A pot experiment was conducted to investigate the effects of various soil treatments on the growth of vetiver grass ( Vetiveria zizanioides (L.) Nash) with the objective of formulating appropriate soil media for use i...A pot experiment was conducted to investigate the effects of various soil treatments on the growth of vetiver grass ( Vetiveria zizanioides (L.) Nash) with the objective of formulating appropriate soil media for use in sulfide-bearing mined areas. An acidic mine site acid sulfate soil (pH 2.8) was treated with different soil conditioner formula including hydrated lime, red mud (bauxite residues), zeolitic rock powder, biosolids and a compound fertilizer. Soils treated with red mud and hydrated lime corrected soil acidity and reduced or eliminated metal toxicity enabling the establishment of vetiver grass.Although over-liming affected growth, some seedlings of vetiver survived the initial strong alkaline conditions. Addition of appropriate amounts of zeolitic rock powder also enhanced growth, but over-application caused detrimental effects. In this experiment, soil medium with the best growth performance of vetiver was 50 g of red mud, 10 g of lime, 30 g of zeolitic rock powder and 30 g of biosolids with 2000 g of mine soils (100% survival rate with the greatest biomass and number of new shoots), but adding a chemical fertilizer to this media adversely impacted plant growth. In addition, a high application rate of biosolids resulted in poorer growth of vetiver, compared to a moderate application rate.展开更多
Dimethylsulfide(DMS) and dimethylsulfoniopropionate(DMSP) production by Scrippsiella trochoidea and Prorocentrum minimum was investigated to characterize the effects of physiological stage and salinity on DMS and DMSP...Dimethylsulfide(DMS) and dimethylsulfoniopropionate(DMSP) production by Scrippsiella trochoidea and Prorocentrum minimum was investigated to characterize the effects of physiological stage and salinity on DMS and DMSP pools of these two marine phytoplankton species.Axenic laboratory cultures of the two marine algae were tested for DMSP production and its conversion into DMS.The results demonstrated that both algal species could produce DMS,but the average concentration of DMS per cell in S.trochoidea(12.63 fmol/L) was about six times that in P.minimum(2.01 fmol/L).DMS and DMSP concentrations in algal cultures varied significantly at different growth stages,with high release during the late stationary growth phase and the senescent phase.DMS production induced by three salinities(22,28,34) showed that the DMS concentrations per cell in the two algal cultures increased with increasing salinity,which might result from intra-cellular DMSP up-regulation with the change of osmotic stress.Our study specifies the distinctive contributions of different physiological stages of marine phytoplankton on DMSP and DMS production,and clarifies the influence of salinity conditions on the release of DMS and DMSP.As S.trochoidea and P.minimum are harmful algal bloom species with high DMS production,they might play an additional significant role in the sulfur cycle when a red tide occurs.展开更多
In this paper, the optimum process parameters were obtained through treating phenol of simulated semi-coking wastewater using heat, Fe2+, Fe^0 and semi-coke to catalyze persulfate. The results of phenol decomposition...In this paper, the optimum process parameters were obtained through treating phenol of simulated semi-coking wastewater using heat, Fe2+, Fe^0 and semi-coke to catalyze persulfate. The results of phenol decomposition using PS catalyzed by heating, Fe2+, Fe^0 and semi-coke were compared for selecting a better activating way. The article investigated the effects of temperature, catalyzer dosage, pH value and reaction time. The experiment showed the four methods can all catalyzed the process. Under the experimental conditions of heating, Fe2+, Fe^0 and semi-coke degradation rate could reach to 20.7%, 75.1%, 94.5% and 40.0%, respectively. On this basis, this study established an Lt6(45) table to analyze the main influencing factors in semi-coke/Fe^0 catalyzing system. Under the optimum conditions, the degradation rate of Phenol reached to 93.6%. However, the PS dosage was reduced by 14.4%.展开更多
An OGCM, LICOM2.0, was used to investigate the effects of different surface boundary conditions for sea surface salinity (SSS) on simulations of global mean salinity, SSS, and the Atlantic Meridional Overturning Cir...An OGCM, LICOM2.0, was used to investigate the effects of different surface boundary conditions for sea surface salinity (SSS) on simulations of global mean salinity, SSS, and the Atlantic Meridional Overturning Circulation (AMOC). Four numerical experiments (CTRL, Expl, Exp2 and Exp3) were designed with the same forcing data-set, CORE.v2, and different surface boundary conditions for SSS~ A new surface salinity boundary condition that consists of both virtual and real salt fluxes was adopted in the fourth experiment (Exp3). Compared with the other experiments, the new salinity boundary condition prohibited a monotonous increasing or decreasing global mean salinity trend. As a result, global salinity was approximately conserved in EXP3. In the default salinity boundary condition setting in LICOM2.0, a weak restoring salinity term plays an essential role in reducing the simulated SSS bias, tending to increase the global mean salinity. However, a strong restoring salinity term under the sea ice can reduce the global mean salinity. The authors also found that adopting simulated SSS in the virtual salt flux instead of constant reference salinity improved the simulation of AMOC, whose strength became closer to that observed.展开更多
A novel saline-tolerant bacterium Bacillus circulans WZ-12 was evaluated for its potential to degrade four chlorinated hydrocarbons under saline conditions. CHECl2 was effectively degraded by Bacillus circulans WZ-12 ...A novel saline-tolerant bacterium Bacillus circulans WZ-12 was evaluated for its potential to degrade four chlorinated hydrocarbons under saline conditions. CHECl2 was effectively degraded by Bacillus circulans WZ-12 cells in the medium containing NaCl concentrations ranging from 5 g.L^-1 to 10 g-L^-1, and the maximum degradation efficiency (85%) was achieved at NaCl concentration of 10 g.L^-1. Similarly, Bacillus circulans WZ-12 was able to degrade CH2BrCl, C2H4Cl2, and C2H2Cl2 in the presence of 10 g NaCl per liter within 24 h. Cells of Bacillus circulans WZ-12 grown in minimal salt medium contained low levels of glycine betaine (GB), but GB levels were 3- to 5-fold higher in cells grown in media with high salt. Kinetic analysis revealed that biodegradation of the four chlorinated hydrocarbons was concentration dependent and a linear inverse correlation (R2= 0.85-0.94) was observed between the rate of biodegradation (V) and salt concentration from 5 g.L〈 to 60 g.L-1. The growing cells (in minimal salt medium) degraded approximately 50% of the CH2C12 within 24 h, whereas the resting cells (in physiological saline) degraded only 25% of the CH2C12 within 24 h and were inactive after 36 h cultivation. Biodegradation could be repeatedly performed for more than 192 h with more than 50% removal efficiency. Bacillus circulans WZ-12 grows well in an aqueous/oil system, hence, it is effective for the treatment of industriai efflu- ents that contain chlorinated hydrocarbons with high salt concentrations.展开更多
Alkylation of toluene With 2-chloro-2-methylpropane (t-Bu-C1) to synthesize para-tert-butyltoluene (PTBT) was carded out in the presence of triethylamine hydrochloride-aluminum chloride ionic liquids used as the c...Alkylation of toluene With 2-chloro-2-methylpropane (t-Bu-C1) to synthesize para-tert-butyltoluene (PTBT) was carded out in the presence of triethylamine hydrochloride-aluminum chloride ionic liquids used as the catalyst. The ionic liquids were prepared with different molar ratios of Et3NHC1 to A1CI3, and the effect of the molar ratio between A1C13 and Et3NHC1, the reaction time, the reaction temperature, the ionic liquid dosage, as well as the molar ratio of toluene to chloro- 2-methylpropane on the alkylation reaction of toluene with chloro-2-methyl-propane was investigated. The test results showed that the acidic ionic liquids prepared with Et3NHC1 and A1C13 had good activity and selectivity for the alkylation reaction of toluene with alkyl chloride to produce PTBT. The optimal reaction conditions were specified at an A1C13 to Et3N- HCI ratio of 1.6, a reaction temperature of 20 ℃, a mass fraction of toluene to ionic liquid of 10%, and a chloro-2-methyl- propane to toluene molar ratio of 0.5. Under the suitable reaction conditions, a 98% conversion of chloro-2-methylpropane and an 82.5% selectivity of PTBT were obtained. Ionic liquids could be reused 5 times with its catalytic activity unchanged, and the regenerated ionic liquids can be recycled.展开更多
基金Project partly supported by a grant from Expressway International Ltd., USA.
文摘A pot experiment was conducted to investigate the effects of various soil treatments on the growth of vetiver grass ( Vetiveria zizanioides (L.) Nash) with the objective of formulating appropriate soil media for use in sulfide-bearing mined areas. An acidic mine site acid sulfate soil (pH 2.8) was treated with different soil conditioner formula including hydrated lime, red mud (bauxite residues), zeolitic rock powder, biosolids and a compound fertilizer. Soils treated with red mud and hydrated lime corrected soil acidity and reduced or eliminated metal toxicity enabling the establishment of vetiver grass.Although over-liming affected growth, some seedlings of vetiver survived the initial strong alkaline conditions. Addition of appropriate amounts of zeolitic rock powder also enhanced growth, but over-application caused detrimental effects. In this experiment, soil medium with the best growth performance of vetiver was 50 g of red mud, 10 g of lime, 30 g of zeolitic rock powder and 30 g of biosolids with 2000 g of mine soils (100% survival rate with the greatest biomass and number of new shoots), but adding a chemical fertilizer to this media adversely impacted plant growth. In addition, a high application rate of biosolids resulted in poorer growth of vetiver, compared to a moderate application rate.
基金Supported by the National Natural Science Foundation of China(Nos. 40525017 and 41030858)the Changjiang Scholars Program,Ministry of Education of China,and the National Basic Research Program of China (973 Program) (No. 2010CB428904)
文摘Dimethylsulfide(DMS) and dimethylsulfoniopropionate(DMSP) production by Scrippsiella trochoidea and Prorocentrum minimum was investigated to characterize the effects of physiological stage and salinity on DMS and DMSP pools of these two marine phytoplankton species.Axenic laboratory cultures of the two marine algae were tested for DMSP production and its conversion into DMS.The results demonstrated that both algal species could produce DMS,but the average concentration of DMS per cell in S.trochoidea(12.63 fmol/L) was about six times that in P.minimum(2.01 fmol/L).DMS and DMSP concentrations in algal cultures varied significantly at different growth stages,with high release during the late stationary growth phase and the senescent phase.DMS production induced by three salinities(22,28,34) showed that the DMS concentrations per cell in the two algal cultures increased with increasing salinity,which might result from intra-cellular DMSP up-regulation with the change of osmotic stress.Our study specifies the distinctive contributions of different physiological stages of marine phytoplankton on DMSP and DMS production,and clarifies the influence of salinity conditions on the release of DMS and DMSP.As S.trochoidea and P.minimum are harmful algal bloom species with high DMS production,they might play an additional significant role in the sulfur cycle when a red tide occurs.
文摘In this paper, the optimum process parameters were obtained through treating phenol of simulated semi-coking wastewater using heat, Fe2+, Fe^0 and semi-coke to catalyze persulfate. The results of phenol decomposition using PS catalyzed by heating, Fe2+, Fe^0 and semi-coke were compared for selecting a better activating way. The article investigated the effects of temperature, catalyzer dosage, pH value and reaction time. The experiment showed the four methods can all catalyzed the process. Under the experimental conditions of heating, Fe2+, Fe^0 and semi-coke degradation rate could reach to 20.7%, 75.1%, 94.5% and 40.0%, respectively. On this basis, this study established an Lt6(45) table to analyze the main influencing factors in semi-coke/Fe^0 catalyzing system. Under the optimum conditions, the degradation rate of Phenol reached to 93.6%. However, the PS dosage was reduced by 14.4%.
基金partially supported by the National Basic Research Program of China[grant number 2013CB956204]the Strategic Priority Research Program of the Chinese Academy of Sciences[grant number XDA11010403],[grant number XDA11010304]the National Natural Science Foundation of China[grant number 41305028]
文摘An OGCM, LICOM2.0, was used to investigate the effects of different surface boundary conditions for sea surface salinity (SSS) on simulations of global mean salinity, SSS, and the Atlantic Meridional Overturning Circulation (AMOC). Four numerical experiments (CTRL, Expl, Exp2 and Exp3) were designed with the same forcing data-set, CORE.v2, and different surface boundary conditions for SSS~ A new surface salinity boundary condition that consists of both virtual and real salt fluxes was adopted in the fourth experiment (Exp3). Compared with the other experiments, the new salinity boundary condition prohibited a monotonous increasing or decreasing global mean salinity trend. As a result, global salinity was approximately conserved in EXP3. In the default salinity boundary condition setting in LICOM2.0, a weak restoring salinity term plays an essential role in reducing the simulated SSS bias, tending to increase the global mean salinity. However, a strong restoring salinity term under the sea ice can reduce the global mean salinity. The authors also found that adopting simulated SSS in the virtual salt flux instead of constant reference salinity improved the simulation of AMOC, whose strength became closer to that observed.
基金Supported by the National Natural Science Foundation of China (20977087, 20976165), Zhejiang Provincial Key Science and Technology Project of China (2011C13023), and Zhejiang Provincial Natural Science Foundation of China (Y5090155, Y5090054).
文摘A novel saline-tolerant bacterium Bacillus circulans WZ-12 was evaluated for its potential to degrade four chlorinated hydrocarbons under saline conditions. CHECl2 was effectively degraded by Bacillus circulans WZ-12 cells in the medium containing NaCl concentrations ranging from 5 g.L^-1 to 10 g-L^-1, and the maximum degradation efficiency (85%) was achieved at NaCl concentration of 10 g.L^-1. Similarly, Bacillus circulans WZ-12 was able to degrade CH2BrCl, C2H4Cl2, and C2H2Cl2 in the presence of 10 g NaCl per liter within 24 h. Cells of Bacillus circulans WZ-12 grown in minimal salt medium contained low levels of glycine betaine (GB), but GB levels were 3- to 5-fold higher in cells grown in media with high salt. Kinetic analysis revealed that biodegradation of the four chlorinated hydrocarbons was concentration dependent and a linear inverse correlation (R2= 0.85-0.94) was observed between the rate of biodegradation (V) and salt concentration from 5 g.L〈 to 60 g.L-1. The growing cells (in minimal salt medium) degraded approximately 50% of the CH2C12 within 24 h, whereas the resting cells (in physiological saline) degraded only 25% of the CH2C12 within 24 h and were inactive after 36 h cultivation. Biodegradation could be repeatedly performed for more than 192 h with more than 50% removal efficiency. Bacillus circulans WZ-12 grows well in an aqueous/oil system, hence, it is effective for the treatment of industriai efflu- ents that contain chlorinated hydrocarbons with high salt concentrations.
基金the financial support from the Beijing University of Chemical Technologythe Key Laboratory of Advanced Chemical Engineering and Technology, Beijing Institute of Petrochemical Technology, for the analysis of samples
文摘Alkylation of toluene With 2-chloro-2-methylpropane (t-Bu-C1) to synthesize para-tert-butyltoluene (PTBT) was carded out in the presence of triethylamine hydrochloride-aluminum chloride ionic liquids used as the catalyst. The ionic liquids were prepared with different molar ratios of Et3NHC1 to A1CI3, and the effect of the molar ratio between A1C13 and Et3NHC1, the reaction time, the reaction temperature, the ionic liquid dosage, as well as the molar ratio of toluene to chloro- 2-methylpropane on the alkylation reaction of toluene with chloro-2-methyl-propane was investigated. The test results showed that the acidic ionic liquids prepared with Et3NHC1 and A1C13 had good activity and selectivity for the alkylation reaction of toluene with alkyl chloride to produce PTBT. The optimal reaction conditions were specified at an A1C13 to Et3N- HCI ratio of 1.6, a reaction temperature of 20 ℃, a mass fraction of toluene to ionic liquid of 10%, and a chloro-2-methyl- propane to toluene molar ratio of 0.5. Under the suitable reaction conditions, a 98% conversion of chloro-2-methylpropane and an 82.5% selectivity of PTBT were obtained. Ionic liquids could be reused 5 times with its catalytic activity unchanged, and the regenerated ionic liquids can be recycled.