Performance Of Pond Research Articles

The Effect of Tailwater on the USBR Type III Stilling Basin Model

This study evaluates the impact of tailwater on the USBR Type III stilling pond model, which is often used to construct reservoirs with low hydrostatic pressure and small flow rates. The model includes channel blocks, barrier blocks, and end barriers to dampen energy, converting flow from supercritical to subcritical. Hydraulic characteristics, including potential jump types, pressure regimes, and forces on the barrier, are not considered. Any change in discharge during the test also changes the tailwater depth position. The purpose of this study was to determine the effects of tailwater conditions on water height (y1 and y2), pool length (Lj), Froude number (Fr), critical depth (yc), and energy dissipation effectiveness (ΔE). This study shows that the average energy dissipation ratio of USBR Type III Quiet Pool is 87.45% without the effect of Tailwater, with an efficiency rate of 12.55%. When exposed to Tailwater, the average energy dissipation ratio drops to 69.47%, resulting in an efficiency rate of 30.53%. The optimum stilling pond performance is affected by the presence of tailwater (Tw), which reduces the energy dissipation ratio. The depth of the tailwater aids in the dissipation that occurs. Technical abbreviations will be explained in the first use. The water level rise under tailwater conditions exceeds that without tailwater. This finding shows tail water's importance for height rise and flow conditions. Flow conditions with Froude Number (Fr2) values of 0.22 (<1) and Tw are classified as subcritical flow.

Temperature and salt concentration behavior of a compact rectangular salinity gradient solar pond

Design of economical and effective solar ponds which are useful thermal energy storage devices, remains a huge challenge. The present work aims at investigating the thermal performance of low cost mini salt gradient solar pond. The portable pond was fabricated as a rectangular configuration having a volume of 0.5m3. Polystyrene and high density polyethylene sheets were employed for insulating the walls. The top of the pond was covered with a slender glass so that the dust accumulation could be prevented without affecting the absorption of solar radiation. Sodium chloride salt was used as the medium and the three salt gradient regions namely lower convective, non-convective, and upper convective regions were established through injection filling technique. The temperature and salt gradient data were observed experimentally for a period of 20 days at Coimbatore, India. The pond could absorb significant amount of available radiation (around 65%) and the maximum temperature of the pond was observed to be 49oC. Frequent washing of the water surface is necessary to maintain stable salt gradient. Nevertheless, portable pond fabricated with low cost materials exhibited good potential of storing solar energy for solar thermal applications.

Enhanced performance and stability of a solar pond using an external heat exchanger filled with nano-phase change material

Salinity gradient solar ponds are a promising technology for harnessing/storing solar thermal energy. The energy storage capacity of solar ponds can be enhanced by incorporating phase change materials (PCMs). However, the low thermal conductivity of PCMs can negatively affect energy charging/discharging rates. In this study, an external energy storage system filled with CuO nanoparticle-enhanced PCM was employed to improve the performance and stability of a solar pond. The results were compared with water and pure PCM (paraffin) as control materials. Energy and exergy analysis was used to assess the effects of nanoparticles and their concentration on the overall solar pond performance. According to the results, the upper convective zone temperature remained consistent across all experiments and varied within the same range throughout the day. A slight temperature variation at specific times indicated the stability of the developed solar pond system. The system's exergy (energy) efficiency was increased from 10.72% (51.83%) for water to 14.71% (70.1%), 22.77% (82.13%), and 25.93% (87.58%) for PCM, PCM with 1 wt% nanoparticles, and PCM with 2 wt% nanoparticles, respectively. Incorporating nanoparticle-enhanced PCMs in external heat exchangers can effectively improve the stability and performance of solar pond systems.

Effect of PCM and nano‐embedded PCM on the solar pond performance as sensible heat storage: An experimental approach

AbstractA solar pond is an environment‐friendly system for storing thermal energy. Solar ponds can balance the energy supply and demand when incorporated with PCM. Solar thermal energy can be stored inside the solar pond and used for solar drying, desalination, and power production. The present study reports the heat change in the solar pond with or without PCM and nanoparticles. From the literature, it was found that handling phase change material is difficult, and added nanomaterials are used to settle with time, which reduces the efficacy of the system. The novelty of present study is to examine the performance of nanoparticle‐embedded paraffin the sensible energy storage in the solar pond. The experiment has been performed, and results have been investigated/compared for four cases, namely, (i) solar pond, (ii) solar pond with heat storage (ie, paraffin wax [PW]), (iii) solar pond with aluminum oxide () mixed PW, and (iv) solar pond with copper oxide (CuO) mixed PW. The results show that with the addition of 1% and 2%, and CuO in PW, the thermal conductivity is increased by 2.94%, 5.92%, 2.99%, and 6.01%, respectively, compared to basic paraffin wax. It can be observed from the results that with the inclusion of CuO in paraffin wax solar pond temperature was high during non‐sunshine hours compared to other solar ponds. The results also show that sensible energy without heat storage material is negligible during non‐sunshine hours compared to heat storage and nanoparticle‐embedded heat storage solar ponds. Incorporating CuO in paraffin wax showed significant potential to store heat energy.

Enhancing microalgal biomass production in lab-scale raceway ponds through innovative computational fluid dynamics-based electrode deflectors

The design of novel electrode deflector structures (EDSs) introduced a promising strategy for enhancing raceway ponds performance, increasing carbon fixation, and improving microalgal biomass accumulation. The computational fluid dynamics, based flow field principles, proved that the potency of arc-shaped electrode deflector structures (A-EDS) and spiral electrode deflector structures (S-EDS) were optimal. These configurations yielded superior culture effects, notably reducing dead zones by 9.1% and 11.7%, while elevating biomass increments of 14.7% and 11.5% compared to the control, respectively. In comparison to scenarios without electrostatic field application, the A-EDS group demonstrated pronounced post-stimulation growth, exhibiting an additional biomass increase of 11.2%, coupled with a remarkable 23.6% surge in CO2 fixation rate and mixing time reduction by 14.7%. A-EDS and S-EDS, combined with strategic electric field integration, provided a theoretical basis for promoting microalgal biomass production and enhancing carbon fixation in a raceway pond environment to similar production practices.

Study on the performance of the burn pond for bubbling and hydrogen distribution

The burn pond is a relatively efficient and safe way to deal with the hydrogen emitted or leaked in experiments. The aim of this paper is to analyze the performance of the burn pond in bubbling and dispersing hydrogen. The numerical simulation is the primary method utilized in this study, with a small-scale experimental validation. And Taguchi method is proposed to process data and quantify the importance of each factor. The results show that the water depth affects the performance of the burn pond most significantly, accounting for more than 56 %, followed by the outer diameter of caps and the number of slots. In addition to these design factors, the velocity of hydrogen also has a considerable impact on the burn pond. Essentially, the four factors determine the size and kinetic energy of bubbles, which then directly affect the process of bubbling and hydrogen distribution. The conclusions provide an orientation for optimizing the parameters related to bubble caps and the burn pond.

Long-term performance of a deep oxidation pond with horizontal subsurface flow constructed wetland for purification of rural polluted river water

A full-scale deep oxidation pond with horizontal subsurface flow constructed wetland (DOP-HSCWs) was constructed and used to investigate the nutrient removal and establish a practical inversion prediction model. The high long-term performances of nearly 7 years were obtained with the average removal efficiencies of 76.48 ± 10.11% (chemical oxygen demand, COD), 60.61 ± 29.21% (ammonia nitrogen, NH4+-N), 54.04 ± 21.92% (total phosphorus, TP) and 88.44 ± 6.86% (suspended solids, SS), respectively. The removal efficiency actually increased after 2016 with outflow concentrations lower as compared to initial phase of operation. The effluent concentration in autumn were obviously higher than that in other seasons because of high influent loadings. The Flaml model achieved good performance demonstrating the ability to predict water quality of DOP-HSCWs without human intervention. In addition, COD, NH4+-N, TP concentration of effluent can be significantly affected by SS concentration of influent according to the generalized additive model (p < 0.001). Compared with HSCWs, the DOPs was mainly contributed to pollutant removal. In summer, Cyanobacteria, Cyanobacteria and Proteobacteria were dominated in DOPs, while Proteobacteria was dominated in winter. Although the relative abundance of Proteobacteria in anaerobic zone decreased by 14.99%, the relative abundance of Firmicutes and Chloroflexi increased by nearly 10%, which ensured decontamination effect of the DOPs. Proteobacteria was also dominated in HSCWs, but it was lower than that in DOPs. This study indicated that DOP-HSCWs can achieve a sustainably excellent purification of rural polluted river water during the long period of operation.

Feasibility of Water Quality from Treated Domestic Wastewater Effluent in Bojongsoang WTTP, Bandung District for Fish Farming

Bojongsoang Wastewater Treatment Plant (WTTP) is a place for processing wastewater in domestic activities in Bandung City, West Java, Indonesia before being released into the aquatic environment. This study aims to determine the feasibility of water quality from domestic wastewater treatment for fish farming activities at the Bojongsoang WTTP in January - June 2023. The survey method was used with purposive sampling technique and conducted at five research stations with two replicates. The efficiency of reducing sewage treatment at the Bojongsoang WTTP is able to reduce the BOD5 value by 73%, reduce ammonia by 66%, reduce TSS by 38%, increase DO by 75% and the temperature and pH parameters are stable as expected. The results of testing six water quality parameters from processed domestic wastewater at the Bojongsoang WTTP, some ponds are at high levels and exceed water quality standards. So that it is not suitable if it is used as a fish farming pond that will be consumed or traded. The performance of each WTTP treatment pond is not yet optimal in accordance with the aims and objectives of wastewater treatment (WTTP), namely to reduce (eliminate) polluting substances so that they can be used for agricultural and fishery needs.

Theoretical and operational investigation of the temperature of the glass surface, floor and effluent inside the solar desalination pond

The purpose of this research is to investigate the effect of salinity percentage on the performance of a solar pond, experimentally and mathematically. Experiments are designed to find the temperature of different parts of the solar desalination pond. Using the mass and energy balance relationships for different components of the solar pond, the temperature of the glass surface, bottom and effluent has been reported operationally. The laboratory results state that if the flooring made of nano aluminum oxide is used, the amount of fresh water production reaches a maximum of 6.67 L. Also, when using nano oxide zinc flooring, the amount of fresh water production reaches a maximum of 6.6 L, and if using a simple flooring, it reaches a maximum of 5 L. The average intensity of sunlight and the average temperature of the environment in this month is approximately 0.285 kW/m2 and 33.7 °C.

Evaluation of pollutant removal efficiency of urban stormwater wet ponds and the application of machine learning algorithms

Wet ponds have been extensively used for controlling stormwater pollutants, such as sediment and nutrients, in urban watersheds. The removal of pollutants relies on a combination of physical, chemical, and biological processes. It is crucial to assess the performance of wet ponds in terms of removal efficiency and develop an effective modeling scheme for removal efficiency prediction to optimize water quality management. To achieve this, a two-year field program was conducted at two wet ponds in Calgary, Alberta, Canada to evaluate the wet ponds' performance. Additionally, machine learning (ML) algorithms have been shown to provide promising predictions in datasets with intricate interactions between variables. In this study, the generalized linear model (GLM), partial least squares (PLS) regression, support vector machine (SVM), random forest (RF), and K-nearest neighbors (KNN) were applied to predict the outflow concentrations of three key pollutants: total suspended solids (TSS), total nitrogen (TN), and total phosphorus (TP). Generally, the concentrations of inflow pollutants in the two study ponds are highly variable, and a wide range of removal efficiencies are observed. The results indicate that the concentrations of TSS, TN, and TP decrease significantly from the inlet to outlet of the ponds. Meanwhile, inflow concentration, rainfall characteristics, and wind are important indicators of pond removal efficiency. In addition, ML algorithms can be an effective approach for predicting outflow water quality: PLS, GLM, and SVM have shown strong potential to capture the dynamic interactions in wet ponds and predict the outflow concentration. This study highlights the complexity of pollutant removal dynamics in wet ponds and demonstrates the potential of data-driven outflow water quality prediction.

Energy storage investigation of solar pond integrated with PCM and nanoparticles during winter season in Chennai

Solar energy is a highly regarded renewable energy sources that are attracting substantial attention owing to its potential to alleviate climate change and provide sustainable energy. Solar ponds are one approach to collect solar energy by capturing and storing thermal energy inside a pond. However, the effectiveness of solar ponds has been hampered by reasons such as heat loss, evaporation, and inadequate heat transmission. Researchers have investigated the use of phase change materials (PCMs) and nano-additives to improve the performance of solar ponds in order to overcome these issues.Large amounts of heat can be stored and released by substances known as phase change materials as they transition between two states. By adding PCMs into solar ponds, heat may be retained throughout the day and released at night when the sun is not shining. Alternatively, nano-additives have the potential to enhance the efficiency of a solar pond by improving the heat transfer properties of the fluid present in it.To measure the thermal efficiency of the solar pond, multiple phases of an experiment have been undertaken to establish the degree of thermal efficiency. During the experiment, various parameters were employed to measure and track the temperature variations in the lower convective zone (LCZ) of the solar pond. These measurements were recorded on a daily, weekly, and hourly basis, taking into account the depth of the solar pond as a determining factor. There was also an experiment carried out using micro PCMs and paraffin waxes (PCMs) that were combined into the matrix. In this study, nanoparticles with high thermal conductivity, such as carbon nanotubes (CNTs), and hybrid nanoparticles, such as AgTiO2, were utilized.The solar pond without phase change material (PCM) had an average temperature of 45 °C in the lower convective zone (LCZ). When PCM was added to the solar pond, the maximum temperature in the LCZ increased by 2 °C compared to the previous 24 h. Furthermore, when carbon nanotube (CNT) nanoparticles were incorporated into the solar pond with PCM at the base, the temperature was observed to be 1.3 °C higher compared to a typical solar pond that only used PCM for heat storage. In another scenario, the solar pond with PCM and a combination of CNT and AgTiO2 nanoparticles had an average temperature of 52.5 °C in the LCZ during the first week of observation.

Numerical study on the performance of circular juvenile fish breeding ponds

Due to the recent tendency to use circular ponds of closed-circuit systems in the fish farming industry, it seems necessary to investigate the flow pattern performance for improving water hydrodynamic behavior considering the input conditions. Although pond inflow conditions play a major role in the formation of rotational flow, in most cases, these ponds cannot be optimally used due to a lack of appropriate solutions. Therefore, this study presents the computational fluid dynamics model of a circular fish farming pond with a volume of 1.57 m3 based on incompressible steady Reynolds averaged Navier-Stokes formation using a realizable K-ε viscous model. Numerical modeling of the angle change of pond inflow is put on the agenda at three levels, and the inflow momentum force is considered at four levels to investigate vortex formation and its effect on the efficiency of ponds. The results indicate TKE is directly correlated with the inflow momentum force. In the case of injecting the flow tangentially to the pond wall, the maximum TKE is observed in the areas tangential to the pond wall. The formed vortices are analyzed using two vortex quantification methods of vortex strength and normalized velocity. The results demonstrate the maximum vortex strength is at 20–40% of the water level when injecting the flow tangentially into the pond wall (α3 = 30°). The model results suggest installing inlet nozzles tangentially to the pond wall and adjusting inflow with the minimum momentum force to improve rotational flow hydrodynamic performance.

PESTIPOND: A descriptive model of pesticide fate in artificial ponds: I. Model development

Some artificial ponds (APs) are designed to collect part of the agricultural water fluxes and dissipate their pesticide contamination through a synergy of physicochemical processes. As part of a two-paper series, this paper describes the development of PESTIPOND, a process-based model for pesticide fate in AP. PESTIPOND comprises a hydrological model and a pesticide transfer model. A test-case simulation shows that PESTIPOND can predict the mass dynamics of different pesticides within AP compartments. Sensitivity analysis evidenced that adsorption–desorption, biotransformation, and photolysis have the most significant impact on the behavior of dissolved pesticides in APs. PESTIPOND is a promising tool for better understanding the performance of ponds and can help improve AP's efficiency in preserving water quality. A second paper addresses the application of PESTIPOND in a real-case scenario and its validation (Bahi et al., 2023a). The model can thus be integrated into landscape modeling tools (e.g., surface water assessment tools) to predict pesticide transfer at the watershed scale.

The effect of porous media on the thermal storage performance of salinity-gradient solar pond

A solar pond is a system that uses a salt concentration gradient to store heat. The application of the system is conducive to solving the problems of long production cycles, low brine temperature, and salt algae in the solar pond lithium extraction process and the solar pond potassium enrichment process. Based on this, our research group laid porous media at the bottom of the solar pond and utilized the heat storage and adsorption capacity of porous media to improve the thermal storage performance of the solar pond. The experimental results show that foam ceramics have good thermal storage performance and the ability to reduce turbidity. Laying foam ceramics on the bottom of the solar pond can not only increase the thermal storage performance of LCZ but also help reduce the turbidity of the pool water. After adding porous media, the heat extraction position of the solar pool moves from the junction of LCZ and NCZ to the bottom of LCZ. In addition, adding transparent film on the upper surface of the solar pond is also conducive to improving the thermal storage performance of the solar pond and reducing the turbidity of the solar pond.

The Effect of Coastal Dike and Retention Pond Performance on Flood and Tidal Control in Pekalongan

Abstract.Pekalongan is one of the areas located in the north of Java Island. The main problem in Pekalongan is tidalflooding. This tidal flood worsens when there is a high discharge in the river. For this reason, the government builta Coastal Dike and a Retention Pond to overcome these problems. The concept of this system is to create a coastaldike that crosses the river to eliminate tidal effects. The retention pond is located along the coastal dike toaccommodate the discharge from the river, then the water will be pumped downstream of the river. This study aimsto obtain pump operating time for each pump built in this system to reduce the flood elevation of Q25 to – 0.5 m inthe retention pond. One dimensional flow modeling was used in the approach with the Hydrologic EngineeringCenter-River Analysis System (HEC-RAS) 6.0 model. This research shows that the pump operating time for theSilempeng and Sengkarang pumps is 150 hours. The addition of Mrican pumps and flap gates can reduce pumpoperating time to support the success of Coastal Dike and Retention Ponds in controlling floods and tidal inPekalongan.Keywords: Tidal flood, coastal dike, retention pond, pump.&#x0D; Abstrak.Pekalongan merupakan salah satu daerah yang terletak di utara Pulau Jawa. Masalah utama di Pekalonganadalah banjir rob. Banjir rob ini semakin parah ketika terjadi debit yang tinggi di aliran sungai. Untuk itupemerintah membangun tanggul rob dan kolam retensi untuk mengatasi permasalahan tersebut. Konsep sistem iniadalah membuat tanggul rob yang melintang sungai, menghalangi backwater dari laut untuk menghilangkan efekpasang surut. Kolam retensi terletak di sepanjang tanggul rob untuk menampung debit dari sungai, kemudian airakan dipompa ke arah hilir sungai. Tujuan dari penelitian ini adalah mendapatkan waktu operasional pompa untukmasing-masing pompa yang terbangun di sistem ini dalam menurunkan elevasi banjir Q25 sampai dengan elevasi –0,5 m di kolam retensi. Di dalam penelitian ini juga dilihat waktu operasional pompa setelah penambahan pompamrican dan pintu klep di Mrican. Pemodelan satu aliran dimensi dilakukan dengan model HEC-RAS 6.0. Hasil daripenelitian ini adalah waktu operasional pompa untuk pompa silempeng dan sengkarang adalah 150 jam.Penambahan pompa Mrican dan pintu klep dapat mengurangi waktu operasi pompa untuk mendukungkeberhasilan Tanggul Pesisir dan Kolam Retensi dalam pengendalian banjir dan pasang surut di Pekalongan.&#x0D; Kata-kata Kunci: Banjir rob, tanggul rob, kolam retensi, pompa.

Investigation of thermal effect of floor coverings made of nano metal oxide on wastewater temperature and solar pond performance

In this research, the exit treated wastewater from the gravity filtration unit, mechanical and chemical treatment unit, biological treatment unit and finally UV disinfection treatment unit enters to a solar desalination unit. Wastewater evaporation process is performed in this unit. In this study, in order to increase the UV waves in solar energy, nano-flooring has been used on the floor of the solar pond. The laboratory results show that the average difference between the experimental data and the theoretical results for simple coating, coating made of zinc oxide nanoparticles and coating made of aluminum oxide nanoparticles is equal to 2%, 2.3% and 1.6%, respectively. Laboratory results show that the average temperature difference between theory and laboratory when simple coating, nano zinc oxide coating and nano aluminum oxide coating are used are 0.5%, 2.89% and 0.67%, respectively. The laboratory results show that the minimum and maximum average temperature of different layers of wastewater are related to the months of January and July, respectively. This research shows that the maximum and minimum temperature difference of the first layer and the last layer of wastewater are in April and March, respectively.

Performance of a Series of Polishing Ponds in the Treatment of Sanitary Sewage

The main objective of this research was to evaluate the functioning of a system of polishing ponds on a pilot scale in the post-treatment of urban sewage discharged from an up-flow anaerobic sludge blanket reactor and followed by a submerged aerated filter. The following variables were analyzed: transparency, temperature, dissolved oxygen (DO), pH, alkalinity, biochemical oxygen demand (BOD), chemical oxygen demand (COD), total Kjeldahl nitrogen (TKN), ammonia (NH3), organic nitrogen, nitrate (N-NO3), total phosphorus (TP), orthophosphate (PO43-), total suspended solids (TSS) and chlorophylla. In addition, the planktonic communities were also identified and quantified. During the study period, the pond system registered the following mean and standard deviation of the removal efficiencies: 32.9±31.7% of BOD, 26.5±33.9% of COD, and 29.0±49.6% of TSS; good performance was observed in the removal of nitrogen compounds, and the following results were obtained: 58.4±28.1%, 87.5±15.4%, 24.4±42.6%, and 9.4±51.8%, respectively for TKN, NH3, organic nitrogen, and N-NO3; and 26.9±25.8 of TP and 34.3±32.7% of PO4 3-. During the research period, the planktonic community was represented by the following classes: Chlorophyceae, Euglenophyceae, Cyanobacteria, Cryptophyceae, Zygnemaphyceae, Chrysophyceae, and Dinophyceae; concurrently, the zooplankton registered low densities and was represented by the Rotiferous, Copepod, and Cladocera groups. The results help us understand the performance of polishing ponds in treating sanitary effluents.

Inlet retrofitting improves the hydraulic performance of a waste stabilization pond

Wastewater is transitioning from being viewed as a waste to being utilized as a resource in the production of reclaimed water. Reclaimed water, obtained through waste stabilization pond treatment technologies, has the potential to offset potable water needs for irrigation purposes as well as fertilizers for crop growth. In developing countries, where waste stabilization ponds are widely used, a major issue is the lack of maintenance which can lead to considerable amounts of sludge piled at the bottom of the pond. This sludge accumulation reduces the treatment capacity of the waste stabilization pond and possibly, the treatment efficiency which is vital for reuse purposes. In cases for which desludging of the pond is a challenge, retrofitting the pond inlet can offer an alternative to improve pond hydraulic performance. In this study, two inlet retrofit geometries are investigated in a waste stabilization pond with significant sludge accumulation using computational fluid dynamics. It is seen that retrofitting the pond with a three-way pipe inlet increases the mean residence time of the pond from 21.9 days to 25 days over a single pipe inlet while significantly reducing the strength of short-circuiting.

Performance of municipal waste stabilization ponds in the Saharan desert (Morocco)

Abstract The majority of cities in the Saharan territory of south Morocco utilize waste stabilization ponds (WSPs) for municipal wastewater treatment because of their relatively low capital, operational costs, and minimal complexity. New national effluent quality regulations have been implemented in Morocco, and they will be applied to all treatment systems. In this study, we chose three cities that are located in the Saharan area characterized by an arid climate and water scarcity. They are facing the challenges of rapid urbanization and the need to improve wastewater treatment and management. Treatment performance is impacted by community water use, pond design, and climate. The performance evaluation concerns seven physicochemical parameters during the year 2020. Monitoring results showed that WSPs in this climate can achieve removal rates between 75% and 85% for organic pollution and total suspended matter, but were challenged to produce effluent quality that meets reuse standards. Performance and statistical analysis have been done and confirm the existence of correlations between these parameters and the climate of the region. For the improvement of the quality of these waters, it is legitimate to upgrade the three WSPs with a tertiary treatment with maturation ponds.

Ornamental ponds as Nature-based Solutions to implement in cities

Small waterbodies such as ponds are widely represented in cities, contributing to the blue-green infrastructure, improving human well-being. Ornamental ponds are particularly abundant in the densest urbanized areas, especially in parks, in private grounds such as gardens and also imbedded in the green infrastructure. However, their multifunctionality remains infrequent, as generally aesthetic enjoyment is the main ecosystem service targeted. The promotion of native biodiversity is rarely a priority, as are other ecosystem services (e.g. flood mitigation or water purification). It is nevertheless questionable if such mono-functional ponds could also be able to provide other services. Indeed, an innovative approach would be to increase the multifunctionality of ornamental ponds, especially for biodiversity. This was investigated in 41 ornamental ponds designed for providing aesthetic enjoyment in the city of Geneva (Switzerland). The biodiversity was assessed, as well as selected ecosystem services (water retention, phytopurification, cooling effect, carbon sequestration). A survey among the population was also conducted. This survey underlined a recognized contribution of ornamental ponds to well-being. However, the assessment of the ecosystem services evidenced a lack of multifunctionality for most of these ponds. They presented a low biodiversity, compared to more natural ponds and to unimpaired ponds. Furthermore, they performed poorly for most other ecosystem services investigated. There were nevertheless exceptions, with selected ponds displaying a multifunctionality, even for ecosystem services for which they were not designed. It was also shown that ornamental ponds could easily be optimized for biodiversity by simple low-cost management measures. Additional ecosystem services could also be promoted. The performance of small ornamental ponds is best when ponds are considered collectively, as pondscapes, with their cumulative benefits. New ornamental pond implementation is therefore encouraged, as their multifunctionality turns them into Nature-based Solutions able to contribute to solving several societal challenges and to improve human well-being.