Several pit lakes exist in the Raipur area due to lime stone mining. The water of pit lakes is used for bathing, washing and irrigation purposes. They are found to be contaminated with toxicants i.e. fluoride, su...Several pit lakes exist in the Raipur area due to lime stone mining. The water of pit lakes is used for bathing, washing and irrigation purposes. They are found to be contaminated with toxicants i.e. fluoride, surfactants and microbes far above the recommended limits. In this work, the water quality of 29 pit lakes locates in two districts: Raipur and Baloda Bazar, Chhattisgarh, India are assessed for drinking and irrigation purposes.展开更多
It is known that one of the causes of pitting corrosion of copper tubes is residual carbon on the inner surface. It was confirmed that type I” pitting corrosion of the copper tube is suppressed by keeping the residua...It is known that one of the causes of pitting corrosion of copper tubes is residual carbon on the inner surface. It was confirmed that type I” pitting corrosion of the copper tube is suppressed by keeping the residual carbon amount at 2 mg/m<sup>2</sup> or less, which is lower than that of the type I’ pitting corrosion, or by removing the fine particles that are the corrosion product of galvanized steel pipes. The developed water treatment chemical was evaluated using three types of copper tubes with residual carbon amounts of 0 mg/m<sup>2</sup>, 0.5 mg/m<sup>2</sup>, and 6.1 mg/m<sup>2</sup>. The evaluation was conducted for three months in an open-circulation cooling water system and compared with the current water treatment chemical. Under the current water treatment chemical conditions, only the copper tube with a residual carbon amount of 6.1 mg/m<sup>2</sup> showed a significant increase in the natural corrosion potential after two weeks, and pitting corrosion occurred. No pitting corrosion and no increase in the natural corrosion potential were observed in any of the copper tubes that were treated with the developed water treatment chemical. In addition, the polarization curve was measured using the cooling water from this field test, and the anodic polarization of two cooling waters was compared. For copper tubes with a large amount of residual carbon, the current density near 0 mV vs. Ag/AgCl electrode (SSE) increased when the developed water treatment chemical was added.展开更多
Studies were carried out to evaluate the effect of distance of sanitary pits on the physicochemical properties of hand-dug well water samples consumed by people living in Akwuke community, Enugu South Local Government...Studies were carried out to evaluate the effect of distance of sanitary pits on the physicochemical properties of hand-dug well water samples consumed by people living in Akwuke community, Enugu South Local Government Area of Enugu State, using standard analytical procedures and instrumentation. The mean range of pH, turbidity, electrical conductivity, total dissolved solids, nitrate and sulphate in the well water samples at the determined sampling distances of 3, 6 and 10 m from the sanitary pits were 5.9 - 7.24, 1.92 - 6.63 NTU, 122.03 - 303.91 μs/cm, 100.00 - 261.90 mg/L, 1.21 - 4.68 mg/L and 28.89 - 49/61 mg/L respectively. The investigated mean physicochemical parameters of the well water samples were generally observed to increase with decrease in the distance of the well water samples from the sanitary pits. The levels of the determined physicochemical parameter of the well water samples at sampling distances of 3, 6, and 10 m respectively from the sanitary pits were statistically significant. The mean pH values of the well water samples at sampling distances of 3 and 6 m respectively from the sanitary pits were below the WHO recommended threshold limits for safe drinking water. Additionally, the mean values of turbidity and total dissolved solids of the well water samples at a sampling distance of 3 m from the sanitary pits were above the WHO permissible limits. The pH, turbidity and total dissolved solids are some of the most important parameters used in assessing the quality of any water source, therefore, the poor physicochemical properties of well water samples at a sampling distance of 3 m from the sanitary pits could put at severe health risk consumption of this water over a prolonged time. Siting well water at a reasonable far distance (above 10 m) for sanitary pits especially in communities with severe water scarcity would definitely help guarantee access to safe drinking water by rural as well as urban dwellers in Nigeria.展开更多
Experiments were conducted to observe the effect of pre-harvest calcium (Ca) applied as calcium chloride (1% W/V) and postharvest hot water treatment (HWT) on “Royal Delicious” apples. For this, apples were divided ...Experiments were conducted to observe the effect of pre-harvest calcium (Ca) applied as calcium chloride (1% W/V) and postharvest hot water treatment (HWT) on “Royal Delicious” apples. For this, apples were divided in 4 lots viz., untreated (neither Ca nor HWT), Ca alone (pre-harvest 3 sprays of CaCl2 (1.0% w/v) in the orchard), HWT (42℃ for 2 h). Apples of all four lots were stored in cold storage maintained at 0℃ ± 1℃ and 90% - 95% relative humidity for 6 months. After storage, fruits were removed to ambient conditions for 5 days, and then observations on decay area and incidence, bitter pit incidence, fruit Ca content, lipoxygenase (LOX) and antioxidant (AOX) activity, fruit firmness and fruit quality parameters were recorded. After 6 months in cold storage plus 5 day at 22℃ ± 2℃ and 70% + 4% RH, apples, which received Ca as pre-harvest spray or those which received postharvest hot water treatment or Ca + HWT had significantly lesser decay area (decay lesions) caused by Penicillium expansum or Botrytis cinerea than untreated ones (control). Ca + HWT treatment was significantly more effective on B. cinerea than P. expansum. Untreated apples exhibited higher incidence of bitter pit (18.2%) than those treated with Ca or HWT or both. Fruit Ca content (2.92% DM) were significantly lower and conversely the LOX activity (6.9 μmoles min–1×g–1FW) was higher in untreated apples. Similarly, total phenolics and AOX activity were also lower in the untreated apples than Ca or HWT treated. HWT or Ca treated apples have beneficial effects on fruit firmness, peel colour and quality parameters like TSS and ascorbic acid content. Thus, it is concluded that pre-harvest sprays of calcium chloride with postharvest HWT is highly useful for “Royal Delicious” for reducing decay loss, maintaining firmness, high levels of antioxidants and fruit quality.展开更多
Studies were carried out to assess the effect of distance of sanitary pits on the microbial and heavy metal levels in hand dug well water samples consumed by people living in Akwuke, Enugu South Local government area ...Studies were carried out to assess the effect of distance of sanitary pits on the microbial and heavy metal levels in hand dug well water samples consumed by people living in Akwuke, Enugu South Local government area of Enugu State, using standard biochemical and spectrophotometric analysis. The well water samples were digested with aqua-regia and four heavy metals (Pb, Cd, Cu and Zn) were assayed in the well water samples at sampling distances of 3, 6 and 10 m respectively from the sanitary pits. The range of mean bacterial counts (cfu/g) for the four detected pathogenic bacteria;<em> S. aureus</em>, <em>Klebsiella pnemeoniae</em>, <em>Echerichia coli</em> and <em>Salmonella enteritidis </em>were 83 - 3730, 510 - 870, 50 - 2535 and 240 - 3420 Cfu/g at sampling distances of 3, 6 and 10 m respectively from the sanitary pits. The mean bacteria counts of the four detected pathogenic organisms in the well water sample at sampling distances of 3 and 6 m respectively from the sanitary pits were above the WHO recommended threshold limits for a safe drinking water. The mean bacterial counts of <em>Salmonella enteritidis</em> in the well water samples of sampling distance of 10 m from the sanitary pits was above the WHO recommended permissible limits. At sampling distances of 3, 6 and 10 m from the sanitary pits, the mean range of Pb, Cd, Cu and Zn in the well water samples were, 0.03 - 0.3, 0.02 - 0.05, 0.46 - 1.71 and 1.63 - 7.03 μg/g respectively. The mean levels of Pb and Cd in the well water samples at sampling distances of 3 and 6 m respectively from the sanitary pits were above their respective WHO recommended threshold limits. The mean heavy metals (Cd, Pb, Cu and Zn) in the well water samples at sampling distances of 3, 6, and 10 m respectively from the sanitary pits were statistically significant at p < 0.05.展开更多
文摘Several pit lakes exist in the Raipur area due to lime stone mining. The water of pit lakes is used for bathing, washing and irrigation purposes. They are found to be contaminated with toxicants i.e. fluoride, surfactants and microbes far above the recommended limits. In this work, the water quality of 29 pit lakes locates in two districts: Raipur and Baloda Bazar, Chhattisgarh, India are assessed for drinking and irrigation purposes.
文摘It is known that one of the causes of pitting corrosion of copper tubes is residual carbon on the inner surface. It was confirmed that type I” pitting corrosion of the copper tube is suppressed by keeping the residual carbon amount at 2 mg/m<sup>2</sup> or less, which is lower than that of the type I’ pitting corrosion, or by removing the fine particles that are the corrosion product of galvanized steel pipes. The developed water treatment chemical was evaluated using three types of copper tubes with residual carbon amounts of 0 mg/m<sup>2</sup>, 0.5 mg/m<sup>2</sup>, and 6.1 mg/m<sup>2</sup>. The evaluation was conducted for three months in an open-circulation cooling water system and compared with the current water treatment chemical. Under the current water treatment chemical conditions, only the copper tube with a residual carbon amount of 6.1 mg/m<sup>2</sup> showed a significant increase in the natural corrosion potential after two weeks, and pitting corrosion occurred. No pitting corrosion and no increase in the natural corrosion potential were observed in any of the copper tubes that were treated with the developed water treatment chemical. In addition, the polarization curve was measured using the cooling water from this field test, and the anodic polarization of two cooling waters was compared. For copper tubes with a large amount of residual carbon, the current density near 0 mV vs. Ag/AgCl electrode (SSE) increased when the developed water treatment chemical was added.
文摘Studies were carried out to evaluate the effect of distance of sanitary pits on the physicochemical properties of hand-dug well water samples consumed by people living in Akwuke community, Enugu South Local Government Area of Enugu State, using standard analytical procedures and instrumentation. The mean range of pH, turbidity, electrical conductivity, total dissolved solids, nitrate and sulphate in the well water samples at the determined sampling distances of 3, 6 and 10 m from the sanitary pits were 5.9 - 7.24, 1.92 - 6.63 NTU, 122.03 - 303.91 μs/cm, 100.00 - 261.90 mg/L, 1.21 - 4.68 mg/L and 28.89 - 49/61 mg/L respectively. The investigated mean physicochemical parameters of the well water samples were generally observed to increase with decrease in the distance of the well water samples from the sanitary pits. The levels of the determined physicochemical parameter of the well water samples at sampling distances of 3, 6, and 10 m respectively from the sanitary pits were statistically significant. The mean pH values of the well water samples at sampling distances of 3 and 6 m respectively from the sanitary pits were below the WHO recommended threshold limits for safe drinking water. Additionally, the mean values of turbidity and total dissolved solids of the well water samples at a sampling distance of 3 m from the sanitary pits were above the WHO permissible limits. The pH, turbidity and total dissolved solids are some of the most important parameters used in assessing the quality of any water source, therefore, the poor physicochemical properties of well water samples at a sampling distance of 3 m from the sanitary pits could put at severe health risk consumption of this water over a prolonged time. Siting well water at a reasonable far distance (above 10 m) for sanitary pits especially in communities with severe water scarcity would definitely help guarantee access to safe drinking water by rural as well as urban dwellers in Nigeria.
文摘Experiments were conducted to observe the effect of pre-harvest calcium (Ca) applied as calcium chloride (1% W/V) and postharvest hot water treatment (HWT) on “Royal Delicious” apples. For this, apples were divided in 4 lots viz., untreated (neither Ca nor HWT), Ca alone (pre-harvest 3 sprays of CaCl2 (1.0% w/v) in the orchard), HWT (42℃ for 2 h). Apples of all four lots were stored in cold storage maintained at 0℃ ± 1℃ and 90% - 95% relative humidity for 6 months. After storage, fruits were removed to ambient conditions for 5 days, and then observations on decay area and incidence, bitter pit incidence, fruit Ca content, lipoxygenase (LOX) and antioxidant (AOX) activity, fruit firmness and fruit quality parameters were recorded. After 6 months in cold storage plus 5 day at 22℃ ± 2℃ and 70% + 4% RH, apples, which received Ca as pre-harvest spray or those which received postharvest hot water treatment or Ca + HWT had significantly lesser decay area (decay lesions) caused by Penicillium expansum or Botrytis cinerea than untreated ones (control). Ca + HWT treatment was significantly more effective on B. cinerea than P. expansum. Untreated apples exhibited higher incidence of bitter pit (18.2%) than those treated with Ca or HWT or both. Fruit Ca content (2.92% DM) were significantly lower and conversely the LOX activity (6.9 μmoles min–1×g–1FW) was higher in untreated apples. Similarly, total phenolics and AOX activity were also lower in the untreated apples than Ca or HWT treated. HWT or Ca treated apples have beneficial effects on fruit firmness, peel colour and quality parameters like TSS and ascorbic acid content. Thus, it is concluded that pre-harvest sprays of calcium chloride with postharvest HWT is highly useful for “Royal Delicious” for reducing decay loss, maintaining firmness, high levels of antioxidants and fruit quality.
文摘Studies were carried out to assess the effect of distance of sanitary pits on the microbial and heavy metal levels in hand dug well water samples consumed by people living in Akwuke, Enugu South Local government area of Enugu State, using standard biochemical and spectrophotometric analysis. The well water samples were digested with aqua-regia and four heavy metals (Pb, Cd, Cu and Zn) were assayed in the well water samples at sampling distances of 3, 6 and 10 m respectively from the sanitary pits. The range of mean bacterial counts (cfu/g) for the four detected pathogenic bacteria;<em> S. aureus</em>, <em>Klebsiella pnemeoniae</em>, <em>Echerichia coli</em> and <em>Salmonella enteritidis </em>were 83 - 3730, 510 - 870, 50 - 2535 and 240 - 3420 Cfu/g at sampling distances of 3, 6 and 10 m respectively from the sanitary pits. The mean bacteria counts of the four detected pathogenic organisms in the well water sample at sampling distances of 3 and 6 m respectively from the sanitary pits were above the WHO recommended threshold limits for a safe drinking water. The mean bacterial counts of <em>Salmonella enteritidis</em> in the well water samples of sampling distance of 10 m from the sanitary pits was above the WHO recommended permissible limits. At sampling distances of 3, 6 and 10 m from the sanitary pits, the mean range of Pb, Cd, Cu and Zn in the well water samples were, 0.03 - 0.3, 0.02 - 0.05, 0.46 - 1.71 and 1.63 - 7.03 μg/g respectively. The mean levels of Pb and Cd in the well water samples at sampling distances of 3 and 6 m respectively from the sanitary pits were above their respective WHO recommended threshold limits. The mean heavy metals (Cd, Pb, Cu and Zn) in the well water samples at sampling distances of 3, 6, and 10 m respectively from the sanitary pits were statistically significant at p < 0.05.
