Full scale experimental study on nitrogen removal for low-carbon wastewater was conducted in reversed A2/O process in Jiguanshi waste water treatment plant in Chongqing,in order to aid the operation and maintenance of...Full scale experimental study on nitrogen removal for low-carbon wastewater was conducted in reversed A2/O process in Jiguanshi waste water treatment plant in Chongqing,in order to aid the operation and maintenance of similar WWTP. When the proposed measures,such as using 0.1% (volume fraction of wastewater) landfill leachate,shortening HRT by 2/3 in the primary sedimentation tank and controlling DO at 0.5 mg/L in the 3rd section of aerobic zone,are applied,15% of the carbon source can be complemented,the favorable property of activated sludge is achieved,and the nitrogen removal effect is significantly improved. The effluent NH3-N is 2 mg/L and the removal rate is 90%. The effluent TN is 17 mg/L and the removal rate is 54%. The up-to-standard discharge of the effluent is achieved. And after the optimization,the unit electricity consumption also reaches 0.21 kW/h and saves 20%.展开更多
This study evaluated the removal of multiple pollutants,i.e.,polybrominated diphenyl ethers(PBDEs),novel halogenated flame retardants(HFRs),sulfonamide antibiotics(SAs),and heavy metals(HMs),by a fullscale reversed A^...This study evaluated the removal of multiple pollutants,i.e.,polybrominated diphenyl ethers(PBDEs),novel halogenated flame retardants(HFRs),sulfonamide antibiotics(SAs),and heavy metals(HMs),by a fullscale reversed A^(2)/O process in a sewage treatment plant(STP)in Guangzhou,China.The reversed A^(2)/O process demonstrated high removal efficiencies(REs)for total PBDEs(60.5%±4.3%),novel HFRs(98.4%±2.8%)and HMs(70.1%±1.2%),and a relatively low RE for SAs(25.0%±2.3%).BDE 209,the dominant PBDE congener,showed a high residual concentration(13.41±5.18 ng/L)in the suspended particulate matter(SPM)of treated effluents.So me novel HFRs,dechlorane plus(DP)and decabromodiphe nyl ethane(DBDPE),were detected in the SPM of the raw sewage(7.50±4.14 ng/L and 11.52±11.65 ng/L,respectively).The removal ofSAs was mainly through biodegradation in the activated sludge bioreactors(ASBs).Ofthe HMs,Mn and Ni exhibited the lowest REs(47.5%±2.2%and 35.0%±2.6%,respectively),while Cr and Cu showed the highest removal(REs>80%).In terms of treatment units in the reversed A^(2)/O process,ASBs showed the highest RE(27.8%)for the multiple pollutants.The information can aid in our understanding of removal properties of STPs on various pollutants and evaluating the ecological/health risks of STPs as point pollutant sources.展开更多
Single phase of Ba1-x MgAl10O17 ： x Eu^2＋ （0.02≤ x ≤ 0. 14） phosphors was first successfully prepared by coprecipitation in aqueous medium with a “reverse strike” method, using oxalic acid and ammonia together...Single phase of Ba1-x MgAl10O17 ： x Eu^2＋ （0.02≤ x ≤ 0. 14） phosphors was first successfully prepared by coprecipitation in aqueous medium with a “reverse strike” method, using oxalic acid and ammonia together as precipitants. Completely crystallized phosphors were obtained at 1300 ℃, which is 300 ℃ lower than the temperature of solid-state reaction. Their photoluminescence was investigated under UV and VUV region, respectively. The emission spectra of Ba1-x MgAl10O17：xEu^2＋ samples excited by 254 or 147 nm showed a characteristic wide band with the peak centred at about 450 454 nm. Optimum emission intensity reached at x = 0.1 and then concentration quenching occurred. The synthesized phosphor shows 10% higher emission intensity than that prepared by solid-state reaction.展开更多
Up to 9% of the global CO_(2) emissions come from the iron and steel industry. Here, a combined chemical looping process to produce CO, a building block for the chemical industry, from the CO_(2) -rich blast furnace g...Up to 9% of the global CO_(2) emissions come from the iron and steel industry. Here, a combined chemical looping process to produce CO, a building block for the chemical industry, from the CO_(2) -rich blast furnace gas of a steel mill is proposed. This cyclic process can make use of abundant Fe_(3)O_(4) and CaO as solid oxygen and CO_(2) carriers at atmospheric pressure. A proof of concept was obtained in a laboratory-scale fixed bed reactor with synthetic blast furnace gas and Fe_(3)O_(4) /CaO = 0.6 kg/kg. CO production from the proposed process was investigated at both isothermal conditions(1023 K) and upon imposing a temperature program from 1023 to 1148 K. The experimental results were compared using performance indicators such as CO yield, CO space time yield, carbon recovery of the process, fuel utilisation, and solids’ utilisation.The temperature-programmed CO production resulted in a CO yield of 0.056 ± 0.002 mol per mol of synthetic blast furnace gas at an average CO space time yield of 7.6 mmol kgFe^(-1) s^(-1) over 10 cycles, carbon recovery of 48% ± 1%, fuel utilisation of 23% ± 2%, and an average calcium oxide and iron oxide utilisation of 22% ± 1% and 11% ± 1%. These experimental performance indicators for the temperature-programmed CO production were consistently better than those of the isothermal implementation mode by 20% to 35%. Over 10 consecutive process cycles, no significant losses in CO yield were observed in either implementation mode. Process simulation was carried out for 1 million metric tonnes per year of equivalent CO_(2) emissions from the blast furnace gas of a steel mill to analyse the exergy losses in both modes of operation. Comparison of the exergy efficiency of the temperature-programmed process to the isothermal process showed that the former is more efficient because of the higher CO concentration achievable,despite 20% higher exergy losses caused by heat transfer required to change temperature.展开更多
Iodine-sulfur （IS） thermochemical water-splitting cycle is the most promising massive hydrogen production process. To avoid the undesirable side reactions between hydriodic acid（HI） and sulfuric acid （H2SO4）, it...Iodine-sulfur （IS） thermochemical water-splitting cycle is the most promising massive hydrogen production process. To avoid the undesirable side reactions between hydriodic acid（HI） and sulfuric acid （H2SO4）, it is necessary to purify the two phases formed by the Bunsen reaction. The purification process could be achieved by reverse reaction of the Bunsen reaction. In this study, the purification of the H2SO4 and HI Phases was studied. The purification proceeded in both batches and the continuous mode, the influences of operational parameters, including the reaction temperature, the flow rate of nitrogen gas, and the composition of the raw material solutions, on the purification effect, were investigated. Results showed that the purification of the H2SO4 phase was dominantly-affected by the reaction temperature, and iodine ion in the sulfuric acid phase could be removed completely when the temperature was above 130℃; although, the purification effect of the HI phase improved with increasing of both the flow rate of nitrogen gas and temperature.展开更多
La-doped Li2Mo0.9La0.2O4 was synthesized as an active anode material via the sol-gel process. The structural and morphological characteristics of the target product and the precursor were analyzed by XRD, SEM, and TG-...La-doped Li2Mo0.9La0.2O4 was synthesized as an active anode material via the sol-gel process. The structural and morphological characteristics of the target product and the precursor were analyzed by XRD, SEM, and TG-DTA. Crystal started to format at 300℃ and the optimum crystal structure was obtained at 700℃. By detecting battery performance, the charged and discharged platform was over 3.6 V; the anode exhibited a discharge capacity decay of 2% from its initial capacity （165 mA·h/g） after 20 cycles. Therefore, it was a perfect anode material.展开更多
基金Project (2009ZX07315-002-01) supported by Water Pollution Control and Management of Major Special Science and Technology
文摘Full scale experimental study on nitrogen removal for low-carbon wastewater was conducted in reversed A2/O process in Jiguanshi waste water treatment plant in Chongqing,in order to aid the operation and maintenance of similar WWTP. When the proposed measures,such as using 0.1% (volume fraction of wastewater) landfill leachate,shortening HRT by 2/3 in the primary sedimentation tank and controlling DO at 0.5 mg/L in the 3rd section of aerobic zone,are applied,15% of the carbon source can be complemented,the favorable property of activated sludge is achieved,and the nitrogen removal effect is significantly improved. The effluent NH3-N is 2 mg/L and the removal rate is 90%. The effluent TN is 17 mg/L and the removal rate is 54%. The up-to-standard discharge of the effluent is achieved. And after the optimization,the unit electricity consumption also reaches 0.21 kW/h and saves 20%.
基金the National Natural Science Foundation of China(No.91851110)Guangzhou University’s 2017 Training Program for Young Top-Notch Personnels(No.BJ201713)+1 种基金Scientific Research Project of Guangzhou University(No.YK2020017)Guizhou Provincial Department of Education Youth Science and Technology Talents Growth Project(No.KY[2017]300)。
文摘This study evaluated the removal of multiple pollutants,i.e.,polybrominated diphenyl ethers(PBDEs),novel halogenated flame retardants(HFRs),sulfonamide antibiotics(SAs),and heavy metals(HMs),by a fullscale reversed A^(2)/O process in a sewage treatment plant(STP)in Guangzhou,China.The reversed A^(2)/O process demonstrated high removal efficiencies(REs)for total PBDEs(60.5%±4.3%),novel HFRs(98.4%±2.8%)and HMs(70.1%±1.2%),and a relatively low RE for SAs(25.0%±2.3%).BDE 209,the dominant PBDE congener,showed a high residual concentration(13.41±5.18 ng/L)in the suspended particulate matter(SPM)of treated effluents.So me novel HFRs,dechlorane plus(DP)and decabromodiphe nyl ethane(DBDPE),were detected in the SPM of the raw sewage(7.50±4.14 ng/L and 11.52±11.65 ng/L,respectively).The removal ofSAs was mainly through biodegradation in the activated sludge bioreactors(ASBs).Ofthe HMs,Mn and Ni exhibited the lowest REs(47.5%±2.2%and 35.0%±2.6%,respectively),while Cr and Cu showed the highest removal(REs>80%).In terms of treatment units in the reversed A^(2)/O process,ASBs showed the highest RE(27.8%)for the multiple pollutants.The information can aid in our understanding of removal properties of STPs on various pollutants and evaluating the ecological/health risks of STPs as point pollutant sources.
基金Project supported bythe National Natural Science Foundation of China (50272026) ,the Excellent Young Teachers ProgramofMOE,China (EYTP) and the Natural Science Foundation of Gansu Province (ZS031-A25-033-C)
文摘Single phase of Ba1-x MgAl10O17 ： x Eu^2＋ （0.02≤ x ≤ 0. 14） phosphors was first successfully prepared by coprecipitation in aqueous medium with a “reverse strike” method, using oxalic acid and ammonia together as precipitants. Completely crystallized phosphors were obtained at 1300 ℃, which is 300 ℃ lower than the temperature of solid-state reaction. Their photoluminescence was investigated under UV and VUV region, respectively. The emission spectra of Ba1-x MgAl10O17：xEu^2＋ samples excited by 254 or 147 nm showed a characteristic wide band with the peak centred at about 450 454 nm. Optimum emission intensity reached at x = 0.1 and then concentration quenching occurred. The synthesized phosphor shows 10% higher emission intensity than that prepared by solid-state reaction.
基金financial support from the project Cabon4PUR which has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 768919support of Dr. Alessandro Longo for Rietveld refinement of XRDsupport of the Wim Rogiers and Micha?l Lottin at the LCT for the fixed bed reactor setup used for experimental validation of the process concept。
文摘Up to 9% of the global CO_(2) emissions come from the iron and steel industry. Here, a combined chemical looping process to produce CO, a building block for the chemical industry, from the CO_(2) -rich blast furnace gas of a steel mill is proposed. This cyclic process can make use of abundant Fe_(3)O_(4) and CaO as solid oxygen and CO_(2) carriers at atmospheric pressure. A proof of concept was obtained in a laboratory-scale fixed bed reactor with synthetic blast furnace gas and Fe_(3)O_(4) /CaO = 0.6 kg/kg. CO production from the proposed process was investigated at both isothermal conditions(1023 K) and upon imposing a temperature program from 1023 to 1148 K. The experimental results were compared using performance indicators such as CO yield, CO space time yield, carbon recovery of the process, fuel utilisation, and solids’ utilisation.The temperature-programmed CO production resulted in a CO yield of 0.056 ± 0.002 mol per mol of synthetic blast furnace gas at an average CO space time yield of 7.6 mmol kgFe^(-1) s^(-1) over 10 cycles, carbon recovery of 48% ± 1%, fuel utilisation of 23% ± 2%, and an average calcium oxide and iron oxide utilisation of 22% ± 1% and 11% ± 1%. These experimental performance indicators for the temperature-programmed CO production were consistently better than those of the isothermal implementation mode by 20% to 35%. Over 10 consecutive process cycles, no significant losses in CO yield were observed in either implementation mode. Process simulation was carried out for 1 million metric tonnes per year of equivalent CO_(2) emissions from the blast furnace gas of a steel mill to analyse the exergy losses in both modes of operation. Comparison of the exergy efficiency of the temperature-programmed process to the isothermal process showed that the former is more efficient because of the higher CO concentration achievable,despite 20% higher exergy losses caused by heat transfer required to change temperature.
基金Supported by the National Defense Fundamental Research Fund (A1420080145)
文摘Iodine-sulfur （IS） thermochemical water-splitting cycle is the most promising massive hydrogen production process. To avoid the undesirable side reactions between hydriodic acid（HI） and sulfuric acid （H2SO4）, it is necessary to purify the two phases formed by the Bunsen reaction. The purification process could be achieved by reverse reaction of the Bunsen reaction. In this study, the purification of the H2SO4 and HI Phases was studied. The purification proceeded in both batches and the continuous mode, the influences of operational parameters, including the reaction temperature, the flow rate of nitrogen gas, and the composition of the raw material solutions, on the purification effect, were investigated. Results showed that the purification of the H2SO4 phase was dominantly-affected by the reaction temperature, and iodine ion in the sulfuric acid phase could be removed completely when the temperature was above 130℃; although, the purification effect of the HI phase improved with increasing of both the flow rate of nitrogen gas and temperature.
文摘La-doped Li2Mo0.9La0.2O4 was synthesized as an active anode material via the sol-gel process. The structural and morphological characteristics of the target product and the precursor were analyzed by XRD, SEM, and TG-DTA. Crystal started to format at 300℃ and the optimum crystal structure was obtained at 700℃. By detecting battery performance, the charged and discharged platform was over 3.6 V; the anode exhibited a discharge capacity decay of 2% from its initial capacity （165 mA·h/g） after 20 cycles. Therefore, it was a perfect anode material.
