Antimony ore dressing wastewater was treated by using Bacillus sp. and the influences of treatment time, temperature, inoculation size, and pH value on Sb removal effect were explored. The results showed that the best...Antimony ore dressing wastewater was treated by using Bacillus sp. and the influences of treatment time, temperature, inoculation size, and pH value on Sb removal effect were explored. The results showed that the best removal efficiency of Sb in mineral processing wastewater could reach 99.75% in 4 d under the optimum conditions of 30 ℃, microbial inoculated quantity 5%, and pH value at 2.0. After the treatment, the concentration of Sb in wastewater was reduced from 122.21 to 0.30mg/L, which was lower than the local industrial wastewater discharge standard of0.50 mg/L.展开更多
The control effect of different concentrations of herbicide atrazine (before seedling after sowing) on weed in foxtail millet field was compared, which provide theoretical basis for screening suitable herbicides con...The control effect of different concentrations of herbicide atrazine (before seedling after sowing) on weed in foxtail millet field was compared, which provide theoretical basis for screening suitable herbicides concentration for foxtail millet production. As a result, after spraying 25 and 40 d, plant control effect and fresh weight control effect were best by 4 500 ml/hm^2 processing, and fresh weight control effect reached 83.16% and 86.43%. Compared with spraying water (CK), yieldincreasing effect was the best in the treatment group with atrazine at 2 250 ml/hm^2, where yield growth rate was 54.31%, followed by the treatment group with atrazine at 3 000 ml/hm^2. Therefore, 2 250 ml/hm^2 was the optiaml concentration of herbicide atrazine for millet production.展开更多
CO2 removal from biogas by water washing system was investigated with various parameters, including liquid/ gas ratio, pressure, temperature, and CO2 content. The results indicate that CO2 removal ratio could reach 34...CO2 removal from biogas by water washing system was investigated with various parameters, including liquid/ gas ratio, pressure, temperature, and CO2 content. The results indicate that CO2 removal ratio could reach 34.6%- 94.2% as liquid/gas ratio increased from 0.14 to 0.50. Increasing pressure (from 0.8 to 1.2 MPa) could improve gas purification with a constant inflow rate of gas. Temperature played a key role in the process and lower temper- ature in absorption tower was beneficial for reducing CO2 content. CO2 removal ratio could reach 24.4%-83.2% when CO2 content in the simulated gas was 25%-45%. The lowest CO2 content after absorption was 2.6% at 1.2 MPa with 400 L·h-1 gas flow and 200 L·h-1 water flow, which meets the requirement of CO2 content in natural Ras for vehicle fuel.展开更多
The effect of coal levels on phosphorus removal from a high phosphorus oolitic hematite ore after direct reduction roasting have been investigated. Raw ore, coal, and a dephosphorizatiou agent were mixed and the mixtu...The effect of coal levels on phosphorus removal from a high phosphorus oolitic hematite ore after direct reduction roasting have been investigated. Raw ore, coal, and a dephosphorizatiou agent were mixed and the mixture was then roasted in a tunnel kiln. The roasted products were treated by two stages of grind- ing followed by magnetic separation. XRD and SEM-EDS examination of the products was used to analyze differences in the roasted products. The results show that coal is one of the most important factors affect- ing the direct reduction roasting process. When the inner coal levels increased from 0% to 15% the iron grade decreased linearly from 94.94%to 88.81% and the iron recovery increased from 55.94% to 92.94%. At the same time the phosphorus content increased from 0.045% to 0.231%. Increasing the inner coal levels also caused more hematite to be reduced to metallic iron but the oolitic structure of the roasted product was preserved in the presence of high coal loading. The phase of the phosphorus in raw ore was not changed after direct reduction roasting. The effect of coal on the phosphorus content in the H-concentrate arises from changes in the difficulty of mechanically liberating the metallic iron from the phosphorus bearing minerals.展开更多
The influence of interlayer anions such as NO3-, 5042- and Cl- on Mg-AI hydrotalcites for Cr(Vl) removal from aqueous solution was studied. The structure of the prepared LDHs was characterized by XRD, SEM, FTIR, TGA...The influence of interlayer anions such as NO3-, 5042- and Cl- on Mg-AI hydrotalcites for Cr(Vl) removal from aqueous solution was studied. The structure of the prepared LDHs was characterized by XRD, SEM, FTIR, TGA, BET surface area and pHzpc. The sorbent ability and sorption mechanisms were also investigated. The LDHs exhibit high removal for Cr(VI), and the sorbed amount depends on the nature of interlayer anion, which decreased in the following order: NO3- 〉 Cl 〉 SO42-, Nitrate-containing LDH reached a Cr(VI) sorption equilibrium within only 30 min. The effects of operating conditions, including initial concentration, solution pH, agitation time and sorbent amount have been studied in batch mode. The optimum conditions were observed at an initial concen- tration of 100 mg. L- 1, pH = 6, agitation time of 60 min and a sorbent dose of 2 g.L- 1. The equilibrium data were fitted to the Langmuir, Freundlich and Dubinin-Radushkevich isotherm models. The Langmuir model was found to sufficiently describe the sorption process, offering a maximum sorption capacity of 71.91 mg-g 1. The sorp- tion kinetic follows pseudo-second-order reaction with high accuracy. Thermodynamic parameters suggested that the sorption process is spontaneous and endothermic in nature.展开更多
With the rapid development of the petroleum industry and oil spill occurredfrequently in recent years, marine oil pollution is serious. Oil pollution from terrestrialsources is an important source of marine oil pollut...With the rapid development of the petroleum industry and oil spill occurredfrequently in recent years, marine oil pollution is serious. Oil pollution from terrestrialsources is an important source of marine oil pollution. In China, oil pollution fromterrestrial sources accounted for more than 80% of the total marine pollutants. Wetlandhas great ecological and environmental value, and researches found that wetland hasthe function of purifying oil pollutants. Beitang Estuary in Tianjin Binhai New Area is amajor fishery port, and also the main sewage outfall. In recent years, with the increaseof oil pollution from terrestrial sources, water quality in Beitang River is deteriorating.The Beitang Estuary has a large area of natural Spartina alterniflora wetland, whichmay effectively remove oil pollution. Environmental investigation was carried out on thewharf, channel and coastal zone near Beitang Estuary. The results showed that theeutrophication in Beitang Estuary is serious, and the water quality is inferior to theworse than the fourth class of sea water quality. Inorganic nitrogen, active phosphateand petroleum hydrocarbons are the main pollutants. Reed, Spartina alterniflora andSeepweed were the dominant species in the Beitang Estuary, and petroleumhydrocarbons were detected in the three plants. It showed that the Beitang Estuary waspolluted by petroleum hydrocarbons, and the three kinds of plants have the ability toabsorb petroleum hydrocarbons. Survey results showed that, whether in the surfaceseawater or sediment, the oil content near the wharf was higher than the channel; thepetroleum hydrocarbon content in the channel was higher than the coastal zone. Theroots, stems and leaves of Spartina alterniflora can intercept oil pollution from terrestrialsources. In addition to absorbing petroleum hydrocarbons, Spartina alterniflora alsoprovides a good habitat for microorganisms,to accelerate microbial degradation ofpetroleum hydrocarbon. Spartina alterniflora wetland has the obvious effect forreducing terrigenous oil pollutants.展开更多
The recovery of indium from waste indium tin oxide (ITO) target has great significance for the economy and environment.Based on our previous study on the optimization of acid leaching technique,the present study foc...The recovery of indium from waste indium tin oxide (ITO) target has great significance for the economy and environment.Based on our previous study on the optimization of acid leaching technique,the present study focuses on tin removal via zinc substitution and indium recovery from a tin-free leach solution.The results show that when the amount of added zinc powder and reaction time increase,the tin removal effect can be improved.The optimal conditions obtained are as follows:additional content of zinc powder from 20 g/L to 25 g/L,reaction temperature of 60 ℃,and reaction time from 3 h to 4 h.Under this condition,the tin removal rate exceeds 98%,and the tin content in the tin removal solution is lower than 0.05 g/L.After tin removal,the substitution time could be reduced from 3-5 d to 1-2 d by neutralizing the residual acid by using alkaline residue and maintaining the pH value less than 2.The indium recovery rate is also improved when this condition is used.The indium content in the tin residue is reduced to lower than 0.1% and the acid-insoluble β-SnO2 could be obtained via the strong nitric acid leaching of the indium-containing tin residue.Indium could be recovered from ITO with a high purity of 99.995% via electrorefining.展开更多
An experimental pectate lyase enzyme was used to scour knitted cotton fabric and the emphasis was on pectin removal.Using an enzyme dosage of 0.2 g/L at temperature 55℃ and pH 6.35 for 30 min,good scouring properties...An experimental pectate lyase enzyme was used to scour knitted cotton fabric and the emphasis was on pectin removal.Using an enzyme dosage of 0.2 g/L at temperature 55℃ and pH 6.35 for 30 min,good scouring properties were obtained.When appropriate concentrations of 1-Hydroxy Ethylidene-1,1-Diphosphonic Acid(HEDP)and CaCl2 were added,the percentage pectin removal improved significantly.展开更多
The effectiveness of CO2 microsize bubbles for removal of Ca2+ ions in the leaching water discharged from the final landfill site was evaluated using imitation water. For the important parameter in the Ca2+ ion remo...The effectiveness of CO2 microsize bubbles for removal of Ca2+ ions in the leaching water discharged from the final landfill site was evaluated using imitation water. For the important parameter in the Ca2+ ion removal, it was found that the treatment in alkaline region above pH = 10 was optimum. The possibility of using CO2 microbubbles was examined by substitution of chemical Na2CO3, which is used in large quantifies today. In addition, the excellence of CO2 microbubbles was demonstrated by comparing with CO2 millimeter size bubbles. @ 2015 The Chemical Industry and Engineering Society of China, and Chemical Industry Press. All rights reserved.展开更多
This study investigated the feasibility of using some natural clay minerals available in Egypt like kaolinite, bentonite, also using of iron oxide, rock phosphate and mixture of these types to minimize the rate of Ni,...This study investigated the feasibility of using some natural clay minerals available in Egypt like kaolinite, bentonite, also using of iron oxide, rock phosphate and mixture of these types to minimize the rate of Ni, Cu, Zn and Mn desorption from sewage soils and to evaluate the effect of these mixtures on Zn equivalent constant values before and after remediation. The obtained results indicated that all mixtures used were minimizing the rate of potential toxic elements (PTE's) release from sewage soils compared to control treatment. According to the decreasing order of different treatments, data indicated that application of the mixture treatment of bentonite, kaolinite and rock phosphate (RP) in sewage soils becomes the best treatment compared to other treatments used. However, the lowest and save Zn equivalent constant value which represents the hazard indicator in the study was observed in sewage soil treated with the mixture of bentonite and RP. The kinetic constants of Elovich, modified Freundlich and Hoerl equations, the best fitted models, were significantly decreased compared to control treatments with different percent of minimization according to type of pollutants and remediation material used. To understand the mechanisms of PTE's retained in treated sewage soil, distribution study was applied which showed that different pollutants studied were removed to hardly available form different mechanisms of PTE's undergo in treated sewage soils were discussed in the study.展开更多
In order to investigate the effect of stripping and catalytic ozone oxidation technology on COD and ammonia nitrogen removal after coagulation and sedimentation, the efficiency of ozone oxidation and catalytic ozone o...In order to investigate the effect of stripping and catalytic ozone oxidation technology on COD and ammonia nitrogen removal after coagulation and sedimentation, the efficiency of ozone oxidation and catalytic ozone oxidation were compared. The experimental results showed that: stripping and catalytic ozone oxidation technology has a significant effect on landfill leachate treatment. The removal rate of the COD and NH3-N can reach 88.60% and 98.00% under the initial concentration of COD and NH3-N were 2053.35 mg/L and l 123. 76 mg/L separately.展开更多
[Objective] The aim was to study the COD removal effect of emulsifier wastewater and provide experimental basis for the design, adjustment and operation of project. [Method] Using UASB+SBR technology to process emulsi...[Objective] The aim was to study the COD removal effect of emulsifier wastewater and provide experimental basis for the design, adjustment and operation of project. [Method] Using UASB+SBR technology to process emulsifier wastewater, the problems in operation process were discussed. [Result] The experiment carried out for 71 d, under the situation of large changes of COD concentration (the highest: 10 924 mg/L, the lowest: 2 880 mg/L, mean value: 5 751 mg/L), COD removal efficiency of UASB was around 70% and the COD removal efficiency of SBR was above 70%, which met the emission standard. [Conclusion] The combined technology had good treatment effect on the emulsifier wastewater.展开更多
Histone acetyltransferases/deacetylases contribute to the activation or inactivation of transcription by modifying the structure of chromatin. Here we examined the effects ofhistone deacetylase inhibitors (HDIs), tr...Histone acetyltransferases/deacetylases contribute to the activation or inactivation of transcription by modifying the structure of chromatin. Here we examined the effects ofhistone deacetylase inhibitors (HDIs), trichostatin A, and sodium butyrate on hsp70 gene transcriptional regulation in Drosophila. The chromatin immunoprecipitation assays revealed that HDI treatments induced the hyperacetylation of histone H3 at the promoter and the transcribing regions of hsp 70 gene, increased the accessibility of heat-shock factor to target heat-shock element, and promoted the RNA polymerase Ⅱ-mediated transcription. Moreover, the quantitative real-time PCR confirmed that the HDI-induced hyperacetylation of histone H3 enhanced both the basal and the inducible expression of hsp70 mRNA level. In addition, the acetylation level ofhistone H3 at the promoter exhibited a fluctuated change upon the time of heat shock. These experimental data implicated a causal link between histone acetylation and enhanced transcription initiation of hsp 70 gene in Drosophila.展开更多
[Objective] This study aimed to investigate the control effect of different concentrations of 80% nicosulfuron·atrazine water-dispersible granules on weeds in spring maize field. [Method] Maize field was sprayed ...[Objective] This study aimed to investigate the control effect of different concentrations of 80% nicosulfuron·atrazine water-dispersible granules on weeds in spring maize field. [Method] Maize field was sprayed with 300, 375, 450, 750 g/hm280% nicosulfuron·atrazine water-dispersible granules respectively, with 40 g/L nicosulfuron suspending concentrate and 38% atrazine suspending concentrate as control agents. Artificial weeding and control(CK) plots were set. [Result] Fresh weight control efficiency of 375-750 g/hm280% nicosulfuron·atrazine water-dispersible granules was significantly higher than that of 40 g/L nicosulfuron suspending concentrate and 38% atrazine suspending concentrate; no obvious phytotoxicity symptoms were observed after application of 300-450 g/hm280% nicosulfuron·atrazine waterdispersible granules; 750 g/hm280% nicosulfuron·atrazine water-dispersible granules posed certain impact on the growth of maize seedlings. Compared with control plots, various doses of 80% nicosulfuron·atrazine water-dispersible granules significantly improved the yield of maize. [Conclusion] In the present study, 375-450 g/hm280% nicosulfuron·atrazine water-dispersible granules exhibited high control effect on weeds in maize field and were safe for the growth of maize seedlings.展开更多
Large quantities of fresh water are used intensively in the washing, cutting, peeling and disinfection of fruits and vegetables, resulting in high solids loading of the wash-water. Review of the literature shows that ...Large quantities of fresh water are used intensively in the washing, cutting, peeling and disinfection of fruits and vegetables, resulting in high solids loading of the wash-water. Review of the literature shows that there is limited information available on how to treat this wash-water on-site. Accordingly, an investigative program was established by sampling wash-water from two industrial partners processing root vegetables to determine the best available approach. Bench scale technologies tested for solids removal were dissolved air flotation (DAF) and centrifuge, followed by ultraviolet (UV) disinfection to evaluate the potential for water reuse. The results showed that DAF and centrifuge were able to remove solids at an efficiency greater than 95%. The DAF process was also able to remove higher levels of dissolved matter and nutrients in comparison to the centrifuge. The DAF process was also able to produce waters with higher transmittance, which leads to improved filtration and UV disinfection for water reuse. Membrane filtration feasibility testing showed that high quality waters can be produced as low as 2 NTU and 4 NTU, following pretreatment with DAF and centrifuge, respectively. However, filtration was unable to remove E. coll. Collimated beam results show that UV disinfection is needed to allow for water reuse.展开更多
基金Supported by National Water Pollution and Treatment Major Project(2009ZX07212001)Hunan Environment Protection Technology Major Project(2009sk4013)~~
文摘Antimony ore dressing wastewater was treated by using Bacillus sp. and the influences of treatment time, temperature, inoculation size, and pH value on Sb removal effect were explored. The results showed that the best removal efficiency of Sb in mineral processing wastewater could reach 99.75% in 4 d under the optimum conditions of 30 ℃, microbial inoculated quantity 5%, and pH value at 2.0. After the treatment, the concentration of Sb in wastewater was reduced from 122.21 to 0.30mg/L, which was lower than the local industrial wastewater discharge standard of0.50 mg/L.
基金Supported by Special Fund for the Construction of Modern Agricultural Industry Technology System(CARS-07-13.5)Ph.D.Program of Shanxi Academy of Agricultural Sciences(YBSJJ1410)~~
文摘The control effect of different concentrations of herbicide atrazine (before seedling after sowing) on weed in foxtail millet field was compared, which provide theoretical basis for screening suitable herbicides concentration for foxtail millet production. As a result, after spraying 25 and 40 d, plant control effect and fresh weight control effect were best by 4 500 ml/hm^2 processing, and fresh weight control effect reached 83.16% and 86.43%. Compared with spraying water (CK), yieldincreasing effect was the best in the treatment group with atrazine at 2 250 ml/hm^2, where yield growth rate was 54.31%, followed by the treatment group with atrazine at 3 000 ml/hm^2. Therefore, 2 250 ml/hm^2 was the optiaml concentration of herbicide atrazine for millet production.
基金Supported by the National Technology Research and Development Program of China(2008AA062402)the China-US International Cooperation Project(2011DFA90800)the Ministry of Science and Technology,China
文摘CO2 removal from biogas by water washing system was investigated with various parameters, including liquid/ gas ratio, pressure, temperature, and CO2 content. The results indicate that CO2 removal ratio could reach 34.6%- 94.2% as liquid/gas ratio increased from 0.14 to 0.50. Increasing pressure (from 0.8 to 1.2 MPa) could improve gas purification with a constant inflow rate of gas. Temperature played a key role in the process and lower temper- ature in absorption tower was beneficial for reducing CO2 content. CO2 removal ratio could reach 24.4%-83.2% when CO2 content in the simulated gas was 25%-45%. The lowest CO2 content after absorption was 2.6% at 1.2 MPa with 400 L·h-1 gas flow and 200 L·h-1 water flow, which meets the requirement of CO2 content in natural Ras for vehicle fuel.
基金the National Natural Science Foundation of China (No. 51074016) for the financial support for this research
文摘The effect of coal levels on phosphorus removal from a high phosphorus oolitic hematite ore after direct reduction roasting have been investigated. Raw ore, coal, and a dephosphorizatiou agent were mixed and the mixture was then roasted in a tunnel kiln. The roasted products were treated by two stages of grind- ing followed by magnetic separation. XRD and SEM-EDS examination of the products was used to analyze differences in the roasted products. The results show that coal is one of the most important factors affect- ing the direct reduction roasting process. When the inner coal levels increased from 0% to 15% the iron grade decreased linearly from 94.94%to 88.81% and the iron recovery increased from 55.94% to 92.94%. At the same time the phosphorus content increased from 0.045% to 0.231%. Increasing the inner coal levels also caused more hematite to be reduced to metallic iron but the oolitic structure of the roasted product was preserved in the presence of high coal loading. The phase of the phosphorus in raw ore was not changed after direct reduction roasting. The effect of coal on the phosphorus content in the H-concentrate arises from changes in the difficulty of mechanically liberating the metallic iron from the phosphorus bearing minerals.
基金financially supported by both the department of Process Engineering and Chemistry of USTHB(Algiers)
文摘The influence of interlayer anions such as NO3-, 5042- and Cl- on Mg-AI hydrotalcites for Cr(Vl) removal from aqueous solution was studied. The structure of the prepared LDHs was characterized by XRD, SEM, FTIR, TGA, BET surface area and pHzpc. The sorbent ability and sorption mechanisms were also investigated. The LDHs exhibit high removal for Cr(VI), and the sorbed amount depends on the nature of interlayer anion, which decreased in the following order: NO3- 〉 Cl 〉 SO42-, Nitrate-containing LDH reached a Cr(VI) sorption equilibrium within only 30 min. The effects of operating conditions, including initial concentration, solution pH, agitation time and sorbent amount have been studied in batch mode. The optimum conditions were observed at an initial concen- tration of 100 mg. L- 1, pH = 6, agitation time of 60 min and a sorbent dose of 2 g.L- 1. The equilibrium data were fitted to the Langmuir, Freundlich and Dubinin-Radushkevich isotherm models. The Langmuir model was found to sufficiently describe the sorption process, offering a maximum sorption capacity of 71.91 mg-g 1. The sorp- tion kinetic follows pseudo-second-order reaction with high accuracy. Thermodynamic parameters suggested that the sorption process is spontaneous and endothermic in nature.
基金supported by the Project of Tianjin with Spill Oil Accident from Penglai Oil field 19-3 Compensation (No. 19-3BC2014-05)Tianjin Municipal Science and Technology Planning Project (15ZCZDSF00620, 15JCYBJC23200)
文摘With the rapid development of the petroleum industry and oil spill occurredfrequently in recent years, marine oil pollution is serious. Oil pollution from terrestrialsources is an important source of marine oil pollution. In China, oil pollution fromterrestrial sources accounted for more than 80% of the total marine pollutants. Wetlandhas great ecological and environmental value, and researches found that wetland hasthe function of purifying oil pollutants. Beitang Estuary in Tianjin Binhai New Area is amajor fishery port, and also the main sewage outfall. In recent years, with the increaseof oil pollution from terrestrial sources, water quality in Beitang River is deteriorating.The Beitang Estuary has a large area of natural Spartina alterniflora wetland, whichmay effectively remove oil pollution. Environmental investigation was carried out on thewharf, channel and coastal zone near Beitang Estuary. The results showed that theeutrophication in Beitang Estuary is serious, and the water quality is inferior to theworse than the fourth class of sea water quality. Inorganic nitrogen, active phosphateand petroleum hydrocarbons are the main pollutants. Reed, Spartina alterniflora andSeepweed were the dominant species in the Beitang Estuary, and petroleumhydrocarbons were detected in the three plants. It showed that the Beitang Estuary waspolluted by petroleum hydrocarbons, and the three kinds of plants have the ability toabsorb petroleum hydrocarbons. Survey results showed that, whether in the surfaceseawater or sediment, the oil content near the wharf was higher than the channel; thepetroleum hydrocarbon content in the channel was higher than the coastal zone. Theroots, stems and leaves of Spartina alterniflora can intercept oil pollution from terrestrialsources. In addition to absorbing petroleum hydrocarbons, Spartina alterniflora alsoprovides a good habitat for microorganisms,to accelerate microbial degradation ofpetroleum hydrocarbon. Spartina alterniflora wetland has the obvious effect forreducing terrigenous oil pollutants.
基金Project(2012BAE06B01)supported by the National High Technology Research and Development Program of China
文摘The recovery of indium from waste indium tin oxide (ITO) target has great significance for the economy and environment.Based on our previous study on the optimization of acid leaching technique,the present study focuses on tin removal via zinc substitution and indium recovery from a tin-free leach solution.The results show that when the amount of added zinc powder and reaction time increase,the tin removal effect can be improved.The optimal conditions obtained are as follows:additional content of zinc powder from 20 g/L to 25 g/L,reaction temperature of 60 ℃,and reaction time from 3 h to 4 h.Under this condition,the tin removal rate exceeds 98%,and the tin content in the tin removal solution is lower than 0.05 g/L.After tin removal,the substitution time could be reduced from 3-5 d to 1-2 d by neutralizing the residual acid by using alkaline residue and maintaining the pH value less than 2.The indium recovery rate is also improved when this condition is used.The indium content in the tin residue is reduced to lower than 0.1% and the acid-insoluble β-SnO2 could be obtained via the strong nitric acid leaching of the indium-containing tin residue.Indium could be recovered from ITO with a high purity of 99.995% via electrorefining.
基金Supported by the Programfor Changjiang Scholors and Innovative Research Teamin University(No.IRT0526)
文摘An experimental pectate lyase enzyme was used to scour knitted cotton fabric and the emphasis was on pectin removal.Using an enzyme dosage of 0.2 g/L at temperature 55℃ and pH 6.35 for 30 min,good scouring properties were obtained.When appropriate concentrations of 1-Hydroxy Ethylidene-1,1-Diphosphonic Acid(HEDP)and CaCl2 were added,the percentage pectin removal improved significantly.
基金Supported by the National Natural Science Funds for Distinguished Young Scholars(21425625)the National Science Foundation for Excellent Young Scholars(21422607)
文摘The effectiveness of CO2 microsize bubbles for removal of Ca2+ ions in the leaching water discharged from the final landfill site was evaluated using imitation water. For the important parameter in the Ca2+ ion removal, it was found that the treatment in alkaline region above pH = 10 was optimum. The possibility of using CO2 microbubbles was examined by substitution of chemical Na2CO3, which is used in large quantifies today. In addition, the excellence of CO2 microbubbles was demonstrated by comparing with CO2 millimeter size bubbles. @ 2015 The Chemical Industry and Engineering Society of China, and Chemical Industry Press. All rights reserved.
文摘This study investigated the feasibility of using some natural clay minerals available in Egypt like kaolinite, bentonite, also using of iron oxide, rock phosphate and mixture of these types to minimize the rate of Ni, Cu, Zn and Mn desorption from sewage soils and to evaluate the effect of these mixtures on Zn equivalent constant values before and after remediation. The obtained results indicated that all mixtures used were minimizing the rate of potential toxic elements (PTE's) release from sewage soils compared to control treatment. According to the decreasing order of different treatments, data indicated that application of the mixture treatment of bentonite, kaolinite and rock phosphate (RP) in sewage soils becomes the best treatment compared to other treatments used. However, the lowest and save Zn equivalent constant value which represents the hazard indicator in the study was observed in sewage soil treated with the mixture of bentonite and RP. The kinetic constants of Elovich, modified Freundlich and Hoerl equations, the best fitted models, were significantly decreased compared to control treatments with different percent of minimization according to type of pollutants and remediation material used. To understand the mechanisms of PTE's retained in treated sewage soil, distribution study was applied which showed that different pollutants studied were removed to hardly available form different mechanisms of PTE's undergo in treated sewage soils were discussed in the study.
文摘In order to investigate the effect of stripping and catalytic ozone oxidation technology on COD and ammonia nitrogen removal after coagulation and sedimentation, the efficiency of ozone oxidation and catalytic ozone oxidation were compared. The experimental results showed that: stripping and catalytic ozone oxidation technology has a significant effect on landfill leachate treatment. The removal rate of the COD and NH3-N can reach 88.60% and 98.00% under the initial concentration of COD and NH3-N were 2053.35 mg/L and l 123. 76 mg/L separately.
文摘[Objective] The aim was to study the COD removal effect of emulsifier wastewater and provide experimental basis for the design, adjustment and operation of project. [Method] Using UASB+SBR technology to process emulsifier wastewater, the problems in operation process were discussed. [Result] The experiment carried out for 71 d, under the situation of large changes of COD concentration (the highest: 10 924 mg/L, the lowest: 2 880 mg/L, mean value: 5 751 mg/L), COD removal efficiency of UASB was around 70% and the COD removal efficiency of SBR was above 70%, which met the emission standard. [Conclusion] The combined technology had good treatment effect on the emulsifier wastewater.
基金grants from The National Basic Research Program of China (2005CB522404) The National Nature Science Foundation of China (30571698).
文摘Histone acetyltransferases/deacetylases contribute to the activation or inactivation of transcription by modifying the structure of chromatin. Here we examined the effects ofhistone deacetylase inhibitors (HDIs), trichostatin A, and sodium butyrate on hsp70 gene transcriptional regulation in Drosophila. The chromatin immunoprecipitation assays revealed that HDI treatments induced the hyperacetylation of histone H3 at the promoter and the transcribing regions of hsp 70 gene, increased the accessibility of heat-shock factor to target heat-shock element, and promoted the RNA polymerase Ⅱ-mediated transcription. Moreover, the quantitative real-time PCR confirmed that the HDI-induced hyperacetylation of histone H3 enhanced both the basal and the inducible expression of hsp70 mRNA level. In addition, the acetylation level ofhistone H3 at the promoter exhibited a fluctuated change upon the time of heat shock. These experimental data implicated a causal link between histone acetylation and enhanced transcription initiation of hsp 70 gene in Drosophila.
文摘[Objective] This study aimed to investigate the control effect of different concentrations of 80% nicosulfuron·atrazine water-dispersible granules on weeds in spring maize field. [Method] Maize field was sprayed with 300, 375, 450, 750 g/hm280% nicosulfuron·atrazine water-dispersible granules respectively, with 40 g/L nicosulfuron suspending concentrate and 38% atrazine suspending concentrate as control agents. Artificial weeding and control(CK) plots were set. [Result] Fresh weight control efficiency of 375-750 g/hm280% nicosulfuron·atrazine water-dispersible granules was significantly higher than that of 40 g/L nicosulfuron suspending concentrate and 38% atrazine suspending concentrate; no obvious phytotoxicity symptoms were observed after application of 300-450 g/hm280% nicosulfuron·atrazine waterdispersible granules; 750 g/hm280% nicosulfuron·atrazine water-dispersible granules posed certain impact on the growth of maize seedlings. Compared with control plots, various doses of 80% nicosulfuron·atrazine water-dispersible granules significantly improved the yield of maize. [Conclusion] In the present study, 375-450 g/hm280% nicosulfuron·atrazine water-dispersible granules exhibited high control effect on weeds in maize field and were safe for the growth of maize seedlings.
文摘Large quantities of fresh water are used intensively in the washing, cutting, peeling and disinfection of fruits and vegetables, resulting in high solids loading of the wash-water. Review of the literature shows that there is limited information available on how to treat this wash-water on-site. Accordingly, an investigative program was established by sampling wash-water from two industrial partners processing root vegetables to determine the best available approach. Bench scale technologies tested for solids removal were dissolved air flotation (DAF) and centrifuge, followed by ultraviolet (UV) disinfection to evaluate the potential for water reuse. The results showed that DAF and centrifuge were able to remove solids at an efficiency greater than 95%. The DAF process was also able to remove higher levels of dissolved matter and nutrients in comparison to the centrifuge. The DAF process was also able to produce waters with higher transmittance, which leads to improved filtration and UV disinfection for water reuse. Membrane filtration feasibility testing showed that high quality waters can be produced as low as 2 NTU and 4 NTU, following pretreatment with DAF and centrifuge, respectively. However, filtration was unable to remove E. coll. Collimated beam results show that UV disinfection is needed to allow for water reuse.