A risk situation of organic pollutants accumulation in the sediments of the dams from Cascade “Middle Iskar” (NW Bulgaria) is simulated in the present study. The aim is risk modelling of organic pollution in lake se...A risk situation of organic pollutants accumulation in the sediments of the dams from Cascade “Middle Iskar” (NW Bulgaria) is simulated in the present study. The aim is risk modelling of organic pollution in lake sediments and on base of the investigated key chemical and enzymological parameters to risk assessment. A model process in lab scale with addition of whey as a source of organic pollutants was simulated. Two situations near to real conditions were studied: 1) at a decreased concentration of organic pollutants (chemical oxygen demand was 0.265 gO<sub>2</sub>.kg<sup>-1</sup>) in the case of discharge of sediments downstream of the river (control situation);2) at an accumulation of organic pollutants (chemical oxygen demand was 1.463 gO<sub>2</sub>.kg<sup>-1</sup>) in the sediments (risk event). The dynamics of chemical oxygen demand (COD), concentration of proteins and lactose as well as of the key enzymological indicators (phosphatase activity index—PAI, anaerobic dehydrogenase activity, protease and ?-galactosidase activities) were investigated. The data from Risk Assessment showed that there is a hazard from higher protein concentration at the end of the process in comparison with the control situation. The risk about COD and lactose concentration during the risk modelling was acceptable. The obtained results showed that the PAI can be used as an indicator for early warning of the organic pollution with protein nature.展开更多
Floating photovoltaic(FPV)systems are one of the globally emerging technologies of renewable energy production that tend to balance the water-energy demand by effectively saving the evaporated water from reservoirs wh...Floating photovoltaic(FPV)systems are one of the globally emerging technologies of renewable energy production that tend to balance the water-energy demand by effectively saving the evaporated water from reservoirs while generating electrical power.This study presents the performance analysis of a model FPV plant in an Indian reservoir.The Mettur dam reservoir located in Tamil Nadu,India with a hydroelectric power plant of 150-MW capacity is considered as a test case.The preliminary design of the FPV plant is proposed based on a detailed study of the key design elements and their suitability for Indian reservoirs.The proposed plant is numerically analysed for various tilt angles,mounting systems and tracking mechanisms in order to assess its potential power generation.A flat-mount system in landscape orientation was found to exhibit a high performance ratio.Further,a fixed-tilt FPV system with a panel slope of 10°and an FPV system with single-axis tracking were found to be suitable for the Mettur reservoir.Further,cost analysis of the FPV system is also presented along with the carbon-footprint estimation to establish the economic and environmental benefits of the system.The results show that the total potential CO_(2) saving by a FPV system with tracking is 135918.87 t CO_(2) and it is 12.5%higher than that of a fixed-mount FPV system.展开更多
文摘A risk situation of organic pollutants accumulation in the sediments of the dams from Cascade “Middle Iskar” (NW Bulgaria) is simulated in the present study. The aim is risk modelling of organic pollution in lake sediments and on base of the investigated key chemical and enzymological parameters to risk assessment. A model process in lab scale with addition of whey as a source of organic pollutants was simulated. Two situations near to real conditions were studied: 1) at a decreased concentration of organic pollutants (chemical oxygen demand was 0.265 gO<sub>2</sub>.kg<sup>-1</sup>) in the case of discharge of sediments downstream of the river (control situation);2) at an accumulation of organic pollutants (chemical oxygen demand was 1.463 gO<sub>2</sub>.kg<sup>-1</sup>) in the sediments (risk event). The dynamics of chemical oxygen demand (COD), concentration of proteins and lactose as well as of the key enzymological indicators (phosphatase activity index—PAI, anaerobic dehydrogenase activity, protease and ?-galactosidase activities) were investigated. The data from Risk Assessment showed that there is a hazard from higher protein concentration at the end of the process in comparison with the control situation. The risk about COD and lactose concentration during the risk modelling was acceptable. The obtained results showed that the PAI can be used as an indicator for early warning of the organic pollution with protein nature.
文摘Floating photovoltaic(FPV)systems are one of the globally emerging technologies of renewable energy production that tend to balance the water-energy demand by effectively saving the evaporated water from reservoirs while generating electrical power.This study presents the performance analysis of a model FPV plant in an Indian reservoir.The Mettur dam reservoir located in Tamil Nadu,India with a hydroelectric power plant of 150-MW capacity is considered as a test case.The preliminary design of the FPV plant is proposed based on a detailed study of the key design elements and their suitability for Indian reservoirs.The proposed plant is numerically analysed for various tilt angles,mounting systems and tracking mechanisms in order to assess its potential power generation.A flat-mount system in landscape orientation was found to exhibit a high performance ratio.Further,a fixed-tilt FPV system with a panel slope of 10°and an FPV system with single-axis tracking were found to be suitable for the Mettur reservoir.Further,cost analysis of the FPV system is also presented along with the carbon-footprint estimation to establish the economic and environmental benefits of the system.The results show that the total potential CO_(2) saving by a FPV system with tracking is 135918.87 t CO_(2) and it is 12.5%higher than that of a fixed-mount FPV system.
