Modified aluminum slag (MAS) was applied as an adsorbent for Congo red (CR) prepared by the hydrothermal treatment of Ca(OH)<sub>2</sub>. At 25°C, with a MAS dosage of 0.3 g, initial CR concentration ...Modified aluminum slag (MAS) was applied as an adsorbent for Congo red (CR) prepared by the hydrothermal treatment of Ca(OH)<sub>2</sub>. At 25°C, with a MAS dosage of 0.3 g, initial CR concentration of 100 mg/L and initial pH = 5, and the adsorption time was 40 min, the CR removal efficiency was 98.41%. The adsorption trend of CR conformed to the second-order kinetics, and the adsorption isotherm follows the Freundlich isotherm model. Compared with RAS, MAS has a larger pore volume and specific surface area. The mechanism of action of MAS on CR was the interaction between membrane diffusion and internal diffusion, and the adsorption rate during the membrane diffusion was the fastest.展开更多
Due to the high energy consumption for separation of salt containing methanol wastewater, in this work, the multi-effect evaporation coupled with mechanical vapor recompression (MVR) heat pump and thermal integration ...Due to the high energy consumption for separation of salt containing methanol wastewater, in this work, the multi-effect evaporation coupled with mechanical vapor recompression (MVR) heat pump and thermal integration technologies were raised for the first time. The ELECNRTL thermodynamic model is used to simulate and optimize the evaporation rectification process. Energy consumption and total annual cost (TAC) are taken as objective functions. The results show that multi-effect evaporation coupled with conventional distillation process can save energy consumption and TAC by 44.12% and 39.14%. The multi-effect evaporation coupled with distillation process based on MVR heat pump technology can save energy consumption and TAC by 55.27% and 47.49%, which is super to three-effect evaporation coupled with conventional distillation process. The three-effect evaporation coupled with MVR heat integration process can save energy consumption and TAC by 81.32% and 58.55%, which is more economical than other processes. It can be clearly seen that three-effect evaporation coupled with MVR heat integration process is more competitive to deal with the salt containing methanol wastewater.展开更多
According to the characteristics of oil containing wastewater, four strains of microorganism, named TA-11, TA-17, HA-9, HD-1, were picked out from the oil contaminated soil and activated sludge of biochemical treatmen...According to the characteristics of oil containing wastewater, four strains of microorganism, named TA-11, TA-17, HA-9, HD-1, were picked out from the oil contaminated soil and activated sludge of biochemical treatment system of an asphalt plant wastewater in Panjin. They can degrade oil and CODCr in oil containing wastewater. The research result showed that each strain of microorganisms can remove oil and CODCr in oil containing wastewater effectively when the pH value was 7.0, the temperature was 30 degree Celsius, the rotation speed was 140r/min and the inoculation amount was 10%. Especially the highest removal ratio of CODCr was 68% after growth of 64 hours. The removal ratio of CODCr in oil containing wastewater of mixed bacilli was much higher than that of unitary bacilli, and mixing a certain amount of domestic sewage with the oil containing wastewater will also improve the removal rate of CODCr.展开更多
Nitrobenzene-containing industrial wastewater was degraded in the presence of ozonecoupled with H2O2 by high gravity technology. The effect of high gravity factor, H2O2 concentration, pH value, liquid flow-rate, and r...Nitrobenzene-containing industrial wastewater was degraded in the presence of ozonecoupled with H2O2 by high gravity technology. The effect of high gravity factor, H2O2 concentration, pH value, liquid flow-rate, and reaction time on the efficiency for removal of nitrobenzene was investigated. The experimental results show that the high gravity technology enhances the ozone utilization efficiency with O3 /H2O2 showing synergistic effect. The degradation efficiency in terms of the COD removal rate and nitrobenzene removal rate reached 45.8% and 50.4%, respectively, under the following reaction conditions, viz.: a high gravity factor of 66.54, a pH value of 9, a H2O2 /O3 molar ratio of 1:1, a liquid flow rate of 140L/h, an ozone concentration of 40mg/L, a H2O2 multiple dosing mode of 6mL/h, and a reaction time of 4h. Compared with the performance of conventional stirred aeration mixers, the high gravity technology could increase the COD and nitrobenzene removal rate related with the nitrobenzene-containing wastewater by 22.9% and 23.3%, respectively.展开更多
A technology of polymerase chain reaction-denaturing gradient gel electrophoresis(PCR-DGGE)was used to profile the structure and dynamic changes of microbial communities in a bioreactor for treating hydrocarbon-sulfid...A technology of polymerase chain reaction-denaturing gradient gel electrophoresis(PCR-DGGE)was used to profile the structure and dynamic changes of microbial communities in a bioreactor for treating hydrocarbon-sulfide-containing(HSC)wastewater.The results showed that the heterotrophic genus of Acinetobacter and the autotrophic genera of Thiobacillus and Thiomonas could survive well in all of three operating conditions.Some special genera were also observed with changes of micro-ecoenvironment in the rea...展开更多
The solid sodium hydroxide neutralized acidic As-containing wastewater till pH value was 6.Green copper arsenite was prepared after copper sulfate was added into the neutralized wastewater when the molar ratio of Cu t...The solid sodium hydroxide neutralized acidic As-containing wastewater till pH value was 6.Green copper arsenite was prepared after copper sulfate was added into the neutralized wastewater when the molar ratio of Cu to As was 2:1 and pH value of the neutralized wastewater was adjusted to 8.0 by sodium hydroxide.The arsenious acid solution and red residue were produced after copper arsenite mixed with water according to the ratio of liquid to solid of 4:1 and copper arsenite was reduced by SO2 at 60℃for 1 h.The white powder was gained after the arsenious acid solution was evaporated and cooled.Copper sulfate solution was obtained after the red residue was leached by H2SO4 solution under the action of air.The results show that red residue is Cu3(SO3)2·2H2O and the white powder is As2O3.The leaching rate of Cu reaches 99.00%when the leaching time is 1.5 h,molar ratio of H2SO4 to Cu is 1.70,H2SO4 concentration is 24%and the leaching temperature is 80℃.The direct recovery rate of copper sulfate is 79.11%and the content of CuSO4·5H2O is up to 98.33%in the product after evaporating and cooling the copper sulfate solution.展开更多
This study investigated the effects of fermentation product containing phytase(FPP) that was fermented using waste vinegar residue(WVR) as substrate from Aspergillus ficuum NTG-23 on productive performance, egg qualit...This study investigated the effects of fermentation product containing phytase(FPP) that was fermented using waste vinegar residue(WVR) as substrate from Aspergillus ficuum NTG-23 on productive performance, egg quality, and phosphorus apparent metabolism of laying hens. First, 375 22-wk-old Jinghong hens were allocated into 5 treatments(5 replicates of 15 hens each) in an 8-wk experiment for evaluating the parameters of productive performance, egg quality, serum, and tibia. Experimental diets contained 4% FPP and 96% corn-soybean diet. The levels of dicalcium phosphate(DCP) were 1.34, 1.01, 0.67, 0.34 and 0%. Next, thirty 31-wk-old Jinghong hens were fed 5 types of diets for evaluating phosphorous apparent metabolism rate. Egg productive rate, egg weight, feed conversion ratio, Haugh unit, egg albumen height, serum calcium, tibia ash, tibia ash calcium and tibia breaking strength were not different significantly among 5 treatments. The significant difference of average daily feed intake was not appeared when the DCP content of corn-soybean-FPP diet was reduced to 0.67%; the eggshell hardness, eggshell thickness and serum phosphorus were not reduced significantly until the DCP content of corn-soybean-FPP diet was reduced to 0.34%. The yolk color was improved when the laying hens fed deficient DCP corn-soybean-FPP diet. A 22.14% reduction in excreta phosphorus was observed when the laying hens fed low phosphorus(0.67% DCP) corn-soybean-FPP diet. A 30% elevation of phosphorus apparent metabolism rate was obtained when the DCP content of corn-soybean-FPP diet was decreased from 1.34 to 1.01%. The reducing cost of layer diet was totalized about 120 CNY 1 000 kg-1 diet when the content of DCP was 0.67% in corn-soybean-FPP diet. These results indicated that FPP could be applied in laying hen as a potential, cost-effective and rational application of WVR.展开更多
High-concentration nitrite-containing wastewater that presents extreme toxicity to human health and organisms is difficult to be treated using traditional biological process. In this study, a novel microwave-enhanced ...High-concentration nitrite-containing wastewater that presents extreme toxicity to human health and organisms is difficult to be treated using traditional biological process. In this study, a novel microwave-enhanced chemical reduction process (MECRP) using sulfaminic acid (SA) was proposed as a new manner to treat such type of wastewater. Based on lab-scale experiments, it was shown that 75%-80% nitrite (NO2-) could be removed within time as short as 4 min under 50 W microwave irradiation in pH range 5-10 when molar ratio of SA to nitrite (SA/NO2-) was 0.8. Pilot-scale investigations demonstrated that MECRP was able to achieve nitrite and chemical oxygen demand (COD) removal with effciency up to 80% and 20%, respectively under operating conditions of SA concentration 80 kg/m3, SA/ NO2- ratio 0.8, microwave power 3.4 kW, and stirring time 3 min. Five-day biological oxygen demand (BOD5)/COD value of treated efluent after MECRP was increased from 0.05 to 0.36 (by 620%), which clearly suggested a considerable improvement of biodegradability for subsequent biological treatment. This study provided a demonstration of using microwave irradiation to enhance reaction between SA and nitrite in a short time, in which nitrite in wastewater was completely converted into nitrogen gas without leaving any sludge and secondary pollutants.展开更多
The oily wastewater generated from pretreatment unit of electrocoating industry contains oils, phosphate, organic solvents, and surfactants. In order to improve the removal efficiencies of phosphate and oils, to mitig...The oily wastewater generated from pretreatment unit of electrocoating industry contains oils, phosphate, organic solvents, and surfactants. In order to improve the removal efficiencies of phosphate and oils, to mitigate the membr ane fouling, coagulation for ceramic membrane microfiltration of oily wastewater was performed. The results of filtration tests show that the membrane fouling d ecreased and the permeate flux and quality increased with coagulation as pret reatment. At the coagulant Ca(OH)2 dosage of 900 mg/L, the removal efficiency of phosphate was increased from 46.4% without coagulation to 99.6%; the removal of COD and oils were 97.0% and 99.8%, respectively. And the permeate flux was about 70% greater than that when Ca(OH)2 was not used. The permeate o btained from coagulation and microfiltration can be reused as make-up water, and the recommended operation conditions for pilot and industrial application are t ransmembrane pressure of 0.10 MPa and cross-flow velocity of 5 m/s. The comparis on results show that 0.2 μm ZrO2 microfilter with coagulation could be used to perform the filtration rather than conventional ultrafilter, with very substanti al gain in flux and removal efficiency of phosphate.展开更多
Copolyesters of phosphorus - containing flame - retardant poly(Ethylene Terephthalate) (PET) have been prepared and characterized with the objection of producing an effective, environmentally friendly, nonfugitive alt...Copolyesters of phosphorus - containing flame - retardant poly(Ethylene Terephthalate) (PET) have been prepared and characterized with the objection of producing an effective, environmentally friendly, nonfugitive alternatives to halogen flame retardant system for practical application. With means of NMR, DSC, DTA/TGA, SEM and LOI, structure, thermal property and flam-mability are investigated which reveal that the flame -retardant PET when copolymerized with 2 - carboxyethyl (phenylphosphinic) acid (CEPP) confers excellent fire retardancy with LOI 】 28, broader thermal degradation temperature and increased char formation.展开更多
For the wastewater containing high-concentration Hg,the feasibility of high-concentration Hg in wastewater treated by coagulation sedimentation,adsorption and the combined process was studied. Research results showed ...For the wastewater containing high-concentration Hg,the feasibility of high-concentration Hg in wastewater treated by coagulation sedimentation,adsorption and the combined process was studied. Research results showed that if using the single coagulation sedimentation process,when FeSO_4·7H_2O dosage was 1. 39 g / L,and NaOH dosage was 0. 40 g / L,it could meet discharge requirement,but the reagent cost was 13. 1yuan / t,which was high. Because that there was subsequent adsorption process,it was selected 0. 28 g / L of FeSO_4·7H_2O and 0. 36 g / L of NaOH,and the estimated reagent cost was 2. 62 yuan / t. In selection process of adsorption materials,powdered activated carbon,granular activated carbon and diatomite all could effectively adsorb Hg,and the technology was feasible. When using the combined process of coagulation sedimentation + adsorption to treat the wastewater containing high-concentration Hg( 800 μg / L),removal rate could reach 99%,and operation cost was 2. 71 yuan. It could meet the requirement of sewage discharged into sewer( 20 μg / L) at the technology,and was acceptable at the economy.Therefore,treatment of wastewater containing high-concentration Hg by the combined process was feasible at the aspects of technology and economy.展开更多
Aimed at the current treatment status of the polymer-flooding wastewater in Bohai oilfield, electrochemical technology used for polymer-degradation and oil-removal was researched. It formed the process flow of cyclone...Aimed at the current treatment status of the polymer-flooding wastewater in Bohai oilfield, electrochemical technology used for polymer-degradation and oil-removal was researched. It formed the process flow of cyclone mixed dosing → electrochemical removal oil → inclined tube removal oil → walnut shell filter, and a set of skid mounted wastewater containing polymer treatment plant was designed and manufactured, which was used for the field test of electrochemical treatment of wastewater containing polymer in offshore oilfield. The result shows that the oil removal rate of the electrochemical treatment process is over 98%, and the synergistic effect is significant especially used in conjunction with water clarifier of BHQ-04. When the amount of water clarifier is 50 - 150 mg/L, the oil content, the median particle diameter and the suspended solids content of the filtered water is 8 - 18 mg/L, 1.9 - 2.26 μm and 1.39 - 2.04 mg/L respectively, which reach the scene water quality standards for water injection.展开更多
The low-concentration methanol-containing wastewater of a gas field mainly consists of the dehydrated water from natural gas,the water at the bottom of a rectifying tower,and the water used to clear tanks and pipes. T...The low-concentration methanol-containing wastewater of a gas field mainly consists of the dehydrated water from natural gas,the water at the bottom of a rectifying tower,and the water used to clear tanks and pipes. The concentration of methanol as its characteristic component is mostly lower than 3%. Its production and water quality change seasonally. It is mainly produced in late autumn,winter,and early spring when temperature is low. In the low-concentration methanol-containing wastewater,the content of organic matter,suspended solids and salts and COD value are high,and it is acidic. According to the physical and chemical properties of methanol such as easily dissolving in water,dissolving in most organic solvents,and having strong molecular polarity,laboratory experiments were made to study the difficulties of using high-temperature rectification,biodegradation,membrane filtration and organic oxidation technology to treat low-concentration methanol in the wastewater as well as the feasibility of industrial application. Ultraviolet catalytic oxidation technology has the advantages of high treatment efficiency,no secondary pollution,and no addition of treatment agent. After the low-concentration methanol-containing wastewater was treated by ultraviolet catalytic oxidation for 90 min,methanol concentration in the wastewater reduced from about 3% to around 0. 1%,thereby rapidly and efficiently degrading methanol in the wastewater. Based on the experimental parameters,a pilot device of ultraviolet catalytic oxidation was developed and used in the continuous treatment of the wastewater. When the flow rate of inflow was 500 L/h,the intensity of UV light was 2 k W,and hydraulic retention time was 60 min,methanol could be removed completely from the wastewater with the methanol concentration of about 0. 3%. This study provides a method for the treatment of low-concentration methanol-containing wastewater of a gas field,and also provides an experimental basis for the efficient degradation of organic wastewater.展开更多
文摘Modified aluminum slag (MAS) was applied as an adsorbent for Congo red (CR) prepared by the hydrothermal treatment of Ca(OH)<sub>2</sub>. At 25°C, with a MAS dosage of 0.3 g, initial CR concentration of 100 mg/L and initial pH = 5, and the adsorption time was 40 min, the CR removal efficiency was 98.41%. The adsorption trend of CR conformed to the second-order kinetics, and the adsorption isotherm follows the Freundlich isotherm model. Compared with RAS, MAS has a larger pore volume and specific surface area. The mechanism of action of MAS on CR was the interaction between membrane diffusion and internal diffusion, and the adsorption rate during the membrane diffusion was the fastest.
文摘Due to the high energy consumption for separation of salt containing methanol wastewater, in this work, the multi-effect evaporation coupled with mechanical vapor recompression (MVR) heat pump and thermal integration technologies were raised for the first time. The ELECNRTL thermodynamic model is used to simulate and optimize the evaporation rectification process. Energy consumption and total annual cost (TAC) are taken as objective functions. The results show that multi-effect evaporation coupled with conventional distillation process can save energy consumption and TAC by 44.12% and 39.14%. The multi-effect evaporation coupled with distillation process based on MVR heat pump technology can save energy consumption and TAC by 55.27% and 47.49%, which is super to three-effect evaporation coupled with conventional distillation process. The three-effect evaporation coupled with MVR heat integration process can save energy consumption and TAC by 81.32% and 58.55%, which is more economical than other processes. It can be clearly seen that three-effect evaporation coupled with MVR heat integration process is more competitive to deal with the salt containing methanol wastewater.
文摘According to the characteristics of oil containing wastewater, four strains of microorganism, named TA-11, TA-17, HA-9, HD-1, were picked out from the oil contaminated soil and activated sludge of biochemical treatment system of an asphalt plant wastewater in Panjin. They can degrade oil and CODCr in oil containing wastewater. The research result showed that each strain of microorganisms can remove oil and CODCr in oil containing wastewater effectively when the pH value was 7.0, the temperature was 30 degree Celsius, the rotation speed was 140r/min and the inoculation amount was 10%. Especially the highest removal ratio of CODCr was 68% after growth of 64 hours. The removal ratio of CODCr in oil containing wastewater of mixed bacilli was much higher than that of unitary bacilli, and mixing a certain amount of domestic sewage with the oil containing wastewater will also improve the removal rate of CODCr.
基金financially supported by the National Natural Science Foundation of China(21206153)Science and Technology Development Program Fund of Taiyuan City(120164053)
文摘Nitrobenzene-containing industrial wastewater was degraded in the presence of ozonecoupled with H2O2 by high gravity technology. The effect of high gravity factor, H2O2 concentration, pH value, liquid flow-rate, and reaction time on the efficiency for removal of nitrobenzene was investigated. The experimental results show that the high gravity technology enhances the ozone utilization efficiency with O3 /H2O2 showing synergistic effect. The degradation efficiency in terms of the COD removal rate and nitrobenzene removal rate reached 45.8% and 50.4%, respectively, under the following reaction conditions, viz.: a high gravity factor of 66.54, a pH value of 9, a H2O2 /O3 molar ratio of 1:1, a liquid flow rate of 140L/h, an ozone concentration of 40mg/L, a H2O2 multiple dosing mode of 6mL/h, and a reaction time of 4h. Compared with the performance of conventional stirred aeration mixers, the high gravity technology could increase the COD and nitrobenzene removal rate related with the nitrobenzene-containing wastewater by 22.9% and 23.3%, respectively.
文摘A technology of polymerase chain reaction-denaturing gradient gel electrophoresis(PCR-DGGE)was used to profile the structure and dynamic changes of microbial communities in a bioreactor for treating hydrocarbon-sulfide-containing(HSC)wastewater.The results showed that the heterotrophic genus of Acinetobacter and the autotrophic genera of Thiobacillus and Thiomonas could survive well in all of three operating conditions.Some special genera were also observed with changes of micro-ecoenvironment in the rea...
文摘The solid sodium hydroxide neutralized acidic As-containing wastewater till pH value was 6.Green copper arsenite was prepared after copper sulfate was added into the neutralized wastewater when the molar ratio of Cu to As was 2:1 and pH value of the neutralized wastewater was adjusted to 8.0 by sodium hydroxide.The arsenious acid solution and red residue were produced after copper arsenite mixed with water according to the ratio of liquid to solid of 4:1 and copper arsenite was reduced by SO2 at 60℃for 1 h.The white powder was gained after the arsenious acid solution was evaporated and cooled.Copper sulfate solution was obtained after the red residue was leached by H2SO4 solution under the action of air.The results show that red residue is Cu3(SO3)2·2H2O and the white powder is As2O3.The leaching rate of Cu reaches 99.00%when the leaching time is 1.5 h,molar ratio of H2SO4 to Cu is 1.70,H2SO4 concentration is 24%and the leaching temperature is 80℃.The direct recovery rate of copper sulfate is 79.11%and the content of CuSO4·5H2O is up to 98.33%in the product after evaporating and cooling the copper sulfate solution.
基金supported financially by a grant of the National Key Technologies R&D Program of China during the 12th Five-Year Plan period(2011BAD26B01-2)the National System for Layer Production Technology of China(CARS-41-K16)
文摘This study investigated the effects of fermentation product containing phytase(FPP) that was fermented using waste vinegar residue(WVR) as substrate from Aspergillus ficuum NTG-23 on productive performance, egg quality, and phosphorus apparent metabolism of laying hens. First, 375 22-wk-old Jinghong hens were allocated into 5 treatments(5 replicates of 15 hens each) in an 8-wk experiment for evaluating the parameters of productive performance, egg quality, serum, and tibia. Experimental diets contained 4% FPP and 96% corn-soybean diet. The levels of dicalcium phosphate(DCP) were 1.34, 1.01, 0.67, 0.34 and 0%. Next, thirty 31-wk-old Jinghong hens were fed 5 types of diets for evaluating phosphorous apparent metabolism rate. Egg productive rate, egg weight, feed conversion ratio, Haugh unit, egg albumen height, serum calcium, tibia ash, tibia ash calcium and tibia breaking strength were not different significantly among 5 treatments. The significant difference of average daily feed intake was not appeared when the DCP content of corn-soybean-FPP diet was reduced to 0.67%; the eggshell hardness, eggshell thickness and serum phosphorus were not reduced significantly until the DCP content of corn-soybean-FPP diet was reduced to 0.34%. The yolk color was improved when the laying hens fed deficient DCP corn-soybean-FPP diet. A 22.14% reduction in excreta phosphorus was observed when the laying hens fed low phosphorus(0.67% DCP) corn-soybean-FPP diet. A 30% elevation of phosphorus apparent metabolism rate was obtained when the DCP content of corn-soybean-FPP diet was decreased from 1.34 to 1.01%. The reducing cost of layer diet was totalized about 120 CNY 1 000 kg-1 diet when the content of DCP was 0.67% in corn-soybean-FPP diet. These results indicated that FPP could be applied in laying hen as a potential, cost-effective and rational application of WVR.
基金supported by the National Natural Science Foundation of China (No.50678045)
文摘High-concentration nitrite-containing wastewater that presents extreme toxicity to human health and organisms is difficult to be treated using traditional biological process. In this study, a novel microwave-enhanced chemical reduction process (MECRP) using sulfaminic acid (SA) was proposed as a new manner to treat such type of wastewater. Based on lab-scale experiments, it was shown that 75%-80% nitrite (NO2-) could be removed within time as short as 4 min under 50 W microwave irradiation in pH range 5-10 when molar ratio of SA to nitrite (SA/NO2-) was 0.8. Pilot-scale investigations demonstrated that MECRP was able to achieve nitrite and chemical oxygen demand (COD) removal with effciency up to 80% and 20%, respectively under operating conditions of SA concentration 80 kg/m3, SA/ NO2- ratio 0.8, microwave power 3.4 kW, and stirring time 3 min. Five-day biological oxygen demand (BOD5)/COD value of treated efluent after MECRP was increased from 0.05 to 0.36 (by 620%), which clearly suggested a considerable improvement of biodegradability for subsequent biological treatment. This study provided a demonstration of using microwave irradiation to enhance reaction between SA and nitrite in a short time, in which nitrite in wastewater was completely converted into nitrogen gas without leaving any sludge and secondary pollutants.
文摘The oily wastewater generated from pretreatment unit of electrocoating industry contains oils, phosphate, organic solvents, and surfactants. In order to improve the removal efficiencies of phosphate and oils, to mitigate the membr ane fouling, coagulation for ceramic membrane microfiltration of oily wastewater was performed. The results of filtration tests show that the membrane fouling d ecreased and the permeate flux and quality increased with coagulation as pret reatment. At the coagulant Ca(OH)2 dosage of 900 mg/L, the removal efficiency of phosphate was increased from 46.4% without coagulation to 99.6%; the removal of COD and oils were 97.0% and 99.8%, respectively. And the permeate flux was about 70% greater than that when Ca(OH)2 was not used. The permeate o btained from coagulation and microfiltration can be reused as make-up water, and the recommended operation conditions for pilot and industrial application are t ransmembrane pressure of 0.10 MPa and cross-flow velocity of 5 m/s. The comparis on results show that 0.2 μm ZrO2 microfilter with coagulation could be used to perform the filtration rather than conventional ultrafilter, with very substanti al gain in flux and removal efficiency of phosphate.
基金Sponsored by Notional Natural Scicnce Foundation of China(No.59203027)
文摘Copolyesters of phosphorus - containing flame - retardant poly(Ethylene Terephthalate) (PET) have been prepared and characterized with the objection of producing an effective, environmentally friendly, nonfugitive alternatives to halogen flame retardant system for practical application. With means of NMR, DSC, DTA/TGA, SEM and LOI, structure, thermal property and flam-mability are investigated which reveal that the flame -retardant PET when copolymerized with 2 - carboxyethyl (phenylphosphinic) acid (CEPP) confers excellent fire retardancy with LOI 】 28, broader thermal degradation temperature and increased char formation.
文摘For the wastewater containing high-concentration Hg,the feasibility of high-concentration Hg in wastewater treated by coagulation sedimentation,adsorption and the combined process was studied. Research results showed that if using the single coagulation sedimentation process,when FeSO_4·7H_2O dosage was 1. 39 g / L,and NaOH dosage was 0. 40 g / L,it could meet discharge requirement,but the reagent cost was 13. 1yuan / t,which was high. Because that there was subsequent adsorption process,it was selected 0. 28 g / L of FeSO_4·7H_2O and 0. 36 g / L of NaOH,and the estimated reagent cost was 2. 62 yuan / t. In selection process of adsorption materials,powdered activated carbon,granular activated carbon and diatomite all could effectively adsorb Hg,and the technology was feasible. When using the combined process of coagulation sedimentation + adsorption to treat the wastewater containing high-concentration Hg( 800 μg / L),removal rate could reach 99%,and operation cost was 2. 71 yuan. It could meet the requirement of sewage discharged into sewer( 20 μg / L) at the technology,and was acceptable at the economy.Therefore,treatment of wastewater containing high-concentration Hg by the combined process was feasible at the aspects of technology and economy.
文摘Aimed at the current treatment status of the polymer-flooding wastewater in Bohai oilfield, electrochemical technology used for polymer-degradation and oil-removal was researched. It formed the process flow of cyclone mixed dosing → electrochemical removal oil → inclined tube removal oil → walnut shell filter, and a set of skid mounted wastewater containing polymer treatment plant was designed and manufactured, which was used for the field test of electrochemical treatment of wastewater containing polymer in offshore oilfield. The result shows that the oil removal rate of the electrochemical treatment process is over 98%, and the synergistic effect is significant especially used in conjunction with water clarifier of BHQ-04. When the amount of water clarifier is 50 - 150 mg/L, the oil content, the median particle diameter and the suspended solids content of the filtered water is 8 - 18 mg/L, 1.9 - 2.26 μm and 1.39 - 2.04 mg/L respectively, which reach the scene water quality standards for water injection.
文摘The low-concentration methanol-containing wastewater of a gas field mainly consists of the dehydrated water from natural gas,the water at the bottom of a rectifying tower,and the water used to clear tanks and pipes. The concentration of methanol as its characteristic component is mostly lower than 3%. Its production and water quality change seasonally. It is mainly produced in late autumn,winter,and early spring when temperature is low. In the low-concentration methanol-containing wastewater,the content of organic matter,suspended solids and salts and COD value are high,and it is acidic. According to the physical and chemical properties of methanol such as easily dissolving in water,dissolving in most organic solvents,and having strong molecular polarity,laboratory experiments were made to study the difficulties of using high-temperature rectification,biodegradation,membrane filtration and organic oxidation technology to treat low-concentration methanol in the wastewater as well as the feasibility of industrial application. Ultraviolet catalytic oxidation technology has the advantages of high treatment efficiency,no secondary pollution,and no addition of treatment agent. After the low-concentration methanol-containing wastewater was treated by ultraviolet catalytic oxidation for 90 min,methanol concentration in the wastewater reduced from about 3% to around 0. 1%,thereby rapidly and efficiently degrading methanol in the wastewater. Based on the experimental parameters,a pilot device of ultraviolet catalytic oxidation was developed and used in the continuous treatment of the wastewater. When the flow rate of inflow was 500 L/h,the intensity of UV light was 2 k W,and hydraulic retention time was 60 min,methanol could be removed completely from the wastewater with the methanol concentration of about 0. 3%. This study provides a method for the treatment of low-concentration methanol-containing wastewater of a gas field,and also provides an experimental basis for the efficient degradation of organic wastewater.
