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Surface waters in the Lepenc river basin have been under the influence of a large number of contamination factors of anthropogenic nature over the last two decades. Contaminations from the soil surface easily reach surface waters, modifying water quality. Today there are many methods that are used to classify surface water quality. This paper aims to demonstrate the state of surface water quality based on the water quality index (WQI). To investigate the WQI in the Lepenc river basin, data was measured in spring, summer, and autumn of 2017. According to WQI, the waters in the Lepenc river basin, including Nerodime and Lepenc rivers, vary from WQI-36 to WQI-76. [ABSTRACT FROM AUTHOR]

The paper presents a synthesis of the researches undertaken to exploit the waste sludge from ponds at the Coroeşti plant in different fields of activity. The proposed goal was to fully process this residue, which until now is only usable in the field of building materials, but which, following the researches carried out, proved to be more than an industrial waste. Last but not least, the full utilization of this industrial waste reduces its impact on the environment, while at the same time reaping large areas of land in the natural circuit. [ABSTRACT FROM AUTHOR]

Fluctuations in environmental parameters are increasingly being recognized as essential features of any habitat. The quantification of whether environmental fluctuations are prevalently predictable or unpredictable is remarkably relevant to understanding the evolutionary responses of organisms. However, when characterizing the relevant features of natural habitats, ecologists typically face two problems: (1) gathering long-term data and (2) handling the hard-won data. This paper takes advantage of the free access to long-term recordings of remote sensing data (27 years, Landsat TM/ETM+) to assess a set of environmental models for estimating environmental predictability. The case study included 20 Mediterranean saline ponds and lakes, and the focal variable was the water-surface area. This study first aimed to produce a method for accurately estimating the water-surface area from satellite images. Saline ponds can develop salt-crusted areas that make it difficult to distinguish between soil and water. This challenge was addressed using a novel pipeline that combines band ratio water indices and the short near-infrared band as a salt filter. The study then extracted the predictable and unpredictable components of variation in the water-surface area. Two different approaches, each showing variations in the parameters, were used to obtain the stochastic variation around a regular pattern with the objective of dissecting the effect of assumptions on predictability estimations. The first approach, which is based on Colwell’s predictability metrics, transforms the focal variable into a nominal one. The resulting discrete categories define the relevant variations in the water-surface area. In the second approach, we introduced General Additive Model (GAM) fitting as a new metric for quantifying predictability. Both approaches produced a wide range of predictability for the studied ponds. Some model assumptions–which are considered very different a priori–had minor effects, whereas others produced predictability estimations that showed some degree of divergence. We hypothesize that these diverging estimations of predictability reflect the effect of fluctuations on different types of organisms. The fluctuation analysis described in this manuscript is applicable to a wide variety of systems, including both aquatic and non-aquatic systems, and will be valuable for quantifying and characterizing predictability, which is essential within the expected global increase in the unpredictability of environmental fluctuations. We advocate that a priori information for organisms of interest should be used to select the most suitable metrics for estimating predictability, and we provide some guidelines for this approach. [ABSTRACT FROM AUTHOR]

In the last decade, studies have focused on identifying the most suitable microalgal species for coupled high rate algal pond (HRAP) wastewater treatment and resource recovery. However, one of the challenges facing outdoor HRAP systems is maintaining microalgal species dominance. By increasing our understanding of the environmental drivers of microalgal community composition within the HRAP environment, it may be possible to manipulate the system in such a way to favour the growth of desirable species. In this paper, we investigate the microalgal community composition in two full-scale HRAPs over a 23-month period. We compare wastewater treatment performance between dominant species and identify the environmental drivers that trigger change in community composition. A total of 33 microalgal species were identified over the 23-month period but species richness (the number of species present at any given time) was low and was not related to either productivity or nutrient removal efficiency. Species turnover of the dominant microalgae happened rapidly, typically <1 week. Changes in the influent NH 4 -N concentration and zooplankton grazer numbers were significantly associated with species turnover, accounting for 80% of the changes in dominant species throughout the 23-month study period. Both nutrient removal and biomass production did not differ between the two HRAPs when the dominant species was the same or differed in the two ponds. These results suggest that microalgal functional groups are more important than individual species for full-scale HRAP performance. This study has increased our understanding of some of the environmental drivers of the microalgae within the HRAP environment, which may assist with improving wastewater treatment and resource recovery. [ABSTRACT FROM AUTHOR]

A better design instruction for waste stabilization ponds is needed due to their growing application for wastewater purification, increasingly strict environmental regulations, and the fact that most of previous design manuals are outdated. To critically review model-based designs of typical pond treatment systems, this paper analyzed more than 150 articles, books, and reports from 1956 to 2016. The models developed in these publications ranged from simple rules and equations to more complex first-order and mechanistic models. From a case study on all four approaches, it appeared that rules of thumb is no longer a proper tool for pond designs due to its low design specification and very high output variability and uncertainty. On the other hand, at the beginning phase of design process or in case of low pressure over land and moderate water quality required, regression equations can be useful to form an idea for pond dimensions. More importantly, mechanistic models proved their capacity of generating more precise and comprehensive designs but still need to overcome their lack of calibration and validation, and overparameterization. In another case study, an essential but often overlooked role of uncertainty analysis in pond designs was investigated via a comparison between deterministic and uncertainty-based approaches. Unlike applying a safety factor representing all uncertainty sources, probabilistic designs quantify the uncertainty of model outputs by including prior uncertainty of inputs and parameters, which generates more scientifically reliable outcomes for decision makers. Based on these findings, we advise engineers and designers to shift from the conventional approaches to more innovative and economic tools which are suitable for dealing with large variations of natural biological systems. [ABSTRACT FROM AUTHOR]

The abundance of antibiotic-resistant bacteria in the prawn pond effluents can substantially impact the natural environment. The settlement ponds, which are the most common treatment method for farms wastewater, might effectively reduce the suspended solids and organic matter. However, the method is insufficient for bacterial inactivation. The current paper seeks to highlight the environmental issue associated with the distribution of antibiotic resistant bacteria (ARB) from prawn farm wastewater and their impact on the microbial complex community in the surface water which receiving these wastes. The inactivation of antibiotic-resistant bacteria in prawn wastewater is strongly recommended because the presence of antibiotic-resistant bacteria in the environment causes water pollution and public health issues. The nanoparticles are more efficient for bacterial inactivation. They are widely accepted due to their high chemical and mechanical stability, broad spectrum of radiation absorption, high catalytic activity, and high antimicrobial activity. Many studies have examined the use of fungi or plants extract to synthesis zinc oxide nanoparticles (ZnO NPs). It is evident from recent papers in the literature that green synthesized ZnO NPs from microbes and plant extracts are non-toxic and effective. ZnO NPs inactivate the bacterial cells as a function for releasing reactive oxygen species (ROS) and zinc ions. The inactivation of antibiotic-resistant bacteria tends to be more than 90% which exhibit strong antimicrobial behavior against bacterial species. • The abundance of antibiotic-resistant bacteria (ARB) in the prawn pond effluent was reviewed. • The potential inactivation of ARB by nanoparticles was discussed. • The green synthesized ZnO NPs from plant extract is non-toxic and economical. • The inactivation mechanism of ARB by NPs was reviewed. [ABSTRACT FROM AUTHOR]

Floating photovoltaic systems (FPV) can be a more sustainable alternative for the energy transition than ground-mounted photovoltaic systems, as they avoid occupying useable land and the power generation is more distributed. This paper presents the first study that calculates the FPV technical potential at the province/municipality level, focusing on water irrigation ponds, which it is a novelty in the literature that usually focuses on large water infrastructures in a national approach. In the province of Jaén (Spain), more than 3000 ponds dedicated to agricultural irrigation have been identified and their surface area and location was obtained. The results, calculated for each pond, reveal that, in a conservative scenario, in which only 25% of their surface area is covered, a minimum of 490 MWp can be installed, which can provide 251% of the province agricultural electricity consumption and 27% of the total electricity needs. This analysis has also been performed at the municipal level, where all possible FPV plants have been aggregated and compared with consumption that would be covered at this scale. Furthermore, this technology brings additional benefits, as it avoids the occupation of 12 km2 of useable land, 8.8·106 m3/year of water evaporated, while creating more than 7000 jobs. • A Technical floating PV potential assessment on water irrigation ponds is done • A Technical floating PV potential assessment at a municipal level is done • A calculation of Multi-benefits of floating PV installation is done • An energy consumption coverage assessment at municipal level with floating PV is done [ABSTRACT FROM AUTHOR]

An experimental scale desalination pond which utilizes solar energy as a heat source is studied in this paper. The marked solar desalination pond is considered as one of the main stages in a proposed zero discharge desalination process. The effluent waste water of the desalination unit of the petrochemical complex is treated in the proposed zero discharge desalination process to produce potable water and salt. Evaporation distillation method is used in the studied solar desalination pond. Basically, this solar desalination pond is working as batch stage. At the first, the solar-powered desalination pond is introduced then the used method for distillation is discussed and the experimental results are represented in this paper, finally. The results show the feasibility of using the proposed solar-powered pond. The rate of gained distilled water by the proposed solar powered pond is compared with conventional solar pond, finally. [ABSTRACT FROM AUTHOR]

Simple Summary: We propose a pond assay for the sensory systems (PASS) of Caenorhabditis elegans as a novel method of behavioral analysis. In PASS, the test solution is injected into a recess(es) formed on agar and the response of C. elegans to its odor and/or taste is examined. Once C. elegans individuals fall into recesses (ponds) filled with liquid, they cannot return to the solid medium. In this way, the animals are trapped with certainty without the use of anesthesia. The anesthesia used to keep animals in the attractant area in conventional chemotaxis assays is no longer required, allowing pure evaluation of the response to specific substances. Furthermore, the test itself can be greatly streamlined because the preparation can be completed simply by providing a recess(es) and filling the liquid. The present paper reports the detailed method and effectiveness of the novel PASS through a series of chemotaxis assays. By using the PASS method, we found that the olfactory system of C. elegans accurately senses odors even at extremely low concentrations lower than the previously known detection threshold. This method can be applied to biosensor technology that uses C. elegans to detect chemical substances present at extremely low concentrations in environmental samples and biological samples with high sensitivity. Chemotaxis in the nematode Caenorhabditis elegans has basically been examined using conventional assay methods. Although these can be problematic, for example, in their use of anesthesia, the method has never been improved. We propose a pond assay for the sensory systems (PASS) of C. elegans as a novel population-based method of behavioral analysis. The test solution is injected into a recess(es) formed on agar and the response of C. elegans to its odor and/or taste is examined. Once C. elegans individuals fall into recesses (ponds) filled with liquid, they cannot return to a solid medium. In this way, the animals are trapped with certainty without the use of anesthesia. The anesthesia used to keep animals in the attractant area in conventional chemotaxis assays is no longer required, allowing pure evaluation of the attractant or repellent response to specific substances. Furthermore, the assay itself can be greatly streamlined because the preparation can be completed simply by providing a recess(es) and filling the liquid. The present paper reports the detailed method and effectiveness of the novel PASS. [ABSTRACT FROM AUTHOR]

Mass migrations by Odonata, although less studied than those of Monarch butterflies and plague locusts, have provoked comment and study for many years. Relatively recently, increasing interest in dragonflies, supported by new technologies, has resulted in more detailed knowledge of the species involved, behavioral mechanisms, and geographic extent. In this paper we examine, in four independent but complementary studies, how larval habitat and emergence phenology interact with climate to shape the evolution of migratory strategy in Anax junius, a common species throughout much of the eastern United States and southern Canada. In brief, we argue that fish predation on larvae, coupled with the need for ample emergent vegetation for oviposition and adult eclosion, dictates that larval development and survival is optimal in ponds that are neither permanent nor extremely ephemeral. Coupled with annual variation in regional weather and winters in much of their range too cold for adult survival, conditions facing newly emerged A. junius may unpredictably favor either local reproduction or long-distance movement to more favorable areas. Both temperature and hydroperiod tend to favor local reproduction early in the adult activity period and migration later, so late emerging adults are more likely to migrate. No single pond is always predictably suitable or unsuitable, however, so ovipositing females also may spread the risk to their offspring by ovipositing at multiple sites that, for migrants, may be distributed over very long distances. [ABSTRACT FROM AUTHOR]

Plant seeds are highly sensitive to environmental stress. The aim of our paper was to assess the effects of high nutrient levels in the water and sediment of thermal ponds and rivers on the ecosystem, based on the seed germination and root elongation of S. alba in the Lëngaricës Valley, Albania. Significant differences were found in the physicochemical parameters of the water and the sediment among samples taken from the river, the thermal ponds, and the control ponds. We found significant differences in the root elongation of S. alba seeds based on the water and the sediment of the river, the thermal ponds, and the control ponds. Significantly longer roots were found in the thermal water and sediment than in the river. Among the physicochemical parameters of the water and the sediment, Cu, K, and Li were stimulants for root elongation. With Cu, Li, Ba, Mg, Ni, carbon-dioxide, and sulphate-ion, a stimulant effect was found on seed germination. Our results indicated that the high mineral level of the water and sediment of these thermal ponds had positive effects on the ecosystem based on seed germination and the root elongation test of S. alba. [ABSTRACT FROM AUTHOR]

In this paper we investigate the potential of melt pond fraction retrieval from X-band polarimetric synthetic aperture radar (SAR) on drifting first-year sea ice. Melt pond fractions retrieved from a helicopter-borne camera system were compared to polarimetric features extracted from four dual-polarimetric X-band SAR scenes, revealing significant relationships. The correlations were strongly dependent on wind speed and SAR incidence angle. Copolarisation ratio was found to be the most promising SAR feature for melt pond fraction estimation at intermediate wind speeds (6:2ms-1), with a Spearman's correlation coefficient of 0:46. At low wind speeds (0:6ms-1), this relation disappeared due to low backscatter from the melt ponds, and backscatter VV-polarisation intensity had the strongest relationship to melt pond fraction with a correlation coefficient of -0:53. To further investigate these relations, regression fits were made both for the intermediate (Rfit2 D 0:21) and low (Rfit2 D 0:26) wind case, and the fits were tested on the satellite scenes in the study. The regression fits gave good estimates of mean melt pond fraction for the full satellite scenes, with less than 4% from a similar statistics derived from analysis of low-altitude imagery captured during helicopter ice-survey flights in the study area. A smoothing window of 51×51 pixels gave the best reproduction of the width of the melt pond fraction distribution. A considerable part of the backscatter signal was below the noise floor at SAR incidence angles above ~40°, restricting the information gain from polarimetric features above this threshold. Compared to previous studies in C-band, limitations concerning wind speed and noise floor set stricter constraints on melt pond fraction retrieval in X-band. Despite this, our findings suggest new possibilities in melt pond fraction estimation from X-band SAR, opening for expanded monitoring of melt ponds during melt season in the future. [ABSTRACT FROM AUTHOR]

Chains of ponds are a discontinuous river type found in Australia. Their unusual morphology, important ecological functions and increasing rarity make them a priority for conservation, and yet very little research has investigated their physical structure, behaviour and evolution. This paper reconstructs the Holocene evolution and environmental history of Crisp's Creek, a headwater chain of ponds in the Southern Tablelands of NSW Australia. This history establishes baseline information on the physical template that can be used to assess a range of other biophysical processes and design appropriate river rehabilitation and management strategies for these rivers. Sedimentary aggradation began in the Late Holocene, at least 3.7–1.3 ka, broadly synchronous with aggradation phases at other sites in southeast Australia. Since European arrival in the Nineteenth Century, parts of the river incised, destroying intact ponds and smothering formerly swampy floodplains with post-incision alluvium. However, sections unaffected by incision provide a rare opportunity to examine the evolutionary trajectory of an intact variant of these rivers. This research deepens our understanding of the evolutionary context for contemporary river behaviour as relevant for designing appropriate and effective conservation and rehabilitation strategies for chains of ponds. [ABSTRACT FROM AUTHOR]

The paper presents the critical analysis of the causes and consequences of the Bozanta Tailing Pond accident in October 2017. This occurred as a result of the breakdown of the last penstock, compromising the last simple and controlled way of exiting the pond water. The gravity of the accident was accentuated by immediate discharges into the nearby river named Sasar. [ABSTRACT FROM AUTHOR]

Natural environment plays a very important role in the life and living of human beings. Culture, the man-made environment has its origin on the earth from the time when human beings started interaction with their natural environment for satisfaction of basic, derived and integrative needs. Religion, an integrated part of culture is also the result of satisfaction of that psychic and integrative need. The concept of Nature-Man-Spirit Complex and Sacred Complex and the concept of Great and Little traditions contributed a lot to the understanding of the religious and cultural complexion of Indian villages. The villagers depend on their natural surroundings for their socio-cultural necessities and believe that various type of spirits reside in village forest, land and water bodies. In Chhattisgarh, ponds not only act as the source of water for the villagers, but also play a very important role in the socio-economic and cultural life of villagers. Present study is an attempt to observe the changing relationships of People-Pond-Spirit complex as a part of little tradition in a village of Chhattisgarh. The paper argues that Ponds are an important part of village life and belief pattern of the villagers in Chhattisgarh in general. [ABSTRACT FROM AUTHOR]

The common means of wastewater pre-treatment is impractical in large-scale wastewater treatment plants (WWTP). There is still a lack of suitable microalgae to treat raw dairy wastewater (DWW) with high organic matter concentration. For screening more diverse microalgae to treat raw DWW, the growth characteristics and metabolite production of ten algal strains cultured in undiluted DWW were studied in this paper, among which three were able to tolerate excessive chemical oxygen demand (COD) concentration and yielded high biomass concentration. Under the condition of 25 ± 1 °C and 55 μmol/m2/s, the most suitable strain were Scenedesmus SDEC-13, Chlorella pyrenoidosa SDEC-35, and Chlorella vulgaris SDEC-34, all of which had biomass concentrations above 1.2 g/L and protein contents above 45%. Based on the feasibility of cultivating microalgae with raw DWW, an alternative alga-based WWTP strategy was provided for the first time. The most important modification was the construction of the photobioreactor (PBR) to replace hydrolytic upflow sludge bed (HUSB) reactor and remove anaerobic-aerobic (AO) pond. The dairy WWTP with a PBR unit (1.68 × 104 m3) will yield a biomass production of 1.44 × 106 kg/year while capturing 2.59 × 106 kg CO 2 /year. Through carbon comparison and economic analysis, we believe that the use of microalgal PBRs for the treatment of wastewater from dairy plants presents a cost-effective and environmentally friendly alternative for the future. And future research should focus on pilot scale photobioreactor in the natural environment and large-scale treatment of dairy wastewater. [Display omitted] • Three algal species tolerated high COD concentration and achieved excellent biomass. • Chlorella pyrenoidosa SDEC-35 obtained 50.2% protein content in dairy wastewater. • A PBR based on mixotrophic algae is a great substitute for HUSB and AO pond in WWTP. • A WWTP with an algal bioreactor unit (1.68 × 104 m3) will capture 2.59 × 106 kg CO 2 /year. [ABSTRACT FROM AUTHOR]

Due to the frequent irrigation and excessive fertilization during the rice production in China, diffuse nitrogen (N) and phosphorus (P) pollution from paddy fields has become a serious environment problem and poses great challenges to national water and food security. Considering the regional heterogeneities of climate, cultivation types and cropping systems of rice planting, many water management strategies have been proposed and implemented to control diffuse N and P pollution. However, the water management optimization at different scales (the field scale, the watershed scale and national scale) is lack of comprehensive analyzed. Here, this paper summarized the characteristics of frequent-used water managements and recommended the optimal water managements after identifying the critical risk periods of diffuse N and P runoff losses at the field scale. The effects of water management optimization on diffuse N and P pollution control at the watershed and national scale were also synthetically reviewed. The results indicated that optimized field water management decreased irrigation water use (38.7–40.0%) and reduced diffuse pollution (25.5–38.8%) without significantly compromising rice yield security (−4.20 to 6.5%). The critical risk periods of diffuse pollution were pre-flooding in the Northeast Plain, pre-flooding, regreening stage for transplanting rice (the seeding-three leaf stage for direct seeding rice) and within 2 weeks after topdressing fertilization in the Yangtze River Basin and Southeast Coast in China. The corresponding water managements for these periods has been proposed after considering the climate, precipitation and fertilization characteristics. Ditches and ponds intercepted water and nutrients and mitigated 6.0–39.0% N and P runoff losses in paddy field watersheds. Furthermore, the extensive implementation of paddy water management optimization (paddy fields, ditches and ponds) combined with other advanced agricultural measures, for example, fertilization optimization, would decrease diffuse N and P pollution by 40.7–80.8% at the watershed scale and 44.7–88.1% at the national scale, respectively. This research provided great insights into the specific characteristics of paddy water managements from the fields, watershed and national scale, proposed optimal water management strategies for the realization of sustainable rice production in China, and also summarized the emerging development trends for future research directions. [Display omitted] • Optimal paddy water managements at field, watershed and national scales were analyzed. • Optimal water managements were proposed for critical risk periods at field scale. • Future emerging prospects of paddy water managements from different scales were proposed. [ABSTRACT FROM AUTHOR]

Pesticides are a non-point source of pollution affecting the quality of drinking water supplies and aquatic environments. Many facilities are set up to reduce the transfer of pesticides from agricultural parcels into the environment, thereby preventing their input into water bodies. Artificial ponds collecting runoff and erosion fluxes represent a complementary tool for mitigating pesticide transfer. Ponds are free-water surface constructed wetlands, rarely dry out, and do not exceed 2 m in depth. Their main compartments include a water column, a sediment layer, living organisms, and suspended particles. The dissipation potential of ponds is due to a combination of physical, chemical, and biological processes that pesticides undergo in an interplay between different pond compartments. Although many studies on the dissipation potential of ponds focus on nitrates and suspended sediments, very little is known about the behavior of pesticides. Also, most studies evaluate a process individually without emphasizing its eventual interaction with other processes. Few papers address and compare mathematical formulations of pesticide transfer and transformation processes for artificial pond modeling. In this review, we investigate the interactions and contribution of multiple processes to artificial pond dissipation function by comparing their rates evaluated at different scales. We also discuss the mathematical formulations of these processes and their relationship with pesticide properties. Our evaluation suggests that quantifying the contribution of each process to pesticide dissipation in artificial ponds is an important tool for the hierarchization of dissipation processes. We believe that quantification and hierarchization may improve the estimation of overall artificial pond efficiency. We anticipate this work to be the basis for developing a process-based model of pesticide fate in artificial ponds. The model will be particularly helpful in setting up the dimensioning criteria to design performant and efficient ponds in order to mitigate pesticide transfer into the environment. [Display omitted] • Identification and formalisms of dissipation processes of pesticides in artificial ponds. • Sorption as a key process for lowly soluble and hydrophobic pesticide dissipation. • Biotransformation enhanced in water-substrate interfaces favoring microbial activity. • Interplay of processes contributes more significantly to the dissipation of pesticides. [ABSTRACT FROM AUTHOR]

Summary: Managed Aquifer Recharge (MAR) is a well-established practice for managing groundwater reserves in a sustainable way. In this paper, we look at the influence of temperature variations of the infiltration water in the recharged aquifer. The paper focuses on MAR systems consisting of an infiltration pond surrounded by extraction wells. A number of different 2D configurations and an operational system in the Belgian dune area are investigated using field observations and numerical modelling with SEAWAT. Seasonally varying temperature in the infiltration water results in a zonation of subsequent lower and higher temperatures in the aquifer. The impact of infiltration water temperature in the aquifer is significant but restricted to the area between the pond and extraction wells, quickly decreasing farther from the infiltration area. Colder water during winter results in a decrease of infiltration capacity which can be as high as 1.5–2 times with respect to summer infiltration. Infiltration water temperature variations equally influence residence times of the infiltrated water. In general, residence times become smaller for water infiltrated during summer and larger for water infiltrated during winter. Infiltration and extraction rate, their ratios and seasonal variability, and location of extraction wells are all contributing factors to the impact of varying temperature of the infiltration water. Finally, it is shown that temperature provides only a rough proxy for residence times of solutes because of the important conduction of heat. [Copyright &y& Elsevier]

Algae-derived biocrude oil is a possible renewable energy alternative to fossil fuel based crude oil. Outdoor cultivation in raceway ponds is estimated to provide a better return on energy invested than closed photobioreactor systems. However, in these open systems, algal crops are subjected to environmental variation in temperature and irradiance, as well as biotic invasions which can cause costly crop instabilities. In this paper, we used an experimental approach to investigate the ability of species richness to maximize and stabilize biocrude production in the face of weekly temperature fluctuations between 17 and 27 °C, relative to a constant-temperature control. We hypothesized that species richness would lead to higher mean biocrude production and greater stability of biocrude production over time in the variable temperature environment. Counter to our hypothesis, species richness tended to cause a decline in mean biocrude production, regardless of environmental temperature variation. However, biodiversity did have stabilizing effects on biocrude production over time in the variable temperature environment and not in the constant temperature environment. Altogether, our results suggest that when the most productive and stable monoculture is unknown, inoculating raceway ponds with a diverse mixture of algae will tend to ensure stable harvests over time. [ABSTRACT FROM AUTHOR]

This paper combines spatial poetics, landscape architecture theory and humanistic geographical ideology, analyzing Tang Dynasty Poet Bai Juyi’s . . . aesthetics of multi-layer landscape architecture on the waterscape of his Lü-dao Garden . . . This paper is divided into five parts. Part One discusses Bai Juyi's Lü-dao Garden as the typical “Dream Home;” the poet projected his subjective values and conducted multi-layer landscape architecture to shape his wooded garden, and waterscape is a crucial element in this project. Part Two discusses the aspect of the material environment in landscape architecture. Livi-dao Garden, with a pond in the center surrounded by meandering water paths, creates a focal point to showcase variations and can be appreciated from 360 degrees. It also offers a space allowing for wandering endlessly in loops. Thirdly, discuss the aspect of the artistic scene which Bai Juyi's created with the arrangement of surrounding waterscapes under the bed, producing the exclusive delight of “comer space” and symbolic imagery of lounging gestures above water. The reflection in the water is used to establish a microcosm, liberating conventional relationships when viewing the space. By re-organizing sceneries from South of the Yangzi River, he created a miniature homeland based on his memory; a transcendental angle is used as if lying on a boat to review the self's perspective. Part Four discusses landscaping actions involved in accordance with the ultimate spiritual principles. Bai Juyi applied a method of contemplative investigation in researching matters and efforts in meditative Zen practices to create a deep, distilled and lucid state for Lu-dao Garden as the ultimate spiritual principle, constructing a blissful condition of self-containment and perfection. Part Five is the conclusion. [ABSTRACT FROM AUTHOR]

In Europe, ponds are an exceptionally numerous and widely distributed landscape feature forming a major part of the continental freshwater resource and contributing significantly to freshwater biodiversity conservation. This has been reflected by a growing scientific concern over the first few years of the twenty-first century and is evidenced by an increasing number of academic publications on pond related topics, particularly those relating to biodiversity. It is essential, however, that this expanding scientific knowledge is widely disseminated to those involved with pond management and is then rapidly translated into action. Inevitably, the task of transferring science to practice remains a significant challenge. As a first step towards meeting this challenge the European Pond Conservation Network (EPCN), at its biennial meeting in 2008 in Valencia (Spain), made this the main theme of the conference together with two special workshops further encouraging exchanges between scientists, practitioners and policy makers. The papers selected for this special issue of Hydrobiologia (from over 120 communications presented) are all from the conference. They represent a diverse collection of themes from across the continent and North Africa and present new and original insights into topics as wide ranging as: pond biodiversity; human disturbance; landscape ecology; ecological assessment and monitoring; practical management measures; ecological restoration; hydrology and climate change; invasive species and threatened species. In all cases, the papers demonstrate an overriding need for the development of a tight link between scientific knowledge and management. Furthermore, scientific advances have to be beneficial for on the ground management and, vitally, have to be disseminated, communicated and implemented into local, national and international policy. As such, national and international networks (such as the EPCN) have a central role to play and have to develop a robust information and communication strategy which will enable the dissemination of best practice materials and advice across the continent and beyond. The work contained in this volume represents a step in the right direction and will help to ensure that ponds remain a characteristic and highly visible feature of the European landscape in the twenty-first century. [ABSTRACT FROM AUTHOR]

Summary: This paper predicts saltwater advection in groundwater from leaky aquaculture ponds. A closed form solution for the potential function, stream function and velocity field is derived via the series solutions method. Numerically integrating along different streamlines gives the location (or advection front) of saltwater throughout the domain for any predefined upper time limit. Extending this process produces a function which predicts advection front location against time. The models considered in this paper are easily modified given knowledge of the required physical parameters. [Copyright &y& Elsevier]

Dissolved oxygen (DO) is a key ecological factor to measure the quality of water in the aquaculture. As the pond water body is affected by the breeding environment, the spatial distribution of DO shows a certain law in the entire pond. Therefore, to simulate the distribution of DO in aquaculture waters and grasp the temporal and spatial variation of DO is the key to achieving precise regulation of DO. For this purpose, this paper proposed a method for simulating the temporal and spatial distribution of DO in pond culture based on a sliding window-temporal convolutional network together with trend surface analysis (SW-TCN-TSA). This paper first utilized SW to construct DO data sets with different prediction durations, and then used the improved TCN model to realize one-dimensional time series prediction for DO at single monitoring point. Based on the prediction results of DO, a TSA method was performed on the predicted values of DO at the extreme moments of all discrete monitoring points, so as to realize the simulation of the temporal and spatial distribution of DO in the pond. Experimental results show that the SW-TCN model has better prediction performance for one-dimensional time series prediction of DO. Compared with traditional deep networks, such as CNN, GRU, LSTM, CNN-GRU and CNN-LSTM, the values of evaluation indicators (MSE, MAE and RMSE) have been greatly improved. In the process of trend surface fitting, all fitting R2 of DO at different water depths are higher than 0.9, indicating that the TSA can accurately reflect the temporal and spatial distribution of DO. This method can provide a basis for the prediction and early warning of DO in the three-dimensional space of the pond and has high practicability in aquaculture. • The accurate time series prediction of DO based on SW-TCN has been realized. • A TSA method was used to simulate temporal and spatial distribution of DO in different water layers. • The proposed method can realize the early warning of DO in the three-dimensional space of the pond. [ABSTRACT FROM AUTHOR]

The paper presents results from an experimental and numerical study of wind-induced flows and transportation patterns in highway wet detention ponds. The study presented here is part of a general investigation on road runoff and pollution in respect to wet detention ponds. The objective is to evaluate the quality of long term simulations based on historical rain series of the pollutant discharges from roads and highways. The idea of this paper is to evaluate the effects of wind on the retention time and compare the retention time for the situation of a spatial uniform wind shear stress with the situation of a "real" spatial non-uniform shear stress distribution on the surface of the pond. The result of this paper shows that wind plays a dominant role for the retention time and flow pattern. Furthermore, the results shows that the differences in retention time between the use of uniform and non-uniform wind field distributions are not significant to this study. [ABSTRACT FROM AUTHOR]

The paper examines the potential of waste stabilisation ponds to provide water for reuse in extreme continental climates such as those of central Asia, where precipitation is low and summer evaporation rates are high. A simple model is used to predict water availability, BOD and faecal coliform removal for different configurations and operating regimes. The results show a significant proportion of flows could be saved for irrigation or river and aquifer replenishment: if current standard designs can be modified for these climates, the outcome is likely to be both more robust and more flexible in terms of types of reuse. The paper concludes with three case studies of evaporation pond systems in Kazakhstan, assessing their potential for conversion to full biological treatment systems for water conservation and reuse. [ABSTRACT FROM AUTHOR]

Abstract: Active filters, which facilitate phosphorus (P) removal via precipitation and/or adsorption, offer a promising ‘appropriate technology’ for upgrading small wastewater treatment systems. Research on active filters for P removal using steel slag material has been conducted in laboratories across the world, however, field experiments have been limited and long-term data is practically non-existent. This paper presents a decade of experience on P removal by active slag filters at a full-scale treatment plant. During 1993–1994 the filter removed 77% of the total phosphorus (TP), and over the first 5 years of the filter''s operation it reduced the mean effluent TP concentration to 2.3mgl−1. However during the sixth year of operation P removal was significantly reduced. Over the 11 years of monitoring, 22.4tonnes of TP was removed by the filter, 19.7tonnes of this in the first 5-year period. It was determined that the slag material maintained its maximum removal potential until reaching a P-retention ratio of 1.23kg TP per tonne of slag. This paper provides the first long-term field data for slag filters, and shows that they can provide P removal for a half a decade before filter replacement/rejuvenation is required. [Copyright &y& Elsevier]

In recent years more and more reclamations have been carried out on waste ponds or mine tailing ponds. The deposits in these ponds are ultra-soft and may still be undergoing self-weight consolidation. Reclamation and soil improvement works in these areas are very challenging. They require special attention. Conventional reclamation and soil improvement methods are no longer workable. This paper highlights the experience obtained from reclamation and soil improvement works on such soil in a project in Singapore. The fill was placed using a sand spreader, and the ultra-soft deposit was strengthened with a high-strength geotextile. Prefabricated vertical drains and staged construction were used to accelerate the consolidation process. The monitoring of settlement and pore pressure requires modification of conventional instruments to cater for the low strength of the ultra-soft soil and the large strain of deformation. The paper also out- lines a new method to estimate the settlement based on large-strain theory. Finally a case study is presented to validate the proposed method in the determination of settlement magnitude and the time rate of settlement. [ABSTRACT FROM AUTHOR]

A watershed-based development approach can solve the problems of rural economy in India. Large-scale watershed development projects are being implemented in India; however, in most areas, conventional practices of soil and water conservation are followed. Certain innovative approaches are being evolved, which have a very high potential to be replicated in arid and semi-arid regions of the country. This paper presents an innovative approach of watershed development using a farm-pond network. This paper is based on a successful project in a watershed of 1,004 ha in the Adihalli-Myllanhalli village area of Hassan district in Karnataka, India. After the implementation of farm-pond based watershed development project between 1996 and 2000, the whole ecosystem and socio-economic scenario has undergone a major change in the area. The availability of water for drinking and agriculture, the establishment of orchards and agro forestry in farmlands, the increase in overall agricultural production, and the creation of local self-employment are some visible impacts. This watershed approach has already been adopted by several organizations in Karnataka and is being replicated in their respective program areas. [ABSTRACT FROM AUTHOR]

Climate change is affecting water quantity and quality, with severe impacts on agricultural production. The use of nature-based solutions to address these challenges is increasing. Natural water retention ponds have been identified as viable solutions for water management in agriculture. This paper aims to characterize water retention ponds, and to quantify their effectiveness, direct and indirect benefits, and costs. The paper analyses the case of the Lamone river catchment in Emilia-Romagna Region (Italy), characterized by large seasonal variability of water flow and availability. This is an important agricultural area that relies heavily on irrigation. Here water retention ponds are systematically applied to store water in winter, for use during the dry season. They can play a strategic role in ensuring irrigation water availability, while preserving minimum environmental flow. The paper analyses both the benefits of ponds for the water balance at sub-catchment scale, and the environmental effects produced by ponds having an ecological functionality. We develop an implementation scenario for new ponds, and we appraise the contribution of new ponds whose siting is chosen in order to maximize landscape connectivity. Their hydrological effects are evaluated under present and future climate change scenarios, showing how they may increase water availability for irrigation, while improving the river flow regime. More water for irrigation can favour additional agricultural production, while a more ecologically oriented design of ponds can favour to landscape ecological improvements. The investment costs of ponds are justified in economic terms, and the additional costs of improved design are expected to be balanced by the ecosystem services obtained. The business model required to operate this type of intervention is discussed, together with potential funding channels. We discuss two innovative incentive models based on compensation of land and production lost, and on tradable development rights that can be applied to widely support NBS implementation. [Display omitted] • Nature-based solutions can mitigate climate change effects on water in agriculture. • We assess values and costs of water retention ponds to mitigate water scarcity. • Water retention ponds should be planned in green infrastructure network perspective. • Building greener water retention ponds involves co-benefits and extra-costs. • Extra-costs should be compensated collectively by financing schemes. [ABSTRACT FROM AUTHOR]

The present study was carried out to measures and analyses the condition of cyprinids, reared in a two IMTA systems by using a few organosomatic indices. The first pond (PCP) was used for rearing common carp in polyculture with other cyprinids. The second pond was divided in two parts: first part-common carp (CP) and the second part - polyculture (PP). During this experimental period (May to September), the biometric measurement was made monthly. Regarding to the feeding regime, fish were feed only in PCP and CP pond (part of CP-PP pond). At the end of the experiment the results showed an increase in viscerosomatic index (VSI), hepatosomatic index (HIS), gastrosomatic index (GaSI) at cyprinids in CP and PCP. This is mainly due to the fact that only in CP and PCP feed was administered. An increase in the relative gut length (RGL) index was observed especially in grass carp, followed by the other cyprinids in the PP pond, part of the CP-PP pond, in which feed was not administered. In conclusion, this shows us that cyprinids can adapt to the natural feeding conditions in case of feed absence (cereals mix). [ABSTRACT FROM AUTHOR]

Ponds are widely distributed throughout Southern China. However, ponds have not fully played their role because of the shortage of the feasible optimal operating schemes for ponds. The main purpose of this paper was to determine an optimal operating scheme of ponds through mathematical statistics method and simulation. Firstly, distribution of a ten-day rainfall in the past 30 years (1981-2012) was fully analyzed. Then the Monte Carlo method was used to simulate the ten-day rainfall in the next 500 years. After that, a model was constructed to calculate the water quantity balances in fields, ponds and reservoirs, with the goal of maximizing the yield per unit area. Based on their built-in flexibility for storing water and their timely and reliable water supply, ponds were firstly used. Then reservoirs and ponds were adopted to irrigate crops in irrigation peak periods. The model was to simulate the different operating rules of ponds in each year, and the optimal operating rule of ponds for each year was selected by using orthogonal experiment method. At last, the operating rule under different typical year was attained by analyzing the above results. The methodology was applied to the Yangshudang reservoir irrigation district, which is a sub-region of Zhanghe irrigation district, to demonstrate its applicability. It features a subtropical monsoon climate with an average annual rainfall of 862.8 mm. Although the Yangshudang reservoir with the active storage capacity of 13.5 million cubic meters is the main irrigation water source, there are more than 3480 ponds with the storage capacity of 3.7295 million cubic meters that can support supplementary irrigation. From the results, in normal year, ponds should reserve 10% in mid-June, reserve 20% in mid-July, reserve 30% in late May, early June, late June, early July, and could be used up in the other ten-day. In dry year, ponds should reserve 10% in late May, reserve 20% in early June and late June, reserve 30% in mid-June, early July and mid-July, and could be used up in the other ten-day. In special dry year, ponds should reserve 10% in late May and mid-July, reserve 20% in late June, early July and late July, reserve 30% in early June and mid-June, and could be used up in the other ten-day. Comparing the probability to ensure basic yield, the irrigation effect was obvious under the optimal operating rule. In normal year, the probability of relative yield greater than 0.6 was increased by 2.38%. In dry year, the probability of relative yield greater than 0.6 was increased by 8.80%. In special dry year, the probability of relative yield greater than 0.6 was increased by 11.29%. This study is of great significance for reservoir-pond co-regulation and improving the irrigation effect. [ABSTRACT FROM AUTHOR]

Ponds are recognized worldwide as biodiversity hotspots; nevertheless in Patagonia studies are still needed that reveal the composition and status of their communities. This paper analyses the temporal patterns of aquatic invertebrates and assesses the environmental factors that best predict the variation in community structure at three small intermittent ponds, subjected to ranching practices (summer stocking) in the Patagonian steppe. Variables identified as important in structuring community assemblages were related to environmental conditions (rainfall and water temperature), chemical features (conductivity and pH) and biotic factors (macrophyte coverage). During the connected phase only a small number of invertebrate species were present, in contrast to the 11 taxa that were frequent and abundant during the isolated period (Eucyclops chilensis, Hyalella curvispinaandRhionaeschnasp. were dominant). In this sequence the submersedMyriophyllum quitenseandLilaeopsis maclovianaplayed a crucial role offering habitat and food resources. The present study provides valuable information that can contribute to minimizing the environmental damage and the development of strategies for the conservation of Patagonian wetlands. [ABSTRACT FROM AUTHOR]

The Ohio Department of Transportation has more than 60 facilities without sewer access generating approximately 19 million gallons of winter maintenance wash water. Off-site disposal is costly, creating the need for sustainable management strategies. The objective of this study was to conduct an exploratory feasibility analysis to assess wash water disposal and potential reuse as brine. Based on a comprehensive literature review and relevant environmental chemistry, a sampling protocol consisting of 31 water quality constituents was utilized for monthly sampling at three geographically distinct Ohio Department of Transportation garages during the winter of 2012. Results were compared to local disposal and reuse guidance limits. Three constituents, including a maximum copper concentration of 858 ppb, exceeded disposal limits, and many constituents also failed to meet reuse limits. Some concentrations were orders of magnitude higher than reuse limits and suggest pre-treatment would be necessary if wash water were reused as brine. These water quality results, in conjunction with copper chemical equilibrium modeling, show pH and dissolved carbon both significantly impact the total dissolved copper concentration and should be measured to assess reuse potential. The sampling protocol and specific obstacles highlighted in this paper aid in the future development of sustainable wash water management strategies. [ABSTRACT FROM AUTHOR]

This paper reports the results of a survey of large-bodies water beetles and bugs in selected protected ponds in Southern Bohemia, using baited traps in the spring and autumn in 2014. We found altogether 21 species of beetles and 5 species of bugs. During the survey we confirmed the presence of the protected diving beetle Graphoderus bilineatus in the Vizir National Nature Monument near Chlum u Třeboně and discovered one new locality of this species at the pond of Smyček in the Velký a Malý Tisy National Nature Reserve near Lomnice nad Lužnicí. [ABSTRACT FROM AUTHOR]

The paper presents the results of a field survey focusing on abandoned water reservoirs in the České Budějovice region (2011-2016) which was combined with research into written and cartographic sources. It is part of a broader research project about historic landscape. The remains of 109 reservoirs in total, which in some cases form larger groupings, were documented. Most of them are situated in forested terrain and some of them could be subjected to a detailed investigation including archaeological and natural science methods. [ABSTRACT FROM AUTHOR]

Urbanisation is one of the greatest threats to freshwater biodiversity, with the area of land covered by towns and cities predicted to increase significantly in the future. Ponds are common features in the urban landscape and have been created for a variety of reasons ranging from ornamental/amenity purposes through to the detention of urban runoff and pollution. This paper aims to quantify the aquatic macroinvertebrate biodiversity associated with garden, ornamental and other urban ponds in Leicestershire, UK. We examined the macroinvertebrate biodiversity of 41 urban ponds (13 garden, 12 park and 16 other urban ponds) within the town of Loughborough, UK. Park ponds supported greater macroinvertebrate richness than garden or other urban ponds. Garden ponds were the most taxon poor. Pond size was strongly correlated with macroinvertebrate diversity. Collectively, urban ponds were found to be physically and biologically heterogeneous and were characterised by high community dissimilarity. Urban ponds provide a diverse range of habitats for a mixture of common and rare aquatic macroinvertebrate taxa and represent a valuable biodiversity resource within anthropogenically dominated landscapes. Recognition of the significant contribution of ponds to urban freshwater biodiversity is important for future aquatic conservation within anthropogenically dominated landscapes. [ABSTRACT FROM AUTHOR]

Algae are potential renewable energy source that provides numerous types of biofuels. Traditional methods of algae harvesting involve high electrical energy in the range of 200–5000 watt-hour for collecting per kilogram of algae. Moreover the added chemicals during the harvesting process degrade the algae quality leading to inferior biomass feedstock. Based on a comparative analysis of the various algae harvesting methods, this paper introduce a novel robotic algae harvesting system. The focus was on algae harvesting with less energy consumption and without the use of chemical flocculants. Design dimensions and size of the robotic algae harvesting system were determined based on the size of the raceway pond where algae was harvested without any operational trouble. Two algae collection units were designed using plankton nets of 5 µm which facilitate in the collection of the algae. With torque analysis on the system design, the electrical actuators and power source for the harvester was resolved. A wireless switch control system was designed for controlling the harvester's locomotion while collecting the algae from the raceway pond. The developed system was tested in a raceway pond where it successfully collected a total of 565.67 g algae in 200 test runs in 1 h and 6 min. The estimated total electrical energy consumed by the robotic algae harvesting system to collect per kilogram of algae was 110.5 watt-hour. • A novel robotic algae harvesting system is introduced which can harvest algae with less energy and without the use of chemical flocculants. • The developed system successfully collected a total of 565.67 g algae in 200 test runs in 1 h and 6 min. • Electrical energy consumed by the robotic system to collect per kilogram of algae was 110.5 watt-hour. [ABSTRACT FROM AUTHOR]

The accumulation of sludge during fish culture has long been regarded as a serious threat to the water quality of intensive aquaculture ponds hence limiting the culture density. Frequent removal of the sludge is beneficial but hard to achieve due to a lack of practical methods that can quickly remove the sludge over a large area of the pond while minimizing the release of toxic substances into water. In this paper, an innovative sludge removing system was developed and tested against the well-known center-drain method. The sludge removing system used a series of water jets instead of suction ports to quickly remove the sludge while rotating on a circular center platform. Based on the Bernoulli's principle and the wall-jet effect, the water jets could form a concentrated flow to create a negative pressure to suck in the surrounding water thereby preventing the spread of the sludge. Numerical analyses were made to verify the flow pattern within the sludge removing system and to determine effects of critical design parameters. Performance tests were conducted for 10 weeks in four 15 m * 10 m shrimp ponds each having a 6 m diameter concrete center platform with a center drainpipe. The results show that the sludge removing system could remove 82.3–99.7% of the sludge on the platform in just 8 min using 3.2 ton of water and left less than 0.33 cm of the sludge on the platform. In contrast, the center-drain method used the same amount of water but could only remove up to 5% of the sludge and allowed the sludge to accumulate to a maximum height of 21.1 cm at the end of the experiment. Most of the sludge removal by the center-drain method occurred in the first minute, but the sludge removing system could continuously remove the sludge during its entire course of rotation around the platform. The effective radius of sludge removal by the center-drain method was less than 0.3 m, whereas the effective radius of the sludge removing system was its length, i.e., 2.8 m. The sludge removing system was modularized so that its length could be increased by connecting more sludge removing modules to have a quadratic effect on its effective area. As such, it is estimated that the sludge removing system could be effective in ponds up to 1.6 ha based on comparison with a biofloc system where proper water circulation around a center sump was accomplished. The sludge removing system could provide automatic sludge removals as frequently as wanted to help maintain the water quality in intensive aquaculture ponds thus may contribute to increasing the culture density and production. Compared to human labor, the sludge removing system may make a saving of nearly 90% of its investment in just one season. • The novel system using water jets instead of suction ports to remove the sludge. • The effective area was 85 times more than the center-drain method. • It could provide fully automatic sludge removal as frequently as needed. • You could monitor the state of the shrimp from the solids in the effluent water. • It could be effective in ponds up to 1.6 ha [ABSTRACT FROM AUTHOR]

Pollution of water resources and a lack of potable water are two important issues that city dwellers in India encounter. The passage of untreated sewage down municipal drains is one of the most significant sources of water resource pollution. In densely populated areas, effective sanitation and wastewater management is becoming increasingly difficult. In many developing nations, centralized sewage and wastewater treatment facilities serve only a section of big cities, and on-site sanitation is frequently insufficient in heavily populated areas. There is a demand for complementary and intermediate solutions. DEWATS (community-managed anaerobic decentralized wastewater treatment systems) is a good option for the possibility of relatively fast sanitation improvements in high-priority neighbourhoods where the local authority is not providing a full sanitation service. The following technical treatment modules are typically seen in DEWATS. The primary treatment consists of sedimentation ponds, settlers, septic tanks or bio digester, secondary treatment consists of anaerobic baffled reactors, anaerobic filters or anaerobic and facultative pond systems, secondary aerobic/facultative treatment consists of horizontal gravel filters and post-treatment consists of aerobic polishing ponds. The experience of India in establishing community-managed DEWATS on a large scale is examined in this review. [Display omitted] • DEWATS have been implemented in different places with suitable treatment methods matching with the community needs. • DEWATS which are connected to communal sanitation centres have the ability to bridge the gap between on-site and centralized wastewater treatment systems. • Very little data is available about the practice of DEWATS other than the handbooks available by different DEWATS implementation agencies. • This paper gives a review on the different DEWATS methods adopted in India which will impart a knowledge on the selection and implementation of different unitary process to be adopted for DEWATS process. [ABSTRACT FROM AUTHOR]

The middle Santonian-lower Campanian carbonate-mud dominated succession deposited in the northeastern margin of the South Iberian Ramp (La Cañadilla Fm, NE Spain) shows a complex set of interfingered facies developed in a low-energy and low-gradient shallow-marine to coastal environment. Three facies belts characterize the environment reconstructed in this work: (1) a low-energy shallow marine lagoon dominated by radiolitid rudist limestones and miliolid-rich facies with variable carbonate-mud content; (2) a transitional belt with a patchy distribution of ponds and mudbanks. This belt mostly consists of miliolid-rich limestones with variable amount of fenestral porosity, which are interfingered with charophytes and gastropod marls and limestones usually mixed with miliolids; (3) a coastal plain with strong freshwater influence characterized by the sedimentation of marls and limestones with charophytes, gastropods and root traces and intraclastic/black pebble limestones. The studied succession is arranged in high-frequency sequences, including meter-scale parasequences bounded by widespread flooding surfaces, which stack in five larger-scale shallowing-upward sequences (6–20 m thick). The time calibration of these sequences obtained from strontium isotopes and biostratigraphic data (benthic foraminifera) suggests a major control in the sedimentation by climate-driven low-amplitude sea level oscillations formed in tune with the long- and short-eccentricity orbital cycles. Cyclic sea level rises controlled the existence of widespread flooding events in the low-gradient carbonate ramp at the onset of parasequences, which in the studied marginal areas of the South Iberian Ramp were mostly sourced from the southern Tethyan realm. Therefore, the La Cañadilla Fm provides an example of a complex shallow marine to coastal system giving rise to a mosaic distribution of carbonate-mud dominated facies, with sedimentation mostly influenced by external factors resulting in a well-defined stratigraphic architecture. The similarities with modern analogous systems such as the Ten Thousand Islands of the Florida Bay are discussed in this paper. • La Cañadilla Fm deposited in a carbonate mud-dominated coastal plain to lagoon • A transitional facies belt with mudbanks and ponds is compared to Florida analogues. • A mid Santonian-early Campanian age is precised by strontium data. • Sea-level changes driven by eccentricity cycles had major control in sedimentation. [ABSTRACT FROM AUTHOR]

The presence of small artificial water reservoirs is typical of the landscape of small agricultural catchments. The old mill dammings are used today mostly for recreation and fish farming. Moreover, they are a very important part of the hydrological system of small rivers, stabilizing and shaping the discharge and physico-chemical characteristics of water. Coupled with the landscape function of the ponds goes their functioning in conditions of strong human pressure in the urban space. A canalised rivers in the urban parts of its courses picks up rubbishes washed down from the surface and coming from a storm sewer system and sometimes from leachate from a sanitary sewage system. An example of hydrological systems operating in such environments are Dzierżązna and Sokołówka catchments (Fig. 1). The first one is located north of Zgierz in the impact zone of the city of Łódź. Despite agro-forestry character, a significant impact on water quality is the chalets area and the A2 motorway crossing the catchment. The Sokołówka catchment is flowing through the urban area of the Łódź city. Both of the river flows are highly variable, and the water is heavily contaminated and has a high load of suspension (Tab. 1) In both of the catchments the role of artificial reservoirs created to improve the quality of water is the important issue. In the Dzierżązna catchment the several retention and infiltration ponds are working for regulating the outflow from the A2 motorway. In the Sokołówka valley the biofilter has been recently built (Fig. 2). It was constructed in order to purify urban storm- and waste water (sequential biofiltration system of Sokołówka - SSBS). The main purpose of the constructed SSBS was to remove sediments, suspended solids, particulate pollutants, petroleum hydrocarbons, heavy metals, nutrients and bacterial contamination from storm-water runoff through sedimentation and filtration mechanisms. The paper discusses the construction of both systems and technical solutions. To evaluate the effectiveness of their operation analyzed changes in the basic characteristics of physicochemical water parameters (water temperature, conductivity (SEC), pH, the concentration of dissolved oxygen, turbidity (NTU)) measured before and after both of cleansing systems in the year and multiyear (Fig. 3, Fig. 4). Attention has been also paid to the distribution of the mineral sediment deposited on the bottom of the biofilter SSBS system (Fig. 5). It was found that lowering the temperature in the winter and the appearance of a compact ice cap adversely affect the ability of biofilm to absorb pollutants causing (relative to the hot half year) an increase of conductivity, a higher pH and reducing of oxygenation of water. Identified mean changes of the selected physicochemical parameters of water discharged from the area of the A2 motorway to the Dzierżązna river system and as a result of the SSBS system operation to Sokołówka river (Fig. 6). All the measured parameters are reduced after passing through both of systems. As a result of mechanical sedimentation the greatest reduction is suspended material transported by water - in the SSBS on average about 16% less than in untreated waters (in the Dzierżązna catchment this element was not measured). The pH of the water in both systems changes to the same extent - decreases by 10% in the Dzierżązna, and 7% in SSBS. [ABSTRACT FROM AUTHOR]

Growing energy demand and water consumption have increased concerns about energy security and efficient wastewater treatment and reuse. Wastewater treatment high rate algal ponds (WWT HRAPs) are a promising technology that could help solve these challenges concurrently where climate is favorable. WWT HRAPs have great potential for biofuel production as a by-product of WWT, since the costs of algal cultivation and harvest for biofuel production are covered by the wastewater treatment function. Generally, 800–1400 GJ/ha/year energy (average biomass energy content: 20 GJ/ton; HRAP biomass productivity: 40–70 tons/ha/year) can be produced in the form of harvestable biomass from WWT HRAP which can be used to provide community-level energy supply. In this paper the benefits of WWT HRAPs are compared with conventional mass algal culture systems. Moreover, parameters to effectively increase algal energy content and overall energy production from WWT HRAP are discussed including selection of appropriate algal biomass biofuel conversion pathways. [ABSTRACT FROM AUTHOR]

With microalgal biofuels currently receiving much attention, there has been renewed interest in the combined use of high rate algal ponds (HRAP) for wastewater treatment and biofuel production. This combined use of HRAPs is considered to be an economically feasible option for biofuel production, however, increased microalgal productivity and nutrient removal together with reduced capital costs are needed before it can be commercially viable. Despite HRAPs being an established technology, microalgal photosynthesis and productivity is still limited in these ponds and is well below the theoretical maximum. This paper critically evaluates the parameters that limit microalgal light absorption and photosynthesis in wastewater HRAPs and examines biological, chemical and physical options for improving light absorption and utilisation, with the view of enhancing biomass production and nutrient removal. [ABSTRACT FROM AUTHOR]

Our knowledge on the algal community structure in waste stabilisation ponds is limited and it is unclear how physical–chemical changes affect the algal community structure and the treatment performance of waste stabilisation ponds. In the present paper we studied the spatial distribution of the algal community in a waste stabilisation pond in Cuenca (Ecuador) and found that the distribution was associated with the BOD concentration of the system. At the upstream end of the facultative pond where the BOD value is relatively high (74 mg L −1 ), the community is dominated by motile algal species such as Euglena and Cryptophytes. More downstream, the algal community is more evenly distributed ( G = 0.26 > 0.18) and also non-motile species such as Chlorophytes and Chrysophytes are present. Throughout the ponds, the reduction of motile algal species was associated with the decrease in BOD concentration. The dominance of Chlorophyta, Chrysophyta and Euglenophyta was highly associated with BOD concentration. Furthermore, it was concluded that the algal abundance (45541 cells mL −1 ), diversity ( D = 0.85), evenness ( G = 0.26) and richness (20.97) of the community in the maturation pond were higher than those of the facultative pond. The results of this research are valuable for a better understanding of the algae-based processes in waste stabilisation ponds. [ABSTRACT FROM AUTHOR]

This paper presents the results of an experimental and numerical modelling of heat and moisture migration conducted on a composite liner comprised of a geomembrane (GMB) and a geosynthetic clay liner (GCL), over a compacted subgrade and subjected to prolonged elevated temperatures at low overburden stresses typical of brine storage ponds or solar evaporation ponds. Results are presented for a GMB sitting on a fully hydrated GCL. Heating the top of the composite liner caused a measurable increase in subgrade temperature to at least to 250 mm below the GCL. However, the presence of an air gap, simulating the presence of a wrinkle in the geomembrane, at the interface between the GMB and the GCL reduced the impact of the high temperatures on the subgrade temperature profile with depth. The change in temperature profile was accompanied by moisture migration from the GCL to the subgrade material. However no desiccation cracks were observed in the GCL and the bentonite was still in a gel form at the end of the time period investigated. Numerical modelling using finite element method (FEM) was performed to simulate the results obtained experimentally. It was found to predict accurately the temperature changes that have occurred in the subgrade material and moisture changes that occurred in both the GCL and subgrade materials. [ABSTRACT FROM AUTHOR]

• Propose a three-dimensional prediction model of dissolved oxygen in pond culture. • Improving the accuracy of GRU prediction model by increasing attention mechanism. • Automatic adjustment of GBRT super parameters by RS. • The three-dimensional distribution characteristics of dissolved oxygen in pond were obtained and analyzed. Pond culture is an open water body, the distribution of dissolved oxygen in water is three-dimensional. The demand for dissolved oxygen in aquatic products living in different water layers is different. The traditional one-dimensional prediction at one single monitoring point can't reflect the real situation of dissolved oxygen in different spaces in the pond. To solve these problems, a three-dimensional prediction method of dissolved oxygen based on Attention-Gated Recurrent Unit (GRU) - Gradient Boost Regression Tree (GBRT) was proposed in this paper. Firstly, the environmental factors affecting the distribution of dissolved oxygen were collected, and the dissolved oxygen prediction model of the central monitoring point was constructed using Attention-GRU. The three-dimensional coordinate system with the central monitoring point as the origin was then established, and the GBRT algorithm optimized by the Random Search algorithm(RS) was used to predict the dissolved oxygen in any position of the pond water. In the one-dimensional prediction of dissolved oxygen at the central monitoring point, the Attention-GRU model proposed in this paper had MSE of 0.121, MAE of 0.219, and RMSE of 0.348, which was a big improvement compared with LSTM model, ELM model and CNN model. In the three-dimensional prediction of dissolved oxygen in the pond, the RS-GBRT model proposed had MSE of 0.097, MAE of 0.191, and RMSE of 0.313. Compared with the models such as ExtraTree model, RandomForest model, and Bagging model, each evaluation index had been greatly improved. The experimental results indicated that the proposed method can accurately predict the dissolved oxygen in the three-dimensional space of the pond. [ABSTRACT FROM AUTHOR]

[Display omitted] • A novel co-process of ABG, WCC and Fe powder is first proposed. • The As-bearing waste (α-Fe phase) can be separated via reduction-magnetic separation. • The weight and volume losses of As-bearing waste were 70 % and 60 %. • The As and F leached content were only 0.053 mg/L and 3.10 mg/L. • The As residual content in non-magnetic phase met standard of solid waste. Arsenic (As) -bearing gypsum sludge, one of the biggest As-bearing wastes, has seriously threatened ecological security due to the great mobility and leaching toxicity of As. Unfortunately, most of this sludge was discharged into tailing ponds without treatment. In this paper, a novel co-process of As-bearing gypsum sludge, waste carbon cathode (WCC) and Fe powder for simultaneous separation and solidification of As is proposed via reduction-magnetic separation. In the reduction process, Ca 3 (AsO 4) 2 was reduced and then enriched to α-Fe (Fe-As solid solution), and the As solidification ratio reached 90.5%. Meanwhile, NaF in waste carbon cathodes was transformed into CaF 2 and NaCa 2 FSiO 4. The As and F leached content were only 0.053 mg/L and 3.10 mg/L, when evaluated using the toxicity characteristic leaching procedure. After magnetic separation, α-Fe (magnetic phase) was separated and recovered, and the weight and volume losses of As-bearing waste were 70% and 60%, respectively, compared with the raw material. The As residual content in the non-magnetic phase met the standard of solid waste (As < 0.1 wt%), which acted as a flux during the smelting process, minimizing the environmental risk and realizing resource recycling. Moreover, waste carbon cathodes can be reused as fuel and as a reducing agent, which significantly reduces production costs. This proposed technique reduces hazardous waste, is more effective, and is also more economical. [ABSTRACT FROM AUTHOR]