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Assessment of Retention Ponds and Its Impacts on Health of Residents in Mogadishu, Somalia: Mixed Methods
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作者 Mohamed Ahmed Kullane Mohamed Ibrahim Abdi-Soojeede 《Journal of Water Resource and Protection》 CAS 2024年第4期293-307,共15页
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 i... 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. 展开更多
关键词 RETENTION ponds CONTAMINATION Water Quality Index Waterborne Diseases Mogadishu SOMALIA
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Carbon isotope ratios of n-alkanoic acids: new organic proxies for paleo-productivity in Antarctic ponds
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作者 CHEN Xin JIN Jing +5 位作者 NIE Yaguang ZHANG Jifeng DONG Liang HUANG Xianyu Steven D()EMSLIE LIU Xiaodong 《Advances in Polar Science》 CSCD 2023年第4期304-317,共14页
Primary productivity in the Antarctic aquatic environment with simple ecosystems is sensitive to climate and environmental fluctuations.We investigatedδ13C values for n-alkanoic acids derived from phototrophic organi... Primary productivity in the Antarctic aquatic environment with simple ecosystems is sensitive to climate and environmental fluctuations.We investigatedδ13C values for n-alkanoic acids derived from phototrophic organisms in a lacustrine sediment core(IIL3)to indicate primary productivity in ponds on Inexpressible Island in the western Ross Sea,Antarctica.Short-chain n-alkanoic acids(C14–C18)were abundant in the IIL3 sediment profile.The carbon isotope ratios of short-chain n-alkanoic acids in the sediment samples and floating microbial mats were similar,indicating that the short-chain n-alkanoic acids in the IIL3 sediment profile predominantly originated from phototrophic organisms.Theδ13C values for the short-chain n-alkanoic acids varied widely through the sediment profile,and 13C-enrichment of n-alkanoic acids was most likely related to high productivity due to carbon-limited conditions caused by enhanced photosynthetic efficiency.Theδ13C values for the n-alkanoic acids changed over the past 3200 years in similar ways to organic proxies for aquatic productivity(n-alkanoic acid and sterol sedimentary fluxes).C16 n-alkanoic acid was enriched in 13C in periods of high aquatic productivity~750–1650 and 3000–3200 a BP but depleted in 13C in periods of relatively low productivity~150–600 and 2500–3000 a BP.The results indicated that carbon isotope ratios of lipids from phototrophic organisms could be used as new proxies to reconstruct paleo-productivity in Antarctic lakes and ponds and therefore improve our understanding of past climate changes. 展开更多
关键词 East Antarctica lipid biomarkers carbon isotopic ratios pond primary productivity climate change
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A resilience-based approach in managing the closure and abandonment of large mine tailing ponds 被引量:4
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作者 Dragan Komljenovic Lazar Stojanovic +1 位作者 Vladimir Malbasic Aleksandar Lukic 《International Journal of Mining Science and Technology》 SCIE EI CSCD 2020年第5期737-746,共10页
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 p... 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. 展开更多
关键词 Mine tailing ponds CLOSURE ABANDONMENT RESILIENCE RISKS UNCERTAINTIES Complexity
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Relationships of Dissolved Oxygen with Chlorophyll-a and Phytoplankton Composition in Tilapia Ponds 被引量:4
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作者 Kornkanok Kunlasak Chanagun Chitmanat +2 位作者 Niwooti Whangchai Jongkon Promya Louis Lebel 《International Journal of Geosciences》 2013年第5期46-53,共8页
This study investigated the relationships among the parameters of dissolved oxygen, chlorophyll-a and phytoplankton composition in tilapia ponds. Each pond (a total of 18 ponds) was sampled once in the dry, winter sea... This study investigated the relationships among the parameters of dissolved oxygen, chlorophyll-a and phytoplankton composition in tilapia ponds. Each pond (a total of 18 ponds) was sampled once in the dry, winter season between January and March and again early in the rainy season between May and June. The data were analyzed by examining correlations among parameters as affected by season, altitude and culture system. Observations were made at sites located in 5 selected provinces of northern Thailand: Chiangrai, Chiangmai, Phayao, Lampang and Nakornsawan. Mean elevation of these areas range from 25 to 582 meters above sea level (masl) and were categorized into low (400 masl) elevation sites. Ponds were 0.8 - 2.0 m deep, 0.16 - 0.64 ha in area and could be further categorized into high and low input systems.Mean air temperature in winter ranged between 16.5°C - 35.8°C while mean water temperature ranged between 25.5°C - 27.1&#176;C. In rainy season, air temperature ranged between 22.0°C - 37.3°C and water temperature ranged between 29.4°C - 31.8°C. The amount of chlorophyll-a in both seasons were comparable (p > 0.05), but chlorophyll-a in high input system was significantly higher (p 0.05) than in low input ponds. Only weak correlation was found between chlorophyll-a, DOmax and DOmin. Multifactor-ANOVA was used to analyze the difference of total bacteria and filamentous cyanobacteria in ponds based upon elevation, culture systems and season. Result shows that there is a significant interaction observed between elevation, culture system and season (p 0.05). Species diversity and composition of phytoplankton in fish ponds in 2 seasons revealed the presence of 90 genera of phytoplankton under all 7 divisions. Divisions Chlorophyta and Cyanophyta had the most number of genera identified in both seasons with Pediastrum spp., and Scendesmus spp., and Anabaena spp. as dominant genera/genus, respectively. 展开更多
关键词 Dissolved Oxygen CHLOROPHYLL-A PHYTOPLANKTON Composition TILAPIA ponds ELEVATION SEASON
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Performance Evaluation of Waste Stabilisation Ponds 被引量:1
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作者 O. P. Gopolang M. W. Letshwenyo 《Journal of Water Resource and Protection》 2018年第11期1129-1147,共19页
Waste stabilisation pond system has been used more especially in developing countries for sewage treatment. The objective of this study was to investigate the hydraulic and performance efficiency of Palapye waste stab... Waste stabilisation pond system has been used more especially in developing countries for sewage treatment. The objective of this study was to investigate the hydraulic and performance efficiency of Palapye waste stabilisation ponds. The hydraulic efficiency was evaluated through drogue, pond geometry and sludge accumulation assessment. The performance efficiency was evaluated through periodic sampling and analysis of physiochemical and bacteriological parameters of individual units and of the system as a whole. Except for the maturation ponds, the depth of the anaerobic pond had reduced from 4 m to 0.45 m, for facultative ponds from 2.0 m to a range of 0.52 m - 0.91 m. The design hydraulic retention time of the system had reduced from 20 days to 7.1 days. The concentration of some physiochemical parameters in the effluent was 305 mg·L-1, 277 Nephelometric Turbidity Units (NTU), 204 mg·L-1, 156 mg·L-1, 110 mg·L-1, and 15 mg·L-1 being total suspended solids, turbidity, nitrates, chemical oxygen demand, biochemical oxygen demand and phosphate respectively. These values were more than the standard limits of the country. Effluent total coliforms concentration was 3.6 log units and within the threshold of 4.3 log units, faecal coliforms concentration was 3.5 log units, slightly higher than the threshold of 3 log units. Though Escherichia coli have no limits for discharge into other environments, the concentration in the effluent was reasonable at 2.5 log units and also within irrigation limit of 3 log counts. Palapye wastewater treatment system hydraulic efficiency is lower than the design criterion. The system was overall poor in physiochemical parameters removal but better in bacteriological removal. 展开更多
关键词 HYDRAULIC Efficiency WASTE Stabilisation ponds Length to WIDTH Ratio POND GEOMETRY
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The research progress on food organism culture and technology utilization in crab seed production in ponds in China 被引量:2
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作者 Jibing Qi Xiaolian Gu +2 位作者 Lingbo Ma Zhenguo Qiao Kai Chen 《Agricultural Sciences》 2013年第10期563-569,共7页
Eriocheirsinensis, Portunus trituberculatus and Scylla paramamosain are important commercial culture crab species in China. Traditional factory breeding of crabs depends on Artemia nauplius. The rising price of Artemi... Eriocheirsinensis, Portunus trituberculatus and Scylla paramamosain are important commercial culture crab species in China. Traditional factory breeding of crabs depends on Artemia nauplius. The rising price of Artemia cysts has led to the decline of the economic benefit of the crab breeding factory. Factory crab breeding has been gradually replaced by pond breeding in recent years. E. sinensis and P. trituberculatus have been bred mainly in ponds. Meanwhile, S. paramamosain is still mainly bred in factories because of the crudeness of pond breeding. The research progress on food organism utilization in the three species of commercially bred crabs was reviewed in this paper. In the workshop seeds production, rotifer and Artemia nauplii were necessary in the early stages from zoea I to zoea II in the three crab species. Adult artemia, minced fish and shellfish were fed to the larvae in the later zoea stages from zoea III to Megalopa.?The rising of the price of artemia eggs made people find other feed organism to replace artemia. Copepods have been used in crab seeds production in pond from zoea III stage to replace artemia in recent years, which has reduced the cost of seeds production. 展开更多
关键词 Food ORGANISMS CRAB SEEDS ponds
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Annual Variation of Water Quality in Aquaculture Ponds for Apostichopus japonicus 被引量:1
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作者 Yaoming LUO Yuan CHENG +4 位作者 Duohui LI Zhiying GAO Luping WANG Jiangyi WU Dawei JIANG 《Asian Agricultural Research》 2019年第11期25-27,共3页
By measuring water temperature,salinity,pH,dissolved oxygen,nitrite and ammonia nitrogen,the annual variation regularity of water quality in the aquaculture ponds for sea cucumbers Apostichopus japonicus in Dalian wer... By measuring water temperature,salinity,pH,dissolved oxygen,nitrite and ammonia nitrogen,the annual variation regularity of water quality in the aquaculture ponds for sea cucumbers Apostichopus japonicus in Dalian were studied.Results showed that the physicochemical indicators kept changing in the year,and the various ranges of water temperature,salinity,pH,dissolved oxygen,nitrite,and ammonia nitrogen were 6.38-27.27℃,29.20‰-33.78‰,7.86-8.38,5.19-13.36 mg/L,0.0037-0.0090 mg/L and 0.0171-0.0908 mg/L,respectively.Analysis indicated that there was an extremely significant negative correlation between water temperature and dissolved oxygen(P<0.01),an extremely significant positive correlation between water temperature and ammonia nitrogen(P<0.01),a significant negative correlation between salinity and nitrite(P<0.05),a significant negative correlation between dissolved oxygen and nitrite(P<0.05),and an extremely significant negative correlation between dissolved oxygen and ammonia nitrogen(P<0.01)in the aquaculture ponds for sea cucumber in Dalian.Research showed that the water quality of aquaculture ponds kept fluctuating all the time during the tested period,there were complicated and close relationships among physicochemical indicators,and a slight variation of external factors would bring consecutive reactions to different indicators in the water quality of aquaculture ponds.A reference for the production and management of sea cucumbers could be provided from the results. 展开更多
关键词 AQUACULTURE ponds for Apostichopus JAPONICUS Water quality PHYSICOCHEMICAL indicator
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Comparison of Phytoplankton Communities Between Melt Ponds and Open Water in the Central Arctic Ocean
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作者 ZHANG Tianzhen ZHUANG Yanpei +4 位作者 JIN Haiyan LI Ke JI Zhongqiang LI Yangjie BAI Youcheng 《Journal of Ocean University of China》 SCIE CAS CSCD 2019年第3期573-579,共7页
Climate warming has a significant impact on the sea ice and ecosystem of the Arctic Ocean.Under the increasing numbers of melt ponds in Arctic sea ice,the phytoplankton communities associated with the ice system are c... Climate warming has a significant impact on the sea ice and ecosystem of the Arctic Ocean.Under the increasing numbers of melt ponds in Arctic sea ice,the phytoplankton communities associated with the ice system are changing.During the 7th Chinese National Arctic Research Expedition cruise in summer 2016,photosynthesis pigments and nutrients were analyzed,revealing differences in phytoplankton communities between melt ponds and open water in the central Arctic.Photosynthetic pigment analysis suggested that Fuco(5-91μg m^-3)and Diadino(4-21μg m^-3)were the main pigments in the open water.However,the melt ponds had high concentrations of Viola(7-30μg m^-3),Lut(4-59μg m^-3)and Chl b(11-38μg m^-3),suggesting that green algae dominated phytoplankton communities in the melt ponds.The significant differences in phytoplankton communities between melt ponds and open water might be due to the salinity difference.Moreover,green algae may play a more important role in Arctic sea ice ecosystems with the expected growing number of melt ponds in the central Arctic Ocean. 展开更多
关键词 the CENTRAL Arctic Ocean MELT ponds photosynthesis PIGMENTS nutrients PHYTOPLANKTON COMMUNITIES
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IN-SITU DETERMINATION OF SEDIMENT OXYGEN DEMAND IN CULTIVATION PONDS
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作者 孙耀 陈聚法 +1 位作者 殷丽 宋云利 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2000年第2期157-161,共5页
This paper presents a method for in situ determining sediment oxygen demand (SOD) in cultivation pond. This method based on sediment surface structure, temperature, and other determining conditions like those in shrim... This paper presents a method for in situ determining sediment oxygen demand (SOD) in cultivation pond. This method based on sediment surface structure, temperature, and other determining conditions like those in shrimp cultivation environments, overcomes defects of old methods and provides more accurate estimation of SOD’s effect on dissolved oxygen in culture waters. Our experiment shows that the sediment surface structure and temperature had important effect on SOD in culture water. Different SOD values were derived from different parts of oxygen consumption curves of sediment, because the curves were not linear. According to the oxygen consumption curves of sediment and saturated DO in culture water, it was thought more suitable to calculate SOD with dissolved oxygen reduction from 5.0 to 2.0 mg/l. This method to determine the SOD of shrimp ponds yielded satisfactory results. 展开更多
关键词 SEDIMENT oxygen DEMAND CULTIVATION ponds in SITU DETERMINATION
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Effi ciency of phosphorus accumulation by plankton,periphyton developed on submerged artifi cial substrata and metaphyton:in-situ observation in two shallow ponds
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作者 Marija PEĆIĆ Slađana POPOVIĆ +3 位作者 Vesna MILUTINOVIĆ Gordana SUBAKOV SIMIĆ Ivana TRBOJEVIĆ Dragana PREDOJEVIĆ 《Journal of Oceanology and Limnology》 SCIE CAS CSCD 2021年第3期928-945,共18页
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 art... 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. 展开更多
关键词 PERIPHYTON phosphorus accumulation shallow ponds (phyto)plankton metaphyton EUTROPHICATION
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Models to predict sunlight-induced photodegradation rates of contaminants in wastewater stabilisation ponds and clarifiers
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作者 Xi-Zhi Niu 《Water Science and Engineering》 EI CAS CSCD 2019年第4期293-297,共5页
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 waste... 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. 展开更多
关键词 Sunlight irradiation PHOTODEGRADATION CONTAMINANTS Stabilisation ponds Solar water treatment
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The Relationship between Salinity and Bacterioplankton in Three Relic Coastal Ponds (Macchiatonda Wetland, Italy)
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作者 Matteo Evangelisti Domenico D’Amelia +2 位作者 Gustavo Di Lallo Maria Cristina Thaller Luciana Migliore 《Journal of Water Resource and Protection》 2013年第9期859-866,共8页
The great environmental importance of wetlands is linked to the high biodiversity of flora and fauna they support, so that the international Ramsar Convention focused on these areas and highlighted the need to preserv... The great environmental importance of wetlands is linked to the high biodiversity of flora and fauna they support, so that the international Ramsar Convention focused on these areas and highlighted the need to preserve them. The bacterial communities that thrive in these ecosystems play a key role in regulating the local biogeochemical processes and yet their distribution, abundance and dynamics are poorly known. This work is aimed to study the bacterial assemblages over a year long, to contribute to the understanding of the natural processes occurring in wetlands at variable salinity. The knowledge of bacterial groups, species or assemblages can provide a useful bioindicator for conservation and restoration efforts. Macchiatonda Natural Reserve (Santa Severa, Rome, Italy) is a relic ecosystem, once found along the entire Tyrrhenian coast. This wetland encompasses three coastal ponds with different salinity, where both peculiar vegetation and highly diverse migratory and resident avifauna can be found. This ancient system has been scarcely investigated and nothing is known about its microbial community. The molecular metagenomic analyses performed to investigate the salinity/bacterioplankton relationship, highlighted differences in the bacterial structure, between ponds and seasons. Analogous trends in SSCP profiles, Shannon Index, and bacterial composition (16S) were observed in the two saltier ponds, whereas the entire set of results was different for the less salty one. The species diversity in the three ponds varied according the salinity gradient, with the maximum diversity corresponding to a salt concentration range between 20 and 30. At higher and lower salinity, the microbial diversity lowers, according to the “Intermediate Disturbance Hypothesis”. 展开更多
关键词 BACTERIOPLANKTON COASTAL ponds Diversity SALINITY SSCP WETLANDS
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Phytoplankton Dynamics of Mokolo and Mopa Ponds in Bertoua City (East-Cameroon)
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作者 Janvier Kengne Tenkeu Gwladys Joelle Mogue Kamdem +4 位作者 Nectaire Lie Nyamsi Tchatcho Narcisse Mvondo Isabelle Appoline Kalieu Wilfried Takam Serge Hubert Zebaze Togouet 《Open Journal of Ecology》 2020年第7期482-496,共15页
This study aims to improve the understanding of algal community’s dynamics in response to different environmental factors in two dam ponds (Mokolo and Mopa) in the city of Bertoua (East-Cameroon). Physicochemical and... This study aims to improve the understanding of algal community’s dynamics in response to different environmental factors in two dam ponds (Mokolo and Mopa) in the city of Bertoua (East-Cameroon). Physicochemical and biological analyzes were carried out monthly by direct sampling at the surface and using Van Dorn bottle at 1 m depth. The organisms were collected using transparent glass vials of about 500 ml and fixed with 2<span style="font-family:Verdana;">.</span><span style="font-family:Verdana;">5 ml of a lugol solution, then analyzed using the Uterm<span style="white-space:nowrap;"><span style="white-space:nowrap;">&#244;</span></span>hl method. Physicochemical analyzes show low transparency (<</span><span style="font-family:Verdana;">75 cm) of the ponds despite their shallow depth (≤150 cm), high le</span><span style="font-family:Verdana;">vels of dissolved oxygen (></span><span style="font-family:Verdana;">60%)</span><span style="font-family:;" "=""><span style="font-family:Verdana;">, BOD</span><sub><span style="font-family:Verdana;">5</span></sub><span style="font-family:Verdana;"> (>30 mg/L) and chlorophyll “a” (></span></span><span style="font-family:Verdana;">30 μg/L). These data made it possible to categorize the Mokolo and Mopa ponds as hypereutrophic with nitrogen as the limiting factor for eutrophication. Biological data show quite diversified ponds with 138 species identifi</span><span style="font-family:;" "=""><span style="font-family:Verdana;">ed in Mokolo Pond and strongly dominated by Diatoms with 2951 ind. representing 46% of the total abundance. In Mopa Pond, 147 species were identified, mainly represented by Chlorophyceae with 3629 ind. representing 52% of the total abundance. </span><i><span style="font-family:Verdana;">Azpeitia</span></i><span style="font-family:Verdana;"></span><i> </i><span style="font-family:Verdana;"><i></i></span><i><i><span style="font-family:Verdana;">africana</span></i><span style="font-family:Verdana;"></span></i> (Mokolo) and <i></i></span><i><i><span style="font-family:Verdana;">Eresmophaera</span></i><span style="font-family:Verdana;"></span></i><i> </i><span style="font-family:Verdana;"><i></i></span><i><i><span style="font-family:Verdana;">gigas</span></i><span style="font-family:Verdana;"></span></i> (Mopa) were the most represented taxa during the study. This study will have deduced that the structure and dynamics of algal communities are under the control of different factors or processes that interact simultaneously, namely ascending factors or bottom-up corresponding to nutrient resources and sunlight and descending factors or top-down that are exerted by grazing and active physiological substances produced by other algae that are known to influence phytoplankton. 展开更多
关键词 Bertoua Dynamics Hypereutrophic PHYTOPLANKTON ponds
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Water budgets for freshwater aquaculture ponds with reference to effluent volume
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作者 K. K. Sharma B. C. Mohapatra +2 位作者 P. C. Das Bikash Sarkar S. Chand 《Agricultural Sciences》 2013年第8期353-359,共7页
This paper presents the consumptive water use for freshwater pond aquaculture for semi-intensive carps farming practices. The consumptive use of water includes evaporation loss, seepage loss and water exchanges requir... This paper presents the consumptive water use for freshwater pond aquaculture for semi-intensive carps farming practices. The consumptive use of water includes evaporation loss, seepage loss and water exchanges requirements. The water requirement has been estimated to be10.3 m3/Kg of fish production under present study for semi-intensive culture and with supplemental feeding. Out of which7.6 m3/Kg of fish production is system associated requirement. On an average the evaporation loss from the pond is1498.3 mm/year and seepage loss per year is about1182.60 mm/year. Seepage and water exchange losses recharge the ground water aquifers and if they are treated and recycled, the water use in aquaculture can be reduced significantly. A further reduction in fresh water use in pond aquaculture is possible through development of intensive and superintensive culture systems and aqua feeds. 展开更多
关键词 Water Budgets FRESHWATER Aquaculture ponds CARPS SEEPAGE POND Evaporation
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Construction of Water-saving Ecological Aquaculture Model in Ponds in North China
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作者 Lihua CHEN Yanhui LIU +4 位作者 Tiegang LIU Bingkun YANG Xiuying LI Zhanwei WANG Xiujie ZU 《Asian Agricultural Research》 2022年第10期18-22,共5页
[Objectives]To explore the ecological aquaculture model in ponds in North China,several single techniques were assembled into the same culture system.[Methods]Three ponds were selected,the species and stocking rate we... [Objectives]To explore the ecological aquaculture model in ponds in North China,several single techniques were assembled into the same culture system.[Methods]Three ponds were selected,the species and stocking rate were exactly the same,the water was not changed during the culture period,and the water loss due to evaporation and leakage was recovered.Since the middle of May,the hydrochemical indicators such as ammonia nitrogen,nitrite nitrogen,water temperature,dissolved oxygen and pH were monitored every 10 d.According to the monitoring results of ammonia nitrogen,carbon sources were added to the culture ponds to adjust the ratio of C to N,and carbon sources were added 9 times during the culture period.The stocking rate and yield per unit area were accurately measured at the beginning and end of the experiment,and no less than 30 fishes were randomly sampled to calculate the relevant growth indicators and feed coefficients.[Results]Except that the nonionic ammonia in pond 3#exceeded the standard by 10.3%on July 25,all other hydrochemical indicators met the Fisheries Water Quality Standard,and there was no significant difference in all hydrochemical indicators at the same time(P>0.05).The survival rate in 3 ponds was more than 95.0%,the average body weight of individuals out of the pond had no difference(P>0.05),and the feed coefficient was 1.41-1.43.There was no disease during the culture period,and the water was saved by 46.6%compared with the traditional culture model.[Conclusions]This study can provide a basis for the construction of a new model suitable for ecological aquaculture in ponds in North China. 展开更多
关键词 ponds in North China Water SAVING ECOLOGY Model CONSTRUCTION
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Water Quality Index of Waste Stabilisation Ponds and Downstream of Discharge Point
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作者 Obenne Pearl Gopolang Moatlhodi Wise Letshwenyo 《Journal of Environmental Protection》 2019年第8期993-1005,共13页
Water quality index has been used in various researches for the assessment of water quality for various uses and discharges into the environment. The purpose of this study was to determine the water quality index of t... Water quality index has been used in various researches for the assessment of water quality for various uses and discharges into the environment. The purpose of this study was to determine the water quality index of the effluent from waste stabilisation ponds and 400 m beyond discharge point. This was achieved by evaluating concentrations of seven parameters from soil, eleven physiochemical parameters from effluent and four microbiological parameters. Corresponding water quality indices calculated from microbiological parameters were 854, 142, 96 and 1539 respectively, at sites 1, 2, 3 and 4. Reductions of magnesium, zinc, lead, sodium adsorption ratio, sodium and electrical conductivity in soil samples at site 4 were 15.5%, 57%, 81.6%, 93.5%, 93.5% and 99% respectively. The percentage increases were 21.4% and 185% respectively, for calcium and iron ions. It can be concluded that the water quality index of the waste stabilisation ponds is unsuitable for discharge into the environment. However, the results revealed improved quality downstream of discharge point. 展开更多
关键词 MICROBIOLOGICAL PARAMETERS Physiochemical PARAMETERS SODIUM Absorption Ratio Soil Sampling Waste Stabilization ponds Water Quality Index
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Production Cost of Heterobranchus longifilis (Valenciennes, 1840) Fingerlings in the Ponds Fertilized with Poultry Droppings
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作者 Hyppolite Agadjihouèdé Clément Agossou Bonou +1 位作者 Carolle Avocèvou-Ayisso Philippe Adédjobi Lalèyè 《Journal of Food Science and Engineering》 2017年第2期93-98,共6页
This study aims to evaluate the production cost of Heterobranchus longifilis larvae reared in fertilized fish ponds. Experiment was carried out in two fish ponds. Each fish pond was filled with 200 liters of water and... This study aims to evaluate the production cost of Heterobranchus longifilis larvae reared in fertilized fish ponds. Experiment was carried out in two fish ponds. Each fish pond was filled with 200 liters of water and fertilized with dry poultry droppings (dose: 0.6 g.L-1) and zooplankton was inoculated with 83±13 individuals/L. Six days after inoculation of zooplankton, larvae of H. longifilis of 2 days after post-hatching were directly introduced into ponds with 300 individuals/m3. These larvae used exclusively zooplankton during the first 7 days. From the 8th day, larvae were fed with Coppens feed until 30 days. At the end, the survival rates were ranged between 58.33% and 56.67%. Final mean weights were brought up to all the ponds and were notsignificantly different (p > 0.05). The production costs ranged between 2.55 FCFA and 2.60 FCFA per fingerling with ratio production cost/weight gain around 0.80 FCFA/g in each pond. Then, this production system of fingerlings in fertilized ponds is very efficient and could be popularized in the rural fish farms. 展开更多
关键词 PRODUCTION COST FINGERLINGS Heterobranchus longifilis fertilized ponds
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Phenoxyacid Herbicides in Stormwater Retention Ponds: Urban Inputs
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作者 Renata Raina Michele L. Etter +2 位作者 Katherine Buehler Kevin Starks Ywomo Yowin 《American Journal of Analytical Chemistry》 2011年第8期962-970,共9页
Surface water runoff from urban centers is a major source of environmental pollution which impacts water quality in downstream aquatic habitats. Phenoxyacid herbicides are some of the most widely globally used herbici... Surface water runoff from urban centers is a major source of environmental pollution which impacts water quality in downstream aquatic habitats. Phenoxyacid herbicides are some of the most widely globally used herbicides in agriculture and urban environments for weed control. Their transformation products which in- clude chlorophenols can be more toxic than the active ingredients. We used LC/MS/MS to analyzed simul- taneously these acid herbicides and their transformation products in stormwater retention ponds taken from an urban environment to examine the occurrence and potential release of these herbicides from urban inputs into downstream waters. 2,4-dichlorophenoxyacetic acid and mecoprop were detected in all samples col- lected from the ponds and at the highest concentrations, while 2-methyl-4-chlorophenoxyacetic acid was de- tected only in spring and summer. Two transformation products, 4-chloro-2-methylphenol and 2,4-di- chlorophenol were detected in samples primarily at inlet locations on the ponds indicating that degradation had occurred in surface soils prior to surface water runoff. 展开更多
关键词 Phenoxyacid HERBICIDES CHLOROPHENOLS STORMWATER Retention ponds LC/MS/MS
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Physico-Chemical and Biological Characteristics of Stagnant Surface Water Bodies (Ponds and Lakes) Used for Drinking and Domestic Purposes in Niger Delta, Nigeria
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作者 Akpofure Rim-Rukeh 《Journal of Environmental Protection》 2013年第9期920-928,共9页
The surface water quality of some stagnant water bodies (ponds and lakes—Obi Lake, Usede pond, Oguta lake, Omuku pond, Ugheghe pond, Karabodone lake, Abua lake, Ikarama lake, Tenmako lake, and Adiegbe lake) in the Ni... The surface water quality of some stagnant water bodies (ponds and lakes—Obi Lake, Usede pond, Oguta lake, Omuku pond, Ugheghe pond, Karabodone lake, Abua lake, Ikarama lake, Tenmako lake, and Adiegbe lake) in the Niger Delta area of Nigeria have been investigated experimentally by analysing the physico-chemical and biological characteristics of the surface water samples. Results show: pH (5.10 - 7.40), temperature (26.4°C - 31.0°C), turbidity (7.83 - 27.7NTU), electrical conductivity (13.5 - 34.8 μS/cm), biochemical oxygen demand (BOD) (1.07 - 19.5 mg/l), chemical oxygen demand (COD) (1.90 - 21.5 mg/l), suspended solids (SS) (9.70 - 37.3 mg/l), dissolved oxygen (DO) (2.7 - 8.7 mg/l), total dissolved solids (TDS) (33.8 - 187.0 mg/l), total phosphorus (0.73 - 2.47 mg/l), ammoniacal nitrogen (AN) (0.018 - 4.70 mg/l) and total fecal coliform count (TFCC) (nil - 2175 cfu/ml). Results on the water quality using Malaysian Water Quality Index (WQI) show that Usede pond and Obi Lake belong to Class II with values that are 75.24 and 76.73 respectively. The WQI of Oguta lake, Omuku pond, Ugheghe pond, Karabodone lake and Abua lake are 67.46, 65.64, 65.87, 50.77, and 67.01 respectively and belongs to class III. The WQI of Ikarama lake, Tenmako lake, and Adiegbe lake are 43.38, 37.60, and 41.40, respectively and belongs to class IV and is described as fair. 展开更多
关键词 Malaysian WATER Quality Index Sewage DRINKING WATER ponds LAKES CLASS II WATER CLASS III WATER CLASS IV WATER
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Impact Assessment of Hillside Rainwater Harvesting Ponds on Agriculture Income: Case Study of Ntarama Sector in Rwanda
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作者 Omar Munyaneza Félicien Majoro +1 位作者 Emmanuel Hagenimana Wilbert Usabyisa 《Journal of Water Resource and Protection》 2016年第9期844-854,共12页
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 ai... 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 m<sup>3</sup> 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 m<sup>3</sup> 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. 展开更多
关键词 Farm Income Impact Assessment Rainwater Harvesting ponds and Technology Rwanda
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