In this paper we discuss ways to obtain information about the quality of ground water and their availability. We classify the different approaches in two categories： geophysical methods, e.g., electroresistivity soun...In this paper we discuss ways to obtain information about the quality of ground water and their availability. We classify the different approaches in two categories： geophysical methods, e.g., electroresistivity sounding, seismic survey, gravimetry, MT （magnetotelluric） method, and geochemical methods. The former ones are able to provide information on the geological structure,meaning depth, range, amount of water and possible connections among different exploration areas or regions at risk due to contamination. On the other hand, the last ones provide information about the quality of water and the possible of use for agriculture, industry or human consumption. As a case study we aim at the Guarani Aquifer, more specifically at its recharge zone on the southern rim.展开更多
The use of renewable sources for obtainment of chemicals, biofuels, materials and energy has become each time larger due to environmental, political and economical problems of non-renewable energies utilization. Among...The use of renewable sources for obtainment of chemicals, biofuels, materials and energy has become each time larger due to environmental, political and economical problems of non-renewable energies utilization. Among several products that can be obtained from lignocellulosic biomass, which is a renewable source, there is furfural, a chemical from which many other value added chemical products can be obtained. The main route for furfural production consists of an acid hydrolysis of hemicelluloses present in lignocellulosic biomass to obtain xylose, which goes through a dehydration reaction to produce furfural. Due to the presence of an aldehyde group and a conjugated system of double bounds, furfural can go through several reactions, allowing the production of a range of value added products. In this sense, this article performs a review about mechanisms of furfural production from lignocellulosic biomass, highlighting its chemical properties which enable its utilization in different industrial applications of economic interest.展开更多
文摘In this paper we discuss ways to obtain information about the quality of ground water and their availability. We classify the different approaches in two categories： geophysical methods, e.g., electroresistivity sounding, seismic survey, gravimetry, MT （magnetotelluric） method, and geochemical methods. The former ones are able to provide information on the geological structure,meaning depth, range, amount of water and possible connections among different exploration areas or regions at risk due to contamination. On the other hand, the last ones provide information about the quality of water and the possible of use for agriculture, industry or human consumption. As a case study we aim at the Guarani Aquifer, more specifically at its recharge zone on the southern rim.
文摘The use of renewable sources for obtainment of chemicals, biofuels, materials and energy has become each time larger due to environmental, political and economical problems of non-renewable energies utilization. Among several products that can be obtained from lignocellulosic biomass, which is a renewable source, there is furfural, a chemical from which many other value added chemical products can be obtained. The main route for furfural production consists of an acid hydrolysis of hemicelluloses present in lignocellulosic biomass to obtain xylose, which goes through a dehydration reaction to produce furfural. Due to the presence of an aldehyde group and a conjugated system of double bounds, furfural can go through several reactions, allowing the production of a range of value added products. In this sense, this article performs a review about mechanisms of furfural production from lignocellulosic biomass, highlighting its chemical properties which enable its utilization in different industrial applications of economic interest.
