Venturi Aeration Research Articles

Aeration and Slow Sand Filter Technology in Drilling Well Water Treatment to Reduce TDS Levels

The quality of borehole water is often affected by the high content of Total Dissolved Solids (TDS) which can disrupt human health and quality of life. This study examines the effectiveness of the combination of venturi aeration and slow sand filter technology in reducing TDS levels in boreholes in East Lombok, NTB. The priority is the use of venturi aeration and slow sand filtration in an integrated manner as a combined treatment for borehole water, which has not been widely explored in previous studies. This method offers a practical, cost-effective, and environmentally friendly solution to overcome high TDS levels, especially in rural areas and areas with limited resources. These findings provide a new perspective on optimizing water treatment technologies to improve community access to clean and safe water. Sampling was carried out from six different locations and initial TDS levels were measured. The borehole water was treated through venturi aeration for 1 hour to remove dissolved gases and organic compounds, followed by filtration using a slow sand filter to filter fine particles, microorganisms, and other dissolved compounds. The results showed that venturi aeration was able to reduce TDS by 6.8% to 17.9%, while the slow sand filter provided an additional reduction of 3.1% to 8.3%. The combination of these two methods resulted in a total reduction in TDS of 11.3% to 25.8%. The effectiveness of the treatment was influenced by the iron content in the air and the structure of the sand media. Data were analyzed using the ANOVA test to determine the significance of the reduction in TDS.

Modelling and prediction of aeration efficiency of the venturi aeration system using ANN-PSO and ANN-GA

The significance of this study involves the optimisation of the aeration efficiency (AE) of the venturi aerator using an artificial neural network (ANN) technique integrated with an optimisation algorithm, i.e., particle swarm optimisation (PSO) and genetic algorithm (GA). To optimise the effects of operational factors on aeration efficiency by utilising a venturi aeration system, aeration experiments were conducted in an experimental tank with dimensions of 90cm×55cm×45cm. The operating parameters of the venturi aerator include throat length (TL), effective outlet pipe (EOP), and flow rate (Q) to estimate the efficacy of the venturi aerator in terms of AE. A 3–6-1 ANN model was developed and integrated with the PSO and GA techniques to find out the best possible optimal operating variables of the venturi aerator. The coefficient of determination (R2), root mean square error (RMSE), and mean absolute error (MAE) determined from the experimental and estimated data were used to assess and compare the performance of the ANN-PSO and ANN-GA modelling. It is shown that ANN-PSO provides a better result as compared to ANN-GA. The operational parameters, TL, EOP, and Q, were determined to have the most optimum values at 50 mm, 6 m, and 0.6 L/s, respectively. The optimised aeration efficiency of the venturi was found to be 0.105 kg O2/kWh at optimum operational circumstances. In fact, the neural network having an ideal design of (3-6-1) and a correlation coefficient value that is extremely close to unity has validated the results indicated above.

Performance of a Drip Irrigation System under the Co-Application of Water, Fertilizer, and Air

The co-application of water, fertilizer, and air is a new water-saving irrigation method based on drip irrigation technology, which can effectively alleviate the phenomenon of soil rhizosphere hypoxia, improve water and fertilizer utilization efficiency, and inhibit the clogging of irrigation equipment in drip irrigation systems. The performance of drip irrigation systems is one of the important factors affecting the effectiveness of the co-application of water, fertilizer, and air. However, the impact of factors such as the aeration method, fertilization device, and working parameters on the performance of drip irrigation systems for the co-application of water, fertilizer, and air is still unclear. Therefore, based on two typical aeration methods, i.e., micro-nano and Venturi aeration, the performance of a drip irrigation system under the co-application of water, fertilizer, and air was studied by comparing and analyzing the effects of different aeration methods, working pressures of the drip irrigation system, and the pressure difference between the inlet and outlet of fertilizer irrigation on the spatial distribution uniformity of water, fertilizer, and air in the drip irrigation pipeline network. The results showed that the pressure difference between the inlet and outlet of fertilization irrigation had no significant impact on system performance, while the working pressure significantly affected system performance. Compared with the effective effect of Venturi aeration on system performance, micro-nano aeration can significantly affect drip irrigation system performance and effectively improve drip irrigation system performance. The micro-nano-aerated drip irrigation system with the co-application of water, fertilizer, and air under a working pressure of 0.1 MPa has better system performance. The research results are of great significance for revealing the mechanism underlying the impact of the co-application of water, fertilizer, and air on the performance of drip irrigation systems and constructing efficient drip irrigation technology for the co-application of water, fertilizer, and air.

An artificial neural network-particle swarm optimization (ANN-PSO) approach to predict the aeration efficiency of venturi aeration system

In the present study, the artificial neural network-particle swarm optimization (ANN-PSO) approach was adopted for optimizing the standard aeration efficiency (SAE) of the venturi aeration system. Standard aeration efficiency (SAE) is the main parameter which is used to evaluate the effectiveness of an aerator. Aeration test were carried out in a 220 litre capacity tank to find out the impacts of operating variables on SAE using venturi aeration system. The operating variable includes throat length (L), hole diameter (d), and flow rate (Q), however, the output variable was selected as SAE to determine the model response. A 3-6-1 ANN model was developed for predicting the SAE of venturi aeration system, and the PSO algorithm was applied to obtain the optimum values of the operating variables of venturi aeration system. The effectiveness of the ANN modelling was evaluated using the coefficient of determination (R2), root mean square error (RMSE), and mean absolute error (MAE) from the test data and forecasted data. The most appropriate optimal values of the operating variables i.e., L, d, and Q were found to be 1.82 mm, 2.00 mm, and 0.31 l/s, respectively. The optimal SAE under ideal working conditions was optimized to be 0.8333 kg O2/kWh. The applied ANN-PSO approaches can predict the optimal values satisfactorily with a maximum of 7.73% difference with the experimental values. Therefore, the suitability of the ANN-PSO approach can be useful to predict the aeration efficiency of venturi aeration system.

An experimental study of venturi aeration system

Aeration with a venturi aerator is efficient method to increase the dissolved oxygen (DO) concentration in water sources like rivers, waterways, ponds and water treatment plants. It is employed in aquatic animals' respiration and other biological processes as well as the removal of dissolved gases, dissolved metals, and volatile organic chemicals (VOC) in water. Aeration system efficiency is a crucial design factor, as aeration systems often account for the most energy draw and consumption. The study aims to evaluate the standard oxygen transfer rate (SOTR), standard aeration efficiency (SAE), volumetric oxygen transfer coefficient (KLa20) of venturi aeration system, air velocity and airflow rates at different water levels of the tank. Venturi aerator designed by Green Pumps and Equipments was used for experimentation. Air entrainment hole was fixed to 25 mm and 66 mm water inlet diameter. It was discovered that the rate of air flow rises as the tank's water level falls. The KLa20 was achieved at a rate of 2.58 h−1, SOTR at a rate of 0.323191 kgO2/hr, and SAE at a rate of 0.293594 kgO2/KWh, respectively. The findings suggest that venturi aeration may have a considerable impact on air entrainment and aeration efficiency. As a result, the venturi aeration system can be employed as an efficient aerator in aeration procedures.

EFEKTIVITAS WADAH BUNDAR BERARUS TERHADAP PENINGKATAN RESPON IMUN BENIH IKAN MAS (Cyprinus carpio) YANG DIINFEKSI OLEH BAKTERI Aeromonas hydrophila

This research focused on determining the best survival performance of carp (C. carpio) fingerlings in circular containers combined with venturi aerators to generate water current, then challenged by A. hydrophila. The research used an experimental method of Completely Randomized Design (CRD) with four treatments and four replications. The treatment used was the use of venturi aerators on circular containers: without water current as a control (A), with a water current of 0.06 ms?¹ (B), 0.1 ms?¹ (C), and 0.14 ms?¹ (D). The study was initiated by rearing 5-7 cm fish fingerlings for 40 days and followed by a challenge test for 14 days. Carp fingerlings were challenged by A. hydrophila intraperitoneally at a density of 10? CFU ml?¹. Each tank consists of 15 fingerlings. Parameters observed included survival rate, the number of red blood cells and white blood cells, macroscopic symptoms, and water quality. The results showed survival rate in treatment (D) was the best (water current of 0.14 ms?¹), 98% before the challenge period and 95% after the challenge period. In addition, it can increase the hematological parameters as seen from the increase in the number of red and white blood cells after the challenge test, from 1.043 x 106 cells mm³?¹ to 2.36 x 106 cells mm³?¹ and 2.7 x 104 cells mm³?¹ to 9.3 x 104 cells mm³?¹ respectively. And it shows an increased immune response as seen from the recovery acceleration in macroscopic symptoms on the seventh day after A. hydrophila injection. While water quality did not differ between control and treatments.Keywords : current circular generating tank, carp fingerling, Aeromonas hydrophila, immune response

Experimental study on design and operational performance of solar-powered venturi aeration system developed for aquaculture – A semi-floating prototype

Venturi-type injectors have been used usually due to the practical use and modular design that allows for quick configuration, ready-to-use, and low-cost solutions in the last years. This study aims to design a solar-powered venturi aeration system (SVAS) and determine its flow characteristics, standard, and real-time operational performance parameters. SVAS has a design providing the maximum vacuum and air velocity at air inlets and allowing for all technical measurements. Moreover, a solar-powered experimental apparatus having a weather station, a pool station, and a data logger station was constructed. Experiments were carried out using a plastic pool with a capacity of 4000 L, a diameter of 3 m and a depth of 0.75 m, four venturi injectors, and a submersible pump of 0.3 kW operated at the constant water flow regime of 4.1 m3 h-1. According to flow tests, the oxygen mass flow rates ranged from 2.77 to 2.84 kg h−1. The specific energy consumption values are 263.2 kJ per cubic meter for water flow and 380 kJ per kg for oxygen transfer.Standard performance experiments were repeated four times. The maximum overall oxygen mass transfer coefficient obtained during the experiments was 5.58 h−1. The maximum values of standard oxygen transfer rate (SOTR), standard aeration efficiency (SAE), and standard oxygen transfer efficiency (SOTE) were 0.206 kgO2 h−1, 0.681 kgO2 kWh−1, and 7.32%, respectively. The pool conditions were simulated using de-oxygenation and mixing systems to determine the operational performance. For simulation experiments, six procedures and two processes were applied. Throughout operational experiments of four days, real-time dissolved oxygen levels fluctuated between 1.05 mg L−1 and 6.65 mg L−1. The maximum performance values were 0.143 kgO2 h−1 for the actual oxygen-transfer rate, 0.474 kgO2 kWh−1 for aeration efficiency, and 5.1% for oxygen transfer efficiency.

Performance Test of Venturi Aerators for Subsurface Drip Irrigation

Performance Test of Venturi Aerators for Subsurface Drip Irrigation

Effect of Varying Discharge Rate on the Performance of Venturi Aeration System

Venturi aeration is an economical method to increase dissolved oxygen (DO) in aquatic water bodies. For this paper, aeration experiments were conducted with 200 litres volume of the water tank, having dimensions of 90 cm length, 55 cm breadth, and 45 cm depth. The venturi was fabricated keeping the dimension of converging and diverging length same, i.e., 76 mm and throat length of 100 mm. The venturi aeration system was operated with six different discharge rates (0.00025, 0.00033, 0.00042, 0.00050, 0.00058 and 0.00067 m3/s). This work is intended to estimate the effect of varying discharges on the efficiency of venturi aerator in terms of standard oxygen transfer rate (SOTR) and standard aeration efficiency (SAE). The experiment shows promising results in terms of SOTR and SAE at moderate to high discharge rates, on the other hand a declining trend is seen when the liquid discharge rate is too high. The oxygen transfer rate was found to have a good relationship with the discharge rate.

Field trials to determine the efficacy of aerators to mitigate hypoxia in inland waterways

Following a series of fish deaths in the lower Darling River in the austral summer of 2018–19, several field trials were undertaken over two summers to determine the efficacy of various aerators to mitigate the effects of hypoxia to prevent fish deaths. The aerators evaluated included: low-powered, solar bubble-plume diffusers; high-flow, single-port Venturi systems; pontoon-mounted multi-port Venturi systems; and an ultra-fine bubble generator. The effectiveness of bubble diffusers appears related to their power, the number of units used and their running time. Pontoon-mounted multi-port Venturi aerators and high-flow, single-port Venturi aerators were much more successful in maintaining oxygen levels and may have prevented fish deaths in the Darling River in early 2019. However, the Venturi aerators were expensive to run, consuming hundreds to thousands of litres of diesel fuel per week. Trial of an ultra-fine oxygen bubble pump showed promise because it supersaturated the water with dissolved oxygen while not elevating total gas pressure to levels that would cause gas-bubble trauma in fish. Although aerators may play a role in emergency responses to hypoxic fish deaths, they have limitations regarding their area of influence (at best thousands of square metres) and their cost to deploy and operate.

Performance evaluation of venturi aeration system

The venturi aeration is an effective practice to increase the dissolved oxygen accessibility in the water bodies. This study aims to optimize the various geometrical parameters of the venturi aeration system. A non-dimensional technique was applied to find the optimum performance of various geometric parameters i.e. throat lengths (tl), number of air holes (N), and converging and diverging angles (α and β). These experiments have been carried out using 1124 L capacity of tank having dimensions of 105 cm long, 105 cm wide and 102 cm deep. The experiments were conducted at a constant flow velocity of water (1.096 m/s) with varying throat length (tl = 20–100 mm keeping 20 mm as interval between two consecutive length), number of air holes (N = 1–17 at an equal hole to hole distance of 5 mm between them), and converging and diverging angles (α and β = 10°, 15°, 20° and 25°). Multiple non-linear regression equations were also developed from the linear relation with the dependent variable (Non-dimensional form of standard aeration efficiency, NDSAE) and independent variables (tl and N). With the geometrically optimized venturi aerator the optimum performance was found for tl =100 mm, N = 17, and α and β = 15°. The maximum value of standard oxygen transfer rate (SOTR) and standard aeration efficiency (SAE) obtained was 0.0216 kgO2/h and 0.611 kgO2/kWh respectively. From the non-dimensional study, it was found that the NDSAE is the function Reynolds number (Re) and Froude number (Fr). The simulation equations were developed on the basis of Re and Fr for NDSAE, and subjected to 7.378 × 10−6 <Re < 3.689 × 10-5 and 0.163 <Fr < 0.817, respectively.

Determination of Standard Oxygen Transfer Rate in Venturi Aeration System

The oxygen transfer is the process of atmospheric oxygen diffusion from a gas stage to a liquid stage in the form of dissolved oxygen (DO). The previous research works have successfully proven that the DO concentration level effortlessly rises by adopting a venturi as an aeration method in aquatic bodies. Present experimental study was conducted on laboratory scale aeration tank with two different sizes of venturi (40 and 80 mm throat length). The objective of the current study was to determine the oxygen transfer coefficient at different discharge rates through venturi aeration system. The system was operated with three different discharges of 0.50, 0.58 and 0.67 liter/second (l/s) to circulate 200 liter volume of water, was aimed for circulation in a closed loop system. During the operations, water moves through the inlet section into the contract section of the venturi, which increases the rate of water flow and reduces the pressure as per the Bernoulli’s theorem. In order to study the oxygen transfer coefficient at varying discharge, the system worked by a single hole and accordingly applied to the larger number of holes for both the throat lengths of venturi. It was observed that the oxygen transfer coefficient proportionally linked to the DO diffusion with increasing rate of discharge. The oxygen transfer coefficient found to be increased by 31% and 55% at 40 and 80 mm throat length respectively, with increasing the discharge. The rate of DO diffusion found higher causes more surface area of contact between air and water through maximum air entrainment. Moreover aeration efficiency also increases with the rate of increasing discharge for the maximum size of throat length. The maximum SOTR values was obtained 0.0035, 0.0041, and 0.0050 kgO2/h at varying discharge of 0.50, 0.58 and 0.67 l/s respectively for 40 mm throat length. For the 80 mm throat length, the SOTR values varies from 0.0042, 0.0062 and 0.0091 kgO2/h at increasing discharge of 0.50, 0.58 and 0.67 l/s respectively with increasing number of holes.

Effect of Stocking Density on Survival Rate and Growth of Tilapia (Oreochromis niloticus Linnaeus, 1758) in Round Container with Water Current Combined with Venturi Aeration System

The aim of this research is determine of the optimal stocking density for survival rate and growth of tilapia in round container with water current combined with venturi aeration system. Place of research in the Aquaculture Laboratory, Building 4 Faculty of Fisheries and Marine Sciences, Universitas Padjadjaran. The research method used is experimentally with using the Completely Randomized Design (CRD) method which consists of three treatments, there are 15 fish, 22 fish, 30 fish, with five replications. Using water of 15 L per container. The fish used are 3-5 cm tilapia fingerlings. Fish were maintained for 40 days. The feed given is 5% from biomass which is adjusted every 10 days. The parameters observed were survival rate (SR) and observed everyday, daily grow rate (DGR), feed conversion ratio (FCR) and feed efficiency were observed every 10 days. The result was significantly different from the analysis of variance (ANOVA) with the F test at 95% confidence intervals and then using Duncan test to compare the rates between treatments. The results showed that the best treatment was stocking density of 15 fish / 15 L in round container with current combined with venturi aeration system with survival rate of 78.67 ±10.95%, daily grow rate of 3.68 ± 0.12%, feed conversion ratio of 1.19 ± 0.13 and feed efficiency of 85.01 ± 8.97%.

An experimental study to evaluate the efficacy of air entrainment holes on the throat of a venturi aeration system

Dissolved oxygen (DO) is a vital nutrient for the health of water bodies such as streams, rivers, and ponds, as it is used in respiration and other biological activity of aquatic animals. Natural replenishment of oxygen through photosynthesis in aquatic bodies is insufficient to meet the high requirements for an intensive aquaculture system, which compels farmers to use aeration systems to supplement the natural process of DO accumulation. When the demand for oxygen (KgO2/h) is lower, venturi aerators may be more effective than other aerators. The venturi device is an aeration system which is highly efficient in providing an adequate supply of DO, and is flexible in nature and easy to operate. To evaluate the efficacy of air entrainment holes on the throat of a venturi, aeration experiments were conducted for different throat lengths (Lt) of 20, 40, 60, 80 and 100 mm, varying the number of air holes according to throat length while maintaining a constant air hole diameter of 2 mm. Aeration efficiency was found to increase with an increasing number of air holes. The highest oxygen transfer coefficients for throat lengths of 20, 40, 60, 80 and 100 mm were 0.497 h−1, 0.756 h−1, 1.045 h−1, 0.627 h−1 and 1.072 h−1, respectively, with the maximum number of air holes (NH). The maximum standard aeration efficiency was found to be 1.25 × 10−2 kgO2/kWh for a throat length of 100 mm with the maximum number of air holes (NH17). Hence, the physical properties of throat length, number of air holes, and distribution of air holes on the throat section were proven to be key factors controlling the performance of the venturi aeration system.

Design Characteristics of Venturi Aeration System

The crucial phenomenon of air and water mixing together is called aeration. The venturi aeration is mainly responsible to transfer air directly through the atmosphere into the flowing water attribute to its simplicity and reliability. A water tank of 1000 litres capacity having dimensions 100 × 100 × 100 cm3 was used to conduct the experiments for aeration for the purpose of studying the characteristics of venturi aeration system design. Venturi having three significant sections i.e. inlet, constricted and outlet section, used as a differential pressure producer basis on Bernoulli’s theorem where the middle section of the venturi often called as constricted section is responsible for the energy conversion, which transfers oxygen by aspirating air into the constricted section and producing interfacial area between the air and water. On the basis of dimensional analysis, non-dimensional numbers associated with geometric, dynamic and process parameters were analysed. The non-dimensional geometric parameters like throat length (tl), hole distance from beginning of throat (hd), throat hole diameter (th) were optimized and additionally conducted at constant flow rate (vw=0.396 m/s). To assess the performance of designed venturi, the selection of different tl as 20, 40, 60, 80 and 100 mm, with varying number of holes inserted, depends on the tl and keeping th constant at 2 mm. The SAE values were initiated more with increasing tl. The maximum SAE values was obtained with maximum number of holes open as 6.200 × 10-3 kg O2/kWh for 100 mm tl. A constant flow rate was maintained to construct the equations for the prediction of venturi aeration system’s characteristics via simulations. For the purpose of simulations different geometric conditions of the venturi design system were considered. The simulation equations developed for tl based on the Re and Fr are subjected to 12.655 × 10-5 &gt; Re &gt; 2.531 × 10-5 and 1.251 &lt; Fr &lt; 6.256, respectively. It was also concluded that from the non-dimensional study, the simulation equation developed for NDSAE based on the tl be valid and subjected to 3.890× 103&lt; NDSAE &lt;0.215× 103.

A comparison of a blower and a Venturi aeration system in a submerged membrane bioreactor

A comparison of a blower and a Venturi aeration system in a submerged membrane bioreactor

Aeration efficiency influenced by venturi aerator arrangement, liquid flow rate and depth of diffusing pipes

The effect of aerator module configuration, liquid flow rate and diffuser submergence on oxygen transfer efficiency was examined in a surface aeration system with venturi injectors using the clean water test. Six venturi aerator modules were evaluated and the results indicated that better aeration efficiencies could be achieved by simply changing the way the venturi aerators were connected. Among all the configurations examined (modules a–f), two and three aerators connected in parallel (modules d, e and f) were able to bring more oxygen into water than the others. An increase in liquid flow rate led to an enhancement of the oxygen transfer coefficients, but the improvement was reduced if the liquid flow rate was too high. The oxygen transfer coefficient was found to have a relationship with the depth of diffusing pipes (surface aeration depth) for the surface aeration system and an optimal depth of around 40 cm was obtained from this study.

Flotation de-inking of 50% ONP/50% OMG recovered papers mixtures using nonionic surfactant, soap, and surfactant/soap blends

A laboratory flotation column equipped with Venturi aerators and an adjustable froth removal system was used to study the effect of calcium soap and a mixture of calcium soap/alkyl phenol ethoxylate surfactant on ink and fibres transfer during flotation de-inking of a 50% old newprint (ONP) / 50% old magazines (OMG) recovered papers mixture. Mass transport phenomena determining the yield of the flotation process were interpreted using model equations describing particle removal in terms of flotation, entrainment, and drainage in the froth. A decrease in the ink and mineral fillers flotation rate constant, drainage through the froth, and in fibre entrainment was observed when increasing the surfactant concentration. These trends were consistent with the typical dispersing action of the studied nonionic surfactant. An opposite effect on ink and fillers was observed when using calcium soap alone, and the increase in the flotation rate constant and drainage through the froth were consistent with the collecting and defoaming action of the calcium soap. Moreover, fibre entrainment decreased when increasing the soap concentration. The study of the surfactant/soap mixture highlighted the absence of synergy between the calcium soap and the surfactant.

Effect of air inlet hole diameter of venturi tube on air injection rate

The oxygen concentration in water is a prime indicator of the water quality for human use as well as for the aquatic biota. The physical process of oxygen transfer or oxygen absorption from the atmosphere acts to replenish the used oxygen. This process is termed re-aeration or aeration. Venturi aeration is a method of aeration that has become popular in recent years. A venturi tube allows air bubbles to be inserted into flowing water from air inlet holes and so increases oxygen levels in the water. In the present study, a series of experiments on venturi tubes were conducted to investigate the effect of air inlet hole diameter on air injection. It was observed from the results that air inlet hole diameter on venturi tube played a significant role in air injection and there was an optimal diameter that maximizes air injection. Moreover, a multiple non-linear regression equation was obtained for venturi tubes relating air flow and water flow to Reynolds number, inlet diameter and air inlet hole diameter.

An experimental study of nozzle diameters, aeration depths and angles on standard aeration efficiency (SAE) in a venturi aerator

A 1.1 kW submersible water pump with a venturi air injector was used in this study to examine the effects of three factors including nozzle diameter (14, 17 and 20 mm), aeration depth (20, 40 and 60 cm), and aeration angle (0, 22.5 and 45°) on standard aeration efficiency (SAE). For maximum air entrainment, HT / DT ratio and DT / DN ratio were equal to zero and 2, respectively. Among the first factor experiments, 14 mm nozzle diameter showed the highest SAE value (P&amp;lt;0.05). Although, 60 cm aeration depth and 45° aeration angle had more SAE value among other depths and angles, but there was not a significant difference (P&amp;gt;0.05) in each aeration depths and angles. Only, the determination coefficient for effect of nozzle diameters on SAE value showed a good result (R2= 0.958). The greatest oxygen transfer efficiency in this study has been achieved with using 14 mm nozzle size, 60 cm depth of aeration, and 45° angle of venturi tube in water aeration that was 1.166 kgO2/ kWh. Venturi aerators are very inexpensive in comparison with other aerators and have some other advantages that can be considered as one of the best devices for water aeration.