Experimental Investigation of a Phase-ChangeMaterial’s Stabilizing Role in a Pilot of Smart Salt-Gradient Solar Ponds

Faced with the world’s environmental and energy-related challenges,researchers are turning to innovative,sustainable and intelligent solutions to produce,store,and distribute energy.This work explores the trend of using a smart sensor to monitor the stability and efficiency of a salt-gradient solar pond.Several studies have been conducted to improve the thermal efficiency of salt-gradient solar ponds by introducing other materials.This study investigates the thermal and salinity behaviors of a pilot of smart salt-gradient solar ponds with(SGSP)and without(SGSPP)paraffin wax(PW)as a phase-change material(PCM).Temperature and salinity were measured experimentally using a smart sensor,with the measurements being used to investigate the stabilizing effects of placing the PCM in the solar pond’s lower convective zone.The experimental results show that the pond with the PCM(SGSPP)achieved greater thermal and salinity stability,with there being a lesser temperature and salinity gradient between the different layers when compared to a solar pond without thePCM(SGSP).The use of the PCM,therefore,helped control the maximum and minimum temperature of the pond’s storage zone.The UCZ has been found to operate approximately 4 degrees above the average ambient temperature of the day in the SGSPP and 7 degrees in SGSP.Moreover,an unstable situation is generated after 5 days from starting the operation and at 1.9 m from the bottom,and certain points have the tendency to be neutral from the upper depths in 1,3 m of the bottom.

Microscopic analysis on eukaryotic algae and cyanobacteria in nine seasonal lakes and ponds in Vestfjella,Dronning Maud Land,Antarctica

Antarctic continental lakes and ponds are among the most impoverished aquatic environments on earth but many of them support flourishing populations of cyanobacteria,eukaryotic algae,protozoans,and some multicellular animals.In this study,we present results of a microscopic analysis of cyanobacteria and eukaryotic algae from nine diverse types of Antarctic continental water bodies during one austral summer.The results supplement and enlarge our previous studies on the limnological characteristics of the epiglacial and supraglacial lakes and ponds in Dronning Maud Land,an area that has received little attention from limnologists.The taxon with highest frequency among the samples(n=79)was Mesotaenium cf.berggrenii,a eukaryotic Zygnematophyceae,which occurred in 82%of the samples with a maximum cell density of 68 cells·mL^(-1).The taxa with second and third highest frequency were the prokaryotes Gloeocapsopsis(60%)and Leptolyngbya(41%),followed by Chlamydomonas(34%)and Cyanothece(29%).The number of taxa varied between 7-21 among the lakes and ponds,being highest in a supraglacial lake,and lowest in an epiglacial lake.The results did not reveal any obvious correlation between the abundance of any taxa and the water chemistry,but water bodies with inorganic sediments had higher cell densities and biomasses than those without sediment.This suggests the importance of sediment in supporting biological diversity in these ultraoligotrophic lakes and ponds.

Assessment of Retention Ponds and Its Impacts on Health of Residents in Mogadishu, Somalia: Mixed Methods

The purpose of this study was to evaluate the effects of retention ponds on the environment and population health by analyzing water samples from various ponds in Mogadishu, to determine the prevalence of waterborne illnesses that occur during the rainy season in Mogadishu, and to find out what experts thought about the effects of retention ponds on the environment as well as population health in Mogadishu. Methods: Mixed designs were used in the study. The first design is an exploratory study where samples are taken from different retention ponds in Mogadishu. The second design involves gathering secondary data from the online FSNAU Dashboard regarding the incidence of rainfall and waterborne illnesses including malaria and cholera. Additionally, a cross-sectional survey of expert opinions using questionnaires was the third design. The 10 water samples were taken from retention ponds in Mogadishu as part of the sample size. Data on the fourth month was also gathered using the FNSAU dashboard, and seventy sample sizes were used for the expert self-administered questionnaire for the third design. Excel was used for data analysis in the initial design. While BMI SPSS versions 22 were used to analyze the data from the Self-administered Questionnaire, additional methods were utilized to compute descriptive statistics, such as mean and standard deviation, and to analyze demographic data in a frequency table. Findings: The results show that three samples had unsatisfactory scores (Grade D): Yaqshid (Warshadda Bastada) had a WQI of 80.85, Boondheer (Bondher Pond) had a WQI of 80.64, and Wartanabad (Xamar Jadiid Pond) had a WQI of 80.89. The remaining samples were all rated as fair (grade), which indicates that they ranged from 50 to 75. The months with the largest rainfall already occurred in December, November, and October, when the prevalence of diseases during the rainy season was highest for cholera cases. Although October and December saw a significant number of malaria cases, November did not. Retention ponds’ overall effects on residential environments were evaluated, and the results showed that the standard deviation was 0.802 and the cumulative average mean scores were 4.41 overall. This indicates that the respondents were in agreement that retention ponds in Mogadishu, Somalia, had an effect on residential areas. Recommendation: The study suggested that in order to identify retention pond contamination and create treatment units for its management, the Ministry of Health forms a district-level public health committee. All districts must have a sewer system installed by the local government, and retention ponds must be made easier in order to move waste outside of the city.

Ecological Remediation Technologies of Freshwater Aquiculture Ponds Environment

The environmental issues confronted by traditional freshwater aquaculture are increasingly sedous, promoting development of ecological remediation technolo- gies. The in-situ remediation represented by fish-vegetable mutualism mode （FVMM） and ex-situ remediation represented by recirculating aquaculture system （RAS） are highlights of related researches. In the paper, the advantages and disadvantages of FVMM and RAS were analyzed and area allocation was discussed in terms of eu- trophication and pond nitrogen cycle. The results showed that the FVMM could re- duce pollutant-discharge coefficient of fish ponds, but the ecological balance would still be hard to be achieved nationwide. In contrast, although the extra cost and land resources would produce inevitably, the application is of great significance in small regions, especially for eutrophication areas thanks for zero-discharge.

Metabolic Characteristics and Functional Diversity of Carbon Source in Microflora of Ponds with Recirculating Aquaculture System

With Biolog Eco microplate, metabolic characteristics and functional diver-sity of carbon source in microflora of ponds were researched based on recitculating ponds and control ponds in order to explore effects of eco-adjustments on microflo-ra in ponds. The results indicate that total number of bacterium, microbial metabolism activity, and diversity index in P7, P8, P1 and P2 kept higher, fol owed by P3, P4, P5 and P6. The utilization rate of microbes on sugars achieved the highest （31.0%-48.7%）, fol owed by carboxylic acid （13.4%-18.0%）, amino acid （10.1%-20.5%）, polymers （9.4%-17.0%）, biopolymer （5.7%-9.7%） and phenol （4.95%-7.50%）. Principal component analysis divided microflora in different ponds, suggesting that microbial community has varied carbon source characteristics and nitrogen-containing compound and biopolymer metabolisms are most affected.

A resilience-based approach in managing the closure and abandonment of large mine tailing ponds

Mining tailing ponds are large infrastructure objects whose life cycle spans over several decades.They are indispensable for certain types of mines where technological process produces and rejects mud.They also have potential to generate risks for human life,property and environment.For that reason,it is essential to adequately manage them throughout all the stages of their life cycle.The phase of their closure and abandonment is less studied and understood.The paper proposes a holistic resilience-based approach for analyzing this phase of their life cycle.The proposed methodology is validated through a case study at an actual surface iron ore mine in Bosnia and Herzegovina.

Multi-stage ponds-wetlands ecosystem for effective wastewater treatment

The performance of the Dongying multi-stage ponds-wetlands ecosystem was investigated in this work. Study of the removal of different pollutants (BOD5, COD, SS, TP, TN, NH3-N, etc.) in different temperature seasons and different units in this system indicated that effluent BOD5 and SS were constant to less than 11 mg/L and 14 mg/L throughout the experimental proc- esses; but that the removal efficiencies of pollutants such as TP, TN, NH3-N, COD varied greatly with season. The higher the temperature was, the higher was the observed removal in this system. Additionally, each unit of the system functioned differently in removing pollutants. BOD5 and SS were mainly removed in the first three units (hybrid facultative ponds, aeration ponds and aerated fish ponds), whereas nitrogen and phosphates were mainly removed in hydrophyte ponds and constructed reed wetlands. The multi-stage ponds-wetlands ecosystem exhibits good potential of removing different pollutants, and the effluent quality meet several standards for wastewater reuse.

Remote Monitoring of Expansion of Aquaculture Ponds Along Coastal Region of the Yellow River Delta from 1983 to 2015

Aquaculture ponds are one of the fastest-growing land use types in valuable and fertile coastal areas and have caused serious environmental problems. Quantitative assessment of the extent, spatial distribution, and dynamics of aquaculture ponds is of utmost importance for sustainable economic development and scientific management of land and water resources in the coastal area. An object-oriented classification approach was applied to Landsat images acquired over three decades to investigate the long-term change of aquaculture ponds in the coastal region of the Yellow River Delta. The results indicated that the aquaculture ponds in the study area undergone a sharp expansion from 40.38 km^2 in 1983 to 1406.89 km^2 in 2015, and the fast expansion occurred during the period of 2010–2015 and 1990–2000. Natural wetlands, especially mudflat, and cropland were main land use types contributing to the increase of aquaculture ponds. The patches of aquaculture ponds were consequently prevalence in the north of the Yellow River Estuary and landscape metrics indicated an increase of the aquaculture ponds of the study area in the quantity and complexity. The expansion of aquaculture ponds inevitably had negative effects on the coastal environment, including loss of natural wetlands, water pollution and land subsidence, etc. The results from this study provide baseline data and valuable information for efficiently planning and managing aquaculture practices and for effectively implementing adequate regulations and protection measures.

Isolation and characterization of halophilic bacteria and archaea from salt ponds in Hangu Saltworks, Tianjin, China

A total of 26 isolates were obtained from solar salt ponds of different salinities(100, 150, 200, and 250) in Hangu Saltworks Co. Ltd., Tianjin, China. Phylogenetic analysis of 16 SrRNA gene sequences indicated that five bacteria genera H alomonas, Salinicoccus, Oceanobacillus, Gracibacillus, and Salimicrobium and one archaea genera H alorubrum were present. The genus H alomonas was predominant with eight strains distributed in a salinity range of 100–200, followed by H alorubrum with six strains in salinity 250. Based on the genus and original sampling salinity, eight bacterial and two archaeal isolates were selected for further morphological, physiological, and biochemical characterization. All of the bacterial strains were moderately halophilic with the optimal salinity for growth being either 50 or 100, while two archaeal strains were extremely halophilic with an optimal growth salinity of 200. Additionally, we put forth strain SM.200-5 as a new candidate S alimicrobium species based on the phylogenic analysis of the 16 SrRNA gene sequence and its biochemical characteristics when compared with known related species.

Impact Assessment of Hillside Rainwater Harvesting Ponds on Agriculture Income: Case Study of Ntarama Sector in Rwanda

Nowadays, rainwater harvesting (RWH) technology is increasingly adopted as a strategic pathway for reducing poverty in rural drought prone areas for enhancing agricultural productivity and boosting farm income. The aim of this study is to assess the level of adoption and the impacts of RWH ponds on farm income in Ntarama sector of Bugesera District in Eastern Province of Rwanda. Fifteen farm ponds were visited and the level at which households adopted RWH ponds, their impact on farm income and performance in storing water were assessed. Interviews and questionnaires methods were used to farm ponds beneficiaries and the storage capacity of farm ponds was calculated to ensure that they meet irrigation water demand. Then, Microsoft excel was used as a data analysis tool. The results show that 42.5% of households have adopted RWH ponds and the adoption level of RWH ponds fails due to the lack of training about the role and use of RWH ponds before their implementation. Beside this the low level of public involvement during the site selection for ponds associated with social conflicts among water users was observed. However, it is further revealed that the use of RWH ponds positively impacts on agricultural income on 1/4 hectare per year by about 2,325,000 RWF (3100USD). The studied portion of area can bear 222 ponds of 120 m3 each if all the rain is harvested throughout the year instead of being three ponds. Furthermore, we found that the quantity of rainwater harvested of 328.5 m3 as a total of the 3 ponds was still too less to meet irrigation water demand. As negative impacts, the RWH technology can cause dangerous effects such as social conflicts, breeding site for mosquitoes, water related diseases, accidents and others with a level of severity of 32%, 24%, 20%, 16% and 8%, respectively. This happens when the RWH ponds are not properly managed.

Water quality characteristics of rivers and ponds in Japan

In Japan, various countermeasures have been taken to improve the water quality of public waters such as rivers and lakes. Though water quality has improved, it is still insufficient. In summer, eutrophication is seen in lakes and inner bays, as well as rivers. As a countermeasure to prevent eutrophication, the removal treatment of nutrient salts such as nitrogen and phosphorus is done, in addition to organic substance elimination in the domestic sewerage system. This report will show the water quality characteristics of rivers and ponds in Japan. It is considered that these investigative results are effective when the water quality improvement of the stabilization ponds where eutrophication occurs are examined in China.

Research on Rural Idle Ponds in the Perspective of Human Asset Specificity

A thorough investigation was carried out to the pond resources of a county, and Grossman-Hart-Moore （GHM） incomplete contract theory was used to do the economic analysis on the idle pond resources. The result indicated that with the deepening of market-oriented economy, the human asset specificity under the incomplete contract had distorted the investment incentives to the governance of ponds that corresponding policies were required to govern the idle ponds.

Models to predict sunlight-induced photodegradation rates of contaminants in wastewater stabilisation ponds and clarifiers

Two kinetic models were established for conservative estimates of photodegradation rates of contaminants under sunlight irradiation,in particular for wastewater stabilisation ponds and clarifiers in conventional wastewater treatment plants.These two models were designated for(1)contaminants with high photolytic rates or high photolytic quantum yields,whose photodegradation is unlikely to be enhanced by aquatic photosensitisers;and(2)contaminants withstanding direct photolysis in sunlit waters but subjected to indirect photolysis.The effortlessly intelligible prediction procedure involves sampling and analysis of real water samples,simulated solar experiments in the laboratory,and transfer of the laboratory results to realise water treatment using the prediction models.Although similar models have been widely used for laboratory studies,this paper provides a preliminary example of translating laboratory results to the photochemical fate of contaminants in real waters.

Evaluating a Three-Fold Continuum of Fry Stocking Density for Rearing Walleye in Lined Ponds

Fry stocking density can affect harvest metrics for fingerling walleye (Stizostedion vitreum) reared in drainable ponds, but few studies have examined these relationships with the use of elevated walleye fry stocking densities in lined ponds. Correlation and regression analyses were used to assess how a three-fold change in walleye fry stocking density (234,375 to 703,125 per hectare) relates to harvest metrics and length of the culture period, as well as the tradeoff experienced between walleye size (grams) and harvest density in 0.32-hectare lined ponds over a nine-year period at Blue Dog State Fish Hatchery, South Dakota. As fry stocking density increased, so did harvest metrics for both number (r = 0.85, P < 0.01) and yield (r = 0.81, P < 0.01). Length of the culture period varied between 24 and 35 days and was negatively related to stocking density (r = -0.66, P The linear relationship between harvest density and yield was highly correlated (r = 0.95, P < 0.01) with highest values measuring 617,625 walleye and 173 kilograms per hectare. Harvest density explained 61% of the variation in walleye size (P 0.01) and exhibited a decreasing curvilinear relationship such that continued increases in harvest density resulted in smaller reductions in fish size. Increasing fry stocking density from 234,375 to 703,125 per hectare in lined ponds coincided with increased rearing efficiencies for number and yield, as well as a reduced culture period. Minimal reduction in walleye size occurred once harvest density exceeded 300,000 per hectare.

Effi ciency of phosphorus accumulation by plankton,periphyton developed on submerged artifi cial substrata and metaphyton:in-situ observation in two shallow ponds

Phosphorus overenrichment of shallow ponds prevailing in wetlands leads to their eutrophication causing the collapse of those vulnerable habitats.The potential of phosphorus accumulation by periphyton developed on artificial substrata has been investigated in two shallow ponds(Bara?ka and?iroki Rit)in northwest Serbia and compared to the same ability of plankton and metaphyton.The periphyton substrate carrier has been submerged from May to October.Both continuously(CS)and monthly developed(MS)periphyton were sampled.Autotrophic component of all investigated communities has been qualitatively assessed.Maximum accumulation of only 14.7 mg TP/m^(2) was recorded in three-month exposed periphyton CS.MS exposed from July to August reached maximal 12.7 mg TP/m^(2).Plankton community that was characterized by more diverse and abundantly developed algal component was more effective in phosphorus accumulation(0.7 mg/g dry weight)in comparison with dominantly inorganic and diatom-dominated periphyton in Bara?ka.Unstable conditions caused by recent revitalization(dredging organic matter and mud from pond basin—redigging)as well as rapid desiccation of?iroki Rit disabled making an unambiguous conclusion about the efficiency of phosphorus accumulation among different communities,but suggested slight potential of phosphorus harvesting by metaphyton in this pond.Due to the shorter exposure time that brings the reduced risk of unpredictable changes in the ecosystem,as well as the considerable amount of accumulated phosphorus,large-scale application of one-month exposed periphyton developed on artificial substrates would be more advisable for phosphorus harvesting in nutrient affected shallow ponds.

Fish Production, Water Quality and Bacteriological Parameters of Koi Carp Ponds Under Live-food and Manure Based Management Regimes

To test the effectiveness of introducing live zooplankton against direct manuring in ornamental fish ponds upon their survival and production, larvae of koi carp, Cyprinus carpio L., were cultured for 11 weeks in earthen ponds maintained according to four management regimes： （1） live zooplankton fed to carp larvae （LF）; （2） direct fertilization with poultry manure （PM）; （3） direct fertilization with cowdung （CD）; and （4） a control treatment （C）. There were three replicates for each treatment. The growth of heterotrophic bacteria and pathogenic microorganisms like Aeromonas sp. and Pseudomonas sp. were also examined in response to pond management. Values of dissolved oxygen were significantly higher （P〈0.05） in the water of LF ponds, compared to other treatments, while the PM and CD treatments recorded were significantly higher （P〈0.05） values of PO4 - P, NH4 - N, NO3 - N, NO2 - N, specific conductivity, alkalinity, and BOD, compared to the LF and C treatments. The percentages of organic carbon and total nitrogen in the bottom sediments were higher in the PM and CD treatments compared to LF （P〈0.05）. Average counts of heterotrophic bacteria in the water of PM and CD ponds were significantly higher than other treatments （P〈0.05）. The development of Aeromonas sp. and Pseudomonas sp. were significantly higher （P〈0.05） in the PM and CD treatments. Weight gain of koi carp stocked in LF was significantly higher （P〈0.05） than that of fish in the other treatments. There was a significant difference in the survival rate of koi carp among the treatments ranging from 67.21% in C to 90.11% in LF. The results suggest that raising koi carp larvae in ponds and feeding them exogenously with zooplankton would support high rates of survival and production through maintenance of better water quality and greater abundance of zooplankton in the system. Significantly lower abundance of Aeromonas sp. and Pseudomonas sp. in the LF treatment considerably lowered any possibility of occurrence of bacterial disease.

Harmful Ciliates and Dominant Genus in Culture Ponds of Young Abalone

By using the methods of qualitative and quantitative analysis, the species composition and dominant genus of harmful ciliates in young abalone culture ponds are studied. Totally 68 ,species of ciliates, belonging to 3 classes16 orders and 46 genus, are found. The dominant ciliate species are Aspidisca leptaspis, Vorticella sp. and Euplotes rariseta. During the young abalone cultivation, the numbers of young abalones increase first, and then show a trend of decreasing. The relationship between the density and composition of ciliates and the density of algae in the young abalone culture ponds is also discussed.

Health Risk Assessment of Heavy Metals in Groundwater： The Effect of Evaporation Ponds of Distillery Spent Wash

The current study was carried out to examine the heavy metals （Cd, Co, Cr, Cu, Mn, Ni, Pb, Zn and As） concentration in GW （groundwater） samples in the vicinity of distillery spent wash evaporation ponds and RGW （reference groundwater） samples collected 2 km to 3 km away from the source. The study examines the potential health risk caused by consumption of heavy metals to local inhabitants living around distillery spent wash evaporation ponds. HM （heavy metals） concentration was determined by AAS （atomic absorption） and the results were compared with permissible limits of PEPA （pakistan environmental Protection Agency） and WHO （World Health Organization）, set for industria effluents and drinking water. The health risk assessment such as CDI （chronic daily intake） and HQ （hazard quotient） were determined on the sources ofHM concentration. The cm of heavy metals in GW were found in following decreasing order Fe, Zn, Mn, Ni, Co, Cu, Cr, Cd, Pb and As. The HQ indexes of HM in the GW samples near the distillery spent wash evaporation ponds was in the order As, C, Ni, Cu, Mn, Zn, Pb and Cr. The results showed that the distillery spent wash is the cause for the change in HM contents of the study area.

Congruence Study between the Continuous Chemical Reactor (CSTR) and the Maturation Oxidation Ponds within Wastewater Treatment

People who are involved in managing wastewater treatment face the challenge of achieving conservation goals with limited funds, and also of balancing needs for nature conservation. This context has been motivated with finding logic explanations of wastewater treatment by oxidation ponds. Description of progressive we have made with developing methods is for understanding how, when and where had done to apply the oxidation ponds for protecting biodiversity. The Rashid oxidation pond facility was highlighted as a model plant for utilizing this technology in wastewater treatment in the city of Rashid, El-Beheira Governorate, Egypt. The main concept is based on the interaction of chemical pollutants NO2, NO3, BOD5-in, and BOD5-out and heavy metals with microorganisms as Chlorophyta Green and cyanophyta, and how these oxidation ponds imitate the Continuous Chemical Reactor (CSTR) to build its core architecture for maximum usefulness. By applying the theoretical equation of (CSTR) on the experimental results of the oxidation pond according to Thirumurthi equation, it was discovered that (CSTR) and oxidation pond are matching together with a satisfactory ratio of congruence (85% - 88%). Also, the heavy metals as (iron, Zinc and copper) are high percentage removal by the algae rules. This investigation established that the oxidation ponds may function as a Continuous Chemical Reactor under ultimate conditions and precautions.

Some Charophyta （Charales） from Coastal Temporary Ponds in Velipoja Area （North Albania）

Charophytes or stoneworts constitute a group of macrophytes that occur mostly in fresh-water environments but can also be found in brackish waters. Knowledge about stoneworts in Albania is still scarce and incomplete. According to published data on charoflora of Albania, there are 24 species and four genera known from different freshwater habitats. The present work is based on plant material sampled from 5 slightly brackish-water temporary ponds in the coastal area of Velipoja （north Albania）. During spring and summer of 2013-2015, field surveys were carried out with the main purpose of filling knowledge gaps concerning brackish water charophytes. Altogether seven species were identified： four typical of brackish water habitat （Chara baltica, Chara canescens, Chara galioides and Chara connivens） and three of broader tolerance （ Chara aspera, Chara vulgaris and Tolypella glomerata）. The first three species, which considered as the rarest and most threatened on the Balkans were found for the first time in Albania.