This paper focused on the removal and transformation of the dissolved organic matter (DOM) in secondary effluent during the granular activated carbon (GAC) treatment. Using XAD-8/XAD-4 resins, DOM was fractionated...This paper focused on the removal and transformation of the dissolved organic matter (DOM) in secondary effluent during the granular activated carbon (GAC) treatment. Using XAD-8/XAD-4 resins, DOM was fractionated into five classes: hydrophobic acid (HPO-A), hydrophobic neutral (HPO-N), transphilic acid (TPI-A), transphilic neutral (TPI-N) and hydrophilic fraction (HPI). Subsequently, the water quality parameters of dissolved organic carbon (DOC), absorbance of ultraviolet light at 254 nm (UV-254), specific ultraviolet light absorbance (SUVA) and trihalomethane formation potential (THMFP) were analyzed for the unfractionated and fractionated water samples. The results showed that the order of the DOC removal with respect to DOM fractions was observed to be HPI〉HPO-A〉HPO-N〉TPI-A〉TPI-N. During the GAC treatment, the THMFP of the unfractionated water samples decreased from 397.4 μg/L to 176.5 μg/L, resulting in a removal efficiency of 55.6%. The removal order of the trilaalomethanes (THMs) precursor was as follows: HPO-A〉TPI-A〉TPI-N〉HPO-N〉HPI. By the GAC treatment, the specific THMFP of HPO-A, TPI-A, TPI-N and the original unfractionated water samples had a noticeable decrease, while that of HPO-N and HPI showed a converse trend. The Fourier transform infrared (FTIR) results showed that the hydroxide groups, carboxylic acids, aliphatic C-H were significantly reduced by GAC treatment.展开更多
In this study,an ultra‐fast and simple solvent‐free microwave method was successfully demonstrated using a series of ultra‐small(~2.5 nm)surfactant‐free Ru_(2)P@Ru/CNT heterostructures for the first time.The struc...In this study,an ultra‐fast and simple solvent‐free microwave method was successfully demonstrated using a series of ultra‐small(~2.5 nm)surfactant‐free Ru_(2)P@Ru/CNT heterostructures for the first time.The structure has a high‐density Ru component and Ru_(2)P component interface,which accelerates the hydrogen evolution reaction(HER).The prepared Ru_(2)P@Ru/CNT demonstrated excellent catalytic effects for the HER in alkaline media and real seawater.The experimental results indicate that ratio‐optimized Ru_(2)P@Ru/CNT(Ru_(2)P:Ru=66:34)requires only 23 and 29 mV to reach 10 mA cm^(-2)in 1.0 mol/L KOH and real seawater,respectively.These values are 10 and 24 mV lower than those of commercial Pt/C in 1.0 mol/L KOH(33 mV)and real seawater(53 mV),respectively,making it among the best non‐Pt HER reported in the literature.Additionally,the TOF of Ru_(2)P@Ru/CNT in alkaline freshwater and seawater were 13.1 and 8.5 s^(-1),respectively.These exceed the corresponding values for Pt/C,indicating that the catalyst has excellent intrinsic activity.The high current activity of Ru_(2)P@Ru/CNT in 1.0 mol/L KOH was explored,and only 77 and 104 mV were required to reach 500 and 1000 mA cm^(-2),respectively.After 100 h of durability testing,the catalyst retained excellent catalytic and structural stability in low current density,high current density,and seawater.展开更多
In this work, the main characteristics of the Qingdao Cold Water Mass were studied by using "the comparison analysis method" based on 1980 temperature,salinity and dissolved oxygen data on the western South ...In this work, the main characteristics of the Qingdao Cold Water Mass were studied by using "the comparison analysis method" based on 1980 temperature,salinity and dissolved oxygen data on the western South Yellow Sea. The formation cause of the water mass was analyzed based on February of 1959 temperature and salinity data for this area and on some other authors’ studies. The results showed that the Qingdao Cold Water Mass has growing and vanishing processes: appears in the last ten days of March; has stable pattern in April; is biggest in its area in May; becomes small in its area in June; vanishes in July. It comes from the northern Shandong Coastal Water and is characterized by low temperature and salinity and high dissolved oxygen. The mass is formed under the joint effects of anticyclonic circulation and solar radiation.展开更多
In this work it presents a strategy to obtain the ozone solubility in water by gradient step method. In this methodology, the ozone in mixture with oxygen is bubbling in a reactor with distilled water at 21℃ and pH 7...In this work it presents a strategy to obtain the ozone solubility in water by gradient step method. In this methodology, the ozone in mixture with oxygen is bubbling in a reactor with distilled water at 21℃ and pH 7. The ozone concentration on gas phase is continually increased after the saturation is reached. The method proposed is faster than conventional method (isocratic method). The solubility from the gradient method is compared with that values obtained from correlations founded in the literature.展开更多
The exothermic efficiency of microwave heating an electrolyte/water solution is remarkably high due to the dielectric heating by orientation polarization of water and resistance heating by the Joule process occurred s...The exothermic efficiency of microwave heating an electrolyte/water solution is remarkably high due to the dielectric heating by orientation polarization of water and resistance heating by the Joule process occurred simultaneously compared with pure water.A three-dimensional finite element numerical model of multi-feed microwave heating industrial liquids continuously flowing in a meter-scale circular tube is presented.The temperature field inside the applicator tube in the cavity is solved by COMSOL Multiphysics and professional programming to describe the momentum,energy and Maxwell's equations.The evaluations of the electromagnetic field,the temperature distribution and the velocity field are simulated for the fluids dynamically heated by singleand multi-feed microwave system,respectively.Both the pilot experimental investigations and numerical results of microwave with single-feed heating for fluids with different effective permittivity and flow rates show that the presented numerical modeling makes it possible to analyze dynamic process of multi-feed microwave heating the industrial liquid.The study aids in enhancing the understanding and optimizing of dynamic process in the use of multi-feed microwave heating industrial continuous flow for a variety of material properties and technical parameters.展开更多
Eutrophication has emerged as a key environmental problem in Chinese coastal waters, especially in the Changjiang (Yangtze) River estuary. In this area, large nutrient inputs result in frequent harmful algal blooms an...Eutrophication has emerged as a key environmental problem in Chinese coastal waters, especially in the Changjiang (Yangtze) River estuary. In this area, large nutrient inputs result in frequent harmful algal blooms and serious hypoxia in bottom waters. Four cruises were made in the estuary in 2006 to assess the concentration and distribution of dissolved inorganic nitrogen (DIN) and phosphorus (DIP). The concentration of DIN decreased gradually in a linear relationship with salinity from the river mouth to outer waters, while DIP was relatively more dispersed. A modified box budget method was used to estimate nutrient fluxes in the estuary and its adjacent waters. Water and nutrient budgets as well as primary production and denitrification rates were estimated from the box budget model. Estimated water residence time in the estuary was about 11 d. The turbid mixing zone released 33% of DIN and 49% of DIP, while in the adjacent outer sea 17.9 mmol DIN/m2·d and 0.36 mmol DIP/m2·d were fixed. Dissolved inorganic phosphorus was imported from the deep open sea waters, supporting primary production and population growth in this zone. Net ecosystem production (NEP) was calculated at 38.2 mmol/m2·d in the outer estuary and the estimated rate (N-fixation minus denitrification) was negative (1.92 mmol/m2·d), implying that a large amount of input nitrogen was taken up by algae and recycled through denitrification in bottom water and sediment.展开更多
基金Project (No. 2004CB418505) supported by the National Basic Research Program (973) of China
文摘This paper focused on the removal and transformation of the dissolved organic matter (DOM) in secondary effluent during the granular activated carbon (GAC) treatment. Using XAD-8/XAD-4 resins, DOM was fractionated into five classes: hydrophobic acid (HPO-A), hydrophobic neutral (HPO-N), transphilic acid (TPI-A), transphilic neutral (TPI-N) and hydrophilic fraction (HPI). Subsequently, the water quality parameters of dissolved organic carbon (DOC), absorbance of ultraviolet light at 254 nm (UV-254), specific ultraviolet light absorbance (SUVA) and trihalomethane formation potential (THMFP) were analyzed for the unfractionated and fractionated water samples. The results showed that the order of the DOC removal with respect to DOM fractions was observed to be HPI〉HPO-A〉HPO-N〉TPI-A〉TPI-N. During the GAC treatment, the THMFP of the unfractionated water samples decreased from 397.4 μg/L to 176.5 μg/L, resulting in a removal efficiency of 55.6%. The removal order of the trilaalomethanes (THMs) precursor was as follows: HPO-A〉TPI-A〉TPI-N〉HPO-N〉HPI. By the GAC treatment, the specific THMFP of HPO-A, TPI-A, TPI-N and the original unfractionated water samples had a noticeable decrease, while that of HPO-N and HPI showed a converse trend. The Fourier transform infrared (FTIR) results showed that the hydroxide groups, carboxylic acids, aliphatic C-H were significantly reduced by GAC treatment.
文摘In this study,an ultra‐fast and simple solvent‐free microwave method was successfully demonstrated using a series of ultra‐small(~2.5 nm)surfactant‐free Ru_(2)P@Ru/CNT heterostructures for the first time.The structure has a high‐density Ru component and Ru_(2)P component interface,which accelerates the hydrogen evolution reaction(HER).The prepared Ru_(2)P@Ru/CNT demonstrated excellent catalytic effects for the HER in alkaline media and real seawater.The experimental results indicate that ratio‐optimized Ru_(2)P@Ru/CNT(Ru_(2)P:Ru=66:34)requires only 23 and 29 mV to reach 10 mA cm^(-2)in 1.0 mol/L KOH and real seawater,respectively.These values are 10 and 24 mV lower than those of commercial Pt/C in 1.0 mol/L KOH(33 mV)and real seawater(53 mV),respectively,making it among the best non‐Pt HER reported in the literature.Additionally,the TOF of Ru_(2)P@Ru/CNT in alkaline freshwater and seawater were 13.1 and 8.5 s^(-1),respectively.These exceed the corresponding values for Pt/C,indicating that the catalyst has excellent intrinsic activity.The high current activity of Ru_(2)P@Ru/CNT in 1.0 mol/L KOH was explored,and only 77 and 104 mV were required to reach 500 and 1000 mA cm^(-2),respectively.After 100 h of durability testing,the catalyst retained excellent catalytic and structural stability in low current density,high current density,and seawater.
文摘In this work, the main characteristics of the Qingdao Cold Water Mass were studied by using "the comparison analysis method" based on 1980 temperature,salinity and dissolved oxygen data on the western South Yellow Sea. The formation cause of the water mass was analyzed based on February of 1959 temperature and salinity data for this area and on some other authors’ studies. The results showed that the Qingdao Cold Water Mass has growing and vanishing processes: appears in the last ten days of March; has stable pattern in April; is biggest in its area in May; becomes small in its area in June; vanishes in July. It comes from the northern Shandong Coastal Water and is characterized by low temperature and salinity and high dissolved oxygen. The mass is formed under the joint effects of anticyclonic circulation and solar radiation.
文摘In this work it presents a strategy to obtain the ozone solubility in water by gradient step method. In this methodology, the ozone in mixture with oxygen is bubbling in a reactor with distilled water at 21℃ and pH 7. The ozone concentration on gas phase is continually increased after the saturation is reached. The method proposed is faster than conventional method (isocratic method). The solubility from the gradient method is compared with that values obtained from correlations founded in the literature.
基金Project(KKSY201503006)supported by Scientific Research Foundation of Kunming University of Science and Technology,ChinaProject(2014FD009)supported by the Applied Basic Research Foundation(Youth Program)of ChinaProject(51090385)supported by the National Natural Science Foundation of China
文摘The exothermic efficiency of microwave heating an electrolyte/water solution is remarkably high due to the dielectric heating by orientation polarization of water and resistance heating by the Joule process occurred simultaneously compared with pure water.A three-dimensional finite element numerical model of multi-feed microwave heating industrial liquids continuously flowing in a meter-scale circular tube is presented.The temperature field inside the applicator tube in the cavity is solved by COMSOL Multiphysics and professional programming to describe the momentum,energy and Maxwell's equations.The evaluations of the electromagnetic field,the temperature distribution and the velocity field are simulated for the fluids dynamically heated by singleand multi-feed microwave system,respectively.Both the pilot experimental investigations and numerical results of microwave with single-feed heating for fluids with different effective permittivity and flow rates show that the presented numerical modeling makes it possible to analyze dynamic process of multi-feed microwave heating the industrial liquid.The study aids in enhancing the understanding and optimizing of dynamic process in the use of multi-feed microwave heating industrial continuous flow for a variety of material properties and technical parameters.
基金Supported by the National Basic Research Program of China (973 Program) (No. 2010CB428706)the National Natural Science Foundation of China for Creative Research Groups (No. 40821004)the National High Technology Research and Development Program of China (863 Program) (No. 2008AA09Z107)
文摘Eutrophication has emerged as a key environmental problem in Chinese coastal waters, especially in the Changjiang (Yangtze) River estuary. In this area, large nutrient inputs result in frequent harmful algal blooms and serious hypoxia in bottom waters. Four cruises were made in the estuary in 2006 to assess the concentration and distribution of dissolved inorganic nitrogen (DIN) and phosphorus (DIP). The concentration of DIN decreased gradually in a linear relationship with salinity from the river mouth to outer waters, while DIP was relatively more dispersed. A modified box budget method was used to estimate nutrient fluxes in the estuary and its adjacent waters. Water and nutrient budgets as well as primary production and denitrification rates were estimated from the box budget model. Estimated water residence time in the estuary was about 11 d. The turbid mixing zone released 33% of DIN and 49% of DIP, while in the adjacent outer sea 17.9 mmol DIN/m2·d and 0.36 mmol DIP/m2·d were fixed. Dissolved inorganic phosphorus was imported from the deep open sea waters, supporting primary production and population growth in this zone. Net ecosystem production (NEP) was calculated at 38.2 mmol/m2·d in the outer estuary and the estimated rate (N-fixation minus denitrification) was negative (1.92 mmol/m2·d), implying that a large amount of input nitrogen was taken up by algae and recycled through denitrification in bottom water and sediment.