The pollution of aquatic ecosystem by heavy metals has assumed serious proportions due to their toxicity and accumulative behavior. The toxicity metal is dependent on its chemical form and therefore removal of metal i...The pollution of aquatic ecosystem by heavy metals has assumed serious proportions due to their toxicity and accumulative behavior. The toxicity metal is dependent on its chemical form and therefore removal of metal is more meaningful than the estimation of its concentrations. In this study, the batch experiments were carried out under 30℃ to study the effect of pH, initial Cr concentration, adsorbent dose and contact time on the removal of Cr (lII). The maximum adsorption efficiency (99%) was observed when 1.5 g of pond mud was used for removal ofCr (Ⅲ) from test solution containing 150 mg·Cr / 100 ml. The optimal pH and contact time recorded during the study were 6 and 10.0, respectively.展开更多
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
Forest ecosystems help conserve the quality of water resources in aquatic habitats. The conservation of biological diversity in aquatic and terrestrial ecosystems remains a communal concern. Aquatic ecosystems and res...Forest ecosystems help conserve the quality of water resources in aquatic habitats. The conservation of biological diversity in aquatic and terrestrial ecosystems remains a communal concern. Aquatic ecosystems and resources are vulnerable but can be preserved and protected by forests. In sub-Saharan regions of Africa, water from ecosystems such as ponds still play important role in the livelihood of local populations. Water from temporary ponds is used by local populations for multiple needs; however, in this part of the world, the population is increasing, thus increasing human needs and activities and land use in the region. Land-use changes lead to deforestation, land degradation and the decline in freshwater, affecting human health and well-being. Forest degradation leads to the decline in ecosystem goods and services, particularly those related to watersheds. This study conducted in eastern Burkina Faso aimed to assess water quality of temporary ponds in protected forest areas (reserves) and surrounding villages. It was conducted in 61 temporary ponds where physical, chemical and biological variables were measured, such as water surface area, depth, transparency, macrophyte cover, pH, dissolved O<sub>2</sub>, conductivity, nutrient concentrations and algae biomass. The results showed that at p < 5%, water surface area (p = 0.02), depth (p = 0.00), nutrient content (p = 0.00), and algae biomass (p = 0.04) were significantly higher outside reserves than inside reserves. In contrast, macrophyte cover (mean cover percentages 53 vs. 44.5%) and water transparency (p = 0.02) were higher inside reserves. The variations in conductivity and pH were not significant. All trends showed the influences of human activities on water characteristics and the role forests and land cover had in preventing negative human impacts and disturbance of temporary ponds. Forests and land cover are important to water quality conservation and algae biomass regulation in temporary ponds. Protecting and managing forests is therefore an essential part of future strategies for limiting algal blooms and their negative consequences, maintaining water quality and providing clean water to citizens.展开更多
In order to study the short-term effects of Nualgi on water quality and phytoplankton in fishpend, we conducted continuous and regular surveys on the phytoplankton community and the water quality indexes in four group...In order to study the short-term effects of Nualgi on water quality and phytoplankton in fishpend, we conducted continuous and regular surveys on the phytoplankton community and the water quality indexes in four groups. The four groups were a Nualgi group ( M1 ), a diatom group ( M2 ), a Nualgi and diatom group (M3), and a control group (C). The results showed that there were no significance differences in pH, dissolved oxygen (DO), total nitrogen (TN) and total phosphorus (TP) among the four groups. The IP concentration of groups MI and M3 was significantly lower than that of groups M2 and C, indicating that Nualgl can reduce the IP concentration of water. The concentrations of NH4+ -N, NO2- -N and CODMn, of groups M1 , M2 and M3 were sigeificantly lower than those of group C, suggesting that both Nualgi and dominant diatom species can adjust water quality by reducing the concentrations of NH4+ -N, NO2- -N and CODMR. In this test, we identified 186 species that belonged to 109 genera of seven phyla. Among them, 86 species were Chlorophyta, 48 were Bacillariophyta, 27 were Cyanophyta, 17 were Euglenophyta, three were Dinophyta, three were Cryptophyta and two were Chrysophyta. Both diatom species and Nualgi can promote the growth of Bacillariophyta, restrain the growth of Chlorophyta and Cyanophyta, and thus change phytoplankton community structure. The biomass of Bacillariophyta in groups M1, M2 and M3 was larger than that in group C from the 20th d of the experiment, while the biomasses of Chlorophyta and Cyanophyta were lower than that in group C. Melo- sira granulata became the dominant algae species in groups M1, M2 and M3 , while Coelastrum microporum and Crucigenia tetrapedia were the dominant algae species in group Conly. Scenedesmus quadr/cauda became the dominant algae in groups M1 , M2 and C. There was no remarkable difference in diversity index among the four groups. The Shannon-Wiener index in all the four groups were all above 2.00, suggesting that the addition of Nualgi or diatom species did not affect the species diversity in this experiment.展开更多
Delayed settling of the ash particles and poor drainage of water from the pond ash are the major problems faced during the hydraulic stowing of pond ash. In this study the effect of polymeric flocculant on settling of...Delayed settling of the ash particles and poor drainage of water from the pond ash are the major problems faced during the hydraulic stowing of pond ash. In this study the effect of polymeric flocculant on settling of the ash particles and drainage of water during pond ash stowing are investigated. In addition, the parameters, viz. drainage and absorption of water during pond ash stowing are quantified by stowing a mine goaf model with pond ash slurries of five different concentrations added with and without flocculant. The study revealed that addition of only 5 10 6 of Sodium Carboxymethyl Cellulose (Na-CMC) flocculant with the pond ash slurries during stowing offers best result in terms of quicker settling of the ash particles and enhanced water drainage from the hydraulically stowed pond ash. Besides, it resulted in drainage of more than 85% of the total water used in the initial 45 min of stowing. The improvement in drainage is caused due to coagulation and flocculation of the pond ash particles because of charge neutralization and particle-particle bridging. This study may provide a basis for estimating the drainage and absorption of water during the real pond ash stowing operation in underground mines.展开更多
Sound pond productivity accompanied with adequate fish health is maintained, when water quality parameters are conducive. The study evaluated the chemical composition of a pond feed from spring water, in Asaba Campus....Sound pond productivity accompanied with adequate fish health is maintained, when water quality parameters are conducive. The study evaluated the chemical composition of a pond feed from spring water, in Asaba Campus. Sampling was carried out from September 2011 to February 2012 on a monthly basis. Surface water samples were collected between the hours of 7:00-9:00 am from the pond on each sampling day. Hydrogen-ion-concentration was in the range of 6.5 to 8.0 units. Dissolved oxygen was the highest in February 2012 with a value of 11.0 mg/L while it was the lowest in December 2011 with a value of 9.0 mg/L. Biological oxygen demand ranged from 3.5 to 5.0 mg/L. The chemical oxygen demand was the highest in December (10.00 mg/L) and lowest between January and February (8.0mg/L). The highest alkalinity was observed in October with a value of 1.05 mg/L and lowest in December with a value of 0.042 mg/L. Conductivity values ranged from 0.075 to 0.12 μS/cm. Total phosphorus was the highest in October with a value of 1.01 mg/L and lowest in December with a value of 0.83 mg/L. Total dissolved solids ranged from 90 to 105 mg/L. Values of physco-chemical parameters revealed that the pond was not polluted. Water quality analysis of the aquatics is of economic advantage to the fish farmer, hence, the need for its assessment at regular intervals. This is a quality assurance process that assures early dictation of toxic substances and mitigation processes to adopt before problems arise. In this way, the good health of organisms in the aquatic ecosystem and those of human dependent on them are guaranteed.展开更多
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
The pond water is used by a variety of animals i.e. mammals, birds, duck, and fish. Sediments play a significant role in determining the overall environmental quality for the living organism. Therefore, in this work, ...The pond water is used by a variety of animals i.e. mammals, birds, duck, and fish. Sediments play a significant role in determining the overall environmental quality for the living organism. Therefore, in this work, chemical characterization of pond water and sediment in the largest coal burning basin of India i.e. Korba basin is described. Elements i.e. C, O, S, F, Cl, Na, Mg, Al, Si, P, K, Ca, Ti, Fe, As, Cr, Cu, Zn, Cd, Pb, and Hg were quantified. Toxic metals i.e. As, Cd, Hg, and Pb were highly enriched in the sediments, ranging from 36 - 154, 0.14 - 1.19, 0.12 - 0.82 and 26 - 127 mg/kg with mean value (p = 0.05) of 95 ± 12, 0.62 ± 0.11, 0.35 ± 0.08 and 75 ± 13 mg/kg, respectively. The concentration variations, pollution indices and sources of elements in water and sediment are discussed.展开更多
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
The stagnant water reservoirs in urban area of India are severely contaminated with surfactant and microbe due to anthropogenic activities. In this work, water quality of pond water of the most industrialized city: Ra...The stagnant water reservoirs in urban area of India are severely contaminated with surfactant and microbe due to anthropogenic activities. In this work, water quality of pond water of the most industrialized city: Raipur, CG, India is described. The concentration of surfactant in the term of sodium lauryl sulfate (SLS) in water (n = 16) is ranged from 7.0 - 27 mg/L with mean value of 17 ± 3 mg/L. All ponds are found to be contaminated with microbes i.e. bacteria, algae and fungi at elevated levels. The physico-chemical characteristics of the pond water are discussed.展开更多
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
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
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
文摘The pollution of aquatic ecosystem by heavy metals has assumed serious proportions due to their toxicity and accumulative behavior. The toxicity metal is dependent on its chemical form and therefore removal of metal is more meaningful than the estimation of its concentrations. In this study, the batch experiments were carried out under 30℃ to study the effect of pH, initial Cr concentration, adsorbent dose and contact time on the removal of Cr (lII). The maximum adsorption efficiency (99%) was observed when 1.5 g of pond mud was used for removal ofCr (Ⅲ) from test solution containing 150 mg·Cr / 100 ml. The optimal pH and contact time recorded during the study were 6 and 10.0, respectively.
文摘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.
基金BIOLOG Program of the German Ministry of Education and Science(BMB+F BIOTA Ⅲ)
文摘Forest ecosystems help conserve the quality of water resources in aquatic habitats. The conservation of biological diversity in aquatic and terrestrial ecosystems remains a communal concern. Aquatic ecosystems and resources are vulnerable but can be preserved and protected by forests. In sub-Saharan regions of Africa, water from ecosystems such as ponds still play important role in the livelihood of local populations. Water from temporary ponds is used by local populations for multiple needs; however, in this part of the world, the population is increasing, thus increasing human needs and activities and land use in the region. Land-use changes lead to deforestation, land degradation and the decline in freshwater, affecting human health and well-being. Forest degradation leads to the decline in ecosystem goods and services, particularly those related to watersheds. This study conducted in eastern Burkina Faso aimed to assess water quality of temporary ponds in protected forest areas (reserves) and surrounding villages. It was conducted in 61 temporary ponds where physical, chemical and biological variables were measured, such as water surface area, depth, transparency, macrophyte cover, pH, dissolved O<sub>2</sub>, conductivity, nutrient concentrations and algae biomass. The results showed that at p < 5%, water surface area (p = 0.02), depth (p = 0.00), nutrient content (p = 0.00), and algae biomass (p = 0.04) were significantly higher outside reserves than inside reserves. In contrast, macrophyte cover (mean cover percentages 53 vs. 44.5%) and water transparency (p = 0.02) were higher inside reserves. The variations in conductivity and pH were not significant. All trends showed the influences of human activities on water characteristics and the role forests and land cover had in preventing negative human impacts and disturbance of temporary ponds. Forests and land cover are important to water quality conservation and algae biomass regulation in temporary ponds. Protecting and managing forests is therefore an essential part of future strategies for limiting algal blooms and their negative consequences, maintaining water quality and providing clean water to citizens.
基金Supported by Plan for Introducing Advanced International Water Conservancy Science and Technology(2015Z-15)National Key Technology Research and Development Program of China during the Twelfth Five-Year Plan Period(2015BAD13B03,2012BAD25B05)Earmarked Fund for Modern Agro-industry Technology Research System of China(CARS-46)
文摘In order to study the short-term effects of Nualgi on water quality and phytoplankton in fishpend, we conducted continuous and regular surveys on the phytoplankton community and the water quality indexes in four groups. The four groups were a Nualgi group ( M1 ), a diatom group ( M2 ), a Nualgi and diatom group (M3), and a control group (C). The results showed that there were no significance differences in pH, dissolved oxygen (DO), total nitrogen (TN) and total phosphorus (TP) among the four groups. The IP concentration of groups MI and M3 was significantly lower than that of groups M2 and C, indicating that Nualgl can reduce the IP concentration of water. The concentrations of NH4+ -N, NO2- -N and CODMn, of groups M1 , M2 and M3 were sigeificantly lower than those of group C, suggesting that both Nualgi and dominant diatom species can adjust water quality by reducing the concentrations of NH4+ -N, NO2- -N and CODMR. In this test, we identified 186 species that belonged to 109 genera of seven phyla. Among them, 86 species were Chlorophyta, 48 were Bacillariophyta, 27 were Cyanophyta, 17 were Euglenophyta, three were Dinophyta, three were Cryptophyta and two were Chrysophyta. Both diatom species and Nualgi can promote the growth of Bacillariophyta, restrain the growth of Chlorophyta and Cyanophyta, and thus change phytoplankton community structure. The biomass of Bacillariophyta in groups M1, M2 and M3 was larger than that in group C from the 20th d of the experiment, while the biomasses of Chlorophyta and Cyanophyta were lower than that in group C. Melo- sira granulata became the dominant algae species in groups M1, M2 and M3 , while Coelastrum microporum and Crucigenia tetrapedia were the dominant algae species in group Conly. Scenedesmus quadr/cauda became the dominant algae in groups M1 , M2 and C. There was no remarkable difference in diversity index among the four groups. The Shannon-Wiener index in all the four groups were all above 2.00, suggesting that the addition of Nualgi or diatom species did not affect the species diversity in this experiment.
文摘Delayed settling of the ash particles and poor drainage of water from the pond ash are the major problems faced during the hydraulic stowing of pond ash. In this study the effect of polymeric flocculant on settling of the ash particles and drainage of water during pond ash stowing are investigated. In addition, the parameters, viz. drainage and absorption of water during pond ash stowing are quantified by stowing a mine goaf model with pond ash slurries of five different concentrations added with and without flocculant. The study revealed that addition of only 5 10 6 of Sodium Carboxymethyl Cellulose (Na-CMC) flocculant with the pond ash slurries during stowing offers best result in terms of quicker settling of the ash particles and enhanced water drainage from the hydraulically stowed pond ash. Besides, it resulted in drainage of more than 85% of the total water used in the initial 45 min of stowing. The improvement in drainage is caused due to coagulation and flocculation of the pond ash particles because of charge neutralization and particle-particle bridging. This study may provide a basis for estimating the drainage and absorption of water during the real pond ash stowing operation in underground mines.
文摘Sound pond productivity accompanied with adequate fish health is maintained, when water quality parameters are conducive. The study evaluated the chemical composition of a pond feed from spring water, in Asaba Campus. Sampling was carried out from September 2011 to February 2012 on a monthly basis. Surface water samples were collected between the hours of 7:00-9:00 am from the pond on each sampling day. Hydrogen-ion-concentration was in the range of 6.5 to 8.0 units. Dissolved oxygen was the highest in February 2012 with a value of 11.0 mg/L while it was the lowest in December 2011 with a value of 9.0 mg/L. Biological oxygen demand ranged from 3.5 to 5.0 mg/L. The chemical oxygen demand was the highest in December (10.00 mg/L) and lowest between January and February (8.0mg/L). The highest alkalinity was observed in October with a value of 1.05 mg/L and lowest in December with a value of 0.042 mg/L. Conductivity values ranged from 0.075 to 0.12 μS/cm. Total phosphorus was the highest in October with a value of 1.01 mg/L and lowest in December with a value of 0.83 mg/L. Total dissolved solids ranged from 90 to 105 mg/L. Values of physco-chemical parameters revealed that the pond was not polluted. Water quality analysis of the aquatics is of economic advantage to the fish farmer, hence, the need for its assessment at regular intervals. This is a quality assurance process that assures early dictation of toxic substances and mitigation processes to adopt before problems arise. In this way, the good health of organisms in the aquatic ecosystem and those of human dependent on them are guaranteed.
文摘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.
文摘The pond water is used by a variety of animals i.e. mammals, birds, duck, and fish. Sediments play a significant role in determining the overall environmental quality for the living organism. Therefore, in this work, chemical characterization of pond water and sediment in the largest coal burning basin of India i.e. Korba basin is described. Elements i.e. C, O, S, F, Cl, Na, Mg, Al, Si, P, K, Ca, Ti, Fe, As, Cr, Cu, Zn, Cd, Pb, and Hg were quantified. Toxic metals i.e. As, Cd, Hg, and Pb were highly enriched in the sediments, ranging from 36 - 154, 0.14 - 1.19, 0.12 - 0.82 and 26 - 127 mg/kg with mean value (p = 0.05) of 95 ± 12, 0.62 ± 0.11, 0.35 ± 0.08 and 75 ± 13 mg/kg, respectively. The concentration variations, pollution indices and sources of elements in water and sediment are discussed.
文摘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.
文摘The stagnant water reservoirs in urban area of India are severely contaminated with surfactant and microbe due to anthropogenic activities. In this work, water quality of pond water of the most industrialized city: Raipur, CG, India is described. The concentration of surfactant in the term of sodium lauryl sulfate (SLS) in water (n = 16) is ranged from 7.0 - 27 mg/L with mean value of 17 ± 3 mg/L. All ponds are found to be contaminated with microbes i.e. bacteria, algae and fungi at elevated levels. The physico-chemical characteristics of the pond water are discussed.
基金the National Oceanic and Public Research Project(201405003).
文摘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.
文摘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.
文摘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.