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Low-computational time and accurate classification of flow regimes in bubble columns for aquaculture aeration using probability density functions of bubble velocity standard deviation
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作者 Natee Thong-Un Wongsakorn Wongsaroj +2 位作者 Jirayut Hansot Weerachon Treenuson Hiroshige Kikura 《Theoretical & Applied Mechanics Letters》 2025年第5期469-478,共10页
This study explores the combination of ultrasound technology with a detection algorithm to categorize flow regimes in bubble columns used for aeration in aquaculture.An ultrasonic velocity profiler is used to obtain t... This study explores the combination of ultrasound technology with a detection algorithm to categorize flow regimes in bubble columns used for aeration in aquaculture.An ultrasonic velocity profiler is used to obtain the standard deviation of the bubble velocity distributed throughout the column.The bubble velocity data for three known flow regimes were used to develop a probability density function(PDF)classification model.The experimental apparatus consisted of a circular tank equipped with a bubble generator and gas hold-up monitoring systems.The flow regimes of the experimental fluid were determined,and the classification was conducted via the PDF method.The results demonstrate that the classification accuracy is not lower than that of traditional machine learning methods. 展开更多
关键词 Aquaculture aeration Bubble column Bubble velocity standard deviation Flow regime Ultrasonic velocity profiler
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DOPA/PEI surface-modified poly-4-methyl-1-pentene membranes and application in membrane aeration biofilm reactor
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作者 Yue Zhou Wenjun Li +2 位作者 Hongjun Hu Zhaohui Wang Zhaoliang Cui 《Chinese Journal of Chemical Engineering》 2025年第1期114-122,共9页
The membrane aeration biofilm reactor(MABR)represents an innovative approach to wastewater treatment,integrating gas separation membranes with biofilm process and demonstrating effectiveness in treating wastewater ric... The membrane aeration biofilm reactor(MABR)represents an innovative approach to wastewater treatment,integrating gas separation membranes with biofilm process and demonstrating effectiveness in treating wastewater rich in ammonia nitrogen.In this system,hollow fiber membranes are essential,serving as a substrate for biofilm attachment while facilitating oxygen transfer to microorganisms through aeration,hydrophobic microporous membranes are utilized in MABR applications.This study focuses on the use of poly-4-methyl-1-pentene(PMP)hollow fiber membranes,which exhibit superior oxygen permeation capabilities compared to traditional hydrophobic microporous membranes.To overcome the challenges posed by the hydrophobic nature and low bubble point of PMP microporous membranes,a hydrophilic modification was conducted using dopamine/poly(ethyleneimine)(DOPA/PEI)co-deposition to enhance microbial adhesion on the membrane surface.The composite membrane modified with DOPA/PEI exhibited an approximately 20%higher NH_(4)^(+)-N removal efficiency than the unmodified membrane.These findings suggest that the incorporation of DOPA/PEI significantly improves MABR performance,underscoring its potential for further research and development in membrane technology for MABR. 展开更多
关键词 Membrane aeration biofilm reactor Poly(4-methyl-1-pentene) Hollow fiber membrane Co-deposition modification
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Effects of Aeration Rates and Patterns on Shortcut Nitrification and Denitrification
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作者 Ali Ibrah Landi Jun Lu 《Journal of Environmental Protection》 CAS 2022年第9期640-656,共17页
The effects of aeration rates and aeration patterns on the oxidation of ammonia-nitrogen into nitrite were investigated. The influent high ammonia-nitrogen synthetic wastewater resembled to those of the catalytic proc... The effects of aeration rates and aeration patterns on the oxidation of ammonia-nitrogen into nitrite were investigated. The influent high ammonia-nitrogen synthetic wastewater resembled to those of the catalytic process of the petrochemical refinery. The method involved the biological shortcut nitrification and denitrification lab-scale’s sequencing batch reactor (SBR) process based on intermittent aerations and aeration patterns. All the operations were carried out in a 20 L working volume SBR bioreactor, and the influent synthetic wastewater’s concentration was always 1000 mg/L ammonia-nitrogen NH<sub>4</sub>-N concentration at a C/N (carbon/nitrogen) ratio of 2.5:1. Effective shortcut nitrification to nitrite was registered at 1.1 mg-O<sub>2</sub>/L (i.e. 9 L-air/min) with 99.1% nitrification efficiency, 99.0% nitritation rate and 2.6 mg-NO<sub>3</sub>-</sup>-N/L nitrate concentration. The best results with 99.3% nitrification efficiency were recorded when operating at 1.4 mg-O<sub>2</sub>/L (i.e. 12 L-air/min). According to these experiments, it results that the nitrite accumulation rate was related to aeration rate and cycle’s duration. However, at 1.7 mg-O<sub>2</sub>/L (i.e. 15 L-air/min), the system was limited by an increase in nitrate concentration with more than 5 mg/L which could be a point of reverse to conventional nitrification. The best total nitrogen (TN) removal was about 71.5%. 展开更多
关键词 Wastewater Treatment SBR Partial Nitrification/Denitrification Intermittent aeration aeration Rate aeration Pattern Total Nitrogen (TN) Removal
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Effect of vacuum degree and aeration rate on sludge dewatering behavior with the aeration-vacuum method 被引量:4
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作者 Yu-feng GAO 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 SCIE EI CAS CSCD 2010年第9期638-655,共18页
Due to large-scale dredging operations, a large amount of sludge is inevitably produced. Large areas of land are occupied when the dredged sludge is discarded in the disposal site as waste material. The sludge dewater... Due to large-scale dredging operations, a large amount of sludge is inevitably produced. Large areas of land are occupied when the dredged sludge is discarded in the disposal site as waste material. The sludge dewatering with aeration-vacuum (SDAV) method is suit for treating the sludge with high water content and high clay content in the disposal site. The water in the sludge can be discharged out. The volume of the sludge can be reduced quickly, and the recycling of the land can be accelerated by this method. Most importantly, this technique is an efficient way to deal with clogging problems when pumping water from high water content, high clay content dredged sludge. Vacuum degree range tests, the aeration rate range tests, and the influencing factors of sludge dewatering behavior tests were conducted with a self-developed SDAV model test device. Sludge samples were taken from the South-to-North Water Diversion East Line Project in Huai’an White-Horse Lake disposal site, Jiangsu Province, China. The optimal range of vacuum degree and aeration rate were obtained through the test results, and the mechanisms for how the two factors work and how they affect the sludge dewatering behavior were analyzed. The suitable vacuum degree range in SDAV is below 50 kPa, and the suitable aeration rate is about 1.0 m3/h. The low-vacuum degree contributes to reduce the ad-sorption effect of micro-channels on soil particles in filter material and to maintain the arch structures. Aeration has the effects of expansion, disturbance, changing Reynolds number, and dynamic sieve separating. The pump quantity of water per meter of filter tube (m) has different change rules as the vacuum degree changes under different aeration rates. The reason is that the formed arch structures’ conformation and permeability differ greatly under different combined-conditions of vacuum degree and aeration rate. The optimal combined-condition for dewatering the sludge is 35 kPa with 1.0 m3/h. 展开更多
关键词 High water content dredged sludge Sludge dewatering with aeration-vacuum (SDAV) Vacuum degree aeration rate Arch structures
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Numerical analysis of aerated heap bioleaching with variable irrigation and aeration combinations 被引量:1
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作者 HUANG Ming-qing WU Ai-xiang 《Journal of Central South University》 SCIE EI CAS CSCD 2020年第5期1432-1442,共11页
Forced aeration is an effective way to accelerate the heap bioleaching process.To reveal the effects of different irrigation and aeration combinations on bioleaching performance of copper sulfides,numerical simulation... Forced aeration is an effective way to accelerate the heap bioleaching process.To reveal the effects of different irrigation and aeration combinations on bioleaching performance of copper sulfides,numerical simulations with COMSOL were carried out.Results showed the oxygen concentration is the highest at the bottom with forced aeration,the airflow transports spherically from the aeration pipeline to the slope,and the horizontal diffusion distance is further than vertical value.When the irrigation-to-aeration ratio is higher,the average heap temperatures are mainly decided by aeration rates;otherwise,temperature distributions are the equilibrium of mineral reaction heat,the livixiant driven heat and the airflow driven heat.When the aeration rate is higher than 0.90 m3/(m2·h),oxygen concentration is no longer a limiting factor for mineral dissolution.Additionally,on the premise of sufficient oxygen supply,Cu recovery rate is higher at the bottom with low irrigation rate;while it is higher at upper regions with high irrigation rate.The numerical analysis uncovered some insights into the dynamics and thermodynamics rules in bioleaching of copper sulfides with forced aeration. 展开更多
关键词 forced aeration irrigation-to-aeration ratio oxygen concentration temperature distribution copper leaching rate
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Effect of aeration on fast gas pressure tests 被引量:1
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作者 CHEN Yu-jia JIANG Cheng-lin LI Xiao-wei TANG Jun WANG Chen YANG Fei-long WANG Fa-kai ZHANG Chao-jie DENG Shu-hua 《Mining Science and Technology》 EI CAS 2009年第6期756-760,共5页
Given the problem of the long time required for testing gas pressure, we propose a fast-test method in which we used a technique of fast borehole sealing and air replenishing. Based on the characteristics of gas emiss... Given the problem of the long time required for testing gas pressure, we propose a fast-test method in which we used a technique of fast borehole sealing and air replenishing. Based on the characteristics of gas emission from boreholes to be tested, we built a theoretical model for calculating parameters during the process of increasing natural pressure and aeration. Using this model, we investigated the effect of different aeration conditions on velocity of pressure tests. The result shows that: 1) aerating air into boreholes can speed up gas pressure tests and 2) the more similar the pressure of the aerated air to the original gas pressure, the smaller the gas volume absorbed by coal and the shorter the time needed in pressure test. A case study in the Lu’an mining area shows that the time needed for gas pressure test is only 4 h using our method of aeration and 29 h under conditions of increasing natural pressure, saving time by 86.2%. This case study also indicates that, by using the aeration method, only one hour is needed for gas pressure to reach a stable state, which breaks the record of the shortest time needed for gas pressure tests in China. 展开更多
关键词 aeration gas pressure fast test aeration pressure adsorption quantity
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Influence of Stand-Alone Vertical Gas Vents on Aeration and Denitrification of Organic Municipal Waste Assessed by Two-Dimensional (2D) Lysimeters
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作者 Tadis Dillon Takayuki Shimaoka Teppei Komiya 《Journal of Geoscience and Environment Protection》 2023年第12期209-228,共20页
Landfilled organic waste, in the presence of oxygen, can undergo aerobic decomposition facilitated by heterotrophic microorganisms. Aerobic degradation of solid waste can quickly consume available oxygen thus curtaili... Landfilled organic waste, in the presence of oxygen, can undergo aerobic decomposition facilitated by heterotrophic microorganisms. Aerobic degradation of solid waste can quickly consume available oxygen thus curtailing further degradation. The aim of this study was the investigation of a low-cost method of replenishing oxygen consumed in landfilled waste. Three 2D lysimeters were established to investigate the effectiveness of stand-alone, vertical ventilation pipes inserted into waste masses. Two different configurations of ventilation were tested with the third lysimeter acting as an unventilated control. Lysimeters were left uninsulated and observed over the course of 6 months with regular collection of gas and leachate samples. Lysimeters were then simulated for Oxygen (O<sub>2</sub>) and Nitrous oxide (N<sub>2</sub>O) to analyze the denitrification contributions of each. The experiment revealed that a single ventilation pipe can increase the mean oxygen level of a 1.7 m × 1.0 m area by up to 13.5%. It also identified that while increasing the density of ventilation pipes led to increased O<sub>2</sub> levels, this increase was not significant at the 0.05 probability level. A single vent averaged 13.67% O<sub>2</sub> while inclusion of an additional vent in the same area only increased the average to 14.59%, a 6.7% increase. Simulation helped to verify that lower ventilation pipe placement density may be more efficient as in addition to the effect on oxygenation, denitrification efficiency may increase. Simulations of N<sub>2</sub>O production estimated between 8% - 20% more N<sub>2</sub>O being generated with lower venting density configurations. 展开更多
关键词 Organic Waste Waste Stabilization Passive aeration 2D Lysimeter COMSOL Multiphysics In-Situ aeration
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Effect of artificial aeration on the performance of vertical-flow constructed wetland treating heavily polluted river water 被引量:38
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作者 Huiyu Dong Zhimin Qiang +2 位作者 Tinggang Li Hui Jin Weidong Chen 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2012年第4期596-601,共6页
Three lab-scale vertical-flow constructed wetlands (VFCWs), including the non-aerated (NA), intermittently aerated (IA) and continuously aerated (CA) ones, were operated at different hydraulic loading rates (... Three lab-scale vertical-flow constructed wetlands (VFCWs), including the non-aerated (NA), intermittently aerated (IA) and continuously aerated (CA) ones, were operated at different hydraulic loading rates (HLRs) to evaluate the effect of artificial aeration on the treatment efficiency of heavily polluted river water. Results indicated that artificial aeration increased the dissolved oxygen (DO) concentrations in IA and CA, which significantly favored the removal of organic matter and NH4+-N. The DO grads caused by intermittent aeration formed aerobic and anoxic regions in IA and thus promoted the removal of total nitrogen (TN). Although the removal efficiencies of CODEr, NH4+-N and TN in the three VFCWs all decreased with an increase in HLR, artificial aeration enhanced the reactor resistance to the fluctuation of pollutant loadings. The maximal removal efficiencies of CODEr, NH4+-N and total phosphorus (TP) (i.e., 81%, 87% and 37%, respectively) were observed in CA at 19 cm/day HLR, while the maximal TN removal (i.e., 57%) was achieved in IA. Although the improvement of artificial aeration on TP removal was limited, this study has demonstrated the feasibility of applying artificial aeration to VFCWs treating polluted river water, particularly at a high HLR. 展开更多
关键词 vertical-flow constructed wetland artificial aeration polluted fiver water hydraulic loading rate
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Effects of overlying water aeration on phosphorus fractions and alkaline phosphatase activity in surface sediment 被引量:20
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作者 Jianjun Chen Shaoyong Lu +2 位作者 Yikun Zhao Wei Wang Minsheng Huang 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2011年第2期206-211,共6页
Microbial activity may influence phosphorus (P) deposit and release at the water sediment interface. The properties of DO (dissolved oxygen), pH, P fractions (TE Ca-E Fe-R OE IP), and APA (alkaline phospfiatase... Microbial activity may influence phosphorus (P) deposit and release at the water sediment interface. The properties of DO (dissolved oxygen), pH, P fractions (TE Ca-E Fe-R OE IP), and APA (alkaline phospfiatase activity) at the water sediment interface were measured to investigate microbial activity variations in surface sediment under conditions of two-month intermittent aeration in overlying water. Results showed that DO and TP of overlying water increased rapidly in the first week and then decreased gradually after 15 day of intermittent aeration. Microorganism metabolism in surface sediment increased pH and decreased DO and TP in the overlying water. After two-month intermittent aeration, APA and OP from surface sediment (0-2 cm) were both significantly higher than those from bottom sediment (6-8 cm) (p 〈 0.05), and surface sediment Fe-P was transferred to OP during the course of microorganism reproduction on the surface sediment. These results suggest that microbial activity and microorganism biomass from the surface sediment were higher than those from bottom sediment after two-month intermittent aeration in the overlying water. 展开更多
关键词 aeration DISTURBANCE SEDIMENT phosphorus fractions alkaline phosphatase
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Effects of Aeration on Root Physiology and Nitrogen Metabolism in Rice 被引量:16
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作者 XU Chun-mei WANG Dan-ying +2 位作者 CHEN Song CHEN Li-ping ZHANG Xiu-fu 《Rice science》 SCIE 2013年第2期148-153,共6页
In order to clarify the effects of aeration on root nitrogen metabolism in rice seedlings,rice cultivars Guodao 6 (indica) and Xiushui 09 (japonica) were investigated for root growth,the activities of glutamine sy... In order to clarify the effects of aeration on root nitrogen metabolism in rice seedlings,rice cultivars Guodao 6 (indica) and Xiushui 09 (japonica) were investigated for root growth,the activities of glutamine synthetase (GS),glutamic acid-pyruvic acid transaminase (GPT) and glutamic acid oxaloacetate transaminase (GOT),the nitrate (NO 3-N) concertration,the contents of free amino acids and soluble sugar in root under hydroponics with continuous aeration treatment.The results showed that rice seedlings grown in oxygenation solutions had higher root dry matter,longer root length,stronger root activity and larger root absorption area compared with the control.In addition,the contents of soluble sugar,root vigor and the activities of GS,GOT and GPT in the aeration solutions were higher than those in the control.The results also indicated that the activities of enzymes involved in root nitrogen metabolism of Xiushui 09 were enhanced by aeration,however,there was no significant influence on root nitrogen metabolism of Guodao 6,which suggested that effect of oxygenation on rice root nitrogen metabolism might be genotype-specific. 展开更多
关键词 RICE aeration root physiology nitrogen metabolism
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Insight into the structural evolution of porous and fractured media by forced aeration during heap leaching 被引量:5
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作者 Yu Shaofeng Wu Aixiang Wang Yiming 《International Journal of Mining Science and Technology》 SCIE EI CSCD 2019年第5期803-807,共5页
Despite lots of techniques in improving the heap leaching performance,many constraints on the industrial applications remain.We proposed a correspondingly effective and new idea of introducing forced aeration to impro... Despite lots of techniques in improving the heap leaching performance,many constraints on the industrial applications remain.We proposed a correspondingly effective and new idea of introducing forced aeration to improve the bad permeability and leaching effect of Yangla Copper Mine(YCM)during heap leaching.The dual-media theory was employed to study the impact mechanism of forced aeration on the variations of porous and fractured media during the column leaching experiments.An X-Ray Computed Tomography(CT)set was utilized to perform the pore imaging of the specimens and the fracture morphology of the particles within the columns was analyzed by Scanning Electron Microscope(SEM)as aeration rate(AR)changed.The results show that there exists copious fine particles within the heap of YCM,the particle size distribution of which is not reasonable.The forced aeration can not only promote the development of the porous and fractured structures but effectively break the blocked seepage paths.Then the leaching degree is improved and the seepage performance of the solute within the solution is enhanced.Therefore,the forced aeration is probable of making the leaching performance greatly improved. 展开更多
关键词 LEACHING performance FORCED aeration POROUS and fractured MEDIA CT SEM aeration rate
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Enhancement of simultaneous nitrogen and phosphorus removal using intermittent aeration mechanism 被引量:5
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作者 Parnian Izadi Parin Izadi Ahmed Eldyasti 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2021年第11期1-14,共14页
Biological nutrient removal grows into complicated scenario due to the microbial consortium shift and kinetic competition between phosphorus(P)-accumulating and nitrogen(N)-removing microorganisms.In this study,three ... Biological nutrient removal grows into complicated scenario due to the microbial consortium shift and kinetic competition between phosphorus(P)-accumulating and nitrogen(N)-removing microorganisms.In this study,three sequential batch reactors with constant operational conditions except aeration patterns at 6 h cycle periods were tested.Intermittent aeration was applied to develop a robust nutrient removal system aimed to achieve high energy saving and removal efficiency.The results showed higher correspondence of Puptake,polymeric substance synthesis and glycogen degradation in intermittent-aeration with longer interval periods compared to continuous-aeration.Increasing the intermittentaeration duration from 25 to 50 min,resulted in higher process performance where the system exhibited approximately 30%higher nutrient removal.This study indicated that nutrient removal strongly depends on reaction phase configuration representing the importance of aeration pattern.The microbial community examined the variation in abundance of bacterial groups in suspended sludge,where the 50 min intermittent aeration,favored the growth of P-accumulating organisms and nitrogen removalmicrobial groups,indicating the complications related to nutrient removal systems.Successful intermittently aerated process with high capability of simple implementation to conventional systems by elemental retrofitting,is applicable for upgrading wastewater treatment plants.With aeration as a major operational cost,this process is a promising approach to potentially remove nutrients in high competence,in distinction to optimizing cost-efficacy of the system. 展开更多
关键词 EBPR Nutrient removal Intermittent aeration Dissolved oxygen PAO POLYHYDROXYALKANOATE
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Application of sewage sludge and intermittent aeration strategy to the bioremediation of DDT- and HCH-contaminated soil 被引量:5
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作者 Qi Liang Mei Lei +3 位作者 Tongbin Chen Jun Yang Xiaoming Wan Sucai Yang 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2014年第8期1673-1680,共8页
Adding organic amendments to stimulate the biodegradation of pesticides is a subject of ongoing interest. The effect of sewage sludge on the bioremediation of dichlorodiphenyltrichloroethane(DDT) and hexachlorocyclo... Adding organic amendments to stimulate the biodegradation of pesticides is a subject of ongoing interest. The effect of sewage sludge on the bioremediation of dichlorodiphenyltrichloroethane(DDT) and hexachlorocyclohexane(HCH) contaminated soil was investigated in bench scale experiments,and intermittent aeration strategy was also used in this study to form an anaerobic–aerobic cycle. Bioremediation of DDT and HCH was enhanced with the addition of sewage sludge and the intermittent aeration. The removal rates of HCH and DDT were raised by 16.8%–80.8% in 10 days. Sewage sludge increased the organic carbon content from 6.2 to218 g/kg,and it could also introduce efficient degradation microbes to soil,including Pseudomonas sp.,Bacillus sp. and Sphingomonas sp. The unaerated phase enhanced the anaerobic dechlorination of DDT and HCH,and anaerobic removal rates of β-HCH,o,p′-DDT and p,p′-DDT accounted for more than 50% of the total removal rates,but the content of α-HCH declined more in the aerobic phase. 展开更多
关键词 BIOREMEDIATION Dichlorodiphenyltrichloroethane(DDT) Hexachlorocyclohexane(HCH) Sewage sludge aeration strategy
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Methanogenesis acceleration of fresh landfilled waste by micro-aeration 被引量:4
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作者 SHAOLi-ming HEPin-jing ZHANGHua YUXiao-hua LIGuo-jian 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2005年第3期371-374,共4页
When municipal solid waste(MSW) with high content of food waste is landfilled, the rapid hydrolysis of food waste results in the imbalance of anaerobic metabolism in the landfill layer, indicated by accumulation of vo... When municipal solid waste(MSW) with high content of food waste is landfilled, the rapid hydrolysis of food waste results in the imbalance of anaerobic metabolism in the landfill layer, indicated by accumulation of volatile fatty acids(VFA) and decrease of pH value. This occurrence could lead to long lag time before the initiation of methanogenesis and to the production of strong leachate. Simulated landfill columns with forced aeration, with natural ventilation, and with no aeration, were monitored regarding their organics degradation rate with leachate recirculation. Hydrolysis reactions produced strong leachate in the column with no aeration. With forced aeration, the produced VFA could be effectively degraded, leading to the reduction in COD of the leachate effluent since the week 3. The CH_4 in the landfill gas from the column with aeration rate of 0.39 m3/(m3·d) and frequency of twice/d, leachate recirculation rate of 12.2 mm/d and frequency of twice/d, could amount to 40%(v/v) after only 20 weeks. This amount had increased up to 50% afterward even with no aeration. Most of COD in the recirculated leachate was removed. Using natural ventilation, CH_4 could also be produced and the COD of the leachate effluent be reduced after 10 weeks of operation. However, the persistent existence of oxygen in the landfill layer yielded instability in methanogenesis process. 展开更多
关键词 MSW landfill METHANOGENESIS leachate recirculation forced aeration natural ventilation
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Effect of intermittent aeration mode on nitrogen concentration in the water column and sediment pore water of aquaculture ponds 被引量:4
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作者 Dantong Zhu Xiangju Cheng +1 位作者 David J.Sample Mohammad Nayeb Yazdi 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2020年第4期331-342,共12页
Nitrogen in pond sediments is a major water quality concern and can impact the productivity of aquaculture.Dissolved oxygen is an important factor for improving water quality and boosting fish growth in aquaculture po... Nitrogen in pond sediments is a major water quality concern and can impact the productivity of aquaculture.Dissolved oxygen is an important factor for improving water quality and boosting fish growth in aquaculture ponds,and plays an important role in the conversion of ammonium-nitrogen(NH4-N)to nitrite-nitrogen(NO2--N)and eventually nitrate-nitrogen(NO3--N).A central goal of the study was to identify the best aeration method and strategy for improving water quality in aquaculture ponds.We conducted an experiment with six tanks,each with a different aeration mode to simulate the behavior of aquaculture ponds.The results show that a 36 hr aeration interval(Tc=36 hr:36 hr)and no aeration resulted in high concentrations of NH4-N in the water column.Using a 12 hr interval time(Tc=12 hr:12 hr)resulted in higher NO2--N and NO3--N concentrations than any other aeration mode.Results from an 8 hr interval time(Tc=8 hr:8 hr)and 24 hr interval time(Tc=24 hr:24 hr)were comparable with those of continuous aeration,and had the benefit of being in use for only half of the time,consequently reducing energy consumption. 展开更多
关键词 Intermittent aeration NITROGEN Water column Sediment resuspension and release SEDIMENT Sediment pore water
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Effects of forced aeration on community dynamics of free and attached bacteria in copper sulphide ore bioleaching 被引量:4
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作者 Wei Chen Shenghua Yin I.M.S.K.Ilankoon 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2022年第1期59-69,共11页
Bacterial community dynamics and copper leaching with applied forced aeration were investigated during low-grade copper sulphide bioleaching to obtain better bioleaching efficiency.Results illustrated that appropriate... Bacterial community dynamics and copper leaching with applied forced aeration were investigated during low-grade copper sulphide bioleaching to obtain better bioleaching efficiency.Results illustrated that appropriate aeration improved bacterial concentrations and leaching efficiencies.The highest bacterial concentration and Cu^(2+)concentration after 14-d leaching were 7.61×10^(7) cells·mL^(−1) and 704.9 mg·L^(−1),respectively,at aeration duration of 4 h·d^(−1).The attached bacteria played a significant role during bioleaching from 1 to 7 d.However,free bacteria dominated the bioleaching processes from 8 to 14 d.This phenomenon was mainly caused by the formation of passivation layer through Fe3+hydrolysis along with bioleaching,which inhibited the contact between the attached bacteria and ore.Meanwhile,16S rDNA analysis verified the effect of Acidithiobacillus ferrooxidans and Acidithiobacillus thiooxidans on the bioleaching process.The results demonstrate the importance of free and attached bacteria in bioleaching. 展开更多
关键词 attached bacteria BIOLEACHING forced aeration free bacteria low-grade copper sulphide ore
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Root Aeration Promotes Cadmium Accumulation in Rice by Regulating Iron Uptake-Associated System 被引量:4
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作者 Huang Qina Wu Yinliang Shao Guosheng 《Rice science》 SCIE CSCD 2021年第5期511-520,I0040-I0044,共15页
Different cadmium(Cd)-accumulated rice genotypes(Erjiunan 1 and Fupin 36)were used to explore the effect of rice rhizosphere aeration on Cd uptake and accumulation.Aeration in the nutrient soluti on influe need the ag... Different cadmium(Cd)-accumulated rice genotypes(Erjiunan 1 and Fupin 36)were used to explore the effect of rice rhizosphere aeration on Cd uptake and accumulation.Aeration in the nutrient soluti on influe need the agronomic characteristics in duced by Cd-stress,such as the in creases of rice root length and root vigor,but the reductions of plant height and shoot dry weight.Aeration also alleviated the decreasing effects of Cd stress on antioxidant enzyme activities and soluble protein,malonaldehyde and nicotianamine contents in rice.Moreover,with aeration treatment,the accumulation and bioavailability of metal elements changed significantly,with a Cd increase and an Fe reduction in both rice genotypes.In addition,at the molecular level,aeration upregulated the expression of Fe-inducible genes(such as OsIRTI,OsNRAMPI,OsYSL15 and OsNAS3).Furthermore,as a Cd^(2+)/Fe^(2+) transporter,the high transcription level of OsNRAMPI can elevate the Cd uptake and translocation in rice due to the Fe reduction caused by aeration and Cd-exposure,which indicated that OsNRAMPI might play a crucial role in the effect of aeration on Cd uptake and accumulation. 展开更多
关键词 aeration antioxidant enzyme CADMIUM gene regulatory network RICE
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Effects of aeration method and aeration rate on greenhouse gas emissions during composting of pig feces in pilot scale 被引量:26
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作者 Tao Jiang Guoxue Li +3 位作者 Qiong Tang Xuguang Ma Gang Wang Frank Schuchardt 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2015年第5期124-132,共9页
The aim of this study was to uncover ways to mitigate greenhouse gas(GHG) emissions and reduce energy consumption during the composting process. We assessed the effects of different aeration rates(0, 0.18, 0.36, an... The aim of this study was to uncover ways to mitigate greenhouse gas(GHG) emissions and reduce energy consumption during the composting process. We assessed the effects of different aeration rates(0, 0.18, 0.36, and 0.54 L/(kg dry matter(dm)·min)) and methods(continuous and intermittent) on GHG emissions. Pig feces and corn stalks were mixed at a ratio of 7:1. The composting process lasted for 10 weeks, and the compost was turned approximately every 2 weeks. Results showed that both aeration rate and method significantly affected GHG emissions. Higher aeration rates increased NH3 and N2O losses,but reduced CH4 emissions. The exception is that the CH4 emission of the passive aeration treatment was lower than that of the low aeration rate treatment. Without forced aeration,the CH4 diffusion rates in the center of the piles were very low and part of the CH4 was oxidized in the surface layer. Intermittent aeration reduced NH3 and CH4 losses, but significantly increased N2 O production during the maturing periods. Intermittent aeration increased the nitrification/denitrification alternation and thus enhanced the N2 O production. Forced aeration treatments had higher GHG emission rates than the passive aeration treatment. Forced aeration accelerated the maturing process, but could not improve the quality of the end product. Compared with continuous aeration, intermittent aeration could increase the O2 supply efficiency and reduced the total GHG emission by 17.8%, and this reduction increased to 47.4% when composting was ended after 36 days. 展开更多
关键词 Intermittent aeration Forced aeration Passive aeration Greenhouse gas Composting
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A Novel Surface Aeration Configuration for Improving Gas-Liquid Mass Transfer 被引量:5
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作者 禹耕之 毛在砂 王蓉 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2002年第1期39-44,共6页
A novel surface aeration configuration featured with aself-rotating and floating baffle (SRFB) and a Rushton disk turbine(DT) with a perforated disk has been developed. The SRFB, consistedof 12 fan blades twisted By a... A novel surface aeration configuration featured with aself-rotating and floating baffle (SRFB) and a Rushton disk turbine(DT) with a perforated disk has been developed. The SRFB, consistedof 12 fan blades twisted By an angle of 30 deg to the horizontalplane, is incorporated onto the impeller shaft to improve gasentrainment, bubble Breakup, mixing in a φ 154 mm agitated vessel.This new configuration is compared to the conventional DT surfaceAeration experimentally. The results suggest that the criticalimpeller speed for onset of gas entrainment is lower for The newconfiguration and it demands greater power consumption. Moreover, theSRFB system produces 30/100-168/100 Higher volumetric mass transfercoefficient per unit power input than that obtained in theconventional DT surface Aerator under the same operation conditions. 展开更多
关键词 surface aeration self-rotating and floating baffle gas-liquid masstransfer
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Dissolved oxygen in aeration-driven piezo-catalytic for antibiotics pollutants removal in water 被引量:3
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作者 Minxian Zhang Wanqian Guo +3 位作者 Yingyin Chen Dechun He Abdulgalim B.Isaev Mingshan Zhu 《Chinese Chemical Letters》 SCIE CAS CSCD 2023年第9期243-247,共5页
The misuse of antibiotics and oxygen-lacking in aquaculture causes serious water environmental problems.Herein,a piezoelectic odd-layered MoS_(2)is prepared and applied to piezo-catalytic remove tinidazole(TNZ)and oth... The misuse of antibiotics and oxygen-lacking in aquaculture causes serious water environmental problems.Herein,a piezoelectic odd-layered MoS_(2)is prepared and applied to piezo-catalytic remove tinidazole(TNZ)and other antibiotic pollutants with aeration as a piezo-driving force.About 89.6%of TNZ can be degraded by MoS_(2)under aeration in the presence of dissolved oxygen with a reaction rate constant of0.15 min^(-1),which is 2.4 times higher than that under N2atmosphere and quiescence conditions.Quenching experiments and electron paramagnetic resonance(EPR)tests identify that singlet oxygen(^(1)O_(2))and superoxide radical(O_(2)^(·-))are dominant reactive oxygen species in MoS_(2)/aeration system.These results demonstrate that MoS2can trigger a piezoelectric effect and produce charge carriers to generate reactive oxygen species with dissolved oxygen(DO)for contaminant degradation with the turbulence and water bubbles rupture driven by aeration. 展开更多
关键词 aeration Piezo-catalysis Dissolved oxygen Reactive oxygen species Antibiotic removal
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