Performance Of Pond Research Articles

Effect of steel-wires and paraffin composite phase change materials on the heat exchange and exergetic performance of salt gradient solar pond

The addition of Phase Change Materials (PCM) to the salt gradient solar pond can significantly increase the heat capacity of the solar pond. Paraffin wax has a suitable range of phase transitions temperature and is feasible to be applied in solar pond. However, the poor thermal conductivity of paraffin is detrimental to thermal storage and release. In this study, the heat transfer behavior for the composite PCM of paraffin and steel wires has been studied firstly, the results shows that adding steel wires in paraffin improve the heat transfer performance obviously. With 10wt% adding percent, the maximum of heat transfer coefficient is 18.17 W/m2 °C−1 with increment of 18.84 % in melting process; and the maximum is 21.59 W/m2 °C−1 with increment of 20.88% during freezing process. Secondly, experiment study has been conducted in an experimental solar pond, with 20 PCM capsule tubes added, adding RT 50 and RT 60 made the day–night temperature differences 2.87 °C and 2.53 °C smaller than that of without any PCM conditions. In this study, adding RT 50 and RT 60 in solar pond achieve 9.34% and 14.13% exergy increments respectively. The study suggested that adding PCM to solar pond improves the quality of the heat energy of solar pond, and further extends the heat application scope of solar pond.

Investigation on the Effect of Nanoparticle Diameter and Concentration on the Performance of Nanofluid Solar Pond

The usage of brine water in a solar pond has triggered concern on its potential to pollute surrounding land ecosystems. Thus, non-toxic, non-polluting nanofluid is proposed to replace brine water in a solar pond. No study on it has been reported. This study is therefore conducted to evaluate the performance of a density gradient nanofluid solar pond. An experimental test rig is built to conduct this evaluation. The nanoparticle used in this study is the widely available non-toxic silicon oxide (SiO2). The effect of nanoparticle diameter and concentration on the solar pond performance is evaluated. The results firmly indicate the potential of SiO2 nanofluid in replacing the brine water. In addition, it was found that both nanoparticle diameter and concentration affect the thermal storage performance.

Hydrologic processes regulate nutrient retention in stormwater detention ponds

Managed stormwater ponds are abundant in urban landscapes in much of the world, performing vital but under-studied functions for attenuation of urban runoff and nutrient pollution. Water quality improvements are widely assumed to arise from settling of nutrients and other contaminants bound to particulates, with less consideration of hydrological and biogeochemical processes. To inform improved management of ponds for nutrient retention, we studied three mature urban detention ponds in the Twin Cities, MN, USA using continuous monitoring of pond hydrology and concentrations of nitrogen and phosphorus, coupled with periodic measurement of physiochemical conditions in the ponds. Across the three sites, annual nutrient retention was high for both nitrogen (>58%) and phosphorus (>48%) despite expectations of poor performance for phosphorus due to old age and internal loading linked to hypolimnetic anoxia. Both annual and event-scale analyses suggested strong hydrologic controls on nutrient retention, with retention for individual storm events strongly regulated by antecedent pond storage capacity. Events with net nutrient export occurred primarily due to low volume retention rather than relatively high outflow concentrations. Together these results suggest that understanding and improving pond hydrologic function is crucial to improving managed stormwater pond performance for meeting downstream water quality goals.

Mechanism and Performance of Algal Pond Assisted Constructed Wetlands for Wastewater Polishing and Nutrient Recovery

Mechanism and Performance of Algal Pond Assisted Constructed Wetlands for Wastewater Polishing and Nutrient Recovery

Experimental investigation and optical visualization of a salt gradient solar pond integrated with PCM

The thermal performance of a solar pond is affected by the amount of heat lost to the ground through the lower convective zone (LCZ) in which the heat is stored. Studies are focused on decreasing the heat losses, to maximize the energy stored and guarantee the stability of the thermohaline system over time. Phase change materials (PCMs) can help to achieve all these goals, since they work as thermal energy storage (TES), exploiting the latent heat absorbed during the solid-liquid phase change. This paper presents an experimental application of PCMs in the LCZ of a small solar pond. The paraffin wax was enclosed in aluminium cylinders which have been arranged on the bottom. The temperature of the solution in deep is monitored both with and without the PCM. The stability of the pond is analyzed through a laser shadowgraph technique, to visualize the effect of the thermal convection on the interfaces. Results show that the LCZ of the solar pond with PCM is around 3 °C colder than the reference case after a 6-h heating period. The shadowgraph analysis proves that the thermal convection in the reference case is stronger and damage the interface until break. The monitoring of the solar pond with PCM shows an improved stability. • A solar pond integrated with PCM has been designed and built. • After the heating period, the system with PCM results colder in the LCZ. • PCM stabilized the LCZ-NCZ interfaces, as proved with the shadowgraph technique.

The effect of inlet width on the performance of sediment retention ponds in thermally induced flows

The effects of inlet configurations in sediment retention ponds (SRPs) have been widely investigated by several researchers. However, when considering temperature differentials in the ponds where density and buoyancy change with temperature the challenges associated with the proper inlet design still exist. The buoyancy forces are generated due to the differences in temperature potentially changing the flow in the pond by forming density currents. This study evaluates the effects of different inlet width ratios (IWRs) on the flow pattern and residence time in a sediment retention pond when inflow is colder or hotter than the water in the pond. In this research, an innovative experimental setup was used to create the temperature differentials. The results in the present study show that when the inflow temperature is colder than the water temperature in the pond, increasing the inlet width to the full pond width can effectively increase the pond’s performance. Likewise, when the inflow temperature is hotter than the water temperature in the pond decreasing the inlet width to 30% of the pond width can successfully improve the performance of the pond.

Investigating the simultaneous effect of effective parameters on the performance of salinity gradient solar ponds using Taguchi analysis: Determination of optimum thickness of the middle layer

The performance of solar ponds is influenced by a number of factors. The purpose of this study is to investigate the effect of the solar pond layers, as well as the climate conditions, on the temperature in the ponds bottom layer. Several analyzes were performed for this purpose employing the Taguchi method. The lower zone temperatures obtained were in a good agreement with the literature data, with an average deviation of 7.9%. The results showed that the thickness of the various layers of the solar pond, as well as the climate conditions, had a variety of effects on the operation of salinity gradient solar ponds. Furthermore, the optimum thickness of the solar pond’s middle layer was calculated to be 190 cm under various conditions. Finally, using the Taguchi analysis results, equations were presented to estimate the temperature of the solar pond’s lowest layer concerning the thickness of each the three layers in different climatic conditions. According to the findings of this study, the thickness of the upper layer of the solar pond had the least effect, while the thickness of the middle layer had the most effect on the maximum temperature and the annual average temperature of the lower layer.

Application of Aluminium Oxide–Water Nanofluids to Augment the Performance of Shallow Pond: a Numerical Study

Application of Aluminium Oxide–Water Nanofluids to Augment the Performance of Shallow Pond: a Numerical Study

Performance of a shallow solar pond coupled with a heat pump cycle for thermal energy in net zero-energy buildings

Refrigerant evaporation, in heat pumping systems, is a particularly complex process. Since the evaporator is subjected to environmental conditions, several factors weigh in on overall system performance, mainly, the additional energy input from the surroundings. This renders the evaporation process especially susceptible to gaps and fluctuations of said energy availability, particularly in solar-assisted setups. Despite the, comparatively, high heat flux associated to this source, these occurrences make them suitable mostly for low-to-medium thermal requirements, especially in regions with more extreme climates. The present work introduces a novel evaporator design, based on solar ponds. The proposed evaporation device incorporates a short-term, passive, thermal storage solution to compensate for gaps in energy availability. A mathematical-thermal model is developed and a performance assessment is conducted based on real seasonal atmospheric and operation conditions. For this study R134a, R152a, R1234yf and R1234ze(E) were used as working fluids. The proposed heat pump configuration is evaluated for hot water production at 55 °C, indoor air heating at 18–22 °C and a combined simultaneous scheme. The results show that this configuration performs well under moderate climate conditions. For hot water production during spring, highest outlet temperature of 68.54 °C for the R1234yf working fluid, were reached and maintained after the first 13 h. Internal thermal capacitor reached an average temperature of 61.88 °C for R1234yf. During winter, these temperatures decrease almost by a third, with 40.6 °C for R1234yf working fluid. However, daily average outlet temperature of 64.8°Care reached within the first 15 h of operation. Despite a lower thermal storage, with average capacitor, the system yielded consistent average outlet temperature of 20.7 °C. For a simultaneous operation scheme, desired outlet water temperature, is reached within the first 16 h of operation, whilst the indoor air temperature reaches comfort levels within the first 12 h. Despite employing part of the energy absorbed to maintain a stable comfort condition within the dwelling, instead of compensating the heat loss of the hot water tank, both goals are achieved. The inclusion of an inner thermal capacitor that collects and stores energy at a much higher rate provides the refrigerant with an additional heat source. This results in a more effective overall energy absorption of the evaporator, which exceeds the rate at which heat is dissipated from the tank/dwelling to the environment. This heat loss buffer lessens, considerably, the thermal demand during periods with lower energy availability, resulting in achievable outlet conditions.

Analysis of Phytoplankton Structure Community, Water Quality and Cultivation Performance in Litopenaeus vannamei Intensive Pond Located in Tembokrejo Village, Muncar, Banyuwangi

Phytoplankton plays an important role in Litopenaeus vannamei cultivation. It plays a role as natural feed, water quality control, and indicator of shrimp cultivation success. The community structure of phytoplankton can be influenced by organic matter concentration in ponds. On the other hand, water quality and phytoplankton community structure also influence the productivity of shrimp cultivation. The research aimed to analyze the phytoplankton structure community, cultivation performance and the water quality in one of vananmei shrimp cultivation located in Muncar District. The research used the descriptive method. The research was conducted in two shrimp intensive system ponds in Tembokrejo Village, Muncar District, Banyuwangi, on February-March 2020. Parameters observed were composition, diversity, and density of phytoplankton, water quality parameters, and production performance in each pond. Based on the results, five phytoplankton classes was found: Bacillariophyceae (12 genera), Chlorophyceae (4 genera), Cyanophyceae (8 genera), Dinophyceae (2 genera), and Euglenophyceae (1 genus). Based on the density, Cyclotella and Chlorella were dominated in both ponds. Diversity index values on ponds 1 and ponds 2 were 1.64 and 1.71, respectively. The productivity of both ponds was 10.794 kg.ha-1 and 11.698 kg.ha-1, FCR (Feed Conversion Ratio) were 0.99 and 1.18, and ADG (Average Daily Growth) on both ponds were 0.16 g.day-1. Water quality parameters in both ponds showed an optimal range for vannamei cultivation, except phosphate, which is quite high. Overall, the cultivation performance of both ponds in our research showed good results. However, cultivation performance obtained in this research was not on its best performance yet due to Infectious Myonecrosis (IMNV) infection.Keywords: Cultivation performance, Litopenaeus vannamei, muncar, phytoplankton.

Improving the performance of waste stabilization ponds in an arid climate

Abstract In many parts of the world, waste stabilization ponds (WSPs) are currently the preferred wastewater treatment method for municipal wastewater. The objective of this research is to examine the performance of a WSP in an arid climate region and to identify ways to improve its purification efficiency so that it can meet the criteria for reuse. The results attributed the poor performance to both improper process and physical design after 12 months of physicochemical and bacteriological analyses, as well as monitoring of operation, maintenance and loading rates. In tertiary treatment, maturation ponds are added, an increase in the capacity of the station, and management of the flow rate and retention time for each pond. By simulating the new WSP with GPS-X, the best pond area ratio obtained is 2.5 m2/capita, with a retention time of 4 days for anaerobic ponds, 20 days for facultative ponds and 3 days for two maturation ponds in series, which is suitable and provides reduction rates of BOD and fecal coliforms of 95 and 99%, respectively, with an average effluent concentration of 20 mg/L and 195 CFU. According to the results, well-maintained WSPs provide a viable, self-sufficient and environmentally friendly wastewater treatment solution for irrigation water supply in dry areas.

Stormwater Detention Ponds in Urban Catchments—Analysis and Validation of Performance of Ponds in the Ouseburn Catchment, Newcastle upon Tyne, UK

The impact of stormwater drainage and detention ponds on flooding is assessed using statistical analysis and physically based computer simulation of a 45-year case study for a peri-urban catchment. In 1978, the 54 km2 Ouseburn catchment in Newcastle upon Tyne was impacted by the connection of a new 2.1 km2 residential development, directly to the Ouseburn River, via a stormwater drain, which reduced the time to peak and increased flood risk. Further residential developments of 1.6 km2 have been built since 2004, again with separated sewer systems, but this time linked to stormwater detention ponds before draining into the Ouseburn River. Detailed analysis of the data, confirmed with computer simulation, shows that in contrast with the 1978 intervention, these new developments had only a minimal effect on the flows in the Ouseburn River, in fact achieving a small reduction in peak flows for large events. This study assesses the post-construction efficiency of such systems, and we show that the stormwater detention ponds are working as designed.

Annual Variation in the Performance of Settat Wastewater Stabilization Ponds Located in Settat City, Morocco

Annual Variation in the Performance of Settat Wastewater Stabilization Ponds Located in Settat City, Morocco

Impact of the algal-bacterial community structure, physio-types and biological and environmental interactions on the performance of a high rate algal pond treating biogas and wastewater

This study investigated the algal and prokaryotic community structure in an outdoors pilot High Rate Algal Pond (HRAP) that was simultaneously used for the treatment of high-strength wastewater and biogas upgrading. The algal and prokaryotic diversity was analyzed and correlated with biological and environmental parameters, and process quality indicators. The results obtained showed that the dominance of a versatile and resistant algae, such as Chlorella vulgaris, which is tolerant to high NH4+ and CO2 concentrations, concomitant to a specific prokaryotic population allowed for the obtention of biomethane with 95.2 ± 0.7% CH4, 1.4 ± 0.1% CO2 and no H2S. The bacterial community, fostered by the algal population, the light hours, and photoperiod had an important role on both biogas upgrading, through O2 and H2S elimination, and wastewater treatment. While the algal population was involved in the elimination of the ammonium of the wastewater through assimilation, the bacterial population was the main factor responsible for organic carbon, nitrate and phosphate removal, as well as nitrification. The low oxygen concentrations at night promoted bacterial denitrification, increasing the nitrite concentration in the treated wastewater. Through these findings, this research encourages photosynthetic biogas upgrading combined with wastewater treatment in HRAPs using an inoculum composed of a dominant microalgae, and an enriched prokaryotic population of aerobic chemo-organoheterotrophs, aerobic nitrifiers, and sulfur bacteria. Unlike the bacterial consortium in this study, this designed consortium can avoid the accumulation of nitrite in the cultivation broth and reduce the content of oxygen in the produced biomethane.

Evaluation of the sustainability of existing rainwater harvesting ponds: A case study of Lay Gayint District, South Gondar zone, Ethiopia

In most of the water-scarce areas, rainwater harvesting (RWH) ponds are essential for meeting the stress of water for various purposes. Besides the performance and sustainability of those rainwater harvesting ponds were not evaluated. This study aimed to evaluate the sustainability of existing rainwater harvesting ponds in Lay Gayint District, Ethiopia. The specific objectives of this study were; (1) to assess the perception of farmers on the potential of RWH ponds, and (2) to identify factors influencing the sustainability of RWH ponds. The demographic characteristics of farm households; farmers' perception about RWH ponds; and the socio-economic conditions of households were collected using household surveys and focused group discussions. The collected data was analyzed through quantitative and qualitative data analysis methods. The results of this study revealed that almost all farmers did not have good perceptions of ponds and had not gained enough awareness of the advantages of ponds. The utilization of the ponds was surrounded by constraints like poor quality and short lifetime of the constructed ponds; low involvement of farmers within the construction of ponds; and wrong-site selection. The incidence of local disputes among the farmers was the most important impact that un-utilized ponds have exerted on the community. About 78 % of the ponds were found in a failed state and 75 % of the ponds have no fences. The construction of RWH ponds in rural districts was based on a quota system which resulted in low sustainability. About 72.2 % of the respondents have not participated in the construction of RWH ponds, on the other hand, 81.5 % didn't get any training about RWH. The majority of the respondents replied that they have no money for constructing and maintaining their ponds. Due to the different factors most of the RWH ponds didn't store and serve for the designed service period which failed to satisfy the water demand. The government shall give attention to the sustainability of ponds by facilitating the involvement of Non-Governmental Organizations (NGOs) in capacity building, technical and financial support.

Thermal/frictional performance of spiral pipe with ring-shape depression used as in-pond heat exchanger

In the present numerical study the ring-shape depressions were created on the wall of spiral pipe that can be employed as a heat exchanger in the solar ponds. Unlike available literature that focused on the optimization of solar ponds through its nature recognition, present study tried to propose an efficient passive method for maximizing heat extraction. This is a simple and cost-efficient technique for enhancing the overall performance of salinity-gradient solar ponds through augmentation of turbulence inside the modified piping system and yielding higher heat extraction accordingly. Indeed, the introduced practical technique not only prevents the increment of size and volume of the piping system but also makes it needless to use additional supplementary equipment like turbulator or even air injectors. Moreover, this is a good way to prevent fouling inside piping system which bears huge costs. 3D numerical simulation was done based on Finite Volume Method (FVM) and turbulent flow simulated by RNG k-epsilon model. Due to the steady-state nature of this problem pressure–velocity coupling algorithm was adopted. The effect of several decisive parameters including Dean, Pr (fluid type and inlet temperature), groove distance, and groove depth on Nu, f, j-factor, and TPF was studied. Interestingly, it was turned out that the values of thermal performance factor (TPF) for all cases were above 1 which shows the justifiability of made modifications. For all flow rates water has the highest Nu and the lowest friction factor compared to Theminol-55 and Ethylene-glycol. Groove pitch of 20 mm makes the highest values of Nu so that 168, 195, and 216 were the maximum obtained Nu for cases with groove depth of 0.7 mm, 1 mm, and 1.3 mm, respectively (working fluid was water and Dean = 1615). Said statement is true for f where its maximum values were 0.1, 0.14, and 0.2, respectively, for cases with groove depth of 0.7 mm, 1 mm, and 1.3 mm (working fluid was water and Dean = 269). The highest Nu of Therminol-55, Ethylene-glycol, and water were 100, 114, and 216, respectively for groove pitch of 20 mm.

Article of Review on Computational Analysis on Performance of Solar Pond using Polycrystalline Material

The Solar pond is a pool of salt water stratified into 3 different layers, when radiations from the sun heats up the pond this heat energy gets stored in the lower most layers, thus making it as a heat source. Latent heat thermal energy storage is constantly an attractive method to store thermal energy due to because of its capacity to give high energy storage density and it also has a property to store heat at almost constant temperatures equivalent to the phase transition temperature of phase change materials (PCM). The aim of the thesis is to develop a CFD-based simulation analysis model of solar pond to analyze the double-diffusive nature of temperature and the saline concentration distributions, also to form a stable three-layer system of energy storage using computational fluid dynamics. The main objective of this study was to design solar pond modal with three layers in it and also to explore the effects of addition of material with high conductivity on the characteristics of heat transfer of pure PCM.

Transient study of a solar pond under heat extraction from non-convective and lower convective zones considering finite effectiveness of exchangers

The transient performance of a salt gradient solar pond, which experiences heat extraction from both gradient and storage regions has been studied for annual performance via accounting for the overall heat transfer coefficient across heat exchangers. The proposed method after reduced complexities is satisfactorily validated with theory and experiment-based results of pertinent literature. The novelty of the work lies in the fact that, the temperature drop across both non-convective and lower-convective zone exchanger surfaces has been accounted by using a local time and space dependent heat transfer coefficient. Here, it takes into the consideration free convection from the pond to the exchanger surface, and forced convection from the exchanger surface to flowing working fluid. Further, temperature variation of thermo-fluidic parameters of water involving, viscosity, density and thermal conductivity is considered. Detailed numerical investigation reveals that by neglecting this coefficient which is assumed in conventional studies, it can lead to significant errors in the prediction of transient temperature profiles in the pond and the exchangers. Calculations reveal an error of about +69% in the annual extraction efficiency and about −9% in entropy production if the conventional assumption is used as opposed to realistic technique presented herein. Interestingly, the present study reveals that there is an optimum radius of exchanger pipe in each of non-convective and lower convective zones that maximises the annual extraction efficiency. This work presents a useful analysis to assess multi zone extraction from solar ponds under transient state in a more practical and accurate manner.

Performance evaluation of technical aspects of ex-situ rainwater harvesting systems at Wag-Lasta, Northern, Ethiopia

The most severe constraints for agriculture are water shortages in semi-arid areas of Northern Ethiopia. Rainfall is extremely variable; therefore, it is necessary to harvest rainwater to safeguard improved crop production. The objective of the study is to characterize, identifying problems and evaluating the performance of existing RWH systems in the Wag-Lasta areas. Tweleve RWH ponds were selected from six kebeles in the study area. Primary and secondary data were collected and evaluated using descriptive statistics to assess the technical performance of water harvesting ponds by field observation, direct measurements, and interviews with zone, woreda, kebele experts, and owners. The technical performance assessment showed that the collected runoff and system efficiency were negligible for the total rainwater catchment area. The problems in a portion of the non-functional ponds had found to be poor site selection, lack of maintenance, and standardization of techniques, and some of them were efficient with low performance.

Evaluation of the performance of Mzuzu Central Hospital wastewater oxidation ponds and its effect on water quality in Lunyangwa River, Northern Malawi

Mzuzu Central Hospital wastewater oxidation ponds discharge effluent onto Lunyangwa River, but data on its performance is scant. It was thus imperative to assess the performance in terms of levels of pH, EC, TDS, phosphates, feacal coliforms, biological oxygen demand (BOD5) and total suspended solids (TSS) removal from the influent. Grab water samples were collected from the influent, facultative pond, effluent and upper, point of discharge and downstream of the discharge point. Levels of temperature, pH, EC, TDS were determined on site using HANNA instrument model H19812 pH-EC-TDS meter. Levels of BOD5 were determined using DO meter. Feacal coliforms were determined using dilution method. Nitrates and phosphates were determined spectrophotometrically, whereas TSS was determined gravimetrically. Data was analysed using Minitab version 17. The removal efficiencies of TSS, TDS, E.coli, nitrates and EC were observed to be 46.67%, 59.43%, 96.23%, 6.34% and 59.34%, respectively. Except for E.coli, the performance of Mzuzu Central Hospital Wastewater Oxidation Ponds in removal of all parameter was generally low (i.e < 60%). In addition, the removal efficiencies of pH, temperature, PO43− and BOD were −23.19%, −4.35%, −20.65% and −69.23%, respectively, indicating that regardless of the weak wastewater (BOD5< 200 mg/L) of a raw wastewater collected, the performance of the oxidation is a challenge. Levels of BOD5, fecal coliform, phosphate, and pH, above Malawi Standards specifications for industrial effluents tolerance limits for Malawi in both the effluent and the receiving waters, were indicative of significant pollution resulting from the oxidation ponds, suggesting a pressing need for improvement in wastewater treatment in order to improve the water quality ratings prior to discharge into Lunyangwa River. There is also a dire need for risk communication and public sensitization with respect to the need to boil and filter the water prior to consumption for communities that rely on downstream of the discharge point as their drinking water sources.