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Effect of surfactant frequently used in soil flushing on oxygen mass transfer in micro-nano-bubble aeration system
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作者 Mei Bai Zhibin Liu +3 位作者 Zhu Liu Chenfei He Zhanhuang Fan Miaoxin Yuan 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2024年第3期174-181,共8页
In-site soil flushing and aeration are the typical synergetic remediation technology for contaminated sites.The surfactant present in flushing solutions is bound to affect the aeration efficiency.The purpose of this s... In-site soil flushing and aeration are the typical synergetic remediation technology for contaminated sites.The surfactant present in flushing solutions is bound to affect the aeration efficiency.The purpose of this study is to evaluate the effect of surfactant frequently used in soil flushing on the oxygen mass transfer in micro-nano-bubble(MNB)aeration system.Firstly,bio-surfactants and chemical surfactants were used to investigate their effects on Sauter mean diameter of bubble(dBS),gas holdup(ε),volumetric mass-transfer coefficient(kLa)and liquid-side mass-transfer coefficient(kL)in the MNB aeration system.Then,based upon the experimental results,the Sardeing's and Frossling's models were modified to describe the effect of surfactant on kL in the MNB aeration.The results showed that,for the twenty aqueous surfactant solutions,with the increase in surfactant concentration,the value of dBS,kLa and kL decreased,while the value ofεand gas-liquid interfacial area(a)increased.These phenomena were mainly attributed to the synergistic effects of immobile bubble surface and the suppression of coalescence in the surfactant solutions.In addition,with the presence of electric charge,MNBs in anionic surfactant solutions were smaller and higher in number than in non-ionic surfactant solutions.Furthermore,the accumulation of surfactant on the gas-liquid interface was more conspicuous for small MNB,so the reduction of kL in anionic surfactant solutions was larger than that in non-ionic surfactant solutions.Besides,the modified Frossling's model predicted the effect of surfactant on kL in MNB aeration system with reasonable accuracy. 展开更多
关键词 Soil flushing Micro-nano-bubble aeration Bio-surfactant Mass transfer coefficient
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Operational guidance for aeration and flow augmentation for the Chicago Area Waterway System—A case study
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作者 Charles S.Melching Jennifer Wasik +1 位作者 Ed Staudacher Thomas Minarik 《Water Science and Engineering》 EI CAS CSCD 2023年第4期345-358,共14页
The Chicago Area Waterway System(CAWS)is a 133.9 km branching network of navigable waterways controlled by hydraulic structures,in which the majority of the flow is treated wastewater effluent and there are periods of... The Chicago Area Waterway System(CAWS)is a 133.9 km branching network of navigable waterways controlled by hydraulic structures,in which the majority of the flow is treated wastewater effluent and there are periods of substantial combined sewer overflows.The CAWS comprises a network of effluent dominated streams.More stringent dissolved oxygen(DO)standards and a reduced flow augmentation allowance have been recently applied to the CAWS.Therefore,a carefully calibrated and verified one-dimensional flow and water quality model was applied to the CAWS to determine emission-based real-time control guidelines for the operation of flow augmentation and aeration stations.The goal of these guidelines was to attain DO standards at least 95%of the time.The“optimal”guidelines were tested for representative normal,dry,and wet years.The finally proposed guidelines were found in the simulations to attain the 95%target for nearly all locations in the CAWS for the three test years.The developed operational guidelines have been applied since 2018 and have shown improved attainment of the DO standards throughout the CAWS while at the same time achieving similar energy use at the aeration stations on the Calumet River system,greatly lowered energy use on the Chicago River system,and greatly lowered discretionary diversion from Lake Michigan,meeting the recently enacted lower amount of allowed annual discretionary diversion.This case study indicates that emission-based real-time control developed from a well calibrated model holds potential to help many receiving water bodies achieve high attainment of water quality standards. 展开更多
关键词 Water quality modeling Water quality management Real-time control Stream aeration Flow augmentation Dissolved oxygen
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Effect of bubble morphology and behavior on power consumption in non-Newtonian fluids’aeration process 被引量:1
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作者 Xiemin Liu Jing Wan +5 位作者 Jinnan Sun Lin Zhang Feng Zhang Zhibing Zhang Xinyao Li Zheng Zhou 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2024年第1期243-254,共12页
Due to a prolonged operation time and low mass transfer efficiency, the primary challenge in the aeration process of non-Newtonian fluids is the high energy consumption, which is closely related to the form and rate o... Due to a prolonged operation time and low mass transfer efficiency, the primary challenge in the aeration process of non-Newtonian fluids is the high energy consumption, which is closely related to the form and rate of impeller, ventilation, rheological properties and bubble morphology in the reactor. In this perspective, through optimal computational fluid dynamics models and experiments, the relationship between power consumption, volumetric mass transfer rate(kLa) and initial bubble size(d0) was constructed to establish an efficient operation mode for the aeration process of non-Newtonian fluids. It was found that reducing the d0could significantly increase the oxygen mass transfer rate, resulting in an obvious decrease in the ventilation volume and impeller speed. When d0was regulated within 2-5 mm,an optimal kLa could be achieved, and 21% of power consumption could be saved, compared to the case of bubbles with a diameter of 10 mm. 展开更多
关键词 Non-Newtonian fluids aeration process Power consumption Volumetric mass transfer rate Bubble size
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Multimodal Machine Learning Guides Low Carbon Aeration Strategies in Urban Wastewater Treatment
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作者 Hong-Cheng Wang Yu-Qi Wang +4 位作者 Xu Wang Wan-Xin Yin Ting-Chao Yu Chen-Hao Xue Ai-Jie Wang 《Engineering》 SCIE EI CAS CSCD 2024年第5期51-62,共12页
The potential for reducing greenhouse gas(GHG)emissions and energy consumption in wastewater treatment can be realized through intelligent control,with machine learning(ML)and multimodality emerging as a promising sol... The potential for reducing greenhouse gas(GHG)emissions and energy consumption in wastewater treatment can be realized through intelligent control,with machine learning(ML)and multimodality emerging as a promising solution.Here,we introduce an ML technique based on multimodal strategies,focusing specifically on intelligent aeration control in wastewater treatment plants(WWTPs).The generalization of the multimodal strategy is demonstrated on eight ML models.The results demonstrate that this multimodal strategy significantly enhances model indicators for ML in environmental science and the efficiency of aeration control,exhibiting exceptional performance and interpretability.Integrating random forest with visual models achieves the highest accuracy in forecasting aeration quantity in multimodal models,with a mean absolute percentage error of 4.4%and a coefficient of determination of 0.948.Practical testing in a full-scale plant reveals that the multimodal model can reduce operation costs by 19.8%compared to traditional fuzzy control methods.The potential application of these strategies in critical water science domains is discussed.To foster accessibility and promote widespread adoption,the multimodal ML models are freely available on GitHub,thereby eliminating technical barriers and encouraging the application of artificial intelligence in urban wastewater treatment. 展开更多
关键词 Wastewater treatment Multimodal machine learning Deep learning Aeration control Interpretable machine learning
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Nitrogen Release Kinetics and Nitrification-Denitrification on Surface Sediments under Aerating Disturbance Condition 被引量:5
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作者 林佩祯 余光伟 +3 位作者 种云霄 肖航 许诺 黄梅 《Agricultural Science & Technology》 CAS 2012年第8期1733-1737,共5页
[Objective] This study aimed to investigate the nitrogen release kinetics and nitrification-denitrification on surface sediments under aerating disturbance condition, with the purpose to solve the sediment nitrogen re... [Objective] This study aimed to investigate the nitrogen release kinetics and nitrification-denitrification on surface sediments under aerating disturbance condition, with the purpose to solve the sediment nitrogen release and secondary pollution problems. [Method] The effect of in situ sediments aeration on the release of nitrogen pollutants was investigated, and the nitrogen release kinetics parameters were analyzed. The process of nitrification and denitrification under sediments aeration condition was investigated in laboratory. [Result] The nitrogen released from sediments was enhanced by aeration disturbance. The concentration of NH4+-N and TN reached the maximum value in 30 min, and release rates were proportional to the disturbance strength. In this study, with the distance of aerator to the sediments surface of 0, 1, 2 and 3 cm, the suspended sediments concentrations were 3.52, 3.41, 3.26 and 3.01 g/L, respectively. Maximum release concentration of NH4+-N and TN were 14.3, 13.8, 13.2, 12.2 mg/L and 33.21, 30.98, 29.83, 27.30 mg/L, respec- tively. In addition, both NH4+-N and TN release kinetics could be described by Double Constant Equation as InC=A+Blnt. Nitrification reaction occurred and was promoted by continued aerating to sediments.The concentration of NH4+-N dropped down from 12.4 mg/L to 0.2 mg/L in 8 d, with the concentration of NO3--N increased to the maximum value of 10.8 mg/L. In addition, concentration of NO3--N and TN decreased from 10.8 mg/L and 37.4 mg/L to 0.36 mg/L and 23.2 mg/L after the stop of aeration for 12 d, indicating the occurrence of denitdfication reaction. Therefore, sediment aeration could accelerate nitrogen release and nitrification reaction, and with intermittent aeration, nitrogen could be removed from sediments in-situ by nitrification and denitrification. [Conclusion] The results provided technical reference for the in situ sediment remediation for the black-odor rivers in cities. 展开更多
关键词 In situ sediments aeration Nitrogen release Nitrification and denitrification Nitrogen removal Kinetics
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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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Root Aeration Promotes Cadmium Accumulation in Rice by Regulating Iron Uptake-Associated System 被引量:2
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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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The effects of aeration and irrigation regimes on soil CO_2 and N_2O emissions in a greenhouse tomato production system 被引量:13
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作者 CHEN Hui HOU Hui-jing +4 位作者 WANG Xiao-yun ZHU Yan Qaisar Saddique WANG Yun-fei CAI Huan-jie 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2018年第2期449-460,共12页
Aerated irrigation has been proven to increase crop production and quality, but studies on its environmental impacts are sparse. The effects of aeration and irrigation regimes on soil CO2 and N2O emissions in two cons... Aerated irrigation has been proven to increase crop production and quality, but studies on its environmental impacts are sparse. The effects of aeration and irrigation regimes on soil CO2 and N2O emissions in two consecutive greenhouse tomato rotation cycles in Northwest China were studied via the static closed chamber and gas chromatography technique. Four treatments, aerated deficit irrigation(AI1), non-aerated deficit irrigation(CK1), aerated full irrigation(AI2) and non-aerated full irrigation(CK2), were performed. The results showed that the tomato yield under aeration of each irrigation regime increased by 18.8% on average compared to non-aeration, and the difference was significant under full irrigation(P〈0.05). Full irrigation significantly increased the tomato yield by 23.9% on average in comparison to deficit irrigation. Moreover, aeration increased the cumulative CO2 emissions compared to non-aeration, and treatment effects were significant in the autumn-winter season(P〈0.05). A slight increase of CO2 emissions in the two seasons was observed under full irrigation(P〉0.05). There was no significant difference between aeration and non-aeration in soil N2O emissions in the spring-summer season, whereas aeration enhanced N2O emissions significantly in the autumn-winter season. Furthermore, full irrigation over the two seasons greatly increased soil N2O emissions compared to the deficit irrigation treatment(P〈0.05). Correlation analysis indicated that soil temperature was the primary factor influencing CO2 fluxes. Soil temperature, soil moisture and NO3^- were the primary factors influencing N2O fluxes. Irrigation coupled with particular soil aeration practices may allow for a balance between crop production yield and greenhouse gas mitigation in greenhouse vegetable fields. 展开更多
关键词 aerated irrigation water management greenhouse gas emissions tomato production system yield
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Simulating Surface Aeration Systems at Different Scale of Mixing Time 被引量:1
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作者 Achanta Ramakrishna Rao Bimlesh Kumar 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2009年第2期355-358,共4页
Macro and micromixing time represent two extreme mixing time scales,which governs the whole hydrodynamics characteristics of the surface aeration systems.With the help of experimental and numerical analysis,simulation... Macro and micromixing time represent two extreme mixing time scales,which governs the whole hydrodynamics characteristics of the surface aeration systems.With the help of experimental and numerical analysis,simulation equation governing those times scale has been presented in the present work. 展开更多
关键词 mass transfer macromixing MICROMIXING surface aerators theoretical power per unit volume rotor speed
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Preparation of New Cementitious System using Fly Ash and Dehydrated Autoclaved Aerated Concrete 被引量:3
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作者 水中和 LU Jianxin +2 位作者 TIAN Sufang SHEN Peiliang DING Sha 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2014年第4期726-732,共7页
We experimentally studied the interaction between pozzolanic material(fly ash) and dehydrated autoclaved aerated concrete(DAAC). The DAAC powder was obtained by grinding aerated concrete waste to particles fi ner ... We experimentally studied the interaction between pozzolanic material(fly ash) and dehydrated autoclaved aerated concrete(DAAC). The DAAC powder was obtained by grinding aerated concrete waste to particles fi ner than 75μm and was then heated to temperatures up to 900 ℃. New cementitious material was prepared by proportioning fly ash and DAAC, named as AF. X-ray diffraction(XRD) was employed to identify the crystalline phases of DAAC before and after rehydration. The hydration process of AF was analyzed by the heat of hydration and non-evaporable water content(Wn). The experimental results show that the highest reactivity of DAAC can be obtained by calcining the powder at 700 ℃ and the dehydrated products are mainly β-C2 S and CaO. The cumulative heat of hydration and Wn was found to be strongly dependent on the replacement level of fl y ash, increasing the replacement level of fl y ash lowered them in AF. The strength contribution rates on pozzolanic effect of fl y ash in AF are always negative, showing a contrary tendency of that of cement-fl y ash system. 展开更多
关键词 dehydrated autoclaved aerated concrete pozzolanic reaction heat of hydration nonevaporable water content strength contribution rate
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Stand-Alone Photovoltaic System to Mitigate Pollution in Bodies of Water CASE Study: Laguna Del Carpintero, Tampico, Tamaulipas
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作者 Adán Hernández-Sánchez Josefina García-Navarro +2 位作者 María Esther Bautista-Vargas Santiago Gómez-Carpizo Raúl Hernández-Martínez 《Journal of Environmental Protection》 2015年第4期351-358,共8页
One of the main environmental issues at present times is the pollution of hydrological resources. Water quality is a major factor to ecosystems, mostly those that support human health, food production and biodiversity... One of the main environmental issues at present times is the pollution of hydrological resources. Water quality is a major factor to ecosystems, mostly those that support human health, food production and biodiversity. The utilization of renewable energy sources as solar energy through Photovoltaic Cells is a competitive and consolidated option to approach the solution of this kind of issues. This document is intended to introduce a prototype powered by photovoltaic cells to aerate a body of water and increase the amount of Dissolved Oxygen (DO) in water. The body of water studied is the lagoon Laguna del Carpintero in Tampico, Tamaulipas, Mexico. A Stand-alone Photovoltaic System (SPS) prototype was designed for this matter with the purpose of powering a pumping system to sprinkle water to the lake’s surface. This system is a way of ventilating the water so that it gets in direct contact with the surrounding atmosphere obtaining mean values compared to prevailing values of DO contained in the lagoon. We obtained DO concentration values going from 7 to 8 mg/L of O2 in different tests which can be considered an appropriate parameter for this body of water. The efficiency of the SPS was proved as it showed good performance by supplying power to the oxygenation system compared to the dimensional estimate. Improving the SPS prototype is the main goal of this work so that this oxygenation system could be used in other urban lagoons in the surrounding area without being powered by electrical grid. This makes possible to locate it at any point of the body of water to mitigate the pollution by increasing the amount of DO. 展开更多
关键词 Photovoltaic system POLLUTION WATER AERATION BODIES of WATER Laguna de Carpintero
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Characterization of the Effect of Programmed Aeration on Energy Efficiency of Microalgae Cultivation System
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作者 Robert Bocsi Dora Rippel-Petho +2 位作者 Geza Horvath Laszlo Hanak Zoltan Hodai 《World Journal of Engineering and Technology》 2017年第3期481-486,共6页
With autotrophic microalgae cultivation,?we can feed back the CO2?content of process streams and we can get lots of valuable organic compounds, among others biofuel components. For the production of energy source,we m... With autotrophic microalgae cultivation,?we can feed back the CO2?content of process streams and we can get lots of valuable organic compounds, among others biofuel components. For the production of energy source,we must reckon with the energy balance of the whole process. Densification and processing of microalgae can consume 50% - 70% of the energy that can be extracted from the cells,?therefore the cultivation should use such a little energy as it possible. In closed cultivation systems,?there are three main energy intensive steps: artificial illumination, dissolution of gas compounds and mixing. We have carried out our measurements in our lab-scale screening photobioreactor system for the investigation of the most energy effective program for aeration. We have found the aeration program considerable solution for lower energy consumption in?algae cultivation. 展开更多
关键词 ENERGY EFFICIENCY MICROALGAE CULTIVATION AERATION
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Changes in the activities of key enzymes and the abundance of functional genes involved in nitrogen transformation in rice rhizosphere soil under different aerated conditions 被引量:3
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作者 XU Chun-mei XIAO De-shun +4 位作者 CHEN Song CHU Guang LIU Yuan-hui ZHANG Xiu-fu WANG Dan-ying 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2023年第3期923-934,共12页
Soil microorganisms play important roles in nitrogen transformation. The aim of this study was to characterize changes in the activity of nitrogen transformation enzymes and the abundance of nitrogen function genes in... Soil microorganisms play important roles in nitrogen transformation. The aim of this study was to characterize changes in the activity of nitrogen transformation enzymes and the abundance of nitrogen function genes in rhizosphere soil aerated using three different methods(continuous flooding(CF), continuous flooding and aeration(CFA), and alternate wetting and drying(AWD)). The abundances of amoA ammonia-oxidizing archaea(AOA) and ammonia-oxidizing bacteria(AOB), nirS, nirK, and nifH genes, and the activities of urease, protease, ammonia oxidase, nitrate reductase, and nitrite reductase were measured at the tillering(S1), heading(S2), and ripening(S3) stages. We analyzed the relationships of the aforementioned microbial activity indices, in addition to soil microbial biomass carbon(MBC) and soil microbial biomass nitrogen(MBN), with the concentration of soil nitrate and ammonium nitrogen. The abundance of nitrogen function genes and the activities of nitrogen invertase in rice rhizosphere soil were higher at S2 compared with S1 and S3 in all treatments. AWD and CFA increased the abundance of amoA and nifH genes, and the activities of urease, protease, and ammonia oxidase, and decreased the abundance of nirS and nirK genes and the activities of nitrate reductase and nitrite reductase, with the effect of AWD being particularly strong. During the entire growth period, the mean abundances of the AOA amoA, AOB amoA, and nifH genes were 2.9, 5.8, and 3.0 higher in the AWD treatment than in the CF treatment, respectively, and the activities of urease, protease, and ammonia oxidase were 1.1, 0.5, and 0.7 higher in the AWD treatment than in the CF treatment, respectively. The abundances of the nirS and nirK genes, and the activities of nitrate reductase and nitrite reductase were 73.6, 84.8, 10.3 and 36.5% lower in the AWD treatment than in the CF treatment, respectively. The abundances of the AOA amoA, AOB amoA, and nifH genes were significantly and positively correlated with the activities of urease, protease, and ammonia oxidase, and the abundances of the nirS and nirK genes were significantly positively correlated with the activities of nitrate reductase. All the above indicators were positively correlated with soil MBC and MBN. In sum, microbial activity related to nitrogen transformation in rice rhizosphere soil was highest at S2. Aeration can effectively increase the activity of most nitrogen-converting microorganisms and MBN, and thus promote soil nitrogen transformation. 展开更多
关键词 rhizosphere aeration gene abundance enzyme activities soil microbial biomass carbon soil microbial nitrogen
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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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Deep learning-based intelligent precise aeration strategy for factory recirculating aquaculture systems
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作者 Junchao Yang Yuting Zhou +2 位作者 Zhiwei Guo Yueming Zhou Yu Shen 《Artificial Intelligence in Agriculture》 2024年第2期57-71,共15页
Factory recirculating aquaculture system(RAS)is facing in a stage of continuous research and technological in-novation.Intelligent aquaculture is an important direction for the future development of aquaculture.Howeve... Factory recirculating aquaculture system(RAS)is facing in a stage of continuous research and technological in-novation.Intelligent aquaculture is an important direction for the future development of aquaculture.However,the RAS nowdays still has poor self-learning and optimal decision-making capabilities,which leads to high aqua-culture cost and low running efficiency.In this paper,a precise aeration strategy based on deep learning is de-signed for improving the healthy growth of breeding objects.Firstly,the situation perception driven by computer vision is used to detect the hypoxia behavior.Then combined with the biological energy model,it is constructed to calculate the breeding objects oxygen consumption.Finally,the optimal adaptive aeration strategy is generated according to hypoxia behavior judgement and biological energy model.Experimental results show that the energy consumption of proposed precise aeration strategy decreased by 26.3%compared with the man-ual control and 12.8%compared with the threshold control.Meanwhile,stable water quality conditions acceler-ated breeding objects growth,and the breeding cycle with the average weight of 400 g was shortened from 5 to 6 months to 3–4 months. 展开更多
关键词 Recirculating aquaculture system Precise aeration Deep learning Intelligent control
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微曝气生物滤池-固相碳源反硝化生物滤池强化脱氮处理新运粮河水的示范工程研究 被引量:2
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作者 朱擎 杨飞飞 +2 位作者 芦婷 冯传平 吴为中 《生态环境学报》 CSCD 北大核心 2015年第7期1216-1221,共6页
滇池是中国富营养化状态最为严重的湖泊,而入湖河流氮磷元素的输入是其主要原因。河流水质的低 C/N 特征是限制氮素去除的关键因素,采用固相反硝化技术能够为反硝化过程提供持续的碳源,因而能够强化受污染河流的脱氮效果。以滇池的... 滇池是中国富营养化状态最为严重的湖泊,而入湖河流氮磷元素的输入是其主要原因。河流水质的低 C/N 特征是限制氮素去除的关键因素,采用固相反硝化技术能够为反硝化过程提供持续的碳源,因而能够强化受污染河流的脱氮效果。以滇池的重点控制入湖河流-新运粮河为研究对象,设计了微曝气生物滤池(Biological aerating filter,BAF)-固相碳源反硝化(Solid-phase denitrification,SPD)组合工艺,在河道旁路展开示范工程研究。组合工艺设计规模为800 m3·d-1,BAF(气水比为3∶1-5∶1)和SPD生物滤池的最大表面水力负荷分别为4.2和1.4 m3·m-2·h-1,其中SPD生物滤池采用新型固相碳源共混可生物降解聚合物与惰性载体共混作为生物膜载体。工艺研究结果表明,在BAF气水比为3∶1-5∶1、HRT为0.5-1 h和SPD滤池HRT为0.5-1 h的运行工况下,BAF对NH4+-N的平均硝化率达到了91.27%,SPD滤池的平均反硝化率93.60%,工艺出水NH4+-N、NO3--N和NO2--N平均浓度分别为0.68、0.70和0.02 mg·L-1。示范工程对各项污染物的去除效果良好,对TN、TP和CODCr的去除率分别达到84.93%、50.15%和31.39%;工艺出水TN、TP和CODCr平均浓度分别为1.75、0.20和22.96 mg·L-1,主要水质指标均达到了地表水V类水质标准。采用新型固相碳源填充的反硝化生物滤池强化了工艺针对低C/N水质特征污染水体的脱氮效果,组合工艺对滇池氮素输入控制具有重要的意义。 展开更多
关键词 曝气生物滤池(Biological aerating filter BAF) 固相反硝化(Solid-phase denitrification SPD) 脱氮 示范工程 BIOLOGICAL aerated FILTER (BAF)
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Study on Eco-restoration of Polluted Rivers 被引量:1
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作者 万玉山 邹涛 +1 位作者 邵敏 李定龙 《Agricultural Science & Technology》 CAS 2016年第10期2386-2389,2409,共5页
[Objective] This study was conducted to find a restoration method suitable for urban polluted rivers. [Method] A segment of a representative river in the old part of a certain city in south Jiangsu was selected as a r... [Objective] This study was conducted to find a restoration method suitable for urban polluted rivers. [Method] A segment of a representative river in the old part of a certain city in south Jiangsu was selected as a research area through previous investigation, and the polluted river was cleaned and restored by 3 methods, i.e. artificial wetland, floating island type wetland and purification floating island. [Resuit] Floating plants (Hydrocotyle verticillata and Myriophyllum spicatum) showed better restoration effects than emergent aquatic plants (Iris wilsonii, Arundo donax, reed, water-cultured Ilex chinensis and Lythrum salicaria). The two types of plants showed the removal rates of total nitrogen of 37.9% and 34.1%, respectively, the removal rates of total phosphorous of 80.1% and 73.5%, respectively, the removal rates of COD of 81.1% and 74.8%, respectively, the removal rates of ammonia nitrogen of 80.6% and 85.9%, respectively, and the removal rates of SS of 59.1% and 77.3%, respectively. Among the purification floating island, the artificial wetland and the floating island type wetland, the purification floating land restoration technique exhibited the best removal effect, with the removal rates of 87.6%, 71.3%, 87.6%, 97.5% and 81.8% for total nitrogen, total phosphorous, ammonia nitrogen COD and SS, respectively. The nitrification and denitdfication rates of bottom mud and water samples in the engineering segment were remarkably higher than those in the reference segment, by 15.4% and 21.1%, respectively. The nitrification and denitrification rates of bottom mud in the engineering segment and the non-engineering segment were higher than those of water samples by 26.9% and 31.8%, respectively. Restoration plants showed better removal effects of total phosphorous, total nitrogen, COD and SS under aeration condition than noeration condition. [Conclusion] The purification floating island has a significant restoration effect on urban polluted river. 展开更多
关键词 Polluted Rivers Eco-restoration AERATION
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Effect of Different Environmental Conditions on Algicidal Effect of Water-soluble Extracts of Chinese Chive
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作者 刘文桃 石光辉 +2 位作者 董昆明 赵海涛 封克 《Agricultural Science & Technology》 CAS 2012年第2期397-400,456,共5页
[Objective] The paper was to study the algicidal effect of water-soluble extracts of Chinese chive under different environmental conditions, so as to provide reference for further study and development of new algicida... [Objective] The paper was to study the algicidal effect of water-soluble extracts of Chinese chive under different environmental conditions, so as to provide reference for further study and development of new algicidal substances. [Method] The effects of water-soluble extracts of Chinese chive on the growth of Microcystis aeruginosa under different pH, light and aeration conditions were compared and studied. [Result] The growth inhibition rate of water-soluble extracts of Chinese chive on M. aeruginosa was greater than 90% under different pH conditions. With the growth of M. aeruginosa, the culture liquid with different initial pH was finally tended to 9-9.5. The growth inhibition rate of water-soluble extracts of Chinese chive on algae cell increased with the prolongation of culture time within the light intensity range of 1 000-4 000 lx. The inhibition effect of water-soluble extracts of Chinese chive on M. aeruginosa under low light intensity(1 000 lx)was better than that under high light intensity, the best light intensity for growth was not conducive to the exertion of allelopathic effect. Meanwhile, aeration condition was more conducive to the inhibition effect of water-soluble extracts of Chinese chive on the growth of M. aeruginosa. [Conclusion] pH, light and aeration conditions all affected the inhibition effect of water-soluble extracts of Chinese chive treated by high temperature on M. aeruginosa. Understanding the effect of these environmental factors on algicidal effect of allelochemicals could provide reference for further study and development of new algicidal substances. 展开更多
关键词 Microcystis aeruginosa Water-soluble extracts of Chinese chive PH LIGHT AERATION
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Research on Modification of Non-limiting Water Range of Soil
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作者 迟春明 《Agricultural Science & Technology》 CAS 2013年第11期1620-1623,1628,共5页
[Objective] The paper was to study and modify non-limiting water range (NLWR) of soil. [Method] The water content when total soil water potential was -0.3 MPa or soil mechanical resistance was 0.85 MPa was selected ... [Objective] The paper was to study and modify non-limiting water range (NLWR) of soil. [Method] The water content when total soil water potential was -0.3 MPa or soil mechanical resistance was 0.85 MPa was selected as the lower limit of NLWR to replace the original water content of permanent wilting point or the water content under soil mechanical resistance of 2.0 MPa. NLWR could be calculated us-ing the minimum value of upper limit minus the maximum value of lower limit. [Re-sult] Compared with original NLWR or least limiting water range (LLWR), the modi-fied NLWR had more practical significance. When Db〉Db-thr, soil physical properties hindered the growth of crops, so the soil should be improved; when Db〉Db-thr, soil physical properties hindered the growth of crops, so-the soil should be improved; wtlen Db〈Db-thr, as long as the soil water content is within NLWR, soil physical properties had no effect on crop growth. NLWR at this time could be used as the basis for irrigation man- agement in farmland. [Conclusion] The study provides theoretical support and scientific basis for relevant researches about evolution rule and regulatory mechanisms of soil physical quality, relationship between soil physical quality and crop growth and yield, water-fertilizer-salt management of soil. 展开更多
关键词 Field water capacity Critical point of aeration Critical point of waterpotential Critical point of mechanical resistance
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Polyurea coating for foamed concrete panel:An efficient way to resist explosion 被引量:12
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作者 Yi-shun Chen Bo Wang +4 位作者 Bei Zhang Qing Zheng Jian-nan Zhou Feng-nian Jin Hua-lin Fan 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2020年第1期136-149,共14页
Autoclaved aerated concrete(AAC) panels have ultra-light weight,excellent thermal insulation and energy absorption,so it is an ideal building material for protective structures.To improve the blast resistance of the A... Autoclaved aerated concrete(AAC) panels have ultra-light weight,excellent thermal insulation and energy absorption,so it is an ideal building material for protective structures.To improve the blast resistance of the AAC panels,three schemes are applied to strengthen the AAC panels through spraying 4 mm thick polyurea coating from top,bottom and double-sides.In three-point bending tests,the polyurea-coated AAC panels have much higher ultimate loads than the un-coated panels,but slightly lower than those strengthened by the carbon fiber reinforced plastics(CEFRPs).Close-in explosion experiments reveal the dynamic strengthening effect of the polyurea coating.Critical scaled distances of the strengthened AAC panels are acquired,which are valuable for the engineering application of the AAC panels in the extreme loading conditions.Polyurea coatings efficiently enhance the blast resistance of the bottom and double-sided polyurea-coated AAC panels.It is interesting that the polyurea-coated AAC panels have much more excellent blast resistance than the CFRP reinforced AAC panels,although the latter have better static mechanical properties. 展开更多
关键词 Autoclaved aerated CONCRETE POLYUREA Explosion FAILURE
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