This article concentrates on the aeration efficiency of venturi air injectors in aquaculture or wastewater treatment.This study was designed to investigate the location of the dissolved oxygen(DO)sensor installation,w...This article concentrates on the aeration efficiency of venturi air injectors in aquaculture or wastewater treatment.This study was designed to investigate the location of the dissolved oxygen(DO)sensor installation,with a focus on investigating the aeration mechanism by studying ten variables,including temperature,pH,oxidation-reduction potential(ORP),electrical conductivity,resistivity,total dissolved solids,salinity,pressure,dissolved oxygen,and the effect of changing the position of DO sensor installations in different locations via oxygen transfer.The water temperature was raised due to the heating of the water pump.It ranged from 29.7°C to 32.78°C,with different temperatures resulting in different oxygen solubility.The pH level increased with the rise in oxygen levels due to an increase in OH-concentration,whereas the ORP decreased when oxygen levels rose,increasing the reduction reaction.A study on the effect of changing the position of DO sensor installations in different locations was discovered using oxygen transfer coefficients(K_(La))variables.The K_(La)values at nozzle depths of 15 cm,30 cm,and 45 cm were 0.0004±0.0001,0.00042±0.0001,and 0.00136±0.00013,respectively.Therefore,there is a slight difference of K_(La)value when changing the position of sensor installations.An inappropriate distance between the DO sensor and nozzle installation is able to cause turbulent flow.This event resulted in an incorrect DO value.Moreover,the installation of the DO sensor too far from the nozzle resulted in a low value of DO.展开更多
Artificial aeration system for aquaculture ponds becomes essential to meet the oxygen requirement posed by the aquatic species.The performance of an aerator is generally mea-sured in terms of standard aeration efficie...Artificial aeration system for aquaculture ponds becomes essential to meet the oxygen requirement posed by the aquatic species.The performance of an aerator is generally mea-sured in terms of standard aeration efficiency(SAE),which is significantly affected by the different geometric and dynamic parameters of the aerator.Therefore,to enhance the aer-ation performance of an aerator,these parameters need to be optimized.In the present study,a perforated pooled circular stepped cascade(PPCSC)aerator was developed,and the geometric and dynamic parameters of the developed aerator were optimized using the hybrid ANN-PSO technique for maximizing its aeration efficiency.The geometric parameters include consecutive step width ratio(W_(i-1)/W_(i))and the perforation diameter to the bottom-most radius ratio(d/R_(b)),whereas the dynamic parameter includes the water flow rate(Q).A 3–6-1 ANN model coupled with particle swarm optimization(PSO)approach was used to obtain the optimum values of geometric and dynamic parameters correspond-ing to the maximum SAE.The optimal values of the consecutive step width ratio(W_(i-1)/W_(i)),the perforation diameter to the bottom-most radius ratio(d/R_(b)),and the water flow rate(Q)for maximizing the SAE were found to be 1.15,0.0027 and 0.0167 m^(3)/s,respectively.The cross-validation results showed a deviation of 3.07%between the predicted and experimen-tal SAE values,thus confirming the adequacy of the proposed hybrid ANN-PSO technique.展开更多
Forced aeration is one of the promising ways to accelerate landfill reclamation,and understanding the relation between aeration rates and waste properties is the prerequisite to implementing forced aeration under the ...Forced aeration is one of the promising ways to accelerate landfill reclamation,and understanding the relation between aeration rates and waste properties is the prerequisite to implementing forced aeration under the target of energy saving and carbon reduction.In this work,landfill reclamation processes with forced aeration were simulated using aged refuses(ARs)of 1,4,7,10,and 13 disposal years,and the potential of field application was also investigated based on a field project,to identify the degradation rate of organic components,the O_(2)consumption efficiency and their correlations to microbes.It was found that the removal rate of organic matter declined from 20.3%(AR_(1))to 12.6%(AR_(13)),and that biodegradable matter(BDM)decreased from 5.2%to 2.4%at the set aeration rate of 0.12 L O_(2)/kg waste(Dry Matter,DM)/day.A linear relationship between the degradation rate constant(K)of BDM and disposal age(x)was established:K=−0.0002193x+0.0091(R^(2)=0.854),suggesting that BDM might be a suitable indicator to reflect the stabilization of ARs.The cellulose/lignin ratio decrease rate for AR1(18.3%)was much higher than that for AR13(3.1%),while the corresponding humic-acid/fulvic-acid ratio increased from 1.44 to 2.16.The dominant bacteria shifted from Corynebacterium(9.2%),Acinetobacter(6.6%),and Fermentimonas(6.5%),genes related to the decompose of biodegradable organics,to Stenotrophomonas(10.2%)and Clostridiales(3.7%),which were associated with humification.The aeration efficiencies of lab-scale tests were in the range of 5.4–11.8 g BDM/L O_(2)for ARs with disposal ages of 1–13 years,and in situ landfill reclamation,ARs with disposal ages of 10–18 years were around 1.9–8.8 g BDM/L O_(2),as the disposal age decreased.The increased discrepancy was observed in ARs at the lab-scale and field scale,indicating that the forced aeration rate should be adjusted based on ARs and the unit compartment combined,to reduce the operation cost.展开更多
基金support from the Faculty of Environmental Management,as well as the High-Potential Talent Fund to strengthen capabilities in the economic,social,and community sectors(Talent Utilization)Type 2 No.TU1-10/2564 from the Graduate School,Prince of Songkla University(PSU)the Southern Industrial Pollutions Research and Warning Center(DIW,Department of Industrial Works)for their invaluable academic guidance,technical resources,and facility support throughout this study.
文摘This article concentrates on the aeration efficiency of venturi air injectors in aquaculture or wastewater treatment.This study was designed to investigate the location of the dissolved oxygen(DO)sensor installation,with a focus on investigating the aeration mechanism by studying ten variables,including temperature,pH,oxidation-reduction potential(ORP),electrical conductivity,resistivity,total dissolved solids,salinity,pressure,dissolved oxygen,and the effect of changing the position of DO sensor installations in different locations via oxygen transfer.The water temperature was raised due to the heating of the water pump.It ranged from 29.7°C to 32.78°C,with different temperatures resulting in different oxygen solubility.The pH level increased with the rise in oxygen levels due to an increase in OH-concentration,whereas the ORP decreased when oxygen levels rose,increasing the reduction reaction.A study on the effect of changing the position of DO sensor installations in different locations was discovered using oxygen transfer coefficients(K_(La))variables.The K_(La)values at nozzle depths of 15 cm,30 cm,and 45 cm were 0.0004±0.0001,0.00042±0.0001,and 0.00136±0.00013,respectively.Therefore,there is a slight difference of K_(La)value when changing the position of sensor installations.An inappropriate distance between the DO sensor and nozzle installation is able to cause turbulent flow.This event resulted in an incorrect DO value.Moreover,the installation of the DO sensor too far from the nozzle resulted in a low value of DO.
文摘Artificial aeration system for aquaculture ponds becomes essential to meet the oxygen requirement posed by the aquatic species.The performance of an aerator is generally mea-sured in terms of standard aeration efficiency(SAE),which is significantly affected by the different geometric and dynamic parameters of the aerator.Therefore,to enhance the aer-ation performance of an aerator,these parameters need to be optimized.In the present study,a perforated pooled circular stepped cascade(PPCSC)aerator was developed,and the geometric and dynamic parameters of the developed aerator were optimized using the hybrid ANN-PSO technique for maximizing its aeration efficiency.The geometric parameters include consecutive step width ratio(W_(i-1)/W_(i))and the perforation diameter to the bottom-most radius ratio(d/R_(b)),whereas the dynamic parameter includes the water flow rate(Q).A 3–6-1 ANN model coupled with particle swarm optimization(PSO)approach was used to obtain the optimum values of geometric and dynamic parameters correspond-ing to the maximum SAE.The optimal values of the consecutive step width ratio(W_(i-1)/W_(i)),the perforation diameter to the bottom-most radius ratio(d/R_(b)),and the water flow rate(Q)for maximizing the SAE were found to be 1.15,0.0027 and 0.0167 m^(3)/s,respectively.The cross-validation results showed a deviation of 3.07%between the predicted and experimen-tal SAE values,thus confirming the adequacy of the proposed hybrid ANN-PSO technique.
基金supported by the National Natural Science Foundation of China(No.42077111)the National Key Research and Development Plans of Special Project for Site soils(No.2018YFC1800601)the Social Development Science and Technology Project of Shanghai“Science and Technology Innovation Action Plan”(No.20dz1203401).
文摘Forced aeration is one of the promising ways to accelerate landfill reclamation,and understanding the relation between aeration rates and waste properties is the prerequisite to implementing forced aeration under the target of energy saving and carbon reduction.In this work,landfill reclamation processes with forced aeration were simulated using aged refuses(ARs)of 1,4,7,10,and 13 disposal years,and the potential of field application was also investigated based on a field project,to identify the degradation rate of organic components,the O_(2)consumption efficiency and their correlations to microbes.It was found that the removal rate of organic matter declined from 20.3%(AR_(1))to 12.6%(AR_(13)),and that biodegradable matter(BDM)decreased from 5.2%to 2.4%at the set aeration rate of 0.12 L O_(2)/kg waste(Dry Matter,DM)/day.A linear relationship between the degradation rate constant(K)of BDM and disposal age(x)was established:K=−0.0002193x+0.0091(R^(2)=0.854),suggesting that BDM might be a suitable indicator to reflect the stabilization of ARs.The cellulose/lignin ratio decrease rate for AR1(18.3%)was much higher than that for AR13(3.1%),while the corresponding humic-acid/fulvic-acid ratio increased from 1.44 to 2.16.The dominant bacteria shifted from Corynebacterium(9.2%),Acinetobacter(6.6%),and Fermentimonas(6.5%),genes related to the decompose of biodegradable organics,to Stenotrophomonas(10.2%)and Clostridiales(3.7%),which were associated with humification.The aeration efficiencies of lab-scale tests were in the range of 5.4–11.8 g BDM/L O_(2)for ARs with disposal ages of 1–13 years,and in situ landfill reclamation,ARs with disposal ages of 10–18 years were around 1.9–8.8 g BDM/L O_(2),as the disposal age decreased.The increased discrepancy was observed in ARs at the lab-scale and field scale,indicating that the forced aeration rate should be adjusted based on ARs and the unit compartment combined,to reduce the operation cost.
