized aggregate containing various functional microorganisms, is considered as a promising green process for wastewater treatment. AnGS has the advantages of high volume loading rate, simple process and low excess sludge generation, thus shows great technological and economical potentials. This review systematically summarizes the recent advances of the microbial community structure and function of anaerobic granular sludge, and discusses the factors affecting the formation and stability of anaerobic granular sludge from the perspective of microbiology. Moreover, future research directions of AnGS are prospected. This review is expected to facilitate the research and engineering application of AnGS.
Sewage/chemistry*
;
Waste Disposal, Fluid
;
Anaerobiosis
;
Microbiota
;
Water Purification
;
Bioreactors/microbiology*
3.Combating a resurgence of poliomyelitis through public health surveillance and vaccination.
Chia Yin CHONG ; Kai Qian KAM ; Chee Fu YUNG
Annals of the Academy of Medicine, Singapore 2023;52(1):17-26
Poliomyelitis, or polio, is a highly infectious disease and can result in permanent flaccid paralysis of the limbs. Singapore was certified polio-free by the World Health Organization (WHO) on 29 October 2000, together with 36 other countries in the Western Pacific Region. The last imported case of polio in Singapore was in 2006. Fortunately, polio is vaccine-preventable-the world saw the global eradication of wild poliovirus types 2 and 3 achieved in 2015 and 2019, respectively. However, in late 2022, a resurgence of paralytic polio cases from vaccine-derived poliovirus (VDPV) was detected in countries like Israel and the US (specifically, New York); VDPV was also detected during routine sewage water surveillance with no paralysis cases in London, UK. Without global eradication, there is a risk of re-infection from importation and spread of wild poliovirus or VDPV, or new emergence and circulation of VDPV. During the COVID-19 pandemic, worldwide routine childhood vaccination coverage fell by 5% to 81% in 2020-2021. Fortunately, Singapore has maintained a constantly high vaccination coverage of 96% among 1-year-old children as recorded in 2021. All countries must ensure high poliovirus vaccination coverage in their population to eradicate poliovirus globally, and appropriate interventions must be taken to rectify this if the coverage falters. In 2020, WHO approved the emergency use listing of a novel oral polio vaccine type 2 for countries experiencing circulating VDPV type 2 outbreaks. Environmental and wastewater surveillance should be implemented to allow early detection of "silent" poliovirus transmission in the population, instead of relying on clinical surveillance of acute flaccid paralysis based on case definition alone.
Child
;
Humans
;
Infant
;
Public Health Surveillance
;
Pandemics
;
Wastewater
;
Wastewater-Based Epidemiological Monitoring
;
COVID-19/epidemiology*
;
Poliomyelitis/prevention & control*
;
Poliovirus
;
Poliovirus Vaccine, Oral
;
Vaccination
;
Global Health
4.Denitrifying phosphate accumulating organisms and its mechanism of nitrogen and phosphorus removal.
Chunxia ZHENG ; Cerong WANG ; Manman ZHANG ; Qifeng WU ; Mengping CHEN ; Chenyu DING ; Tengxia HE
Chinese Journal of Biotechnology 2023;39(3):1009-1025
Water eutrophication poses great threats to protection of water environment. Microbial remediation of water eutrophication has shown high efficiency, low consumption and no secondary pollution, thus becoming an important approach for ecological remediation. In recent years, researches on denitrifying phosphate accumulating organisms and their application in wastewater treatment processes have received increasing attention. Different from the traditional nitrogen and phosphorus removal process conducted by denitrifying bacteria and phosphate accumulating organisms, the denitrifying phosphate accumulating organisms can simultaneously remove nitrogen and phosphorus under alternated anaerobic and anoxic/aerobic conditions. It is worth noting that microorganisms capable of simultaneously removing nitrogen and phosphorus absolutely under aerobic conditions have been reported in recent years, but the mechanisms remain unclear. This review summarizes the species and characteristics of denitrifying phosphate accumulating organisms and the microorganisms capable of performing simultaneous nitrification-denitrification and phosphorous removal. Moreover, this review analyzes the relationship between nitrogen removal and phosphorus removal and the underlying mechanisms, discusses the challenges of denitrifying phosphorus removal, and prospects future research directions, with the aim to facilitate process improvement of denitrifying phosphate accumulating organisms.
Phosphorus
;
Phosphates
;
Wastewater
;
Denitrification
;
Waste Disposal, Fluid
;
Nitrogen
;
Bioreactors/microbiology*
;
Nitrification
;
Sewage
5.The toxicity of ZnO and CuO nanoparticles on biological wastewater treatment and its detoxification: a review.
Yuran YANG ; Can ZHANG ; Zhenlun LI
Chinese Journal of Biotechnology 2023;39(3):1026-1039
The wide use of ZnO and CuO nanoparticles in research, medicine, industry, and other fields has raised concerns about their biosafety. It is therefore unavoidable to be discharged into the sewage treatment system. Due to the unique physical and chemical properties of ZnO NPs and CuO NPs, it may be toxic to the members of the microbial community and their growth and metabolism, which in turn affects the stable operation of sewage nitrogen removal. This study summarizes the toxicity mechanism of two typical metal oxide nanoparticles (ZnO NPs and CuO NPs) to nitrogen removal microorganisms in sewage treatment systems. Furthermore, the factors affecting the cytotoxicity of metal oxide nanoparticles (MONPs) are summarized. This review aims to provide a theoretical basis and support for the future mitigating and emergent treatment of the adverse effects of nanoparticles on sewage treatment systems.
Wastewater/toxicity*
;
Sewage/chemistry*
;
Zinc Oxide/chemistry*
;
Waste Disposal, Fluid
;
Nanoparticles/chemistry*
;
Metal Nanoparticles/chemistry*
;
Nitrogen/metabolism*
;
Water Purification
6.Pyridine degradation characteristics of Rhodococcus sp. LV4 under high salinity conditions.
Ying WANG ; Hu CHEN ; Mengdi XU ; Yongkang LÜ
Chinese Journal of Biotechnology 2023;39(3):1202-1216
Biodegradation of pyridine pollutant by microorganisms is one of the economical and effective methods to solve the environmental pollution of pyridine under high salinity conditions. To this end, screening of microorganisms with pyridine degradation capability and high salinity tolerance is an important prerequisite. In this paper, a salt-resistant pyridine degradation bacterium was isolated from the activated sludge of Shanxi coking wastewater treatment plant, and identified as a bacterium belonging to Rhodococcus on the basis of colony morphology and 16S rDNA gene phylogenetic analysis. Salt tolerance experiment showed that strain LV4 could grow and degrade pyridine with the initial concentration of 500 mg/L completely in 0%-6% saline environment. However, when the salinity was higher than 4%, strain LV4 grew slowly and the degradation time of pyridine by strain LV4 was significantly prolonged. Scanning electron microscopy showed that the cell division of strain LV4 became slower, and more granular extracellular polymeric substance (EPS) was induced to secrete in high salinity environment. When the salinity was not higher than 4%, strain LV4 responded to the high salinity environment mainly through increasing the protein content in EPS. The optimum conditions for pyridine degradation by strain LV4 at 4% salinity were 30 ℃, pH 7.0 and 120 r/min (DO 10.30 mg/L). Under these optimal conditions, strain LV4 could completely degrade pyridine with an initial concentration of 500 mg/L at a maximum rate of (29.10±0.18) mg/(L·h) after 12 h adaptation period, and the total organic carbon (TOC) removal efficiency reached 88.36%, indicating that stain LV4 has a good mineralization effect on pyridine. By analyzing the intermediate products in pyridine degradation process, it was speculated that strain LV4 achieved pyridine ring opening and degradation mainly through two metabolic pathways: pyridine-ring hydroxylation and pyridine-ring hydrogenation. The rapid degradation of pyridine by strain LV4 in high salinity environment indicates its application potential in the pollution control of high salinity pyridine environment.
Rhodococcus/genetics*
;
Phylogeny
;
Extracellular Polymeric Substance Matrix/metabolism*
;
Sewage
;
Biodegradation, Environmental
;
Pyridines/metabolism*
7.Enhanced nitrogen removal by bioelectrochemical coupling anammox and characteristics of microbial communities.
Lai XIE ; Min YANG ; Enzhe YANG ; Zhihua LIU ; Xin GENG ; Hong CHEN
Chinese Journal of Biotechnology 2023;39(7):2719-2729
To investigate the bioelectrochemical enhanced anaerobic ammonia oxidation (anammox) nitrogen removal process, a bioelectrochemical system with coupled anammox cathode was constructed using a dual-chamber microbial electrolysis cell (MEC). Specifically, a dark incubation batch experiment was conducted at 30 ℃ with different influent total nitrogen concentrations under an applied voltage of 0.2 V, and the enhanced denitrification mechanism was investigated by combining various characterization methods such as cyclic voltammetry, electrochemical impedance spectroscopy and high-throughput sequencing methods. The results showed that the total nitrogen removal rates of 96.9%±0.3%, 97.3%±0.4% and 99.0%±0.3% were obtained when the initial total nitrogen concentration was 200, 300 and 400 mg/L, respectively. In addition, the cathode electrode biofilm showed good electrochemical activity. High-throughput sequencing results showed that the applied voltage enriched other denitrifying functional groups, including Denitratisoma, Limnobacter, and ammonia oxidizing bacteria SM1A02 and Anaerolineaceae, Nitrosomonas europaea and Nitrospira, besides the anammox bacteria. These electrochemically active microorganisms comprised of ammonium oxidizing exoelectrogens (AOE) and denitrifying electrotrophs (DNE). Together with anammox bacteria Candidatus Brocadia, they constituted the microbial community structure of denitrification system. Enhanced direct interspecies electron transfer between AOE and DNE was the fundamental reason for the further improvement of the total nitrogen removal rate of the system.
Denitrification
;
Wastewater
;
Anaerobic Ammonia Oxidation
;
Nitrogen
;
Oxidation-Reduction
;
Bioreactors/microbiology*
;
Ammonium Compounds
;
Bacteria/genetics*
;
Microbiota
;
Sewage
8.Estimation of the consumption level of four drugs in Beijing using wastewater-based epidemiology.
Jiawulan ZUNONG ; Mu Shui SHU ; Meng Long LI ; Yeerlin ASIHAER ; Meng Ying GUAN ; Yi Fei HU
Chinese Journal of Preventive Medicine 2023;57(5):674-678
Objective: To estimate the consumption level of four drugs in Beijing using wastewater-based epidemiology (WBE). Methods: The primary sludge from one large wastewater treatment plants (WWTPs) was collected in Beijing from July 2020 to February 2021. The concentrations of codeine, methadone, ketamine and morphine in the sludge were detected through solid-phase extraction-liquid chromatography-tandem mass spectrometry. The consumption, prevalence and number of users of four drugs were estimated by using the WBE approach. Results: Among 416 sludge samples, codeine had the highest detection rate (82.93%, n=345) with a concentration [M (Q1, Q3)] of 0.40 (0.22-0.8) ng·g-1, and morphine had the lowest detection rate (28.37%,n=118) with a concentration [M (Q1, Q3)] of 0.13 (0.09, 0.17) ng·g-1. There was no significant difference in the consumption of the four drugs on working days and weekends (all P values>0.05). Drug consumption was significantly higher in winter than that in summer and autumn (all P values <0.05). The consumption [M (Q1, Q3)] of codeine, methadone, ketamine and morphine in winter was 24.9 (15.58, 38.6), 9.39 (4.57, 26.72), 9.84 (5.18, 19.45) and 5.67 (3.57, 13.77) μg·inhabitant-1·day-1, respectively. For these drugs, there was an upward trend in the average drug consumption during summer, autumn and winter (the Z values of the trend test were 3.23, 3.16, 2.19, and 3.32, respectively and all P values<0.05). The prevalence [M (Q1, Q3)] of codeine, methadone, ketamine and morphine were 0.0056% (0.003 4%, 0.009 2%), 0.0148% (0.009 6%, 0.026 7%),0.0333% (0.0210%, 0.0710%) and 0.0072% (0.003 8%, 0.011 7%), respectively. The estimated number of drug users [M (Q1, Q3)] was 918 (549, 1 511), 2 429 (1 578, 4 383), 5 451 (3 444, 11 642) and 1 173 (626, 1 925),respectively. Conclusion: Codeine, methadone, ketamine and morphine have been detected in the sludge of WWTPs in Beijing, and the consumption level of these drugs varies in different seasons.
Humans
;
Beijing
;
Wastewater-Based Epidemiological Monitoring
;
Sewage/analysis*
;
Wastewater
;
Ketamine/analysis*
;
Codeine/analysis*
;
Methadone/analysis*
;
Water Pollutants, Chemical/analysis*
9.The mechanism of microbial removal of Mn(Ⅱ) and its influencing factors: a review.
Wenzhou TIE ; Xiaofang NONG ; Yi ZHAO ; Kang LIANG ; Xuejiao HUANG
Chinese Journal of Biotechnology 2022;38(1):14-25
Manganese is an element essential for living organisms. Development of industrial technologies and exploitation of mineral resources have led to the release of large amount of Mn(Ⅱ) into the environment, posing a serious threat to human health. Bioremediation can remove the Mn(Ⅱ) from the environment rapidly and effectively without generating secondary pollution, thus received increasing attention. This review summarized the diversity and distribution of Mn(Ⅱ) removal microorganisms and the associated mechanisms, followed by discussing the effect of environmental factors on microbial Mn(Ⅱ) removal. Finally, the challenges and prospects for bioremediation of Mn(Ⅱ) polluted wastewater were proposed.
Biodegradation, Environmental
;
Humans
;
Manganese
;
Oxidation-Reduction
;
Waste Water
10.Research progress of combined anaerobic ammonium oxidation (ANAMMOX) process for nitrogen removal.
Jiaxiu WAN ; Jiaqi WANG ; Ping ZHENG ; Baolan HU ; Zhenhua SHI
Chinese Journal of Biotechnology 2022;38(4):1351-1359
Anaerobic ammonia oxidation (ANAMMOX) process is an efficient and low-cost biological nitrogen removal process. However, it still faces some challenges in mainstream applications due to the limitation of substrate types and nitrate accumulation. In recent years, the combined process of anammox has been widely studied to solve the above problems. In this paper, the combined processes of anammox developed in recent years are reviewed, and discussed from the process principle, advantages and disadvantages, influencing factors, process extensibility and the key bottlenecks existing in the promotion and application, as well as the relevant work of the subject group. Finally, we take an outlook on the development of the combined anaerobic ammonia oxidation process in municipal domestic wastewater treatment.
Ammonium Compounds
;
Anaerobiosis
;
Bioreactors
;
Denitrification
;
Nitrogen
;
Oxidation-Reduction
;
Sewage
;
Waste Water

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