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Nitrogen and Phosphorus Removal from Lake Kinneret Inputs
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作者 Moshe Gophen 《Open Journal of Ecology》 2024年第2期165-182,共18页
The Hula Valley was drained in 1957. The land use was modified from natural wetland and old shallow lake ecosystems to agricultural development. About half of the drained land area was utilized for aquaculture. Popula... The Hula Valley was drained in 1957. The land use was modified from natural wetland and old shallow lake ecosystems to agricultural development. About half of the drained land area was utilized for aquaculture. Population size was enhanced and the diary was developed intensively resulting in the enhancement of domestic and husbandry sewage production that increased as well. The natural intact Hula Valley-Lake Kinneret ecosystem was heavily anthropogenically interrupted: The Hula was drained and Kinneret became a national source for domestic water supply. Some aspects of the environmental and water quality protection policy of the system are presented. The causation and operational management implications for the reduction of Nitrogen and Phosphorus migration from the Hula Valley are discussed. Drastic (81%) restriction of aquaculture accompanied by sewage totally removed achieved a reasonable improvement in pollution control which was also supported by the Hula Project. The implications of anthropogenic intervention in the process of environmental management design are presented. 展开更多
关键词 Hula Valley JORDAN Kinneret nitrogen phosphorus Peat Soil Fish Ponds Sewage removal
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Analysis of the Effect and Influencing Factors of Rural Domestic Sewage Treatment Based on A^(2)O-MBBR Integrated Process
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作者 Wangang WU Aiping WU +2 位作者 Guixiang YUAN Yuyuan ZHOU Junwei LU 《Agricultural Biotechnology》 2024年第2期27-32,共6页
[Objectives] This study was conducted to solve the prominent problems in the treatment of domestic sewage in southern rural areas of China. [Methods] An integrated process treatment mode of anaerobic/anoxic/aerobic mo... [Objectives] This study was conducted to solve the prominent problems in the treatment of domestic sewage in southern rural areas of China. [Methods] An integrated process treatment mode of anaerobic/anoxic/aerobic moving bed biofilm reactor (A 2O-MBBR) was proposed to analyze and study its operating effect and influencing factors. [Results] The A^(2)O-MBBR mode had good COD removal efficiency and nitrogen and phosphorus removal performance, and the water quality index of the effluent met the Class A standard of GB181918-2002. This mode is suitable for treating rural domestic sewage, and has high treatment effects in different operating periods. In spring, the average removal rates of COD, NH_(4)^(+)-N, TN, TP and SS reached (83.53 ± 2.15)%, (89.44 ± 4.97)%, (67.36±18.53)%, (88.22±11.21)% and (91.73±2.25)%, respectively;In the autumn period, the average removal rates of COD, NH_(4)^(+)-N, TN, TP and SS were (83.49±2.64)%, (89.26±9.19)%, (66.05±17.00)%, (87.48±9.68)%, and (91.13±2.35)%. [Conclusions] This study provides theoretical reference and technical support for the popularization and application of A^(2)O-MBBR integrated process. 展开更多
关键词 A^(2)O-MBBR process Rural domestic sewage nitrogen and phosphorus removal
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Removal of nitrogen and phosphorus in a combined A^2/O-BAF system with a short aerobic SRT 被引量:15
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作者 DING Yong-wei WANG Lin +1 位作者 WANG Bao-zhen WANG Zheng 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2006年第6期1082-1087,共6页
A bench-scale anaerobic/anoxic/aerobic process-biological aerated filter (A^2/O-BAF) combined system was carded out to treat wastewater with lower C/N and C/P ratios. The A^2/O process was operated in a short aerobi... A bench-scale anaerobic/anoxic/aerobic process-biological aerated filter (A^2/O-BAF) combined system was carded out to treat wastewater with lower C/N and C/P ratios. The A^2/O process was operated in a short aerobic sludge retention time (SRT) for organic pollutants and phosphorus removal, and denitrification. The subsequent BAF process was mainly used for nitrification. The BAF effluent was partially returned to anoxic zone of the A^2/O process to provide electron acceptors for denitrification and anoxic P uptake. This unique system formed an environment for reproducing the denitdfying phosphate-accumulating organisms (DPAOs). The ratio of DPAOs to phosphorus accumulating organisms (PAOs) could be maintained at 28% by optimizing the organic loads in the anaerobic zone and the nitrate loads into the anoxic zone in the A^2/O process. The aerobic phosphorus over-uptake and discharge of excess activated sludge was the main mechanism of phosphorus removal in the combined system. The aerobic SRT of the A^2/O process should meet the demands for the development of aerobic PAOs and the restraint on the nitrifiers growth, and the contact time in the aerobic zone of the A^2/O process should be longer than 30 min, which ensured efficient phosphorus removal in the combined system. The adequate BAF effluent return rates should be controlled with 1--4 mg/L nitrate nitrogen in the anoxic zone effluent of A^2/O process to achieve the optimal nitrogen and phosphorus removal efficiencies. 展开更多
关键词 nitrogen and phosphorus removal denitrifying phosphorus removal denitrifying phosphorus accumulating organisms (DPAOs) anaerobic/anoxic/aerobic process (A^2/O) biological aerated filter (BAF) aerobic sludge retention time (SRT)
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Simultaneous removal of nitrogen and phosphorus from swine wastewater in a sequencing batch biofilm reactor 被引量:4
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作者 海热提 何一群 +1 位作者 王晓慧 李媛 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2015年第1期303-308,共6页
In this study, the performance of a sequencing batch biofilm reactor(SBBR) for removal of nitrogen and phosphorus from swine wastewater was evaluated. The replacement rate of wastewater was set at 12.5% throughout the... In this study, the performance of a sequencing batch biofilm reactor(SBBR) for removal of nitrogen and phosphorus from swine wastewater was evaluated. The replacement rate of wastewater was set at 12.5% throughout the experiment. The anaerobic and aerobic times were 3 h and 7 h, respectively, and the dissolved oxygen concentration of the aerobic phase was about 3.95 mg·L-1. The SBBR process demonstrated good performance in treating swine wastewater. The percentage removal of total chemical oxygen demand(COD), ammonia nitrogen(NH4+-N), total nitrogen(TN), and total phosphorus(TP) was 98.2%, 95.7%, 95.6%, and 96.2% at effluent concentrations of COD85.6 mg·L-1, NH4+-N 35.22 mg·L-1, TN 44.64 mg·L-1, and TP 1.13 mg·L-1, respectively. Simultaneous nitrification and denitrification phenomenon was observed. Further improvement in removal efficiency of NH4+-N and TN occurred at COD/TN ratio of 11:1, with effluent concentrations at NH4+-N 18.5 mg·L-1and TN 34 mg·L-1, while no such improvement in COD and TP removal was found. Microbial electron microscopy analysis showed that the filler surface was covered with a thick biofilm, forming an anaerobic–aerobic microenvironment and facilitating the removal of nitrogen, phosphorus and organic matters. A long-term experiment(15 weeks) showed that stable removal efficiency for N and P could be achieved in the SBBR system. 展开更多
关键词 Sequencing batch biofilm reactor Swine wastewater Simultaneous nitrogen and phosphorus removal
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Removal Rate of Phosphorus by Different Constructed Wetland Substrates 被引量:1
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作者 LIU Yang 《Meteorological and Environmental Research》 2012年第3期61-64,共4页
[ Objective] The study aimed to discuss the removal rate of phosphorus by different constructed wetland substrates. [ Methed] Based on static experiments, we analyzed the removal rate and characteristics of phosphorus... [ Objective] The study aimed to discuss the removal rate of phosphorus by different constructed wetland substrates. [ Methed] Based on static experiments, we analyzed the removal rate and characteristics of phosphorus by different constructed wetland substrates like steel slag, cin- der slag, shale, boiler slag, soil and gravel. [ Result~ The maximum adsorption of phosphorus by various substrates showed as follows, steel slag 〉 cinder slag 〉 shale 〉 boiler slag 〉 soil 〉 gravel. When the initial concentration of phosphorus was 5 mg/L, the removal rate of phosphorus by the steel slag, cinder slag, shale, boiler slag, soil and gravel was 99.76%, 85.8%, 71.2%, 63.0%, 46.8% and 11.7% respectively. It is suggested that shale and boiler slag can be used as the substrate of subsurface-flow constructed wetlands; cinder slag can be chosen as a renewable sub- strate for intensifying phosphorus removal; steel slag could be used at the end of subsurface-flow constructed wetlands for treating TP in outflows. [Concluslon] The research could provide theoretical references for choosing a suitable substrate for constructed wetlands to remove phosphorus in future. 展开更多
关键词 Constructed wetland SUBSTrate removal rate of phosphorus Steel slag China
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Dynamics of Nitrogen Transformation and Removal in a Pilot High Rate Pond
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作者 Aloyce W. Mayo Emmanuel E. Hanai 《Journal of Water Resource and Protection》 2014年第5期433-445,共13页
The transformation and removal of nitrogen was studied in a pilot high rate pond with a surface area of 10.2 m2 and water depth of 60 cm. The pilot unit received wastewater from an existing field scale primary faculta... The transformation and removal of nitrogen was studied in a pilot high rate pond with a surface area of 10.2 m2 and water depth of 60 cm. The pilot unit received wastewater from an existing field scale primary facultative pond at the University of Dar es Salaam. Wastewater samples were collected from the influent and effluent of high rate pond and were analyzed for physical-chemical parameters in the laboratory and in situ. An appropriate model complexity was selected, from which a conceptual model was then developed to model various processes in the system using STELLA 6.0.1 software. The study demonstrated that dominant nitrogen transformation processes in HRP were nitrification and denitrification, which transformed 0.95 and 0.87 gN/m2·d, respectively. These were followed by mineralization (0.37 gN/m2·d), ammonia uptake by microorganisms (0.34 gN/m2·d), volatilization (0.30 gN/m2·d), sedimentation (0.24 gN/m2·d), and regeneration (0.15 gN/m2·d). Uptake of nitrate was not observed because of microorganisms preference for ammonia, which was abundant in the pond. The major nitrogen transformation mechanisms in high rate pond were denitrification, net sedimentation and volatilization, which accounted for 69.1%, 7.1% and 23.8% of the total permanent removal mechanisms of nitrogen in High Rate Pond. 展开更多
关键词 High rate PONDS NITRIFICATION DENITRIFICATION nitrogen Transformation nitrogen removal
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Salt effect on MUCT system performance of nitrogen and phosphorus removal
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作者 Huining Zhang Zhuowei Zhang +4 位作者 Kewei Jiang Zhili Li Kefeng Zhang Jianqing Ma Yongxing Qian 《Green Energy & Environment》 SCIE CSCD 2021年第5期670-677,共8页
The effect of salinity on biological nitrogen and denitrifying phosphorus removal was investigated in a Modified University of Cape Town(MUCT)system.Removal rates of COD,NH_(4)^(+)-N,NO_(3)^(-)-N,NO_(2)^(-)-N,phosphor... The effect of salinity on biological nitrogen and denitrifying phosphorus removal was investigated in a Modified University of Cape Town(MUCT)system.Removal rates of COD,NH_(4)^(+)-N,NO_(3)^(-)-N,NO_(2)^(-)-N,phosphorus and the sludge characteristics at salt concentrations(0.0,3.2,6.4,11.2 and 16.0 g L^(-1))were analyzed.With the salt concentration increasing,all the COD,NH_(4)^(+)-N,TN and TP removal rates exhibited a trend of decline,and exhibited an initial reduction and subsequent increase at every stage of salt concentration.NH_(4)^(+)-N,TN and TP removal rates were 92.7%,51.5%and 67.2%in 16 g L^(-1) salt concentration,respectively.And they were outperformed the literature reported and acceptable in practical applications.When the salinity of wastewater changed from 0.0 to 16.0 g L^(-1),the biomass yield coefficients increased from 0.0794 to 0.126 g VSS/g COD.Increased salinity had a detrimental effect on phosphorus-accumulating organisms(PAOs)and denitrifying PAOs(DPAOs)(especially DPAOs).Therefore,phosphorus removal gradually depended on PAO.The simultaneous nitrification and denitrification(SND)rate and nitrogen removal rate(including nitrification rate,denitrification rate,and total nitrogen removal rate)gradually decreased with the increased salinity. 展开更多
关键词 Aquaculture wastewater Denitrifying phosphorus removal MUCT process TP SND rate
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Research Development and Application of Nitrogen and Phosphorus Removal in Sequencing Batch Biofilm Reactor
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作者 Cao Shan Cao Xiuqin 《Meteorological and Environmental Research》 CAS 2014年第3期1-3,6,共4页
Frequent variations of the wastewater quality and quantity and other uncertain factors are the challenges faced by many wastewater treatment plants during the operation. Sequencing batch biofilm reactor( SBBR) proce... Frequent variations of the wastewater quality and quantity and other uncertain factors are the challenges faced by many wastewater treatment plants during the operation. Sequencing batch biofilm reactor( SBBR) process provides a new idea for an effective solution to this problem. This paper introduces the basic processes and characteristics of the sequencing batch biofilm reactor( SBBR) process,and summarizes the research status of this process in wastewater treatment. Factors affecting the nitrogen and phosphorus removal effect of the SBBR process are also analyzed. 展开更多
关键词 Sequencing batch biofilm reactor Wastewater treatment nitrogen and phosphorus removal FILLER BIofILM China
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Discussion on nitrogen and phosphorus removal process characteristics of improved oxidation ditch
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作者 SHEN Lian-feng JIN Yue +1 位作者 ZHANG Jian-xin LI You 《Journal of Environmental Science and Engineering》 2008年第5期31-34,共4页
In order to enhance efficiency of the nitrogen and phosphorus removal of sewage treatment plant, Taking Wu Long kou sewage treatment plant project in Zhengzhou as an example, this article introduces the structure, the... In order to enhance efficiency of the nitrogen and phosphorus removal of sewage treatment plant, Taking Wu Long kou sewage treatment plant project in Zhengzhou as an example, this article introduces the structure, the working principle, the craft character, as well as the problems existed in the practical application of the improved oxidation ditch, and raises some corresponding processing countermeasures. Looked from the running situation of Wu Long kou sewage treatment plant, the improved oxidation ditch have certain advantages in city sewage treatment, such as high organic removing efficiency, good removing effect of nitrogen and phosphorus, low investing expenses and operating cost and so on. It is a craft that is worth promoting in urban sewage treatment. 展开更多
关键词 improved oxidation ditch urban sewage nitrogen and phosphorus removal
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Phosphorus and Nitrogen Removal by Saturated Vertical-Flow Constructed Wetlands (SVCWs) Type Micro-Pilot Using Shale from Ivory Coast as a Substrate
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作者 Dan Eude Kpannieu Norbert Kouakou Kouadio +4 位作者 N’Dri Séraphin Konan Coulibaly Nagnonta Hippolyte Martine Mallet Lacina Coulibaly Christian Ruby 《Journal of Geoscience and Environment Protection》 2022年第8期24-38,共15页
This study evaluates the performance of shale from Ivory Coast used as substrate in vertical-flow constructed wetlands in removal of phosphates and nitrogen. The pilot-scale artificial wetland has been duplicated: fil... This study evaluates the performance of shale from Ivory Coast used as substrate in vertical-flow constructed wetlands in removal of phosphates and nitrogen. The pilot-scale artificial wetland has been duplicated: filter planted with Panicum maximun and unplanted. They were set up outdoors, and fed with a municipal wastewater. The wetlands have been fed with three batches per week (intermittent) over a period of 3 months. During the operation period, the hydraulic residence time (HRT) 52 h was used, while wastewater temperatures varied from about ~33&#176;C. The removal performance of the constructed wetland units was very good, since it reached on an average 98%, 89.4%, 89.4%, 84%, 80%, 84.8% and 92% for TSS, DOC, BOD<sub>5</sub>, , TKN, TP and respectively. In addition, the vegetation did not demonstrate superior performance to unplanted controls. Therefore, this study focuses on the role of shale in the phosphorus and nitrogen removal from wastewater by constructed wetland. 展开更多
关键词 Constructed Wetlands Vertical Flow SHALE Panicum maximun phosphorus removal nitrogen
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Nitrogen and phosphorus removal in pilot-scale anaerobic-anoxic oxidation ditch system 被引量:35
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作者 PENG Yongzhen HOU Hongxun +2 位作者 WANG Shuying CUI Youwei Zhiguo Yuan 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2008年第4期398-403,共6页
To achieve high efficiency of nitrogen and phosphorus removal and to investigate the rule of simultaneous nitrification and denitrification phosphorus removal (SNDPR), a whole course of SNDPR damage and recovery was... To achieve high efficiency of nitrogen and phosphorus removal and to investigate the rule of simultaneous nitrification and denitrification phosphorus removal (SNDPR), a whole course of SNDPR damage and recovery was studied in a pilot-scale, anaerobicanoxic oxidation ditch (OD), where the volumes of anaerobic zone, anoxic zone, and ditches zone of the OD system were 7, 21, and 280 L, respectively. The reactor was fed with municipal wastewater with a flow rate of 336 L/d. The concept of simultaneous nitrification and denitrification (SND) rate (rSND) was put forward to quantify SND. The results indicate that: (1) high nitrogen and phosphorus removal efficiencies were achieved during the stable SND phase, total nitrogen (TN) and total phosphate (TP) removal rates were 80% and 85%, respectively; (2) when the system was aerated excessively, the stability of SND was damaged, and rSND dropped from 80% to 20% or less; (3) the natural logarithm of the ratio of NOx to NH4^+ in the effluent had a linear correlation to oxidation-reduction potential (ORP); (4) when NO3^- was less than 6 mg/L, high phosphorus removal efficiency could be achieved; (5) denitrifying phosphorus removal (DNPR) could take place in the anaerobic-anoxic OD system. The major innovation was that the SND rate was devised and quantified. 展开更多
关键词 oxidation ditch biological nitrogen removal biological phosphorus removal simultaneous nitrification and denitrification (SND) pilot scale municipal wastewater
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Nitrogen removal efficiency of iron-carbon micro-electrolysis system treating high nitrate nitrogen organic pharmaceutical wastewater 被引量:4
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作者 周健 段送华 +1 位作者 陈垚 胡斌 《Journal of Central South University》 SCIE EI CAS 2009年第S1期368-373,共6页
The nitrate nitrogen removal efficiency of iron-carbon micro-electrolysis system was discussed in treating pharmaceutical wastewater with high nitrogen and refractory organic concentration. The results show that the g... The nitrate nitrogen removal efficiency of iron-carbon micro-electrolysis system was discussed in treating pharmaceutical wastewater with high nitrogen and refractory organic concentration. The results show that the granularity of fillings,pH,volume ratios of iron-carbon and gas-water,and HRT. have significant effects on the nitrogen removal efficiency of iron-carbon micro-electrolysis system. The iron-carbon micro-electrolysis system has a good removal efficiency of pharmaceutical wastewater with high nitrogen and refractory organic concentration when the influent TN,NH4+-N,NO3--N and BOD5/CODCr are 823 mg/L,30 mg/L,793 mg/L and 0.1,respectively,at the granularity of iron and carbon 0.425 mm,pH 3,iron-carbon ratio 3,gas-water ratio 5,HRT 1.5 h,and the removal rates of TN,NH4+-N and NO3--N achieve 51.5%,70% and 50.94%,respectively. 展开更多
关键词 IRON-CARBON MICRO-ELECTROLYSIS nitrogen NITrate nitrogen removal efficiency removal rate
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EFFECT OF NITROGEN AND PHOSPHORUS ON THE GROWTH OF A RED TIDE DINOFLAGELLATE SCRIPPSIELLA TROCHOIDEA (STEIN) LOEBLICH III 被引量:5
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作者 秦晓明 钱培元 邹景忠 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 1999年第3期212-218,共7页
Scrippsiella trochoidea (Stein) Loeblich III was grown in a nitrogen or phosphorus limited batch culture system in laboratory. Growth rates and cellular Chl a were measured as functions of nitrate and phosphate concen... Scrippsiella trochoidea (Stein) Loeblich III was grown in a nitrogen or phosphorus limited batch culture system in laboratory. Growth rates and cellular Chl a were measured as functions of nitrate and phosphate concentrations. Growth rates were hyperbolic with both nitrate and phosphate concentration and fit the Monod equation. The minimum cell quota of nitrogen and phosphorus and then the optimum N:P ratio of S. trochoidea were estimated in this study. Measurement of phosphate concentration in Jiaozhou Bay suggest that phosphorus is the limiting factor of S. trochoidea growth. 展开更多
关键词 SCRIPPSIELLA trochoidea nitrogen LIMITATION phosphorus LIMITATION GROWTH rate cellular CHL a red tide
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Simultaneous nitrogen and phosphorus removal under low dissolved oxygen conditions 被引量:3
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作者 XIA Si-qing GAO Ting-yao ZHOU Zeng-yuan 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2001年第1期46-50,共5页
A full-scale test was operated by using low dissolved oxygen activated sludge process to enhance biological nitrogen and phosphorus removal. When the influent concentrations of CODCr, TN and TP varied in a range of 35... A full-scale test was operated by using low dissolved oxygen activated sludge process to enhance biological nitrogen and phosphorus removal. When the influent concentrations of CODCr, TN and TP varied in a range of 352.9 mg/L-1338.2 mg/L, 34.4 mg/L-96.3 mg/L, and 2.21 mg/L-24.0 mg/L, the average removal efficiencies were 94.9%, 86.7% and 93.0%, respectively. During the test period of two months, effluent meas of CODCr,, BOD5, NH3-N, TN and TP were below 50 mg/L, 25 mg/L, 10 mg/L and 1.0 mg/L respectively. The low dissolved oxygen activated sludge process has a simple flow sheet, fewer facilities and high N and P removal efficiency. It is very convenient to retrofit the conventional activated sludge process with the above process. 展开更多
关键词 high concentration activated sludge low dissolved oxygen process nitrogen removal phosphorus removal
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Internal Loads and Bioavailability of Phosphorus and Nitrogen in Dianchi Lake,China 被引量:2
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作者 WU Yalin HUANG Tao +7 位作者 HUANG Changchun SHEN Yinyin LUO Yang YANG Hao YU Yanhong LI Ruixiao GAO Yan ZHANG Mingli 《Chinese Geographical Science》 SCIE CSCD 2018年第5期851-862,共12页
Sediments have a significant influence on the cycling of nutrient elements in lake environments. In order to assess the distribution characteristics and estimate the bioavailability of phosphorus and nitrogen in Dianc... Sediments have a significant influence on the cycling of nutrient elements in lake environments. In order to assess the distribution characteristics and estimate the bioavailability of phosphorus and nitrogen in Dianchi Lake, organic and inorganic phosphorus and nitrogen forms were analysed. The 210 Pb radiometric dating method was employed to study temporal changes in the phosphorus and nitrogen pools in Dianchi Lake. The result show that the total phosphorus(TP) and total nitrogen(TN) were both at high concentrations, ranging from 697.5–3210.0 mg/kg and 1263.7–7155.2 mg/kg, respectively. Inorganic phosphorus(IP) and total organic nitrogen(TON) were the main constituents, at percentages of 59%–78% and 74%–95%, respectively, in the sediments. Spatially, there was a decreasing trend in phosphorus and nitrogen contents from the south and north to the lake centre, which is related to the distribution pattern of local economic production. The burial rates of the various phosphorus and nitrogen forms increased in same spatially and over time. Particularly in the past two decades, the burial rates doubled, with that TN reached to 1.287 mg/(cm^2·yr) in 2014. As the most reactive forms, nitrate nitrogen(NO_3-N) and ammonia nitrogen(NH_4-N) were buried more rapidly in the south region, implying that the potential for releasing sedimentary nitrogen increased from north to south. Based on their concentrations and burial rates, the internal loads of phosphorus and nitrogen were analysed for the last century. A TP pool of 71597.6 t and a TN pool of 81191.7 t were estimated for Dianchi Lake. Bioavailable phosphorus and nitrogen pools were also estimated at 44468.0 t and 5429.7 t, respectively, for the last century. 展开更多
关键词 sediment phosphorus nitrogen burial rate internal load BIOAVAILABILITY Dianchi Lake
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Yield performance and optimal nitrogen and phosphorus application rates in wheat and faba bean intercropping 被引量:2
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作者 XIAO Jing-xiu ZHU Ying-an +3 位作者 BAI Wen-lian LIU Zhen-yang TANG Li ZHENG Yi 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2021年第11期3012-3025,共14页
Yield performance in cereal and legume intercropping is related to nutrient management,however,the yield response of companion crops to nitrogen(N)input is inconclusive and only limited efforts have focused on ratione... Yield performance in cereal and legume intercropping is related to nutrient management,however,the yield response of companion crops to nitrogen(N)input is inconclusive and only limited efforts have focused on rationed phosphorous(P)fertilization.In this study,two multi-year field experiments were implemented from 2014-2019 under identical conditions.Two factors in a randomized complete block design were adopted in both experiments.In field experiment 1,the two factors included three planting patterns(mono-cropped wheat(MW),mono-cropped faba bean(MF),and wheat and faba bean intercropping(W//F))and four N application rates(N0,0 kg N ha^(-1);N1,90 and 45 kg N ha^(-1) for wheat and faba beans,respectively;N2,180 and 90 kg N ha^(-1) for wheat and faba beans,respectively;and N3,270 and 135 kg N ha^(-1) for wheat and faba beans,respectively).In field experiment 2,the two factors included three P application rates(P0,0 kg P_(2)O_(5) ha^(-1);P1,45 kg P_(2)O_(5) ha^(-1);and P2,90 kg P_(2)O_(5) ha^(-1))and the same three planting patterns(MW,MF,and W//F).The yield performances of inter-and mono-cropped wheat and faba beans under different N and P application rates were analyzed and the optimal N and P rates for intercropped wheat(IW)and MW were estimated.The results revealed that intercropping favored wheat yield and was adverse to faba bean yield.Wheat yield increased by 18-26%,but faba bean yield decreased by 5-21% in W//F compared to MW and MF,respectively.The stimulated IW yield drove the yield advantage in W//F with an average land equivalent ratio(LER)of 1.12.N and P fertilization benefited IW yield,but reduced intercropped faba bean(IF)yield.Nevertheless,the partial LER of wheat(pLER_(wheat))decreased with increasing N application rates,and the partial LER of faba bean(pLER_(faba bean))decreased with increasing P application rates.Thus,LER decreased as N input increased and tended to decline as P rates increased.IW maintained a similar yield as MW,even under reduced 40-50% N fertilizer and 30-40% P fertilizer conditions.The estimated optimum N application rates for IW and MW were 150 and 168 kg ha^(-1),respectively,and 63 and 62 kg ha^(-1) for P_(2)O_(5),respectively.In conclusion,W//F exhibited yield advantages due to stimulated IW yield,but the intercropping yield benefit decreased as N and P inputs increased.Thus,it was concluded that modulated N and P rates could maximize the economic and ecological functions of intercropping.Based on the results,rates of 150 kg N ha^(-1) and 60 kg P_(2)O_(5) ha^(-1) are recommended for IW production in southwestern China and places with similar conditions. 展开更多
关键词 land equivalent ratio nitrogen and phosphorus optimal application rate wheat and faba bean intercropping yield performance
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Nitrogen and phosphorus removal under intermittent aeration conditions 被引量:1
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作者 XIA Si\|qing, GAO Ting\|yao, ZHOU Zeng\|yan (State Key Laboratory of Pollution Control and Resource Reuse, Tongji University, Shanghai 200092, China.) 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2002年第4期541-546,共6页
A practice wastewater treatment plant was operated using intermittent aeration activated sludge process to enhance biological nitrogen and phosphorus removal. When the influent concentrations of COD Cr , BOD 5, T... A practice wastewater treatment plant was operated using intermittent aeration activated sludge process to enhance biological nitrogen and phosphorus removal. When the influent concentrations of COD Cr , BOD 5, TN, TP, NH 3\|N, TKN, and SS varied in a range of 207.5—1640 mg/L, 61.8—637 mg/L, 28.5—75.6 mg/L, 4.38—20.2 mg/L, 13.6—31.9 mg/L, 28.5—75.6 mg/L, and 111—1208 mg/L, the effluent means were less than 50 mg/L, 20 mg/L, 5 mg/L, 1.0 mg/L, 5 mg/L, 10 mg/L, and 20 mg/L, respectively. Based on a long time of operating results, this process is very suitable for nutrient biological removal for treating the municipal wastewater those water characteristics are similar as that of the Songjiang Municipal Waste Water Treatment Plant(SJMWTP). 展开更多
关键词 intermittent aeration process high concentration activated sludge nitrogen removal phosphorus removal
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Influence of pH on short-cut denitrifying phosphorus removal 被引量:16
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作者 Wei Li Hui-yan Zhang +3 位作者 Hui-zhi Sun Fei Zeng Yu-nan Gao Lei Zhu 《Water Science and Engineering》 EI CAS CSCD 2018年第1期17-22,共6页
Through a series of experiments using denitrifying phosphorus-accumulating sludge in sequencing batch reactors (SBRs), the variations of the intracellular polymers during the anaerobic phosphorus release process at ... Through a series of experiments using denitrifying phosphorus-accumulating sludge in sequencing batch reactors (SBRs), the variations of the intracellular polymers during the anaerobic phosphorus release process at different pH values were compared, the probable reasons for different performances of phosphorus removal were examined, and system operations in a typical cycle were investigated. The results show that the phosphorus removal rate was positively correlated with pH values in a range of 6.5-8.5. When the pH value was 8.0, the anaerobic phosphorus release rate and anoxic phosphorus uptake rate of the activated sludge were 20.95 mg/(g, h) and 23.29 mg/(g, h), respectively; the mass fraction of poly-13-hydroxybutyrate (PHB) increased to 62.87 mg/g under anaerobic conditions; the mass fraction of polyphosphate was 92.67 mg/g under anoxic conditions; and the effluent concentration of total phosphorus (TP) was 1.47 mg/L. With the increase of pH, the mass fraction of acetic acid and PHB also increased, and the absorption rate of acetic acid was equal to the disintegration rate of polyphosphate. When the pH value was above 8.0, biological phosphorus removal was achieved by chemical phosphorus precipitation, and the phosphorus removal rate decreased. 展开更多
关键词 Denitrifying phosphorus removal PH removal rate PHB
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Effects of low temperature on sludge settleability and nutrients removal performance treating domestic wastewater 被引量:2
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作者 彭赵旭 彭永臻 +2 位作者 刘旭亮 于振波 柴同志 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2011年第5期55-60,共6页
In order to investigate the effect of temperature on activated sludge systems,sludge settleability,nitrogen and phosphorus removal processes were investigated by changing temperature variation patterns using 4 sequenc... In order to investigate the effect of temperature on activated sludge systems,sludge settleability,nitrogen and phosphorus removal processes were investigated by changing temperature variation patterns using 4 sequencing batch reactors (SBR).The results showed that no matter temperature changes in the range of 15-22 ℃ (decrease or increase) gradually or sharply,it has little effect on nitrogen and phosphorus removal processes.But when temperature decreases to 12 ℃,biochemical reactions will be inhibitted obviously.At least 1 sludge retention time (SRT) is needed for nitrification adapt to new temperature envirionment,and more time is necessary for phosphorus removal process.When temperature increases from 12 ℃ to 22 ℃ sharply,nitrification process deteriorates seriously,but phosphorus removal process shows no change.In addition,sludge settleability deteriorates when temperature changes sharply (decrease or increase),but the reasons are different.Under temperature decrease condition,it is mainly caused by the increase of accumulated extracellular polymeric substances (EPS).Under temperature increase condition,the loosing sludge flocs' configuration is the main reason.It should be pointed out that the filamentous bacteria content during the entire experiment keeps almost constant,and the sludge settleability variations are the reflection of the change of sludge physicochemical characteristics. 展开更多
关键词 low temperature activated sludge SBR nitrogen and phosphorus removal sludge settleability
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Study on the Removal of Ammonia Nitrogen from Wastewater Using Microwave Coupled with Active Carbon 被引量:4
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作者 Zl Pei-jian CHEN Can +2 位作者 DAI You-zhi CHENG Ying-xiang XIANG Ren-jun 《Meteorological and Environmental Research》 2012年第7期51-54,共4页
[ Objective] The study aimed to discuss the feasibility and optimal conditions of removing ammonia nitrogen by using microwave coupled with active carbon. [ Method ] In the study, a novel process, microwave radiation ... [ Objective] The study aimed to discuss the feasibility and optimal conditions of removing ammonia nitrogen by using microwave coupled with active carbon. [ Method ] In the study, a novel process, microwave radiation coupled with active carbon, was applied to remove ammonia nitro- gen from wastewater, and the influences of solution pH, air conditions, active carbon usage, microwave power and time on the removal effect of ammonia nitrogen were studied. [ Result] Microwave coupled with active carbon can remove ammonia nitrogen efficiently, and pumping air into the wastewater can also increase the removal rate of ammonia nitrogen to a certain extent. Higher pH, intensive microwave power and longer treating time could also increase the removal rate of ammonia nitrogen using microwave radiation coupled with active carbon, whereas the usage of active carbon contributed a small impact. It was proved that microwave coupled with active carbon was an effective method for the removal of ammonia ni- trogen from wastewater. Meanwhile, the orthogonal experiment results showed that the removal rate of ammonia nitrogen reached 92.5% under the optimal conditions, that is, the usage of active carbon was 0.5 g, pH = 11, microwave radiation power was 850 W, and microwave action time was 4 minutes. [ Conclusion] The research provided a new method to remove ammonia nitrogen from wastewater, namely microwave coupled with ac- tive carbon. 展开更多
关键词 MICROWAVE Active carbon Ammonia nitrogen removal rate Orthogonal experiment China
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