Acid cleaning processes were performed on a class 100 laminar flow clean bench assembled inside a class 1000 clean room.The ultrapure water was produced by Millipore RO (Reverse Osmosis) and Milli-Q water purification...Acid cleaning processes were performed on a class 100 laminar flow clean bench assembled inside a class 1000 clean room.The ultrapure water was produced by Millipore RO (Reverse Osmosis) and Milli-Q water purification systems.The three purity grades of nitric acid used for cleaning include Merck reagent grade HNO3,Fisher 'TraceMetal' grade HNO3,and the purest Fisher 'Optima' grade HNO3.The various bottles,containers and other labware,which are in contact with the samples,are made of low-density polyethylene (LDPE) and FEP or PFA Teflon materials.The acid cleaning procedures of the bottles and other containers follow a successive four times cleaning through immersion in increasing purity of nitric acid baths at different concentrations during four weeks.The first acid bath is performed at room temperature,but the following three acid baths are heated on ceramic hotplates with a surface temperature of 45℃.In order to verify the efficiency of the acid cleaning method,cleaned bottles underwent a blank determination procedure using ELAN 6100 inductively coupled plasma spectrometry (ICP-MS).Results show that most measured trace elements are not detected and the elements detected are at very low concentrations.The blank values are comparable with that of bottles cleaned at Korea Polar Research Institute (KOPRI).Although the acid cleaning method is developed mainly for reliable measurements of trace elements in snow and ice samples,it can also be used for investigations of trace elements in other environmental samples.展开更多
12-Tungstophosphoric acid（PW） supported on KSF montmorillonite, PW/KSF, was used as catalyst for deep oxidative desulfurization（ODS） of mixed thiophenic compounds in model oil and crude oil under mild conditions u...12-Tungstophosphoric acid（PW） supported on KSF montmorillonite, PW/KSF, was used as catalyst for deep oxidative desulfurization（ODS） of mixed thiophenic compounds in model oil and crude oil under mild conditions using hydrogen peroxide（H2O2） as an oxidizing agent. A one-factor-at-a-time method was applied for optimizing the parameters such as temperature, reaction time, amount of catalyst, type of extractant and oxidant-tosulfur compounds（S-compounds） molar ratio. The corresponding products can be easily removed from the model oil by using ethanol as the best extractant. The results showed high catalytic activity of PW/KSF in the oxidative removal of dibenzothiophene（DBT） and mixed thiophenic model oil under atmospheric pressure at 75 ℃ in a biphasic system. To investigate the oxidation and adsorption effects of crude oil composition on ODS, the effects of cyclohexene, 1,7-octadiene and o-xylene with different concentrations were studied.展开更多
Industrial production process including nitric acid production is an important greenhouse gas emission source. Although IPCC guidelines have given calculation methods and emission factors for N2O emission from nitric ...Industrial production process including nitric acid production is an important greenhouse gas emission source. Although IPCC guidelines have given calculation methods and emission factors for N2O emission from nitric acid production, emission factors of nitric acid production in China are not given. And it can be seen from the comparison of the guidelines and registered CDM projects in China that the N2O emission factors given in the IPCC guidelines and actual N2O emission from nitric acid production in China differ greatly while measured N2O emission data is not available, so determination of emission factors for N2O emission from nitric acid production is an important basic research for N2O emission calculation in China. The method that calculate N2O emission factors from nitric acid production in China is studied with baseline emission factors based on actual measurement of registered CDM projects and the calculated emission factor is compared with that given in the IPCC guidelines in the text.展开更多
基金supported by National Natural Sciences Funds for Distinguished Young Scholar (40825017)the Chinese Academy of Sciences (SKLCS-ZZ-2008-06)
文摘Acid cleaning processes were performed on a class 100 laminar flow clean bench assembled inside a class 1000 clean room.The ultrapure water was produced by Millipore RO (Reverse Osmosis) and Milli-Q water purification systems.The three purity grades of nitric acid used for cleaning include Merck reagent grade HNO3,Fisher 'TraceMetal' grade HNO3,and the purest Fisher 'Optima' grade HNO3.The various bottles,containers and other labware,which are in contact with the samples,are made of low-density polyethylene (LDPE) and FEP or PFA Teflon materials.The acid cleaning procedures of the bottles and other containers follow a successive four times cleaning through immersion in increasing purity of nitric acid baths at different concentrations during four weeks.The first acid bath is performed at room temperature,but the following three acid baths are heated on ceramic hotplates with a surface temperature of 45℃.In order to verify the efficiency of the acid cleaning method,cleaned bottles underwent a blank determination procedure using ELAN 6100 inductively coupled plasma spectrometry (ICP-MS).Results show that most measured trace elements are not detected and the elements detected are at very low concentrations.The blank values are comparable with that of bottles cleaned at Korea Polar Research Institute (KOPRI).Although the acid cleaning method is developed mainly for reliable measurements of trace elements in snow and ice samples,it can also be used for investigations of trace elements in other environmental samples.
基金Razi University Research Council for support of this work
文摘12-Tungstophosphoric acid（PW） supported on KSF montmorillonite, PW/KSF, was used as catalyst for deep oxidative desulfurization（ODS） of mixed thiophenic compounds in model oil and crude oil under mild conditions using hydrogen peroxide（H2O2） as an oxidizing agent. A one-factor-at-a-time method was applied for optimizing the parameters such as temperature, reaction time, amount of catalyst, type of extractant and oxidant-tosulfur compounds（S-compounds） molar ratio. The corresponding products can be easily removed from the model oil by using ethanol as the best extractant. The results showed high catalytic activity of PW/KSF in the oxidative removal of dibenzothiophene（DBT） and mixed thiophenic model oil under atmospheric pressure at 75 ℃ in a biphasic system. To investigate the oxidation and adsorption effects of crude oil composition on ODS, the effects of cyclohexene, 1,7-octadiene and o-xylene with different concentrations were studied.
文摘Industrial production process including nitric acid production is an important greenhouse gas emission source. Although IPCC guidelines have given calculation methods and emission factors for N2O emission from nitric acid production, emission factors of nitric acid production in China are not given. And it can be seen from the comparison of the guidelines and registered CDM projects in China that the N2O emission factors given in the IPCC guidelines and actual N2O emission from nitric acid production in China differ greatly while measured N2O emission data is not available, so determination of emission factors for N2O emission from nitric acid production is an important basic research for N2O emission calculation in China. The method that calculate N2O emission factors from nitric acid production in China is studied with baseline emission factors based on actual measurement of registered CDM projects and the calculated emission factor is compared with that given in the IPCC guidelines in the text.
