The direct sulfation of limestone from different sources in Iran was studiedin a thermogravimetric analyzer under atmospheric pressure. All limestone samples tested have higherthan 97% CaCO_3. Experimental conditions ...The direct sulfation of limestone from different sources in Iran was studiedin a thermogravimetric analyzer under atmospheric pressure. All limestone samples tested have higherthan 97% CaCO_3. Experimental conditions were as follows: particle size levels ranging from 1.6 μmto 7.8 μm, four level reaction temperatures (700℃, 750℃, 800℃ and 850℃), and two SO_2concentrations (2.4 x 10^(-3) and 3.2 x 10^(-3) mol · mol^(-1)). The particle size and temperatureshowed dominant influences on the rate and level of conversion while the effect of SO_2concentration was weak. The shrinking core model can be used to describe the behavior of thesulfation process. The reaction kinetics and diffusion mechanism are both important in controllingthe rate of the process. The two key parameters of the model, chemical rate constant K_s andeffective diffusion coefficient D_(eff) were obtained. Model predictions are in good agreement withthe experimental data.展开更多
Maria sites are important historical sites, backing to the Byzantine period. The sites suffer from weathering noted as honeycomb, exfoliation and discoloration with white salt efflorescence at some parts. These are di...Maria sites are important historical sites, backing to the Byzantine period. The sites suffer from weathering noted as honeycomb, exfoliation and discoloration with white salt efflorescence at some parts. These are diagnostic features for salt weathering as confirmed by the laboratory investigations using thin section analysis. The salt is found to be from three sources, namely, water spray, chemical alteration of the mortar＇s carbonate content into sulfate salts by acid rain, and wet deposition of air pollutants on the surface of the stones ruins. The cracks noted in the structures of this archeological building are the results of landslides in this area. Knowledge of the archeological sites material examined can be greatly enhanced by understanding the process in their formation of degradation. This paper aims to describe the use of thin sections/micromorphology in the archeological sites. Analysis data of physical sitting, geology, geomorphology, and climate have been done to determine the main nature of hazards in this sites. Dynamic processing problems are existing along Alexandria coast including beach erosion, pollution and manmade. Thin section analysis is used to determine the factor in increasing the hazard level.展开更多
Monitoring water quality is important for maintaining a healthy watershed, but it is mostly ignored in watershed planning and management. In the Dhrabi watershed of Pakistan, the quality of surface water was monitored...Monitoring water quality is important for maintaining a healthy watershed, but it is mostly ignored in watershed planning and management. In the Dhrabi watershed of Pakistan, the quality of surface water was monitored at 16 locations to assess suitability for irrigation over regular intervals during the period 2007-2010. Similarly, groundwater quality was monitored at 10 locations for drinking and irrigation purposes. There was high spatial and temporal variability in surface water quality. Electrical conductivity （EC） and residual sodium carbonate （RSC） either exceeded or fluctuated around permissible limits at most of the locations throughout the monitoring period. Therefore, the use of such water for irrigation needs special care, otherwise its prolonged use may pose soil salinity and sodicity problems. The trend of EC and RSC for groundwater was similar to that for surface water. Exchangeable Mg2＋ exceeded permissible limits for most of the surface water and groundwater samples. In addition, microbial analysis of groundwater revealed that only two out of eight monitoring points during August 2009, none out of eight points during February 2010, and one out of nine points during June 2010 provided water fit for drinking. Soil samples were collected from the catchment areas of the major contributing streams and from the beds of the Kallar Kahar Lake and the Dhrabi Reservoir. The soil samples from the catchments showed high salinity and sodicity that may be the cause of high salinity and sodicity in the streams. The highest EC, sodium adsorption ratio （SAP,） and exchangeable sodium percentage （ESP） in the bed samples from the Kallar Kahar Lake were about 43 dS/m, 56, and 45, respectively. These high values were due to the saline water brought into the lake with the runoff.展开更多
The potability of water wells, drilling and tap water is the determining factor for the quality management of health of the urban and rural population. This study has been done on the basis of monitoring aspect such a...The potability of water wells, drilling and tap water is the determining factor for the quality management of health of the urban and rural population. This study has been done on the basis of monitoring aspect such as pH, content ammonium, nitrate, nitrite and chloride from a physico chemical point of view. This study allowed the chemical and bacteriological analysis of samples, based on the result obtained, and the potability of water was defined. The bacteriological analysis was carried out taking account of the total flora, coliforms and Escherichia coll. This work gave rise to analyze 36 samples of water from wells, eight samples of drilling water and nine samples of water taps from municipalities such as Mamou, Dalaba and Pita. Water wells represent 90% of water supplies in drinking water to the population. In this research, collection of samples was very important. This study shows that 16 samples from 52 are potable, therefore, it is urgent to focus on the treatment of sewage in order to ensure better health for the population from administrative region of Mamou.展开更多
文摘The direct sulfation of limestone from different sources in Iran was studiedin a thermogravimetric analyzer under atmospheric pressure. All limestone samples tested have higherthan 97% CaCO_3. Experimental conditions were as follows: particle size levels ranging from 1.6 μmto 7.8 μm, four level reaction temperatures (700℃, 750℃, 800℃ and 850℃), and two SO_2concentrations (2.4 x 10^(-3) and 3.2 x 10^(-3) mol · mol^(-1)). The particle size and temperatureshowed dominant influences on the rate and level of conversion while the effect of SO_2concentration was weak. The shrinking core model can be used to describe the behavior of thesulfation process. The reaction kinetics and diffusion mechanism are both important in controllingthe rate of the process. The two key parameters of the model, chemical rate constant K_s andeffective diffusion coefficient D_(eff) were obtained. Model predictions are in good agreement withthe experimental data.
文摘Maria sites are important historical sites, backing to the Byzantine period. The sites suffer from weathering noted as honeycomb, exfoliation and discoloration with white salt efflorescence at some parts. These are diagnostic features for salt weathering as confirmed by the laboratory investigations using thin section analysis. The salt is found to be from three sources, namely, water spray, chemical alteration of the mortar＇s carbonate content into sulfate salts by acid rain, and wet deposition of air pollutants on the surface of the stones ruins. The cracks noted in the structures of this archeological building are the results of landslides in this area. Knowledge of the archeological sites material examined can be greatly enhanced by understanding the process in their formation of degradation. This paper aims to describe the use of thin sections/micromorphology in the archeological sites. Analysis data of physical sitting, geology, geomorphology, and climate have been done to determine the main nature of hazards in this sites. Dynamic processing problems are existing along Alexandria coast including beach erosion, pollution and manmade. Thin section analysis is used to determine the factor in increasing the hazard level.
文摘Monitoring water quality is important for maintaining a healthy watershed, but it is mostly ignored in watershed planning and management. In the Dhrabi watershed of Pakistan, the quality of surface water was monitored at 16 locations to assess suitability for irrigation over regular intervals during the period 2007-2010. Similarly, groundwater quality was monitored at 10 locations for drinking and irrigation purposes. There was high spatial and temporal variability in surface water quality. Electrical conductivity （EC） and residual sodium carbonate （RSC） either exceeded or fluctuated around permissible limits at most of the locations throughout the monitoring period. Therefore, the use of such water for irrigation needs special care, otherwise its prolonged use may pose soil salinity and sodicity problems. The trend of EC and RSC for groundwater was similar to that for surface water. Exchangeable Mg2＋ exceeded permissible limits for most of the surface water and groundwater samples. In addition, microbial analysis of groundwater revealed that only two out of eight monitoring points during August 2009, none out of eight points during February 2010, and one out of nine points during June 2010 provided water fit for drinking. Soil samples were collected from the catchment areas of the major contributing streams and from the beds of the Kallar Kahar Lake and the Dhrabi Reservoir. The soil samples from the catchments showed high salinity and sodicity that may be the cause of high salinity and sodicity in the streams. The highest EC, sodium adsorption ratio （SAP,） and exchangeable sodium percentage （ESP） in the bed samples from the Kallar Kahar Lake were about 43 dS/m, 56, and 45, respectively. These high values were due to the saline water brought into the lake with the runoff.
文摘The potability of water wells, drilling and tap water is the determining factor for the quality management of health of the urban and rural population. This study has been done on the basis of monitoring aspect such as pH, content ammonium, nitrate, nitrite and chloride from a physico chemical point of view. This study allowed the chemical and bacteriological analysis of samples, based on the result obtained, and the potability of water was defined. The bacteriological analysis was carried out taking account of the total flora, coliforms and Escherichia coll. This work gave rise to analyze 36 samples of water from wells, eight samples of drilling water and nine samples of water taps from municipalities such as Mamou, Dalaba and Pita. Water wells represent 90% of water supplies in drinking water to the population. In this research, collection of samples was very important. This study shows that 16 samples from 52 are potable, therefore, it is urgent to focus on the treatment of sewage in order to ensure better health for the population from administrative region of Mamou.
