scholarly journals Characterization of the performance of venturi-based aeration devices for use in wastewater treatment in low-resource settings

Water SA ◽  
2019 ◽  
Vol 45 (2 April) ◽  
Author(s):  
Jean-David Therrien ◽  
Peter A Vanrolleghem ◽  
Caetano C Dorea
Keyword(s):  
Wastewater Treatment ◽  
Flow Rate ◽  
Tap Water ◽  
Water Flow Rate ◽  
Sodium Dodecyl ◽  
Low Flow ◽  
Low Resource Settings ◽  
Low Resource ◽  
Tds Concentration ◽  
The Impact

Low-cost aerators relying on the venturi principle to entrain air into flowing water have the notable advantage of contributing both to water mixing and oxygen transfer, making them attractive for wastewater treatment in low-resource settings. This study aimed to characterize the performance of such aerators by describing the impact of different design characteristics, including water flow rate, the number of nozzles used, and the nozzle depth. The study also explored the effect on aeration performance of temperature, total dissolved solids (TDS) concentration, and addition of the archetypal surfactant sodium dodecyl sulphate (SDS). Tests were conducted in a 200 L reactor with 2, 3 or 4 nozzles, at depths of 20, 40 or 60 cm, while circulating water through the aeration device at a rate of 400, 600 or 800 L/h. The configuration that yielded the highest mass transfer coefficient (KLa20 of 20.8 h-1) had both the highest flow rate (800 L/h) and the smallest number of nozzles (2). Nozzle depth had no detectable effect on performance. The configuration with the highest standard aeration efficiency (SAE) had a low flow rate (400 L/h) and 4 nozzles. The effect of TDS concentration was not detected in the concentration range typical of domestic wastewater (300–1 250 mg/L). The effect of temperature on KLa followed a first-order exponential curve, as reported in the literature (θ = 1.02). Addition of SDS was found to increase the KLa20 of the tested aerator design by up to 60% of its value in tap water, in contrast to results from literature. The performance data obtained herein was compared to other types of aerators. Though venturi nozzles were found to be less efficient than other available technologies, it is proposed that using plunging rather than immersed venturi nozzles could increase performance to an attractive level for low-resource applications.

scholarly journals ANALISIS EKSPERIMEN LAJU ALIRAN VOLUME AIR TERHADAP TEMPERATUR AIR PANAS PADA HEAT RECOVERY SISTEM AC JENIS WATER CHILLER

2011 ◽  
Vol 1 (2) ◽  
Author(s):  
I Made Rasta
Keyword(s):  
Water Temperature ◽  
Water Flow ◽  
Flow Rate ◽  
Heat Recovery ◽  
Tap Water ◽  
Water Flow Rate ◽  
Maximum Heat ◽  
Heating Water ◽  
Compressor Work ◽  
Heat Released

Refrigerant in refrigeration machines will absorb heat from a room space and released the heat to the environment. The heat balancing in the system is heat released from condenser equal with heat absorbed from room space added by the heat equivalent from compressor work. Based on this heat cycle, the writer try to conduct research on using this heat rejection from condenser to heating tap water, focusing on water flow rate increased from 0.5 liter/min to 2.5 liter/min. From experiment and analysis result obtained that the maximum heat water temperature which can be reached is 47.5°C in 0.5 liter/min, with the equipment specifications are 2 HP- split air conditioning and the tank volume is 75 liters. The additional result is heating water temperature is fallen when the water flow rate is increased.

scholarly journals Analysis of the impact of water flow rate of selected Turbo type nozzle on the distribution of sprinkling intensity

2019 ◽  
Author(s):  
Jerzy Gałaj ◽  
Tomasz Drzymała ◽  
Adam Pełech ◽  
Ritoldas Šukys
Keyword(s):  
Water Flow ◽  
Flow Rate ◽  
Water Flow Rate ◽  
Fire Service ◽  
Graphical Form ◽  
Operating Pressure ◽  
Nozzle Outlet ◽  
Maximum Value ◽  
Trade Name ◽  
The Impact

In the work, the distribution of the sprinkling intensity for a selected nozzle with the trade name Turbomatic was tested and analysed. The device meets Polish legal requirements, has a CNBOP approval certificate and is classified as a TURBO type nozzle. The research was aimed at extending the knowledge about spray jets generated by nozzles, in particular analysing the impact of water flow rate on selected parameters of the sprinkling surface. These dependencies can in practice save water and more effectively extinguish during rescue and firefighting operations. The tests were carried out in the laboratory of the Rescue and Fire-Fighting Equipment of the Main School of Fire Service partly in field conditions. Two different water flow rates of 200 and 400 dm3/min were assumed at a set operating pressure at the nozzle outlet of 0.4 MPa. The position and methodology of conducted research was discussed. Selected results were presented in tabular and graphical form. Their analysis was carried out and conclusions were made based on it. They shows that the flow rate of the nozzle has a significant impact on sprinkling surface parameters such as: its size and shape, range projection, maximum value of sprinkling intensity, location of maximum, etc.

scholarly journals Performance Enhancement of Split Air Conditioner During Evaporative Cooling Application

2021 ◽  
Vol 86 (2) ◽  
pp. 147-156
Author(s):  
Rahmat Iman Mainil ◽  
Ahmad Wisnu Sulaiman ◽  
Afdhal Kurniawan Mainil ◽  
Azridjal Aziz
Keyword(s):  
Air Temperature ◽  
Flow Rate ◽  
Air Conditioning ◽  
Evaporative Cooling ◽  
Water Flow Rate ◽  
Coefficient Of Performance ◽  
Air Conditioner ◽  
Discharge Water ◽  
Cooling Module ◽  
The Impact

The increase of condenser temperature and pressure in air-conditioning leads to decreased cooling capacity and the increase of power consumption. Evaporative cooling could improve the thermal performance of the system. In this study, the evaporative cooling module was installed before the condenser to reduce the inlet air temperature to the condenser unit. The impact of condenser air temperature on the air conditioning system's overall performance was determined by varying the cooling pad discharge water flowrate of 880, 1040, and 1200 mL/min. The cooling load of 2000 W was employed in this experiment. The obtained results were compared with the air conditioning without an evaporative cooling module. It shows that the coefficient of performance (COP) increases with the increase of discharge water flow rate. The highest COP obtained is 7.09 at the flow rate of 1200 mL/min. The compressor work reduces about 6.57 % as compared with the air conditioner without evaporative cooling application. Besides, the COP increases by 12. 95 % at the highest flow rate.

THE IMPACT OF CLIMATE PARAMETERS ON THE SURFACE OF BUILDINGS’ WALLS

2014 ◽  
Vol 1 (1) ◽  
Author(s):  
Ruta Miniotaite
Keyword(s):  
Moisture Content ◽  
Flow Rate ◽  
Paint Film ◽  
Water Flow Rate ◽  
Physical And Mechanical Properties ◽  
High Water ◽  
Vapor Flow ◽  
High Moisture Content ◽  
High Moisture ◽  
The Impact

The durability of surface layers of enclosures (outside walls of buildings) is highly influenced by stresses occurring in the plane of contact between finishing materials and that of the enclosure. Damage to external walls depends on a high moisture content, which in turn depends on high water absorption during driving rains. One example of such damage is damage due to direct water penetration in homogeneous walls. The other negative effects of a high moisture content are impaired heat insulation and accelerated degradation. This article investigates the external layer of walls and the durability of different paints. In case of bi-laminar system “paint film-the wall being painted” two opposite processes take place: the water flow rate from the outside towards the wall, and the water vapor flow rate of the wall to the outside. The optimum selection of paint is necessary. An investigation of the durability of wall surface paints in a climatic chamber is instructive only after intermediate investigations and measurements of the substrates’ physical and mechanical properties that aid in predetermining durability. The influence of moisture deformations upon degradation of coatings depends on the porosity of surface materials being coated, and on the origin and macrostructure of the coating.

scholarly journals The effect of the mixing of water from different sources in the water supply system on tap water quality – a full-scale technical investigation case study

2018 ◽  
Vol 19 (1) ◽  
pp. 303-312
Author(s):  
A. Szuster-Janiaczyk ◽  
J. Bylka
Keyword(s):  
Water Quality ◽  
Distribution System ◽  
Water Distribution ◽  
Tap Water ◽  
Low Flow ◽  
Quality Of Water ◽  
Tap Water Quality ◽  
The Impact ◽  
Different Sources

Abstract The paper presents a detailed analysis of the quality of water pumped into a network and sampled from 39 monitoring points located on the network. A difference in the quality of water sampled from two different sources was demonstrated, as well as the impact of the mixing of the two waters in the water distribution system (WDS) on tap water quality. A mathematical model was used to identify the zones of water mixing and the areas of unfavourable hydraulic conditions (low flow rates and long retention times).

scholarly journals Corrosion Localization Analysis in T-Shape Pipe Junction Based on Multielectrode Current Measurements

2020 ◽  
Vol 2020 ◽  
pp. 1-8
Author(s):  
Georgii S. Vasyliev
Keyword(s):  
Water Flow ◽  
Flow Rate ◽  
Water Distribution ◽  
Tap Water ◽  
Water Flow Rate ◽  
Galvanic Current ◽  
Steel Electrode ◽  
Steel Pipes ◽  
Inner Surface ◽  
Localization Analysis

The water flow rate and galvanic current distribution in the T-shape junction of steel pipes were investigated using the multielectrode array approach. The inner surface of polypropylene pipes junction was divided into 15 separate sections, and a steel plate was placed in every section to form a single inner surface. The tap water flow rate varied between 0.28 and 0.57 m/s, and the water distribution in the junction was between 5 : 1 and 1 : 5. The galvanic current flowing through each steel electrode was mapped on the 3D model of the T-shape junction. Two differential aeration pairs were found with high anodic current densities.

scholarly journals A Non-Intrusive Signal-Based Fault Diagnosis Method for Proton Exchange Membrane Water Electrolyzer Using Empirical Mode Decomposition

Energies ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4458
Author(s):  
Farid Aubras ◽  
Cedric Damour ◽  
Michel Benne ◽  
Sebastien Boulevard ◽  
Miloud Bessafi ◽  
...  
Keyword(s):  
Fault Diagnosis ◽  
Empirical Mode Decomposition ◽  
Flow Rate ◽  
Proton Exchange Membrane ◽  
Water Flow Rate ◽  
Proton Exchange ◽  
Rate Variation ◽  
Mode Decomposition ◽  
Exchange Membrane ◽  
The Impact

This work focuses on a signal-based diagnosis approach dedicated to proton exchange membrane water electrolyzer (PEM WE) anode pump fault. The PEM WE cell measurements are performed with an experimental test bench to highlight the impact of water flow rate in the anode compartment. This approach is non-intrusive, and it can detect anode flow rate variation during the electrolysis and is designed to fulfill online diagnosis requirements. Contrary to electrochemical impedance spectroscopy-based approaches (EIS), this method stands out from existing procedures as a result of its few requirements, excluding any signal with perturbing amplitude. Therefore, the electrolyzer remains continuously available, even while the analysis is performed. The empirical mode decomposition (EMD) is used to decompose the signal variation into a sum of amplitude modulation and frequency modulation (AM-FM) components, called intrinsic mode functions (IMFs). In this work, the PEM WE current signal is decomposed into several IMFs using EMD. Then, the energetic contribution of each IMF is calculated. Experimental results exhibited that the energetic contribution of IMFs can be used as relevant criteria for fault diagnosis in PEM WE systems. This process only requires monitoring of the PEM WE current and has a low computational cost, which is a significant economic and technical advantage.

scholarly journals TITANIUM DIOXIDE SUSPENSION PHOTOCATALYSIS IN A TUBULAR PHOTOREACTOR AND TITANIUM DIOXIDE REUSE ON THE REMOVAL OF PHENOL

2018 ◽  
Vol 4 (2) ◽  
Author(s):  
Dhanus Suryaman
Keyword(s):  
Titanium Dioxide ◽  
Flow Rate ◽  
Tap Water ◽  
Deionized Water ◽  
Degradation Efficiency ◽  
Low Flow ◽  
Single Pass ◽  
Flow Treatment ◽  
Optimum Flow ◽  
Dioxide Suspension

We studied flow rate, electrolytes effects, titanium dioxide separation and reuse and sunlight application on photocatalysis in a tubular photoreactor integrated with the titanium dioxide separation/reuse. The circulative flow treatment was preferred over the single pass treatment. Phenol and TOC removals in tap and deionized waters were a maximum at the circulative flow rate of 600 ml min-1 and the transmittance of 0.26%. At low flow rate, titanium dioxide particles were sedimented in tap water, but those were perfectly suspended in deionized water. The titanium dioxide slurry was sedimented spontaneously by standing and was repeatedly reused without decreasing the degradation efficiency.  Keywords : Photocatalytic, Optimum flow, Electrolytes, Separation, Solra 

scholarly journals The impact of antenatal syphilis point of care testing on pregnancy outcomes: A systematic review

PLoS ONE ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. e0247649
Author(s):  
Dana Brandenburger ◽  
Elena Ambrosino
Keyword(s):  
Pregnancy Outcomes ◽  
Clinical Studies ◽  
Point Of Care ◽  
Adverse Pregnancy Outcomes ◽  
Low Resource Settings ◽  
Low Resource ◽  
Laboratory Screening ◽  
Modelling Studies ◽  
Adverse Pregnancy ◽  
The Impact

Background Mother-to-child transmission of syphilis remains a leading cause of neonatal death and stillbirth, disproportionally affecting women in low-resource settings where syphilis prevalence rates are high and testing rates low. Recently developed syphilis point-of-care tests (POCTs) are promising alternatives to conventional laboratory screening in low-resource settings as they do not require a laboratory setting, intensive technical training and yield results in 10–15 minutes thereby enabling both diagnosis and treatment in a single visit. Aim of this review was to provide clarity on the benefits of different POCTs and assess whether the implementation of syphilis POCTs is associated with decreased numbers of syphilis-related adverse pregnancy outcomes. Methods Following the PRISMA guidelines, three electronic databases (PubMed, Medline (Ovid), Cochrane) were systematically searched for intervention studies and cost-effectiveness analyses investigating the association between antenatal syphilis POCT and pregnancy outcomes such as congenital syphilis, low birth weight, prematurity, miscarriage, stillbirth as well as perinatal, fetal or infant death. Results Nine out of 278 initially identified articles were included, consisting of two clinical studies and seven modelling studies. Studies compared the effect on pregnancy outcomes of treponemal POCT, non-treponemal POCT and dual POCT to laboratory screening and no screening program. Based on the clinical studies, significantly higher testing and treatment rates, as well as a significant reduction (93%) in adverse pregnancy outcomes was reported for treponemal POCT compared to laboratory screening. Compared to no screening and laboratory screening, modelling studies assumed higher treatment rates for POCT and predicted the most prevented adverse pregnancy outcomes for treponemal POCT, followed by a dual treponemal and non-treponemal POCT strategy. Conclusion Implementation of treponemal POCT in low-resource settings increases syphilis testing and treatment rates and prevents the most syphilis-related adverse pregnancy outcomes compared to no screening, laboratory screening, non-treponemal POCT and dual POCT. Regarding the benefits of dual POCT, more research is needed. Overall, this review provides evidence on the contribution of treponemal POCT to healthier pregnancies and contributes greater clarity on the impact of diverse diagnostic methods available for the detection of syphilis.

201 Impact of Water Flow Rate on Finishing Pig Performance

2021 ◽  
Vol 99 (Supplement_1) ◽  
pp. 68-69
Author(s):  
Hannah E Miller ◽  
Jorge Y Perez-Palencia ◽  
Crystal L Levesque ◽  
Robert C Thaler
Keyword(s):  
Body Weight ◽  
Water Flow ◽  
Flow Rate ◽  
Water Flow Rate ◽  
Low Flow ◽  
Flow Rates ◽  
Finishing Pig ◽  
Daily Water ◽  
Pig Performance ◽  
High Treatment

Abstract A survey of South Dakota pork producers in 2019 demonstrated that water flow rate for nipple drinkers was highly variable among barns. Sixty-eight percent had water flow rates above the recommended rate of 500–1,000 mL/min (NSNG, 2010). The objective of this study was to determine the impact of water flow rate on finishing pig performance during the summer months. A total of 396 mixed-sex pigs, in two groups, were utilized in a 77-day trial (34.55 to103.8 kg BW) with 6 pigs/pen. Pens were assigned to one of three water flow rates (high, medium, low) based on the 3-hole diameters of the commercial water nipples used in the facility (2.0, 1.0, 0.80 mm; n = 22 pens/treatment). Daily water usage was recorded for each treatment along with room temperature, outside temperature, and relative humidity. Individual pen water flow rate was recorded every two weeks. At every diet phase change (26± 2.6 days), feed disappearance and individual pig body weight were recorded. Water flow rates averaged 1846±188, 906±214, 508±100 mL/min for high, medium, and low flow rates, respectively. Daily water disappearance for high, medium, and low treatments were 6.8, 2.3, 1.7±3.2 liters/pig, respectively. Final body weight (BW; 103.8±7.4 kg) did not differ. Daily gain (ADG) from 34.5±4.5 to 55.5±4.6 kg BW was greatest (P < 0.05) for high treatment. Daily intake (ADFI) and gain:feed (G:F) from 55.5±4.6 to 79.1±5.3 kg BW were greatest (P < 0.05) for high treatment. Cumulative ADFI was 2.27, 2.18, 2.16±0.16 kg (P < 0.05) in high, medium, and low flow ranges, respectively. There was no differences in cumulative ADG or G:F. Water flow rate had a significant impact on ADFI although there was minimal impact on gain and G:F. Water nipples should be regularly checked as part of normal barn maintenance to ensure adequate, but not excessive, water is available.

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