Papers by Keyword: Hydroxyl Radical

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Authors: Kang Lin Wei, Ming Chen, Fei Wang, Qiong Fang
Abstract: Chemical Oxygen Demand (COD) is an much important key water quality parameter . In view of the technical defects of existing detection methods and monitoring instruments for measuring COD, a new detection method based on ultrasonic assisted sample digestion and spectrum analysis was put forward in this paper, and the automatic monitoring system prototype based on such detection method had been developped. Aiming at environmental water samples, the spot experiment had been carried out to contrast prototype with Chinas national standard analysis method for measuring COD, and the results showed that the automatic monitoring instrument prototype had good repeatability (10%) and high accuracy (±10%), which met the technical qualifications of Chinas envirormental protection industry standards.
1295
Authors: Qin Li, Chi Zhang
Abstract: In this article,Cordyceps militaris,that from Hubei and Yunnan,were used as the research objects, to extract seleno-polysaccharide ,then the antioxidant activity of seleno-polysaccharide were determined by reducing power,the scavenging capacity on superoxide anion radical and hydroxyl radical.The results indicated that,the content of selenium in Hubei and Yunnan Cordyceps militaris samples were 210.0μg/g and 57.5μg/g,respectively;the share of Se-polysaccharide in total selenium were 11.086% and 26.713%,respectively,lower degree to turn the selenium organic in Hubei Cordyceps militaris.The reducing power of seleno-polysaccharide from Hubei and Yunnan Cordyceps militaris were 0.0253,0.0297,respectively;two kinds of Cordyceps militaris have certain ability to remove superoxide anion radical and different between them,the seleno-polysaccharide of Yunnan Cordyceps militaris has a better effect to remove superoxide anion radical under different sample amount.About hydroxyl radical,there were no ability to remove it.
1984
Authors: De Min Yang, Jian Mei Yuan
Abstract: Advanced treatment of biochemical treated coking wastewater was studied experimentally with ozonation process. The effects of initial pH value, ozone concentration, reaction temperature, and reaction time on the COD and color removal rate were investigated. The results showed that ozonation was an effective method for advanced treatment of biochemical treated coking wastewater. The increasing of initial pH value, ozone concentration, reaction temperature, and reaction time has enhanced the removal rate of COD and color. Meanwhile, the results also revealed that the maximal COD and color removal rate of 69.65% and 92.27% could be reached under the optimal conditions of the initial pH value is 10.5, ozone concentration is 150 mg/L, reaction temperature is 298 K, and reaction time is 30 min.
2515
Authors: Xian Yun Liu, Ya Jun Yang, Zhen Ya Wang, Wei Jun Zhang
Abstract: To understand the effects of environmental factors, such as the light intensity, reaction time, the concentration of reactant on the growth of secondary organic aerosol is very important. This paper investigated the effect of environmental factors on SOA formation from biogenic volatile organic compounds (BVOCs), results show that SOA formed from OH-initiated photooxidation of BVOCs is predominantly in the form of fine particles, which have diameters less than 2.5 µm. This paper also highlighted that both the number and mass concentration of SOA particles were increasing with the prolonging of the radiation time, the increasing of light intensity, and the increasing of the reactant concentrations. The results could provide useful information to infer possible emission sources of atmospheric particles in future field measurement.
963
Authors: Quan Yi Fu, Xu Cong Yu, Lin Li, Guo Qin Liu, Bing Li
Abstract: Brewers’ spent grain (BSG) is the most common by-product of the brewing industry, contains about 16.8% cellulose, 28.4% non-cellulosic polysaccharides and 27.8% lignin, which is a good raw material for industrial production of soluble dietary fiber (SDF).The antioxidant activity of crude dietary fiber (CDF) and grade dietary fiber (GDF) isolated from BSG was investigated in vitro. The scavenging hydroxyl radical capability of CDF and GDF was respectively reached to15.4% and 69.2% at the concentration of 0.1mg /mL. DF concentration from 0.02mg /mL to 0.1m g /mL was used. The scavenging capability of CDF and GDF to superoxide anion radical was increased from 10.68% and 12.33% to 35.78% and 78.39%. Both of the two DF showed some effect in scavenging superoxide radical and 2, 2-Diphenyl-1-picrylhydrazyl (DPPH) radical with the concentration increase. The result showed that BSG DF can be used as a good additive with some functionality.
2824
Authors: Ying Jie Zhang, Yue Xiao Tian, Da Peng Li, Guo Rui Liu, Li Zhang, Li Li, Jun Ma
Abstract: A new Fenton-like catalyst was prepared to degrade Orange IV in water by catalytic decomposition of H2O2. The optimal preparation conditions were discussed. The catalytic activity of catalyst was evaluated by the degradation of Orange IV and the decomposition of H2O2. The results show that solid super acid (S2O82-/FexOy) soaked in (NH4)2S2O8 is the most effective catalyst among the synthesized iron oxides soaked in other oxidants. The optimal conditions for solid super acid preparation are calcined at 500 for 2 h in the air.
1710
Authors: Wei Na Fu, Tuo Ping Li, You Feng Jia, Zhong Sheng Zhao, Wei Hou, Ying Chen
Abstract: Anthocyanins, which possess strong antioxidant activities, are abundant in purple sweet potato wine. In the present study, changes in the antioxidant activity of purple sweet potato wine during storage were investigated. The results showed that purple sweet potato wine had high 2,2-dipheny-l-picrylhydrazyl (DPPH) free-radical and superoxide-radical scavenging activities, which were stable during storage periods. Compared with these two scavenging activities, the hydroxyl-radical scavenging activity of purple sweet potato wine was concentration-dependent and only presented relatively obvious scavenging activity at high concentrations. This hydroxyl-radical scavenging activity was also stabile during storage periods. The results are valuable in purple sweet potato wine research and development.
1462
Authors: Shu Rong Yu, Ting Zhang, Hui Xia Feng
Abstract: Fe2O3/attapulgite(ATP) catalyst was successfully prepared for Fenton reaction to degrade an anion surfactant, sodium dodecyl benzene sulfonate(SDBS),in an aqueous solution. BET, SEM, FT-IR were performed to characterize Fe2O3/ ATP catalyst. Comparative studies indicated that the SDBS degradation ratios were much higher in presence of Fe2O3/ATP and H2O2 than those in presence of Fe2O3/ATP or H2O2 only, which suggested that the Fe2O3/ATP-catalyzed Fenton-like reaction governed the SDBS removal process. It also can be seen that Fe2O3/ATP-catalyzed Fenton-like reaction almost has the same efficiency as homogeneous Fenton reaction, while the former can be reused and has no secondary pollutants.
128
Authors: Ting Zhang, Yi Wang, Shu Rong Yu, Hui Xia Feng
Abstract: Fe2O3 and Fe2O3/attapulgite(ATP) catalyst was used for Fenton reaction to degrade an anion surfactant, sodium dodecyl benzene sulfonate(SDBS),in an aqueous solution. Comparative studies indicated that Fe2O3/ATP-catalyzed Fenton system and Fe2O3-catalyzed Fenton system have the same catalysis capability. These two systems all have a widely pH range (2-10), and the catalysts can be reused and have no secondary pollutants. It also can be seen that Fe2O3/ATP-catalyzed Fenton-like reaction has much efficiency than Fe2O3-catalyzed Fenton reaction.
696
Authors: Jian Xin Chen, Zhao Ji Hu, Xue Xia Yuan, Yan Hong Yao, Jun Li
Abstract: In this paper, degradation of Orange II by homogeneous UV-Fenton process with low concentration of Fe3+ as catalyst was detected. And the effects of UV light wavelength, initial pH and reaction temperature on degradation of Orange II in homogeneous UV-Fenton system were studied in detail. It was found that the arithmetic sum of the rate constants of dye degradation in Fenton and UV-H2O2 and UV was much lower than that in UV-Fenton system with low concentration of Fe3+ as catalyst. The result showed that using low concentration of metallic salts as homogeneous catalyst would be a good alternative in UV-Fenton system for wastewater treatment.
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