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Simultaneous pyridine biodegradation and nitrogen removal in an aerobic granular system

Journal of Environmental Sciences 2018年第5期30卷 318-329页

作者： Xiaodong Liu Shijing Wu Dejin Zhang Jinyou Shen Weiqing Han Xiuyun Sun Jiansheng Li Lianjun Wang Jiangsu Key Laboratory of Chemical Pollution Control and Resources Reuse School of Environmental and Biological EngineeringNanjing University of Science and Technology

Simultaneous pyridine biodegradation and nitrogen removal were successfully achieved in a sequencing batch reactor（SBR） based on aerobic granules. In a typical SBR cycle, nitritation occurred obviously after the majority of pyridine was removed, while denitrification occurred at early stage of the cycle when oxygen consumption was aggravated. The effect of several key operation parameters, i.e., air flow rate, influent NH4~＋-N concentration,influent p H and pyridine concentration, on nitritation, pyridine degradation and total nitrogen（TN） removal, was systematically investigated. The results indicated that high air flow rate had a positive effect on both pyridine degradation and nitritation but a negative impact of overhigh air flow rate. With the increase of NH4~＋ dosage, both nitritation and TN removal could be severely inhibited. Slightly alkaline condition, i.e., pH 7.0–8.0, was beneficial for both pyridine degradation and nitritation. High pyridine dosage often resulted in the delay of both pyridine degradation and nitritation. Besides, extracellular polymeric substances production was affected by air flow rate, NH4~＋ dosage, pyridine dosage and p H.In addition, high-throughput sequencing analysis demonstrated that Bdellovibrio and Paracoccus were the dominant species in the aerobic granulation system. Coexistence of pyridine degrader, nitrification related species, denitrification related species, polymeric substances producer and self-aggregation related species was also confirmed by highthroughput sequencing.

关键词： Aerobic granule Biodegradation Nitritation denitrification Pyridine

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Performances of biological aerated filter employing hollow fiber membrane segments of surface-improved poly(sulfone) as biofilm carriers

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Journal of Environmental Sciences 2007年第7期19卷 811-817页

作者： SHEN Ying-jie WU Guang-xia FAN Yao-bo ZHONG Hui WU Lin-lin ZHANG Shao-lai ZHAO Xian-hong ZHANG Wei-jun Research Center for Eco-Environmental Sciences Chinese Academy of Sciences Beijing 100085 China. Research Institute for Beijing Tongrentang Limited Company Beijing 100062 China.

Using the surface of poly （sulfone） hollow fiber membrane segments as grafted layer, the hydrophilic acrylamide chain was grafted on by UV-photoinduced grafting polymerization. The gained improvement of surface wettability for the modified membrane was tested by measuring the contact-angle as well as FTIR spectra. Then correlation between the hydrophilic ability of support material and the biofilm adherence ability was demonstrated by comparing the pollutant removal rates from urban wastewater via two identical lab-scale up-flow biological aerated filters, one employed the surface wettability modified poly （sulfone） hollow fiber membrane segment as biofilm carder and the other employed unmodified membrane segment as biofilm carder. The experimental results showed that under the conditions of influent flux 5 L/h, hydraulic retention time 9 h and gas to liquid ratio （G/L） 10： 1, the removal rates of chemical oxygen demand （COD） and ammonium nitrogen （NH4^＋-N） for the modified packing filter and the unmodified packing filter was averaged at 83.64% and 96.25%, respectively, with the former filter being 5%-20% more than the latter. The effluent concentration of COD, NH4^＋-N and turbidity for the modified packing filter was 25.25 mg/L, 2 mg/L and 8 NTU, respectively. Moreover, the ammonium nitrogen removal performance of the filter packing the modified PSF was compared with the other bioreactor packing of an efficient floating medium. The biomass test indicated that the modified membrane matrixes provided better specific adhesion （3310-5653 mg TSS/L support）, which gave a mean of 1000 mg TSS/L more than the unmodified membrane did. In addition, the phenomenon of simultaneous denitrification on the inner surface of the support and nitrification on the outer surface was found in this work.

关键词： surface modification UV-photoinduced grafting polymerization nitrification denitrification hollow fiber membrane biofilm attachment

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Nitrous oxide emission by denitrifying phosphorus removal culture using polyhydroxyalkanoates as carbon source

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Journal of Environmental Sciences 2012年第9期24卷 1616-1623页

作者： Yan Zhou Melvin Lim Soekendro Harjono Wun Jern Ng Advanced Environmental Biotechnology Center (AEBC-NEWRI) 60 Nanyang Avenue North Wing Level B2 Room O1 Nanyang Technological University 639798 Singapore Keppel Environmental Technology Centre Pte Ltd. 61 Old Toh Tuck Road 597656 Singapore Division of Environmental and Water Resources Engineering School of Civil and Environmental Engineering Nanyang Technological University 639798 Singapore

Nitrous oxide （N2O） emission has been reported to be enhanced during denitrification when internally-stored compounds are used as carbon sources. However, negligible N2O emissions have been detected in the few studies where polyhydroxyalkanoates （PHA） were specifically used. This study investigated and compared the potential enhancement of N2O production, based on utilization of an internally-stored polymer and external carbon （acetate） by a denitrifying phosphorus removal culture. Results indicated that at relatively low chemical oxygen demand-to-nitrogen （COD/N） ratios, more nitrite was reduced to N2O in the presence of an external carbon source as compared to an internal carbon source （PHA）. At relatively higher COD/N ratios, similar N2O reduction rates were obtained in all cases regardless of the type of carbon source available. N2O reduction rates were, however, generally higher in the presence of an internal carbon source. Results from the study imply that when the presence of an external carbon source is not sufficient to support denitrification, it is likely competitively utilized by different metabolic pathways of denitrifying polyphosphate accumulating organisms （DPAOs） and other ordinary denitfifiers. This study also reveals that the consumption of PHA is potentially the rate-limiting step for N2O reduction during denitrification.

关键词： N2O denitrification carbon source enhanced biological phosphorus removal DPAOs PHA

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Bioaugmentation and quorum sensing disruption as solutions to increase nitrate removal in sequencing batch reactors treating nitrate-rich wastewater

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Journal of Environmental Sciences 2020年第12期32卷 179-185页

作者： Xinyi Ruan Jun Yin Xueyan Cui Na Li Dongsheng Shen School of Environmental Science and Engineering Zhejiang Gongshang UniversityHangzhou 310012PR China Zhejiang Provincial Key Laboratory of Solid Waste Treatment and Recycling Hangzhou 310012PR China

Bioaugmentation of denitrifying bacteria can serve as a promising technique to improve nutrient removal during wastewater treatment. While denitrification inhibition by bacterial quorum sensing(QS) in Pseudomonas aeruginosa has been indicated, the application of bacterial QS disruption to improve nitrate removal from wastewater has not been investigated. In this study, the effect of bioaugmentation of P. aeruginosa SD-1 on nitrate removal in sequencing batch reactors that treat nitrate rich wastewater was assessed. Additionally, the potential of a quorum sensing inhibitor(QSI) to improve denitrification following bacterial bioaugmentation was evaluated. Curcumin, a natural plant extract, was used as a QSI. The chemical oxygen demand(COD) and initial nitrate concentration of the influent were 700 ±20 mg/L and 200 ±10 mg/L respectively, and their respective concentrations in the effluent were 56.9 ±3.2 mg/L and 9.0 ±3.2 mg/L. Thus, the results revealed that bioaugmentation of P. aeruginosa SD-1 resulted in an increased nitrate removal to 82% ±1%. Further, nitrate was almost completely removed following the addition of the QSI, and activities of nitrate reductase and nitrite reductase increased by 88% ±2% and 74% ±2% respectively. The nitrogen mass balance indicated that aerobic denitrification was employed as the main pathway for nitrogen removal in the reactors. The results imply that bioaugmentation and modulation of QS in denitrifying bacteria, through the use of a QSI, can enhance nitrate removal during wastewater treatment.

关键词： Bioaugmentation denitrification Nitrate removal Quorum sensing inhibitor Curcumin

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Effects of long-term amendment of organic manure and nitrogen fertilizer on nitrous oxide emission in a sandy loam soil

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Journal of Environmental Sciences 2007年第2期19卷 185-193页

作者： DING Wei-xin MENG Lei CAI Zu-cong HAN Feng-xiang State Key Laboratory of Soil and Sustainable Agriculture Institute of Soil Science Chinese Academy of Sciences Nanjing 210008 China College of Agriculture South China University of Tropical Agriculture Danzhou 571737 China Department of Plant and Soil Sciences Mississippi State University StarkviUe MS 39759 USA

To understand the effects of long-term amendment of organic manure and N fertilizer on N2O emission in the North China Plain, a laboratory incubation at different temperatures and soil moistures were carried out using soils treated with organic manure （OM）, half organic manure plus half fertilizer N （HOM）, fertilizer NPK （NPK）, fertilizer NP （NP）, fertilizer NK （NK）, fertilizer PK （NK） and control （CK） since 1989. Cumulative N2O emission in OM soil during the 17 d incubation period was slightly higher than in NPK soil under optimum nitrification conditions （25℃ and 60% water-filled pore space, WFPS）, but more than twice under the optimum denitrification conditions （35℃ and 90% WFPS）. N2O produced by denitrification was 2.1-2.3 times greater than that by nitrification in OM and HOM soils, but only 1.5 times greater in NPK and NP soils. These results implied that the long-term amendment of organic manure could significantly increase the N2O emission via denitrification in OM soil as compared to NPK soil. This is quite different from field measurement between OM soil and NPK soil. Substantial inhibition of the formation of anaerobic environment for denitrification in field might result in no marked difference in N2O emission between OM and NPK soils. This is due in part to more rapid oxygen diffusion in coarse textured soils than consumption by aerobic microbes until WFPS was 75% and to low easily decomposed organic C of organic manure. This finding suggested that addition of organic manure in the tested sandy loam might be a good management option since it seldom caused a burst of N2O emission but sequestered atmospheric C and maintained efficiently applied N in soil.

关键词： denitrification N fertilizer nitrification N2O emission organic manure

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Study on the role of copper converter slag in simultaneously removing SO_(2)and NO_(x)using KMnO_(4)/copper converter slag slurry

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Journal of Environmental Sciences 2021年第10期33卷 33-43页

作者： Jiacheng Bao Kai Li Ping Ning Chi Wang Xin Song Yansu Luo Xin Sun Faculty of Environment Science and Engineering Kunming University of Science and TechnologyKunming 650500China Faculty of Chemical Engineering Kunming University of Science and TechnologyKunming 650500China

To achieve"waste controlled by waste",a novel wet process using KMnO_(4)/copper converter slag slurry for simultaneously removing SO_(2)and NO_(x)from acid-making tail gas was proposed.Through the solid-liquid separation for copper slag slurry,the liquid-phase part has a critical influence on removing NO_(x)and SO_(2).Also,the leached metal ions played a crucial role in the absorption of SO_(2)and NO_(x).Subsequently,the effects of single/multi-metal ions on NO_(x)removal was investigated.The results showed that the leached metal from copper converter slag(Al^(3+),Cu^((2+),and Mg^((2+))and KMnO_(4)had a synergistic effect on NO_(x)removal,thereby improving the NO_(x)removal efficiency.Whereas Fe^(2+) had an inhibitory effect on the NO_(x)removal owing to the reaction between Fe^(2+) and KMnO_(4),thereby consuming the KMnO_(4).Besides,SO_(2)was converted to SO_(4)^(2-) completely partly due to the liquid catalytic oxidation by metal ions.The XRD and XPS results indicated that the Fe(Ⅱ)species(Fe_(2)SiO_(4),Fe_(3)O_(4))in copper slag can react with H+ions with the generation of Fe^(2+),and further consumed the KMnO_(4),thereby resulting in a decrease in the NO_(x)removal.The characterization of the slags and solutions before and after reaction led us to propose the possible mechanisms.The role of copper slag is as follows:(1)the alkaline substances in copper slag can absorb SO_(2)and NO_(2)by KMnO_(4)oxidation.(2)copper slag may function as a catalyst to accelerate SO_(2)conversion and improve NO_(x)removal by synergistic effect between leached metal ions and KMnO_(4).

关键词： Copper slag slurry Metal ions Desulfurization denitrification Reaction mechanism

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Quorum sensing systems regulate heterotrophic nitrification-aerobic denitrification by changing the activity of nitrogen-cycling enzymes

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Environmental Science and Ecotechnology 2020年第2期2卷 40-47页

作者： Ziqian Zhu Yang Yang Anran Fang Yu Lou Guojun Xie Nanqi Ren Defeng Xing State Key Laboratory of Urban Water Resource and Environment School of EnvironmentHarbin Institute of TechnologyHarbin150090China

Heterotrophic nitrification-aerobic denitrification(HNAD)is essential in diverse nitrogen-transforming processes.How HNAD is modulated by quorum sensing(QS)systems is still ambiguous.The QS system in Pseudomonas aeruginosa manipulates colony behavior.Here,we described the influence of the Pseudomonas quinolone signal(PQS)and N-acyl-L-homoserine lactone(AHL)on HNAD.The HNAD of P.aeruginosa was inhibited by the oversecretion of PQS.AHL-or PQS-deficient P.aeruginosa mutants had a higher ability for nitrogen removal.QS inhibited heterotrophic nitrification mainly via controlling the activity of nitrite oxidoreductase(NXR)and the depressed aerobic denitrification by regulating the catalytic abilities of nitric oxide reductase(NOR),nitrite reductase(NIR),and nitrate reductase(NAR).The addition of citrate as the sole carbon source increased the nitrogen removal efficiency compared with other carbon sources.Nitrite,as the sole nitrogen source,could be used entirely with only the moderate concentration of PQS contained.AHL and PQS controlled both nitrification and denitrification,suggesting that QS plays an important role in nitrogen cycle under aerobic conditions.

关键词： Heterotrophic nitrification-aerobic denitrification Quorum sensing Pseudomonas aeruginosa Nitrogen cycle Wastewater treatment

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In situ nitrogen removal processes in intertidal wetlands of the Yangtze Estuary

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Journal of Environmental Sciences 2020年第7期32卷 91-97页

作者： Cheng Liu Lijun Hou Min Liu Yanling Zheng Guoyu Yin Hongpo Dong Xia Liang Xiaofei Li Dengzhou Gao Zongxiao Zhang State Key Laboratory of Estuarine and Coastal Research East China Normal UniversityShanghai 200241China Key Laboratory of Geographic Information Science(Ministry of Education) East China Normal UniversityShanghai 200241China School of Geographic Sciences East China Normal UniversityShanghai 200241China Key Laboratory for Humid Subtropical Eco-geographical Processes of the Ministry of Education Fujian Normal UniversityFuzhou 350007China

Estuarine and intertidal wetlands are important sites for nitrogen transformation and elimination.However,the factors controlling nitrogen removal processes remain largely uncertain in the highly dynamic environments.In this study,continuous-flow experiment combined with 15 N isotope pairing technique was used to investigate in situ rates of denitrification and anaerobic ammonium oxidation(anammox)and their coupling with nitrification in intertidal wetlands of the Yangtze Estuary.The measured rates varied from below the detection limit to 152.39μmol N/(m^2·hr)for denitrification and from below the detection limit to 43.06μmol N/(m^2·hr)for anammox.The coupling links of nitrogen removal processes with nitrification were mainly dependent on nitrate,organic carbon,sulfide,dissolved oxygen and ferric iron in the estuarine and intertidal wetlands.Additionally,it was estimated that the actual nitrogen removal processes annually removed approximately 5%of the terrigenous inorganic nitrogen discharged into the Yangtze Estuary.This study gives new insights into nitrogen transformation and fate in the estuarine and intertidal wetlands.

关键词： denitrification Anammox Sediment Intertidal wetland Yangtze estuary

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Simultaneous removal of SO2 and NO using a spray dryer absorption(SDA) method combined with O3 oxidation for sintering/pelleting flue gas

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Journal of Environmental Sciences 2020年第10期32卷 64-71页

作者： Maoyu Cai Xiaolong Liu Tingyu Zhu Yang Zou Wenliang Tao Mengkui Tian School of Chemistry and ChemicalEngineering Guizhou UniuersityGuiyang 550025China National Engineering Laboratory for Hydrometallurgical Cleaner Production Technology Institute of Process EngineeringChinese Academy of SciencesBeijing 100190China Center for Excellence in Regional Atmospheric Enuironment Institute of Urban EnuironmentChinese Academy of SciencesXiamen 361021China

Based on the demand of sintering/pelleting flue gas ultra-low emission,a semi-dry method using a spray dryer absorber (SDA) combined with O3 oxidation was proposed for simultaneous removal of SO2 and NO.Effects of O3 injection site,O3/NO molar ratio,and spray tower temperature on the removal efficiencies were investigated.It was revealed that both desulfurization and denitrification efficiencies could reach to 85%under the conditions of setting O3 injection site inside of tower,O3/NO molar ratio 1.8,spray tower temperature 85°C,Ca/(S+2N) molar ratio 2.5 and slurry flow rate 300 m L/hr.CaSO3/Ca(OH)2 mixture slurry was used as absorbent to simulate operating conditions in iron and steel industry.The result shows that the addition of CaSO3 weakens both removal efficiencies.In addition,the reaction mechanism of simultaneous removal of SO2 and NO using SDA combined with O3 oxidation was proposed.

关键词： O_3 oxidation Desulfurization denitrification Semi-dry method Spray dryer absorption

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Marine aquaculture regulates dissimilatory nitrate reduction processes in a typical semi-enclosed bay of southeastern China

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Journal of Environmental Sciences 2021年第6期33卷 376-386页

作者： Yinghui Jiang Guoyu Yin Lijun Hou Min Liu Yanling Zheng Ping Han Dongsheng Zheng Cheng Chen Maotian Li Key Laboratory of Geographic Information Science(Ministry of Education) East China Normal UniversityShanghai 200241China School of Geographic Sciences East China Normal UniversityShanghai 200241China State Key Laboratory of Estuarine and Coastal Research East China Normal UniversityShanghai 200241China

Marine aquaculture in semi-enclosed bays can significantly influence nutrient cycling in coastal ecosystems.However,the impact of marine aquaculture on the dynamics of dissimilatory nitrate reduction processes(DNRPs)and the fate of reactive nitrogen remain poorly understood.In this study,the rates of DNRPs and the abundances of related functional genes were investigated in aquaculture and non-aquaculture areas.The results showed that marine aquaculture significantly increased the denitrification(DNF)and dissimilatory nitrate reduction to ammonium(DNRA)rates and decreased the rate of anaerobic ammonium oxidation(ANA),as compared with non-aquaculture sites.DNF was the dominant pathway contributing to the total nitrate reduction,and its contribution to the total nitrate reduction significantly increased from 66.72%at non-aquaculture sites to 78.50%at aquaculture sites.Marine aquaculture can significantly affect the physicochemical characteristics of sediment and the abundances of related functional genes,leading to variations in the nitrate reduction rates.Although nitrate removal rates increased in the marine aquaculture area,ammonification rates and the nitrogen retention index in the aquaculture areas were 2.19 and 1.24 times,respectively,higher than those at non-aquaculture *** reactive nitrogen retention exceeded nitrogen removal in the aquaculture area,and the retained reactive nitrogen could diffuse with the tidal current to the entire bay,thereby aggravating N pollution in the entire study area.These results show that marine aquaculture is the dominant source of nitrogen pollution in semi-enclosed bays.This study can provide insights into nitrogen pollution control in semi-enclosed bays with well-developed marine aquaculture.

关键词： denitrification Anaerobic ammonium oxidation Dissimilatory nitrate reduction to ammonium Marine aquaculture Sansha Bay

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