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Two streams of wastewater from the Kraft Pulp and Paper Mills at Webuye are released from the pulping, bleaching and paper pressing departments. One stream is made up of clear wastewater and the second is made up of turbid wastewater. The wastewaters from the mills are treated using oxidation ponds, after which the treated wastewater is discharged into the River Nzoia. The wastewater was analysed for Cd, Cr, Cu, Ni, Pb, Zn, Ca, K, Mg and Na. The results are that the concentrations of Ca and Na significantly increased in the treated wastewater. The concentrations of Cd, Pb, Zn, K and Mg also increased in the treated wastewater, though not significantly. The concentrations of Cr, Cu and Ni decreased in the treated wastewater but not significantly. Mass loadings of the metals discharged into River Nzoia were calculated. It was found that the mean mass loading of two metals (Ca and Na) significantly increased in the treated wastewater. Five metals (Cd, Pb, Zn, K and Mg) increased in the treated wastewater although not significantly. Three metals (Cr, Cu and Ni) decreased in the treated wastewater but the decrease was not significant. The concentrations of Cd, Cu, Ni, Pb and Zn were all above the limits set by EC for drinking water. These findings pose serious questions of the effectiveness of oxidation ponds system to safeguard the receptor against pollutants from the pulp and paper industry at Webuye. [Copyright &y& Elsevier]

Water samples were collected on three dates at 24 sites influenced by effluent from Georgia-Pacific's Palatka Pulp and Paper Mill Operation, a bleached and unbleached kraft mill near Palatka, Florida, USA. The sampling sites were located within the mill retention ponds, Rice Creek, and the St. John's River. Samples were analyzed by gas chromatography--mass spectrometry for abietic, dehydroabietic, and isopimaric acids, all of which are potentially toxic by-products of pulp production. Isopimaric acid concentrations greater than 12 mg/L were measured at the mill's effluent outfall but were less than 20 µg/L at the end of Rice Creek. This result indicates that the waters of Rice Creek provide dilution or conditions conducive for degradation or sorption of these compounds. Large differences in resin acid concentrations were observed between sampling events. In two sampling events, the maximum observed concentrations were less than 2 mg/L for each analyte. In a third sampling event, all of the compounds were detected at concentrations greater than 10 mg/L. Data from the three sample dates showed that resin acid concentrations were below 20 µg/L before the confluence of Rice Creek and the St. John's River in all cases. [ABSTRACT FROM AUTHOR]

The paper is aimed at reconstruction of a source term for external exposure of population that inhabited the banks of the Techa River from 1949 to 1956. The composition of γ-emitting nuclides contributing to radiation environment of the river banks and floodplain is also studied. The γ-emitting nuclides entered the river system both in solutions and as industrial and natural suspended matter. The paper considers archive data on measured parameters of radiation contamination of the Techa bottom sediments and riverside area. Results of the present-day radiation surveys of the Techa River show that the distribution of the exposure dose rate has a pronounced spotted and non-monotonic character along the entire river stretch and is due to sedimentation of suspended particles contaminated with the γ-emitting nuclides on the soil surface. The activity of γ-emitting nuclides accumulated in the upper reaches of the river due to sorption of water-soluble radionuclides onto bottom sediments and to sedimentation of contaminated suspended matter on the surface of bottom sediments was calculated using a stationary sorption model and a hydrodynamic model of settling ponds. Until July 1951, when the river runoff did not exceed 1 m3/s, practically all industrial and natural suspended particles settled to and accumulated at the bottom of Metlinsky Pond. Only a small portion of clay particles could enter the river below the dam of Metlinsky Pond. 95Zr and 95Nb are of high importance for reconstruction of the radiation environment in the Techa riverside area, because before 1953 the activity of the bottom sediments in all segments of the river was predominantly determined by these γ-emitting nuclides. There is practically no sorption of 95Nb onto bottom sediments and suspended matter, and the river flow carries predominantly soluble 95Nb species. 95Zr, on the contrary, is strongly sorbed onto bottom sediments and can be transferred for long distances only as suspended matter or bed silt. Until October 1951, the radiation environment along the entire river stretch below Metlinsky Pond was contributed predominantly by 95Nb and was characterized by uniform and stable contamination level in all swampy areas of the floodplain. Vast contamination of the bottom sediments and the floodplain along the entire river stretch by other γ-emitting nuclides (95Zr, 137Cs, 141,144Ce, 103,106Ru, etc.) could result only from "washing" of Metlinsky Pond in October 1951, when the flow rate in the upper reaches of the river was up to 30 m3/s. This was accompanied by intensive stirring-up of the bottom sediments and activity transfer out of Metlinsky Pond. [ABSTRACT FROM AUTHOR]

Technologies based on microalgae-bacteria seem to be sustainable options for wastewater treatment and reuse, with lower costs than conventional biological treatment technologies. Furthermore, they can generate added-value products produced from algae biomass. Among other advantages, the consortium bacteriaalgae produce photosynthetic oxygen through the microalgae, which can be used by aerobic bacteria for oxidizing organic matter and nitrogen, thus reducing the need for introducing artificial oxygen. In this review paper, the main systems that use microalgaebacteria consortium are discussed. Microalgae-bacteria present advantages in the removal of organics, nitrogen and phosphorus, when compared with conventional biological treatment systems (e.g., activated sludge, percolating filters and ponds), and are able to produce final effluents for reuse (e.g., in agricultural irrigation, industry or aquifer recharge) and excess of microalgae that can be converted to added-value products such as biogas and biofuels. Attention is given to the innovative aspects of applying photobioreators to the treatment and reuse of pulp and paper effluents and fiber-waste-based recycling wastewaters, which seems to open a new opportunity for the pulp, paper and recycling paper industries. [ABSTRACT FROM AUTHOR]

Inland waters are among the most threatened biodiversity hotspots. Ponds located in alpine areas are experiencing more rapid and dramatic water temperature increases than any other biome. Despite their prevalence, alpine ponds and their biodiversity responses to climate change have been poorly explored, reflecting their small size and difficult access. To understand the effects of climate change on alpine pond biodiversity, we performed a comprehensive literature review for papers published since 1955. Through analysis of their geographic distribution, environmental features, and biodiversity values, we identified which environmental factors related to climate change would have direct or indirect effects on alpine pond biodiversity. We then synthesized this information to produce a conceptual model of the effects of climate change on alpine pond biodiversity. Increased water temperature, reduced hydroperiod, and loss of connectivity between alpine ponds were the main drivers of biodiversity geographic distribution, leading to predictable changes in spatial patterns of biodiversity. We identified three major research gaps that, if addressed, can guide conservation and restoration strategies for alpine ponds biodiversity in an uncertain future. [ABSTRACT FROM AUTHOR]

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. • Depth of water influences the burn pond most significantly. • Distance between the neighboring slots determines the bubbling situation. • Richardson number indicates that the flow in the bubble cap is a plume. [ABSTRACT FROM AUTHOR]

Ponds constitute a pivotal component of aquatic ecosystems. The aquatic ecosystem of the Huai River Basin (HRB) in China was once damaged by severe pollution, and numerous ponds in the basin have not been secured. In this paper, Shenqiu County, a typical county in HRB with many ponds, is selected. Based on high-resolution images with ALOS in 2010, GF-2 in 2016, and GF-1 in 2022, we employed discriminant analysis (DA), classification and regression tree, support vector machine, and random forest to extract the ponds based on object-oriented and further analyzed the spatial-temporal variations of the ponds in this county. The results of the DA in these three years exhibited a higher kappa coefficient (>0.7), and overall accuracy (>75%), signifying superior performance when compared to the other three methods. There were 4625, 5315, and 4748 ponds in 2010, 2016, and 2022, with a total area of 12.87, 11.99, and 9.37 km2, respectively. The number of ponds had a trend of rising in the initial period (2010–2016) and falling later (2016–2022), while the total area revealed a continuous decline. Meanwhile, these ponds showed a clustering phenomenon with three main clustering areas, and the scope of the clustering areas also changed to a certain extent from 2010 to 2022. Our study offers valuable methodological support for the ecological monitoring and management of water environments in regions characterized by a dense concentration of ponds. The crucial data related to ponds in this study will help inform both environmental and social development initiatives within the area. [ABSTRACT FROM AUTHOR]

In this paper, a multi-objective decision model is formulated utilizing both single-layer and three-layer radon reduction layer materials by considering radon emanation rate and cost as decision objectives. Through a multi-objective non-dominated ranking method, the optimal solution is identified from a range of feasible alternatives. In the case of the example uranium tailings pond, the optimized three-layer radon reduction layer materials reduce the comprehensive cost by 47.8% compared with the single-layer radon reduction layer materials while meeting the radon emanation rate limit. Furthermore, the utilization of non-dominated multi-objective optimization techniques demonstrates higher efficiency in optimizing each radon reduction layer schemes. [ABSTRACT FROM AUTHOR]

Ponds are generally understudied. Quality problems in urban freshwaters can arise from eutrophication, and trophic status classification gives information related to their ecological situation. Ponds may strongly differ from larger lakes for which most current trophic status classification methods have been developed. This paper seeks to compare and contrast the suitability of six trophic status indexes (TSI) and OECD trophic classifications system currently used to evaluate the eutrophication level of urban ponds in the Subtropical region. The trophic status was evaluated based on total phosphorus (TP), soluble reactive phosphorus (SRP), total nitrogen (TN) and phytoplankton chlorophyll a (Chl a) in 12 ponds placed in different cities from the Pampean region (Argentina), in the warm and cold seasons. Our results demonstrate that there was no relationship between pond size (0.08–2.45 ha) and trophic status. TSIs estimated with Chl a showed significant differences between seasons and the range oligotrophic‐hypertrophic of trophism was encountered. Conversely, TSIs estimated with nutrient concentrations (TP, SRP, TN) did not. The pond's classification in trophic levels fell in the eutrophic‐hypertrophic extreme, and only considering TN/TP broadened the trophic range. No relationship was encountered between Chl a and P; however, Chl a and TN/TP were positively correlated during the warm season. Lower trophic levels regarding TSI (Chl a) were generally associated with a dense floating‐macrophyte cover. We suggest that the TSI considered should correspond to the latitudinal region in which the ponds are located. Our results indicate that it appears restrictive to consider only P contents in ponds to assess eutrophication. Under the proposed framework, the key issues for the study of pond trophic classification will be to include not only P but N concentrations and TN/TP. Also, phytoplankton Chl a concentration jointly with floating macrophytes biomass/coverage should be considered as diagnosis parameters. [ABSTRACT FROM AUTHOR]

Pearlspot (Etroplus suratensis) is an indigenous fish endemic to India and Sri Lanka. It is the state fish of Kerala and very popular in the main tourist destinations/cousins in Kerala. It is mainly collected from brackish water creeks and canals for domestic consumption. However, several environmental and ecological problems lead to the significant reduction of pearlspot in natural water bodies. The promotion of Pearlspot farming is the only sustainable solution for this crisis. Nevertheless, one of the main issues in Pearlspot farming is the lack of quality seeds in sufficient quantities to undertake commercial farming. Massive seed production is the only way to meet the ever-increasing demand for Pearlspot seed. Several attempts to produce Pearlspot seed stock under hatchery conditions have been unsuccessful. The present paper reports the methods to achieve the mass-scale seed production using pond based seed production method. In this, two brackishwater ponds, each with dimensions of 40 m × 50 m × 0.9 m and water access from the creek, were selected. Scientific procedures were followed to produce large Pearlspot seeds throughout the year. The technology ensures the production of 50,000 seeds from a single breeding pond of 0.5-acre area, which can meet the seed requirement for above 3 ha area. The present study proved that Pearlspot reproduction in natural ponds could produce seed stock on a commercial scale. [ABSTRACT FROM AUTHOR]

Mine pollution from mining activities is often widely recognised as a serious threat to public health, with mine solid waste causing problems such as tailings pond accumulation, which is considered the biggest hidden danger. The construction of tailings ponds not only causes land occupation and vegetation damage but also brings about potential environmental pollution, such as water and dust pollution, posing a health risk to nearby residents. If remote sensing images and machine learning techniques could be used to determine whether a tailings pond might have potential pollution and safety hazards, mainly monitoring tailings ponds that may have potential hazards, it would save a lot of effort in tailings ponds monitoring. Therefore, based on this background, this paper proposes to classify tailings ponds into two categories according to whether they are potentially risky or generally safe and to classify tailings ponds with remote sensing satellite images of tailings ponds using the DDN + ResNet-50 machine learning model based on ML.Net developed by Microsoft. In the discussion section, the paper introduces the environmental hazards of mine pollution and proposes the concept of "Healthy Mine" to provide development directions for mining companies and solutions to mine pollution and public health crises. Finally, we claim this paper serves as a guide to begin a conversation and to encourage experts, researchers and scholars to engage in the research field of mine solid waste pollution monitoring, assessment and treatment. [ABSTRACT FROM AUTHOR]

This paper reports the morphology and land use/land cover of palaeochannels along the Chambal River and it explores the prospects of their revival. A total of 104 palaeochannels were identified covering a distance of 465 km. Further, the study has identified that palaeochannels have a natural valley structure that facilitates limited and seasonal water inundation at irregular places, forming pond-like structures. The ponds are a direct consequence of blockages of natural drainage, mainly, by human construction activities. It has been found that the palaeochannels, despite having a valley structure, have private ownership and have been under cultivation. Further, this paper explores revival prospects of the palaeochannels and ponds, including their inclusion in the Amrit Sarovar Scheme (a Government Scheme). These results are significant in understanding of the geomorphological evolution of the Chambal River and in the possibility of using the areas (palaeochannels and ponds) in a more meaningful way. [ABSTRACT FROM AUTHOR]

Monitoring the condition (water quality, biodiversity, hydromorphology) of small water bodies presents a challenge for the relevant authorities in terms of time and resources (labour and financial) due to the extensive length of the stream network or the sheer number of small standing water bodies. Citizen science can help address information gaps, but the effort required should not be underestimated if such projects are to generate reliable and sustained data collection. The overall aim of this paper is to propose a framework for operationalisation of citizen science targeting collection of data from small water bodies. We first consider the data gaps and the elements (water chemistry, ecology, hydromorphology) to be addressed, in order to define where citizen science could best make an impact. We review examples of tools and methods that are appropriate for small water bodies, based on experience from a selection of freshwater citizen science projects, and the support that is needed for effective and sustained small water body projects across Europe. [ABSTRACT FROM AUTHOR]

Saltpans extraction is vital for coastal resource utilization and production management. However, it is challenging to extract saltpans, even by visual inspection, because of their spatial and spectral similarities with aquaculture ponds. Saltpans are composed of crystallization and evaporation ponds. From the whole images, existing saltpans extraction algorithms could only extract part of the saltpans, i.e., crystallization ponds. Meanwhile, evaporation ponds could not be efficiently extracted by only spectral analysis, causing the degeneration of saltpans extraction. In addition, manual intervention was required. Thus, it is essential to study the automatic saltpans extraction algorithm of the whole image. As to the abovementioned problems, this paper proposed a novel method with an amendatory saltpan index (ASI) and local spatial parallel similarity (ASI-LSPS) for extracting coastal saltpans. To highlight saltpans and aquaculture ponds in coastal water, the Hessian matrix has been exploited. Then, a new amendatory saltpans index (ASI) is proposed to extract crystallization ponds to reduce the negative influence of turbid water and dams. Finally, a new local parallel similarity criterion is proposed to extract evaporation ponds. The Landsat-8 OLI images of Tianjin and Dongying, China, have been used in experiments. Experiments have shown that ASI can reach at least 70% in intersection over union (IOU) and 78% in Kappa for extraction of crystallization in saltpans. Moreover, experiments also demonstrate that ASI-LSPS can reach at least 82% in IOU and 89% in Kappa on saltpans extraction, at least 13% and 17% better than comparing algorithms in IOU and Kappa, respectively. Furthermore, the ASI-LSPS algorithm has the advantage of automaticity in the whole imagery. Thus, this study can provide help in coastal saltpans management and scientific utilization of coastal resources. [ABSTRACT FROM AUTHOR]

Water color is an important representation reflecting the characteristics of its quality in inland lakes or ponds; however, sufficient water color image samples are often difficult to obtain due to the limitation of fishery production. For few color image samples, the existing data enhancement methods based on the depth generation model have the problems of low quality of generated data, difficulty of network training, and so on; moreover, for image classification, traditional methods based on convolutional neural network (CNN) cannot effectively extract the potential manifold structure features in the image and the full connection layer in CNN cannot simulate biological neurons well, resulting in high time cost and low efficiency. In this paper, a water quality classification method has been proposed to solve the above problems, the improved semisupervised triple-generation adversarial network (triple-GAN) algorithm is used to enhance the few water color image samples, and the feature data can then be extracted from enhanced data by manifold learning method t-distributed stochastic neighborhood embedding (t-SNE). Moreover, convolutional spiking neural network (CSNN), in which spiking neural network (SNN) has replaced the original full connection layer of CNN, is used for final water quality classification. The main contribution of this paper is to build a new algorithm framework, introduce triple-GAN and CSNN into the field of classification of few water color image samples for the first time, and make an exploration of integrating artificial intelligence (AI) and water quality analysis problems. By comparing with traditional methods, the proposed method is proved to have the advantages of less time-consuming, low operation cost, and high classification accuracy. [ABSTRACT FROM AUTHOR]

To accelerate the green development of the aquaculture industry,solve the shrimp pond aquaculture non-point source pollution and achieve a balance between the economy and ecology,this paper studied shrimp pond culture environment restoration technology to realize the purpose of water saving and emissions reduction. The study mainly included solid waste collection facilities’ efficiency and tail water treatment. The aquaculture waste collection facilities are mainly composed of sedimentation towers for solid waste collection. The tailwater was treated in a three-stage upward vertical flow processing bucket by the nitrification-denitrification-secondary nitrification principle. The results showed that the solid waste collection efficiency of the sedimentation tower was 10. 6%±1. 8%,31. 1%±5. 7%,and 52. 2%±5. 2%,respectively,in the early,middle,and late stages of shrimp pond culture. The total nitrogen collection ratio was 1. 4%±0. 2%,3. 4%±0. 6%,and 9. 1%±0. 1%,respectively. Three-stage upward vertical flow processing bucket filled with biological brush under wastewater flowing condition for 60 d. After 30 days of aeration and anaerobic treatment,the dissolved oxygen content range remains 1. 11-1. 98 mg/ L,0. 27-0. 45 mg/ L,and 4. 60-5. 82 mg/ L,respectively. After determination and analysis,the removal rates of total nitrogen and ammonia nitrogen in the tailwater after solid waste collection could reach 45. 5% and 93. 6%. High-throughput sequencing analysis was conducted on the biological brush in the thirdstage treatment bucket,and it was found that the abundance of nitrifying bacteria in the third-stage bucket was the highest. They mainly include Nitrosomonas,Nitrosospira,and Nitrospira,which can well explain the effect of third-stage nitrification. The construction of the " sedimentation tower" + " three-stage upward vertical flow processing bucket" mode,will provide a leading technology and demonstration mode for promoting the shrimp seawater pond aquaculture industry transformation and upgrading. [ABSTRACT FROM AUTHOR]

The developed karst caves may become the seepage channels of heavy metal to the soil and underground water in Southwest China. Therefore, it is necessary to apply effective seepage treatments to the base of heavy metal tailing reservoirs. This paper addressed the high-pressure rotary jet technology and slurry systems used in the seepage treatment of the deep tailing sand of the Shenxiandong tailing pond located in Southwest China. In this study, the factors of fluidity, initial and final setting times, compressive strength, and permeability coefficient of the slurry were conducted. The mechanism analysis was investigated by X-ray diffraction (XRD), scanning electron microscope (SEM), and inductively coupled plasma-mass spectrometry (ICP-MS). Three different types of slurry systems were proposed, and the permeability coefficients of the solidification body following 28 days of curing were less than 1 × 10−7 cm/s. The concentrations of Pb and Zn in the slurry system containing bentonite were reduced by 26.2% and 45.7%, respectively. In the presence of slaked lime and fly ash, the concentrations of Pb and Zn could be reduced by 26.8% and 30%, respectively. A total of 2142 high-pressure rotary jet piles were completed by the high-pressure rotary jet method in the field trial. The diffusion radius of these piles was over 1 m. Following 28 days of curing, the solidification body's compressive strength was 7.45 MPa and the permeability coefficient was 6.27 × 10−8 cm/s. Both the laboratory and on-site trials showed that this method produced a good pollution barrier effect, which could prevent the diffusion of heavy metal into the adjacent underground water through the karst caves. It is also an effective way of engineering technology concerning heavy metal pollution control that occurs in tailing ponds. [ABSTRACT FROM AUTHOR]

Urban surfaces are often covered by impermeable materials such as concrete and asphalt which intensify urban runoff and pollutant concentration during storm events, and lead to the deterioration of the quality of surrounding water bodies. Detention ponds are used in urban stormwater management, providing two-fold benefits: flood risk reduction and pollution load minimization. This paper investigates the performance of nine proposed detention ponds (across the city of Renton, Washington, USA) under different climate change scenarios. First, a statistical model was developed to estimate the pollutant load for the current and future periods and to understand the effects of increased rainfall on stormwater runoff and pollutant loads. The Personal Computer Storm Water Management Model (PCSWMM) platform is employed to calibrate an urban drainage model for quantifying stormwater runoff and corresponding pollutant loads. The calibrated model was used to investigate the performance of the proposed nine (9) detention ponds under future climate scenarios of 100-year design storms, leading to identifying if they are likely to reduce stormwater discharge and pollutant loads. Results indicated significant increases in stormwater pollutants due to increases in rainfall from 2023 to 2050 compared to the historical period 2000–2014. We found that the performance of the proposed detention ponds in reducing stormwater pollutants varied depending on the size and location of the detention ponds. Simulations for the future indicated that the selected detention ponds are likely to reduce the concentrations (loads) of different water quality constituents such as ammonia (NH3), nitrogen dioxide (NO2), nitrate (NO3), total phosphate (TP), and suspended solids (SS) ranging from 18 to 86%, 35–70%, 36–65%, 26–91%, and 34–81%, respectively. The study concluded that detention ponds can be used as a reliable solution for reducing stormwater flows and pollutant loads under a warmer future climate and an effective adaptation option to combat climate change related challenges in urban stormwater management. [ABSTRACT FROM AUTHOR]

Among the several methods investigated over the past few years for the thermal mitigation of buildings in urban areas, green roof systems seem to be one of the most suitable solutions for several reasons, and researchers encourage the further study and implementation of these roofing techniques because of the potential benefits that they offer. So far, intensive, extensive and semi-intensive green roofs are considered to be a better option in terms of both energy efficiency and green area increase. However, there are some aspects that cause green roofs not to be suitable to every application, preventing their use from spreading, such as high maintenance and costs required by these sophisticated systems. Few studies aimed at overcoming the limits of green roofs have hinted at the possibility of implementing hydroponic cultures in green roof systems. This soil-less technology might overcome some issues, such as identifying the suitable substrate to support the growth of the vegetation. This paper aims to provide a systematic review of hydroponic green roof systems (HGRS), based on the rigorous analysis of the evidence gathered from the thorough evaluation of the available literature on the subject, in order to assess their potential use as an alternative to traditional green roofs. The review was carried out by analyzing studies that have assessed the performance of hydroponic green roofs as well as those of comparable systems, such as pond roofs and green roofs. The results of these studies show that HGRS provide similar performances to the above-mentioned systems in terms of the passive conditioning effect, lowering the cooling/heating load of buildings, with slight changes depending on the climatic conditions. However, they offer other significant properties such as higher efficiency in water runoff management, alongside others discussed in this paper, while also requiring minor maintenance. Significant results have been provided; however, gaps in the knowledge have also emerged, and further studies need to be conducted to provide exhaustive information. [ABSTRACT FROM AUTHOR]

This paper introduces an evaluation of the hydrodynamic performance of the flow in the screens used on the physical unit operations in a selected full-scale wastewater treatment plant (WWTP) based on Computational Fluid Dynamics (CFD) simulations. The numerical study was carried out with the ANSYS Fluent, CFD software by using the three-dimensional (3 D), steady, incompressible flow based on the Reynolds-Average Navier-Stokes equations with three different turbulence modeling. The hydrodynamic behavior of the screening facility, combined with head pond-upstream channel-bar screens was evaluated under different conditions of the mass flow rate and velocity fields. Also, the numerical study was validated against the experimental study, which implemented in-situ measurements by Acoustic Doppler Velocimeter (ADV), and consistent results were obtained between the numerical and experimental study. Interestingly, while the Realizable (real) k-ε turbulence model with the relative error of 9.31% gave the best predicting results in the head pond, the renormalization group (RNG) k-ɛ turbulence model with the relative error of 9.05% gave the best predicting results in the upstream channel and through bar screens. As a result of the experimental measurements and CFD analyses carried out in the full-scale WWTP, the function of the screening facility was found to be incomplete. Moreover, a hydraulically improved new geometry was presented to operate the existing WWTP efficiently. [ABSTRACT FROM AUTHOR]

The Chinese pond mussel Sinanodonta woodiana (Lea, 1834) (Bivalvia: Unionidae) is among the most invasive freshwater species worldwide. The last decades have seen its rapid geographical spread beyond the species' natural range, particularly in anthropogenically modified water bodies across Asia, America, and Europe where it is now very common. In this paper, we also confirm the presence of S. woodiana in Africa (Algeria) by establishing the UNESCO Biosphere Reserve and Ramsar site Oubeira Lake as a new locality for its occurrence. In all likelihood, S. woodiana was accidentally introduced in the 1980s with Asian fish species imported from Hungary for stocking purposes. The present survey was conducted in the summer of 2020, and here we present the first data on several biological aspects of 141 S. woodiana specimens collected in the lake fringe area. The age structure varied from two to over height years old; medium- and large-sized individuals with shell lengths ranging from 102.23 to 183.55 cm accounted for 96% of sampled mussels. A study of the conchological features revealed that bivalves adopt the species' typical morphological trends. Overall, our findings showed that S. woodiana succeeded in establishing a viable population in Oubeira Lake, which allows for the assumption that additional records can be predicted at a regional scale in locations related to the lake water system in Algeria and Tunisia. [ABSTRACT FROM AUTHOR]

Dissolved oxygen content is an important factor affecting eel culture. To improve the prediction accuracy of dissolved oxygen concentration in eel ponds, this paper proposes a model for predicting dissolved oxygen concentration in eel ponds based on the sparrow search algorithm (SSA) and long short-term memory neural network ( LSTM), after optimizing the hyperparameters of LSTM model using SSA algorithm, the dissolved oxygen in circulating water eel culture ponds was predicted. The results showed that the prediction accuracy of SSA-LSTM model was 96. 77%, which was 2. 09%, 3. 34% and 0. 55% higher than the control models LSTM, GRU and PSO-LSTM, respectively. The other indicators of this model, EMSE, EMAE and ERMSE, were 0. 67, 0. 53, and 0. 81, respectively, which also showed significant decreases compared with the control model. The results indicate that the SSA-LSTM model has good accuracy and robustness in predicting dissolved oxygen concentration in eel ponds, which can provide a basis for accurate regulation of water quality parameters in eel culture. [ABSTRACT FROM AUTHOR]

The paper presents the estimated changes in the soil water content, the total runoff, the sediment yield and the actual evapotranspiration for the small Bystra catchment in the east of Poland. The findings are based on the results of three simulations covering the years of 2041–2050. The simulations were based on a calibrated and validated SWAT model (2010–2017). The first variant covers just the climate change and the existing structure of soil cultivation for the three regional climate models supported by the EC-EARTH global climate model in the emission scenarios RCP4.5 and RCP8.5. Variants two and three are based on the first variant in terms of the changing climate. The second variant, however, involves placing a pond in each farm in the catchment, while the third variant involves designing huge reservoirs as a result of land consolidation. Variants two and three occur in five adaptation scenarios each. The first adaptation scenario (V2.1 and V3.1) involves only increasing the number of ponds on the farm or increasing the number of reservoirs for non-irrigated arable land crops, i.e., WWHT (winter cereals), BARL (spring cereals), CANP (rapeseed) and CRDY (other crops). The second adaptation scenario (V2.2 and V3.2) involves growing vegetables without irrigation (instead of cereals). The third adaptation scenario (V2.3 and V3.3) involves growing vegetables with irrigation (instead of cereals). The fourth adaptation scenario (V2.4 and V3.4) involves partial cultivation of vegetables and cereals. The fifth adaptation scenario (V2.5 and V3.5) involves partial cultivation of orchards and cereals. The adaptation scenarios of the irrigation of vegetables from deep water-bearing layers (second variant) or reservoirs (third variant) contribute to the increase in water content in the soil, especially in summer, in comparison with the adaptation scenarios for vegetable cultivation without irrigation. What is more, the actual evapotranspiration was higher in the adaptation scenarios involving irrigation than in scenarios without irrigation. It is known that the changes in water content in soil and the intensification of water erosion are gravely affected by modifications in crops and soil cultivation. A change from cereal cultivation to irrigated vegetable cultivation or orchards increased the water content in the soil in most climatic projections. However, the increase in the number of ponds in the second variant had little impact on the soil water content, actual evapotranspiration and overall runoff, while the erosion loss decreased. With the lower precipitation levels in the years 2041–2050 relative to 2010–2017, as presented in the emissive scenario RCP 4.5, the soil water content decreases by up to 14% for most variants. Total runoff for most variants will also be lower by 4–35%. The percentage change in sediment yield will fluctuate between −86% and 116%. On the other hand, the actual evapotranspiration for most variants will be higher. With higher precipitation levels in the years 2041–2050 relative to 2010–2017, as presented in the emissive scenario RCP 8.5, the soil water content changes slightly from −7% to +3%. Total runoff for most variants will also be higher by as much as 43%. Sediment yield for most scenarios may increase by 226%. The actual evapotranspiration for most variants will also be higher. Irrigation variants tend to increase soil available water while increasing evapotranspiration and total outflow in the catchment as compared to non-irrigated LULC. The largest increase in the soil water content is observed in most irrigation variants for RCP 4.5 (annual average 316–319 mm) (V2.3-V2.5, V3.2, and V3.3) and RCP 8.5 (annual average 326–327 mm) (V2.3-V2.5 and V3.3) as compared to V1 (BaU) (315 mm–RCP 4.5 and 324 mm–RCP 8.5) for the years 2041–2050. On the other hand, the lowest increase in soil water content is observed in the V3.5 variant, with an annual average of 292 mm for RCP 4.5 and an annual average of 311 mm for RCP 8.5. Thus, for future climate change scenarios, irrigation with water reservoirs (ponds and storage reservoirs) should be considered. The study proves the rationale behind building ponds in small catchments in order to increase water resources in a landscape and also to counteract adverse effects of climate changes, i.e., sediment outflow and surface water erosion. [ABSTRACT FROM AUTHOR]

In the process of extracting tailings ponds from large scene remote sensing images, semantic segmentation models usually perform calculations on all small-size remote sensing images segmented by the sliding window method. However, some of these small-size remote sensing images do not have tailings ponds, and their calculations not only affect the model accuracy, but also affect the model speed. For this problem, we proposed a fast tailings pond extraction method (Scene-Classification-Sematic-Segmentation, SC-SS) that couples scene classification and semantic segmentation models. The method can map tailings ponds rapidly and accurately in large scene remote sensing images. There were two parts in the method: a scene classification model, and a semantic segmentation model. Among them, the scene classification model adopted the lightweight network MobileNetv2. With the help of this network, the scenes containing tailings ponds can be quickly screened out from the large scene remote sensing images, and the interference of scenes without tailings ponds can be reduced. The semantic segmentation model used the U-Net model to finely segment objects from the tailings pond scenes. In addition, the encoder of the U-Net model was replaced by the VGG16 network with stronger feature extraction ability, which improves the model's accuracy. In this paper, the Google Earth images of Luanping County were used to create the tailings pond scene classification dataset and tailings pond semantic segmentation dataset, and based on these datasets, the training and testing of models were completed. According to the experimental results, the extraction accuracy (Intersection Over Union, IOU) of the SC-SS model was 93.48%. The extraction accuracy of IOU was 15.12% higher than the U-Net model, while the extraction time was shortened by 35.72%. This research is of great importance to the remote sensing dynamic observation of tailings ponds on a large scale. [ABSTRACT FROM AUTHOR]

Carbon capture and utilization (CCU) is an emerging technology with commercial potential to convert atmospheric carbon dioxide (CO2) into net zero or negative emission products. In microalgae-based CCU, microalgae utilize CO2 and sunlight to generate biomass for commercial applications. This paper reviews the current state of microalgal culture development for CCU and highlights its potential contribution to addressing climate change challenges. Current microalgal culture systems have not been designed for high throughput biomass growth and carbon capture. Raceways, high-rate algal ponds, and photobioreactors are the most widely used for microalgal cultivation at a large-scale. The limitations of these systems are related to microalgal growth requirements. Ponds are operated at narrow depth to ensure sufficient light distribution and thus need a large land surface. CO2 gas needs to be in a dissolved form for efficient utilization by microalgae. Innovative system designs to achieve optimized distribution of light, nutrient, and CO2 utilization for enhanced biomass production are crucial to achieve large-scale CO2 capture by microalgae. Data corroborated in this review highlights several innovative techniques to deliver CO2 effectively and enhance light illumination to microalgal cells. Submerged and internal illuminations can enhance light distribution without compromising culture volume and land requirements. CO2 delivery technique selections mainly depend on CO2 sources. The carbonation column appears to be the best option regarding efficiency, easy operation, and simple design. The downstream processes of microalgal culture (i.e. harvesting, biomass utilization, and water reuse) are important to make microalgae-based CCU a significant contribution to global carbon mitigation solutions. [ABSTRACT FROM AUTHOR]

Simple Summary: Marine waters are the most susceptible to exposure to contaminants, specifically polyaromatic hydrocarbons (PAHs) and heavy metals that are poisonous and carcinogenic. On the other hand, a marine environment can provide various natural materials that can perform biodegradation and biosorption. This research seeks to investigate various species of symbiotic sponge bacteria and assess the feasibility of developing bacterial consortium formulations for the remediation of these hazardous contaminants. Several species of symbiotic sponge bacteria are capable of biodegrading polyaromatic compounds. According to the search and analysis results, several species of symbiotic sponge bacteria have the potential to biodegrade polyaromatic compounds, such as naphthalene, anthracene, and pyrene. Other sponge symbiont bacteria or bacteria isolated from the same sponge can also be used for the biosorption of heavy metals. The ability of the symbiotic sponge bacteria to be formulated as a consortium of bacteria for pollutant remediation applications, which we refer to as the metallohydrocarbonoclastic formula, is another feature that sets them apart. The proposed use is a bioremediation approach that the community can implement to the isolation processes, such as the remediation of contaminants in water used for fish farming and shrimp plotting methods, including in ponds, to provide aquaculture products free of toxic pollutants. Toxic materials in waste generally contain several components of the global trending pollutant category, especially PAHs and heavy metals. Bioremediation technology for waste management that utilizes microorganisms (bacteria) has not been fully capable of breaking down these toxic materials into simple and environmentally friendly chemical products. This review paper examines the potential application of a consortium of marine sponge symbionts with high performance and efficiency in removing PAHs and heavy metal contaminants. The method was carried out through a review of several related research articles by the author and published by other researchers. The results of the study conclude that the development of global trending pollutant (GTP) bioremediation technology could be carried out to increase the efficiency of remediation. Several types of marine sponge symbiont bacteria, hydrocarbonoclastic (R-1), metalloclastic (R-2), and metallo-hydro-carbonoclastic (R-3), have the potential to be applied to improve waste removal performance. A consortium of crystalline bacterial preparations is required to mobilize into GTP-exposed sites rapidly. Bacterial symbionts of marine sponges can be traced mainly to sea sponges, whose body surface is covered with mucus. [ABSTRACT FROM AUTHOR]

The environmental concerns about fossil energy and rising oil prices are regular global phenomena. In such an exigency where fossil fuel sources are dwindling, carbon‐neutral biodiesel derived from microalgae lipid seems to be an important renewable energy resource. In recent years, microalgae have become a lucrative feedstock for economically viability of commercial‐scale biofuel production owing to its high biomass growth and high oil yield compared with other crops. The screening and selection of promising microalgae strain should be based on their fatty acid profile and culture conditions. The laboratory to pilot scale culture of microalgae species requires systematic experimental designs to maximize microalgal growth using open or raceway ponds, closed photo bioreactors and hybrid systems. The pros and cons of each harvesting technique, including filtration, centrifugation, sedimentation and flocculation as well cell disruption by thermal, mechanical, chemical and biological techniques, are deliberated in details. Furthermore, the application of homogeneous, heterogeneous and enzyme catalysts in transesterification processes as well as purification technologies are emphasized to ensure high‐quality biodiesel production as per ASTM norms. Microalgae comprise a potential feedstock and biodiesel synthesis from them requires a series of complex up‐streaming and down‐stream processes which are inherently disadvantageous in technology transfer from laboratory to industrial scale. This review paper is mainly focused on microalgal cultivation, harvesting, oil extraction, biodiesel production and purification technologies, and each vital process is critically reviewed in each step. © 2022 Society of Chemical Industry and John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

A new analysis method for the environmental stability of uranium tailing ponds is established in this paper, and the stability intervals and environmental stability rates of indicators are defined in precise mathematical language and analyzed with examples. The results show that the overall environmental stability of this uranium tailings pond is still in a poor state after the first phase of decommissioning treatment, and special decommissioning treatment should be carried out for factors such as pH and radionuclides Po and Pb. Using the powerful nonlinear mapping function of the artificial neural network, a radial basis function neural network algorithm was constructed to predict the environmental stability of the uranium tailing pond. It provides a new feasible method for the comprehensive evaluation technology of uranium tailings ponds. Accuracy in DOA Estimation. The research work in this paper mainly analyzed the environmental stabilization process and stability of decommissioned uranium tailings ponds, proposed a new concept of environmental stability with ecological and environmental protection concepts and gave it a new connotation, established an environmental stability evaluation index system for decommissioned uranium tailings ponds through index screening by using rough set theory, comprehensively considered the influence of environmental factors such as external wastewater and exhaust gas, and realized the multifactor. The system of evaluation indexes for the stability of decommissioned uranium tailings ponds was established by combining multiple factors, and the long-term monitoring and modeling of the environmental stabilization process of decommissioned uranium tailings ponds was carried out by using mathematical methods. The results show that the RBFNN-GA algorithm can reduce the training error of the random radial basis function neural network, improve the generalization ability of the network, and make it capable of handling large data sets. [ABSTRACT FROM AUTHOR]

The seepage accident of a tailings pond poses a serious threat to the stability of tailings dams and the surrounding environment. To reduce the occurrence of seepage accidents, this paper studies the identification of seepage hazards, the propagation law of seepage risk, the importance of hazards, and the priority of hazard treatment. To overcome the subjectivity and omission of hazard identification, according to the complexity and dynamics of tailings seepage, this paper proposes the evidence-based identification method of three-dimensional seepage hazards (EIMTSH) to identify the hazards of the tailings seepage system and the relationship between hazards. Then, on the basis of identifying the hazards of the tailings seepage system, the propagation network of seepage risk in tailing ponds (PNSRTP) is constructed based on the complex network theory. By analyzing the characteristics of the PNSRTP, it can be found that the propagation of seepage risk is scale-free and small-world. Through the node deletion method, this paper finds that the nodes with a higher degree value can reduce the network efficiency more quickly and should be governed first. By giving priority to the treatment of hazards with higher degree, the propagation of seepage risk can be reduced more quickly and the risk management level of tailings ponds can be improved, which is helpful to realize the sustainable development of mining production. [ABSTRACT FROM AUTHOR]

Aquaculture operates according to a principle of rational use of nature's trophic base, being in strict correlation with the biological period of growth and development of the fish stock in an area unit. In practice, the period during which the biological material is developing (polyphagy period) is exploited on the one hand, and the period during which the food spectrum is differentiated on the other. This gives polyculture particular advantages over monoculture, thus broadening the possibilities for exploiting the natural food base, when the biological material populated has a different food spectrum. Expanding the food base of ponds leads to increased final productivity. Obtaining and maintaining live food over a longer period of time is the main goal, followed by the processes initiated to achieve phytoplankton and zooplankton production through the administration of different types of manure. [ABSTRACT FROM AUTHOR]

With the rapid development of industrial and agricultural production, the rapid growth of population, and the acceleration of urbanization, the problem of water pollution is becoming more and more serious. Water shortages and pollution disrupt the balance of ecosystems and seriously limit people's health and rapid economic development. Nowadays, the method of repairing sewage bodies using microbial landscape aquatic plants is attracting more and more attention, and it is a big challenge to maintain the sustainable development of human beings and nature. This paper uses floating rafts to combine microorganisms and landscape aquatic plants to conduct sewage treatment experiments. According to microorganisms, landscape aquatic plants absorb nutrients in the water body, examine the changes in water quality during the restoration of microorganisms' landscape aquatic plants, and establish the growth of microorganisms' landscape aquatic plants. The relationship with changes in water quality aims to provide a theoretical basis for the treatment of slow-flowing water bodies such as lakes, reservoirs, large artificial ponds, and rivers. In this paper, the experiments are divided into four groups (A (experimental sewage + microbial inoculant), B (experimental sewage + plant), C (experimental sewage + microbial inoculant + plant), and D (experimental sewage)). It can be divided into the total nitrogen content, total phosphorus content, and COD value data, and chromaticity detection of each group of the test is continuously monitored weekly to comprehensively detect and observe the repair effect on contaminated water bodies. The experiment proved that the water quality of the three treatment groups was significantly clearer than that of the blank control group, and its clarity: microorganism + plant > microorganism > plant > blank control group. This shows that the combination of microorganisms and landscape aquatic plants can effectively reduce the various pollutants contained in sewage and reduce the color of sewage. Treating sewage using plant technology that combines microorganisms is feasible and promising. [ABSTRACT FROM AUTHOR]

The climate of Brahmaputra valley (located in the North-eastern Indian state of Assam) witnesses considerable changes with sub-tropical rain-storm atmosphere and has four well-defined seasons (monsoon, post-monsoon, winter and pre-monsoon) in a year. The state is experiencing extreme climatic events like erratic rainfall patterns (causing abnormally high floods) and drought-like situations in recent years, which adversely affects fish seed production thereby affecting pond aquaculture and fisheries enhancements in open-waters of the region. The present paper describes the major constraints faced by fish seed producers of the region because of extreme climatic events (abnormally high floods and prolonged dry spells) based on field studies in 27 fish seed production farms (randomly selected) located in three districts of Lower Brahmaputra Valley Zone of Assam, India. Primary data on different aspects of constraints faced by the fish seed producers because of extreme climatic events were collected and analysed. Rank Based Quotient values were calculated, based on ranks given by the fish seed producers for each constraint to prioritize them. Dominant constraint related to abnormally high floods faced by the fish seed producers was 'loss of brood stock' (Rank based quotient=99.1) whereas the least important constraint was 'entry of weeds/macrophytes' during floods (Rank Based Quotient=25.5). Constraints related to drought-like situations ranged from the least important ones like 'low milt production of male brood fishes' that had the lowest value (12.5) to the over-arching constraint of 'inadequate water depth in fish ponds' during pre-monsoon and prolonged dry spells (Rank Based Quotient=100.0). Adaptive strategies developed by fish seed producers of the study region to overcome the major constraints have been outlined in the paper. The need for developing improved risk management at macro-level through appropriate policy support to fish seed producers in the fish-deficit region and suggested policy support measures for ensuring sustainability are discussed. [ABSTRACT FROM AUTHOR]

Pike-perch is a very active predatory fish in its natural environment, but extremely sensitive in aquaculture units. Usually, the frequent manipulations may cause many losses in the fish farms, especially during artificial or controlled reproduction. This paper presents the obtained results at S.C.D.P. Nucet, in 2018-2020 period, regarding the pikeperch controlled reproduction in ponds units. The fish were divided into three experimental variants, in triplicate: V1- controlled reproduction, without hormonal induction, V2-controlled reproduction with hormonal induction (carp pituitary), V3 -controlled reproduction, with hormonal induction (synthetic analogue hormone-Nerestin 5A). Each variant used 5 females and 5 males with an average body weight of 2 kg/fish. The best technological indicators were registered in V3 variant, which was based on hormonal induction with Nerestin 5A hormone (88-92% eggs fertilization rate, 71-78% eggs hatching rate, about 2.7 million 7-8 days larvae). The smallest brood stock losses were recorded in V1 variant (without hormonal induction). [ABSTRACT FROM AUTHOR]

Increasing demand for fishes has necessitated boosting aquaculture production worldwide. Development of aquaculture system is possible by using manmade devices called aerators. Aerators have been used over the years which are typically installed in ponds to facilitate water movement also help to supply sufficient dissolved oxygen (DO). The main point of concern is selecting a suitable aerator in optimizing the benefits with less operational cost of aeration. The aim of this paper is the economic evaluation of the proposed venturi aerator (VA) with different existing aerators, i.e., 1HP 4 paddle wheel aerator (PWA), 2HP 4 submersible venturi jet aerator (SVJA1), 1HP submersible venturi jet aerator (SVJA2), and aspirating aerator (AA) for different pond volumes, different initial DO concentration values of pond, and varying operating hours of aerators. To find out the suitability of an aerator, analysis is based on the aeration cost assessment per unit time of operational hours. It was found that the proposed VA has a meagre aeration cost as compared to other aerators for initial DO concentration of pond when considering the low volumes of pond. Thus, the VA can be considered efficient to meet the aeration demand in an aquaculture system. [ABSTRACT FROM AUTHOR]

• The growth of solar energy usage and solar power generated in India is exponential. • Theoretical and experimental research efforts in India on solar ponds are elaborated. • The possible scopes of applications of solar ponds in India are detailed. • Problems faced by the solar pond researchers are discussed. • Future of solar pond research in India is illustrated. Solar pond is generally a shallow artificial pool of water in which considerable temperature can be established within its lower layers by suppression of convective transport. Generally, for prevention of convection, some suitable salt solution is used. In this paper, various aspects of solar pond, in terms of both simulation and experimental research advances, practical applications, economic features, challenges faced and future prospects, particularly with respect to Indian context have been reviewed. In general, the importance and the position of India at global level in terms of solar energy harvesting potential have been discussed. Apart from conventional uses of solar ponds in process heating and salt production, their applications in water distillation and thermoelectric power generation are also highlighted. Besides, stability aspect and its importance are revisited from simulations and experimental observations. Important identified areas requiring future research and development to recognize more technically feasible solar pond-based systems include organic Rankine cycle for electrical power production, crop drying, building cooling and air-conditioning based on absorption systems, thermoelectric cooling, and integration of solar ponds with other renewable energy resources. The present literature is proposed to offer guidelines in policy making aimed at addressing various societal requirements in a sustainable and affordable manner by utilizing available natural resources. [ABSTRACT FROM AUTHOR]

The effective monitoring and early warning capability of metal mine tailings ponds can improve the associated safety risk management level. The infiltration line is an important core index of tailings pond stability. In this paper, a tailings pond monitoring and early warning system, which provides technical support for the design and daily management of tailings reservoir early warning systems, is constructed. Based on a deep learning bidirectional recurrent long and short memory network, an infiltration line prediction model with univariate input and an infiltration line prediction model with multivariate input are proposed. The data adopted are those from four monitoring points of the same cross-section at different positions and data from one adjacent internal lateral displacement and internal vertical displacement monitoring point. Using the adaptive moment estimation (Adam) optimization algorithm and the root mean square error (RMSE) model evaluation metric, the multilayer perceptron model, univariate input model, and multivariate input model are compared. This work shows that their RMSEs are 0.10611, 0.09966, and 0.11955, respectively. [ABSTRACT FROM AUTHOR]

Pond aquaculture is the main form of aquaculture worldwide. However, there are problems with water quality being difficult to control, discharge pollution, low production quality, etc. Therefore, an efficient, low-carbon, and controllable pond system should be established. In this paper, we introduce two facilities' pond systems: a segregated pond aquaculture system (SPA) and a batch pond aquaculture system (BPA). In these two systems, we evaluated a rearing period with bream (Megalobrama amblycephala) and detected ecological and economic indexes such as yield, nitrogen and phosphorus conversion efficiency, and energy utilization efficiency in different aquaculture pond systems. The results showed that the yields of the SPA and BPA were 12.81 % and 74.29 %, respectively, greater than those of traditional ponds. The feed conversion ratios (FCRs) of the BPA and SPA were 1.8 and 2.1, respectively, but those of the traditional ponds were 2.3. The proportions of nitrogen converted to fish in the SPA, BPA, and traditional ponds were 29.67 %, 33.45 %, and 26.19 %, respectively, and the percentages of phosphorus converted to fish in the SPA, BPA and traditional ponds were 53.68 %, 63.38 %, and 52.20 %, respectively. With the production of 1 kg of aquatic products, the utilization of solar and feed energy in the SPA, BPA, and traditional ponds was 60.28 ± 1.12 MJ/kg, 66.59 ±0.26 MJ/kg, and 37.05 ±1.33 MJ/kg, respectively. In addition, the SPA and BPA can also use 60 % less water, reduce wastewater discharge by 80 % and use 35 % less land. These results showed that construction facility pond systems could improve pond aquaculture efficiency and have great development potential. [ABSTRACT FROM AUTHOR]

In Greece, a new bi-polar high voltage direct current (HVDC) transmission system with a ground return was designed with nominal characteristics of ±500 kV, 1 GW, between Attica in the continental country and the island of Crete, which is an autonomous power system based on thermal diesel units. The interconnection line has a total length of about 380 km. The undersea section is 330 km long. In this paper, the use of the Aegean Sea as an active part of the ground return, based on shoreline pond electrodes, was proposed to avoid EUR 200 Μ of expenses. According to the general guidelines for HVDC electrode design by the International Council on Large Electric Systems (CIGRE) working group B4.61/2017, the electric field and ground potential rise of shoreline electrodes should be studied to analyze safety, electrical interference and corrosion impacts related to the operation of the electrodes. Two kinds of studies are available; one is a simplified approach based on a spherical/pointed electrode centered at the edge of the seashore and seabed, assuming it to be sloping to the horizontal, and the other is a detailed simulated model using a suitable electric field software package. The first approach usually gives more unfavorable results than the second one, especially in the near electric field, while it can not take into account obstacles, i.e., dams, near to electrode position. The second approach demands a detailed description of the wider installation area, which cannot be available during the preliminary study, significant computational time and considerable financial resources for the purchase of a reliable specialized software package. In this research, a two-step modification of the CIGRE simplified model was proposed. The first modification deals with the obstacles in the near electric field, and the second modification deals with the use of a linear current source (instead of a point one), which can give more accurate results. Additionally, the electric field for complex electrode formation is calculated by applying the superposition method, which can be easily achieved using a common software package, i.e., MATLAB. The proposed simplified approaches were applied on shoreline pond electrode locations for the Attica–Crete HVDC interconnection line (between Stachtoroi island in Attica and Korakia beach in Crete), allowing the preliminary study to be conducted swiftly, giving satisfactory results about electric field gradient, ground potential rise and resistance to remote earth of electrodes stations for the near and far electric field. [ABSTRACT FROM AUTHOR]

The presence of ephemeral ponds and perennial lakes in the Sudano-Sahelian region of West Africa is strongly variable in space and time. Yet, they have important ecological functions and societies are reliant on their surface waters for their lives and livelihoods. It is essential to monitor and understand the dynamics of these lakes to assess past, present, and future water resource changes. In this paper, we present an innovative approach to unravel the sediment and water balance of Lac Wégnia, a small ungauged lake in Mali near the capital of Bamako. The approach uses optical remote sensing data to identify the shoreline positions over a period of 22 years (2000–2021) and then attributes water surface heights (WSHs) to each observation using the lake bathymetry. We then present a novel methodology to identify and quantitatively analyze deposition and erosion patterns at lakeshores and in lake beds. The method therefore represents a significant advancement over previous attempts to remotely monitor lakes in the West African drylands, since it considers not only changes in water depth to explain recent declining trends in lake areas, but also changes in the storage capacity. At Lac Wégnia, we recognize silting at the tributaries to the lake, but overall, erosion processes are dominant and threaten the persistence of the lake because of progressive erosion through the natural levee at the lake outlet. This factor contributes 66%±18% to the decreasing WSH trend, while 34%±18 % of the dry-season lake level changes are explained by increasing evaporation from the lake and by possibly falling groundwater tables. Due to the decreasing reservoir capacity of the lake, WSHs are declining even in the wet season in spite of positive rainfall patterns. [ABSTRACT FROM AUTHOR]

Disease outbreaks have been seen as the major threat to sustainable aquaculture worldwide. Injectable vaccines have been one of the few strategies available to control the diseases, however, the adoption of this technology globally is limited. Genetic selection for disease resistance has been proposed as the alternative strategy in livestock and aquaculture. Economic analysis for such strategies is lacking and this study assesses the economic worth of using tilapia fingerlings resistant to Streptococcosis in both cage and pond production systems. The paper also assesses the profitability of paying the higher price for such fingerlings. Partial-budgeting was used to develop a stochastic simulation model that considers the benefits and costs associated with the adoption of tilapia fingerlings resistant to Streptococcosis at the farm level, in one production cycle. In both ponds and cage production systems, the use of genetically selected Streptococcus resistant tilapia fingerlings was found to be profitable where Streptococcus infection is prevalent. In the cages and ponds where Streptococcus related mortality was ≥ 10%, the Nile tilapia aquaculture was found to be profitable even if the amount paid for genetically selected Streptococcus resistant tilapia fingerlings was 100% higher than the amount paid for standard fingerlings. [ABSTRACT FROM AUTHOR]

In species with complex life cycles, such as anuran amphibians, several traits are influenced by ecological factors during ontogeny. The anuran Physalaemus nattereri shows an aquatic spawning behavior, placing foam nests at the edges of a pond where the water contacts land, exposing tadpoles to dehydration once the pond dries. P. nattereri tadpoles are known to present an intermediate ability to survive out of water when compared to other species reproducing in permanent or temporary ponds. A decrease in size of tadpole tails has been suggested to represent a response to cope with dehydration stress, but might impair swimming performance. We investigated the effect of dehydration on morphological traits, focusing especially on tail proportions, as well as burst swimming speed. P. nattereri tadpoles were exposed to hydric stress on moist paper substrates and morphology and locomotor performance was compared within the same individuals before and after hydric stress. Our experiment showed that morphological changes induced by hydric stress were directly related to swimming performance. Individuals having smaller tails, due primarily to contractions of the medial to distal tail portions, exhibited reduced times to reach burst speed and reduced burst speeds. [ABSTRACT FROM AUTHOR]

Carrying out the treatment of aquaculture tail water and realizing the discharge and recycling of the aquaculture tail water are the inevitable trend in the development of the fishery industry at present and in the future. For this reason, this paper reviewed the characteristics of pond aquaculture tail water, the sources of pollutants in intensive aquaculture tail water, the important parameters in the water body that affect the growth of cultured organisms, and the water treatment methods in the process of aquaculture, and prospected from the technical level and industrial policy level, hoping to accumulate data for promoting the green development of aquaculture and cleaner production. [ABSTRACT FROM AUTHOR]

This paper reviews the application of computational fluid dynamics (CFD) to numerically model the two-phase flow of water and sediment in the complex environment of a stormwater retention pond. The review is intended to draw the attention of the hydraulic engineering community, specifically those involved in pond design, to the recent advancements in computational modeling of sediment transport in ponds. It provides an up-to-date survey of current simulation capability, focusing on the potential of fully three-dimensional methods for solving sediment transport in complex pond flows. An additional goal of this paper is to alert new researchers engaged in stormwater retention pond design to the research opportunities presented by CFD. Even though pond configurations have become more complex to improve their performance, many studies have continued to rely solely on single-phase models. At the present time, unsteady three-dimensional two-phase models are becoming available to study these problems. Of the multiphase models that might be considered, the particle tracking (Eulerian-Lagrangian) method and two-fluid (Eulerian-Eulerian) method both are potentially applicable to modeling sediment transport in pond-type flows. To date, only the particle-tracking method has been applied to stormwater retention ponds. The two-fluid method is capable of simulating sediment transport in retention ponds. It would be advantageous for a simulation of large-scale ponds in which the number of particles required for particle-tracking becomes excessive. Currently, fully three-dimensional CFD methods are being successfully used to model a variety of multiphase flows in mechanical and chemical engineering, as well as some specific applications in hydraulic engineering. Its application to predict sediment transport in a retention pond shows significant promise, especially when the effect of turbulence becomes challenging to model. [ABSTRACT FROM AUTHOR]

Mediterranean ecosystems are increasingly threatened by disturbances such as wildfires. These disturbances are expected to shift the selective pressures that determine trait‐dependent community assembly. In addition, the stochasticity in species assembly may decrease because of the introduction of strong selection regimes or may increase because of random variation in recruitment. However, these changes in the selection profile and stochasticity in disturbed communities have seldom been evaluated.We examined the relative roles of wildfire disturbance, local conditions and successional dynamics on the assembly of aquatic macroinvertebrate communities. We used the theory of community assembly by trait selection (CATS) to identify traits under selection and to estimate their dependence on wildfire disturbance and environmental gradients. We took advantage of a natural wildfire that partially burned a Mediterranean system of temporary ponds, which were surveyed before and after the wildfire, creating a natural before‐after‐control‐impact design.Before the wildfire, the burned and unburned ponds did not show differences in the selected traits. After the wildfire event, species with larger body sizes and scrapers were favoured in the burned ponds, while collectors and active dispersers were underrepresented. Nonetheless, local environmental conditions and successional dynamics had greater relevance in the selection of traits than the wildfire. This suggests that assembly mechanisms were largely determined by seasonal successional changes regardless of wildfire disturbance. Finally, the relevance of the analysed traits diminished during the hydroperiod, suggesting more stochastic assemblages and/or a replacement in the set of selected traits.Despite the prominent role of seasonal succession over wildfire, this disturbance was associated with a change in the selection strength over specific traits related with feeding strategies and species life histories. Both hydroperiod and wildfire highlighted a strong role of trait‐mediated processes (i.e. niche assembly). Therefore, the predicted increase in the frequency and intensity of wildfires is likely to result in community functional shifts. Furthermore, stochasticity was also important for community assembly, particularly from the middle towards the end of the hydroperiod. Our results evidenced the strong relevance of successional changes in trait‐mediated assembly mechanisms and its interplay with wildfire disturbance in temporary pond communities. [ABSTRACT FROM AUTHOR]

The text of this contribution provides a comprehensive summary of the issue of sedimentation. In the descriptive part of the paper, the issue of pond sedimentation is analyzed from both the quantitative and the qualitative point of view. The experimental part is subsequently focused on the quality of pond sediment. Detailed attention is given to land use and the quality of soil on adjacent agricultural land and their influence on sediment quality. The paper is unique in providing detailed monitoring of sediments and adjacent agricultural land at a selected pilot location, which is characterized by intensive agricultural use and by the presence of numerous water bodies (ponds used for semi-intensive fish breeding). The paper presents in detail results obtained from a laboratory analysis, especially concerning contamination by risk elements and foreign substances. Laboratory results are further compared against Czech legislation dealing with the reapplication of sediments on agricultural land. Lastly, the paper deals with the nutrient potential of sediments and with the potential impacts of their application on agricultural land. [ABSTRACT FROM AUTHOR]

This paper presents a methodology to construct a water pond in sand using bioslurry layer via the microbially induced carbonate precipitation (MICP) process. Bioslurry is calcium carbonate crystals containing high-urease active bacteria cells, allowing further microbially induced calcium carbonate precipitation when introducing cementation solutions (urea and calcium ions). With the effect of a top sand layer, the daily seepage rate of the water pond was dramatically reduced to 3 mm/day through four rounds of treatments with 1.6 M of cementation solution. In this way, a bioslurry-based waterproofing layer was formed for the construction of a water pond. Due to the bonding strength gained from calcium carbonate crystal precipitation, the flexural strength of bioslurry layer was in the range of 3.6–4.2 MPa. This is sufficient to support the hydrostatic pressure and avoid bending for water pond. With the low seepage rate and high flexural strength, the proposed bioslurry layer is a promising method for the construction of a fishpond in sand; other potential applications include stabilization of sand dunes and concrete healing. [ABSTRACT FROM AUTHOR]

Abandoned ash pond beds have been considered for their reclamation through the construction of lightweight structures. Under static conditions, an ash pond bed can sustain these structures but its stability must be ascertained under seismic conditions. This paper presents the results of geotechnical characterization and dynamic properties of pond ash samples that were collected from three different locations ranging from the inflow point to the outflow point of the ash pond of the Ropar thermal power plant (India). Strain-controlled cyclic triaxial tests were conducted on collected samples, considering the effect of various parameters, such as shear-strain amplitude, confining pressure, frequency, and density. The shear modulus of the coarser pond ash sample near the inflow was observed to be greater than that of the finer pond ash near the outflow. The shear-strain amplitude and frequency of cyclic loading increases with a decrease in the shear modulus. The damping ratio is greater in the case of finer ash. Moreover, damping ratio increases with an increase in strain amplitude and frequency of loading. The dynamic behavior of the pond ash sample was also compared with that of sand. The area near the inflow of the ash pond, where there is coarser ash was found to be more suitable for reclamation of the ash pond bed under seismic conditions. [ABSTRACT FROM AUTHOR]

[Display omitted] • Barriers to microalgal mass cultivation depend on the value of the final product. • Low value products such as biofuels have the greatest barriers to production. • Different cultivation systems and strategies present a subset of barriers. Economically successful microalgal mass cultivation is dependent on overcoming several barriers that contribute to the cost of production. The severity of these barriers is dependent on the market value of the final product. These barriers prevent the commercially viable production of algal biofuels but are also faced by any producers of any algal product. General barriers include the cost of water and limits on recycling, costs and recycling of nutrients, CO 2 utilization, energy costs associated with harvesting and biomass loss due to biocontamination and pond crashes. In this paper, recent advances in overcoming these barriers are discussed. [ABSTRACT FROM AUTHOR]