A novel process aimed at the comprehensive utilization of sintering dust was developed by combining wetting grinding with sulfidization flotation. The mineralogical characteristics of the sintering dust and products w...A novel process aimed at the comprehensive utilization of sintering dust was developed by combining wetting grinding with sulfidization flotation. The mineralogical characteristics of the sintering dust and products were studied by powder wettability analysis, X-ray diffraction（XRD）, scanning electron microscopy（SEM） and mineral liberation analyzer（MLA）. It was found that the primary lead species was laurionite and most of the particles were overwrapped with KCl. Wetting grinding was shown to accelerate the dispersion of sintering dust and transform the KCl overlay to a leachate with 20.78 g/L of K＋. A lead and silver concentrate consisting of 40.82% of Pb and 0.96 kg/t of Ag was achieved, while an iron concentrate with 60.89% of Fe was gained as tailings among sulfidization flotation. The recoveries of Pb, Ag and Fe were 89.57%, 87.85% and 88.58%, respectively. The results indicate that this method is a feasible and promising process for the comprehensive utilization of sintering dust.展开更多
The hydroxyl radical（-OH）-scavenging ability of culture filtrates from submerged culture of Lentinula edodes AX3 and five mildews on lignocellulose substance was analysed. Only L. edodes AX3 showed significant -OH-s...The hydroxyl radical（-OH）-scavenging ability of culture filtrates from submerged culture of Lentinula edodes AX3 and five mildews on lignocellulose substance was analysed. Only L. edodes AX3 showed significant -OH-scavenging ability which reached 52.2% at about the 48th hour. All mildews could hardly scavenge -OH under the experimental conditions. -OH-scavenging ability is considered related to the mode and ability of lignocellulose degradation of a strain. The degradation or bioconversion products might be the substance base for.this effect.展开更多
The basic objective of this research is to determine the effects of acetate, propionate and butyrate on the biological phosphate(bio p) release and poly β hydroxybutyrate(PHB) synthesis and...The basic objective of this research is to determine the effects of acetate, propionate and butyrate on the biological phosphate(bio p) release and poly β hydroxybutyrate(PHB) synthesis and to test the effects of different acetate concentrations on the bio p release as well as the effect of butyrate on the bio p release and PHB synthesis in the presence of nitrates. Oxidation reduction potential probes are used to monitor the relative anaerobic and anoxic states of the sewage. The author quantified PHB, PHV in activated sludge by gas liquid chromatography. It has been demonstrated through a series of batch experiments that phosphorus release and PHB synthesis both take place in anaerobic zone of the bio p removal process, and the key factors to the maximization of PHB synthesis are that simple carbon substrates should be added to the anaerobic zone and that the addition of electron acceptors should be avoided.展开更多
In this paper, saponins were extracted from Northern Shaanxi＇ s big jujubes using organic solvent method and also the oxidation resistance of the extractives was analyzed. In the experiment, the crude extractives of ...In this paper, saponins were extracted from Northern Shaanxi＇ s big jujubes using organic solvent method and also the oxidation resistance of the extractives was analyzed. In the experiment, the crude extractives of the saponins from jujubes were obtained using ethyl alcohol soaking method and Soxhlet extraction method and also qualitatively tested using 3 color reactions, and the test result was positive; the oxidation resistance of jujube saponins was analyzed through DPPH, hydroxyl radical scavenging experiment and reducibility measurement, and the results showed that the capability of jujube saponins in DPPH free radical scavenging was enhanced along with the improvement of the to- be-test material concentration, so saponins played a significant role on hydroxyl radical scavenging and possessed certain reducibility. Northern Shaanxi＇ s big jujubes are rich in saponins and possess excellent antioxidant ability that will be enhanced along with the increase of saponins content. Thus, a basis is provided for the effective extension of the jujube industry chain.展开更多
The removal of cadmium, copper, and zinc from aqueous solution using activated carbon impregnated with 8-Hydroxyquinoline （oxine） was investigated in this study. The study was conducted using a completely mixed batc...The removal of cadmium, copper, and zinc from aqueous solution using activated carbon impregnated with 8-Hydroxyquinoline （oxine） was investigated in this study. The study was conducted using a completely mixed batch technique. Quantitative evaluation of the experimental results showed that the adsorption capacity of oxine impregnated activated carbon was higher than that of the virgin activated carbon for the three heavy metals. For oxine impregnated activated carbon, the Freundlieh distribution coefficient, kd , values were 23, 100, and 104 times larger than those of the virgin activated carbon for cadmium, copper, and zinc, respectively. Moreover, for oxine impregnated activated carbon, the kd values followed the sequence Cu 〉 Zn 〉 Cd which aggress well with the stability constants reported in the literature for the complexation of the three heavy metals with 8-Hydroxyquinoline.展开更多
Agrochemicals have been used throughout the ages to eradicate weeds and pests. Use of agrochemicals is now commonplace, serving as an aid in farming procedures and contributing to greater agricultural production. Howe...Agrochemicals have been used throughout the ages to eradicate weeds and pests. Use of agrochemicals is now commonplace, serving as an aid in farming procedures and contributing to greater agricultural production. However, the indiscriminate use of agrochemicals is a cause for concern because they can exert toxic effects on the environment and hence on living beings. This work involved a genotoxic analysis of controlled release formulations of the herbicide ametryn encapsulated in microspheres of poly（hydroxybutyrate） and poly（hydroxybutyrate-co^valerate）. Genotoxicity was analyzed using cytogenetic, micronucleus, comet and Allium cepa assays, as well as molecular analysis. The results showed that the rate of chromosome breakdown caused by unencapsulated ametryn was much higher than that caused by ametryn encapsulated in the polymer microspheres （p 〈 0.05）. This indicates that controlled release delivery systems employing the polymer formulations should be significantly safer for the environment and for living beings.展开更多
The aim of this work was to study the influence of effluent organic matter （EfOM） on micropollutants removal by ozone and UV/H2O2. To perform the experiments, deionized water and municipal secondary effluents （SE）...The aim of this work was to study the influence of effluent organic matter （EfOM） on micropollutants removal by ozone and UV/H2O2. To perform the experiments, deionized water and municipal secondary effluents （SE） were artificially contaminated with atrazine （ATZ） and treated by the two proposed methods. ATZ concentration, COD and TOC were recorded along the reaction time and used to evaluate EfOM effect on the system efficiency. Results demonstrate that the presence of EfOM can significantly reduce the micropollutant removal rate due to competition of EfOM components to react with radicals and/or molecular ozone. The hydroxyl radical scavenging caused by EfOM was quantified as well as the contribution of molecular ozone and .OH radicals during the ozonation of SE. EfOM components promoted higher inhibition of ATZ oxidation by hydroxyl radicals than by molecular ozone.展开更多
Hybrid antioxidants cinnamoyldopamine（2a）, p-coumaroyldopamine（2b）, caffeoyldopamine（2c）, feruloyldopamine（2d） and sinapoyldopamine（2e） were synthesized by conjugation of dopamine（DA） and hydroxycinnamic a...Hybrid antioxidants cinnamoyldopamine（2a）, p-coumaroyldopamine（2b）, caffeoyldopamine（2c）, feruloyldopamine（2d） and sinapoyldopamine（2e） were synthesized by conjugation of dopamine（DA） and hydroxycinnamic acids（HCAs）. The stabilities were studied in buffers at p H 1.3, p H 5.0, and p H 7.4 including the human plasma. All the compounds were found highly stable at acidic p H, but underwent hydrolysis at neutral p H. Furthermore, the hydrolysis proceeded much faster in plasma in the following order as indicated by half-life values（t1/2）, 2c（1.21 h）〈2e（1.52 h）〈2d（1.85 h）〈2b（3.38 h）〈2a（3.88 h）, correlating with the number of electron-donating groups. It has been proven by UV spectrum that 2c, 2d, and 2e displayed red shift of more than 50 nm as compared to 2a and 2b, because of the presence of OH and OCH3 groups. In addition, the compounds（2b–e） showed no cytotoxicity on normal HUVEC cells as DA, although 2a displayed a 16% inhibition of proliferation at 40 μM following 48 h incubation. Their free radical-scavenging activities were evaluated using ABTS^＊＋ and superoxide anion assays and the mechanisms were proposed. It was found that they all exhibited higher activities than trolox, a recognized antioxidant. Amazingly, in the case of the hybrids（2a–e）, their activity was higher than that of HCAs while lower or comparable to that of DA, suggesting that there may be a ＂saturation effect＂ with the hybrid molecules in the antioxidant activities.展开更多
基金Project(CX2015B053)supported by the Hunan Provincial Innovation Foundation for PostgraduateChinaProject(B14034)supported by National 111 Project of China
文摘A novel process aimed at the comprehensive utilization of sintering dust was developed by combining wetting grinding with sulfidization flotation. The mineralogical characteristics of the sintering dust and products were studied by powder wettability analysis, X-ray diffraction（XRD）, scanning electron microscopy（SEM） and mineral liberation analyzer（MLA）. It was found that the primary lead species was laurionite and most of the particles were overwrapped with KCl. Wetting grinding was shown to accelerate the dispersion of sintering dust and transform the KCl overlay to a leachate with 20.78 g/L of K＋. A lead and silver concentrate consisting of 40.82% of Pb and 0.96 kg/t of Ag was achieved, while an iron concentrate with 60.89% of Fe was gained as tailings among sulfidization flotation. The recoveries of Pb, Ag and Fe were 89.57%, 87.85% and 88.58%, respectively. The results indicate that this method is a feasible and promising process for the comprehensive utilization of sintering dust.
文摘The hydroxyl radical（-OH）-scavenging ability of culture filtrates from submerged culture of Lentinula edodes AX3 and five mildews on lignocellulose substance was analysed. Only L. edodes AX3 showed significant -OH-scavenging ability which reached 52.2% at about the 48th hour. All mildews could hardly scavenge -OH under the experimental conditions. -OH-scavenging ability is considered related to the mode and ability of lignocellulose degradation of a strain. The degradation or bioconversion products might be the substance base for.this effect.
文摘The basic objective of this research is to determine the effects of acetate, propionate and butyrate on the biological phosphate(bio p) release and poly β hydroxybutyrate(PHB) synthesis and to test the effects of different acetate concentrations on the bio p release as well as the effect of butyrate on the bio p release and PHB synthesis in the presence of nitrates. Oxidation reduction potential probes are used to monitor the relative anaerobic and anoxic states of the sewage. The author quantified PHB, PHV in activated sludge by gas liquid chromatography. It has been demonstrated through a series of batch experiments that phosphorus release and PHB synthesis both take place in anaerobic zone of the bio p removal process, and the key factors to the maximization of PHB synthesis are that simple carbon substrates should be added to the anaerobic zone and that the addition of electron acceptors should be avoided.
文摘In this paper, saponins were extracted from Northern Shaanxi＇ s big jujubes using organic solvent method and also the oxidation resistance of the extractives was analyzed. In the experiment, the crude extractives of the saponins from jujubes were obtained using ethyl alcohol soaking method and Soxhlet extraction method and also qualitatively tested using 3 color reactions, and the test result was positive; the oxidation resistance of jujube saponins was analyzed through DPPH, hydroxyl radical scavenging experiment and reducibility measurement, and the results showed that the capability of jujube saponins in DPPH free radical scavenging was enhanced along with the improvement of the to- be-test material concentration, so saponins played a significant role on hydroxyl radical scavenging and possessed certain reducibility. Northern Shaanxi＇ s big jujubes are rich in saponins and possess excellent antioxidant ability that will be enhanced along with the increase of saponins content. Thus, a basis is provided for the effective extension of the jujube industry chain.
文摘The removal of cadmium, copper, and zinc from aqueous solution using activated carbon impregnated with 8-Hydroxyquinoline （oxine） was investigated in this study. The study was conducted using a completely mixed batch technique. Quantitative evaluation of the experimental results showed that the adsorption capacity of oxine impregnated activated carbon was higher than that of the virgin activated carbon for the three heavy metals. For oxine impregnated activated carbon, the Freundlieh distribution coefficient, kd , values were 23, 100, and 104 times larger than those of the virgin activated carbon for cadmium, copper, and zinc, respectively. Moreover, for oxine impregnated activated carbon, the kd values followed the sequence Cu 〉 Zn 〉 Cd which aggress well with the stability constants reported in the literature for the complexation of the three heavy metals with 8-Hydroxyquinoline.
文摘Agrochemicals have been used throughout the ages to eradicate weeds and pests. Use of agrochemicals is now commonplace, serving as an aid in farming procedures and contributing to greater agricultural production. However, the indiscriminate use of agrochemicals is a cause for concern because they can exert toxic effects on the environment and hence on living beings. This work involved a genotoxic analysis of controlled release formulations of the herbicide ametryn encapsulated in microspheres of poly（hydroxybutyrate） and poly（hydroxybutyrate-co^valerate）. Genotoxicity was analyzed using cytogenetic, micronucleus, comet and Allium cepa assays, as well as molecular analysis. The results showed that the rate of chromosome breakdown caused by unencapsulated ametryn was much higher than that caused by ametryn encapsulated in the polymer microspheres （p 〈 0.05）. This indicates that controlled release delivery systems employing the polymer formulations should be significantly safer for the environment and for living beings.
文摘The aim of this work was to study the influence of effluent organic matter （EfOM） on micropollutants removal by ozone and UV/H2O2. To perform the experiments, deionized water and municipal secondary effluents （SE） were artificially contaminated with atrazine （ATZ） and treated by the two proposed methods. ATZ concentration, COD and TOC were recorded along the reaction time and used to evaluate EfOM effect on the system efficiency. Results demonstrate that the presence of EfOM can significantly reduce the micropollutant removal rate due to competition of EfOM components to react with radicals and/or molecular ozone. The hydroxyl radical scavenging caused by EfOM was quantified as well as the contribution of molecular ozone and .OH radicals during the ozonation of SE. EfOM components promoted higher inhibition of ATZ oxidation by hydroxyl radicals than by molecular ozone.
基金The National Natural Science Foundation of China(Grant No.21302079)the Fundamental Research Funds for the Central Universities(Grant No.lzujbky-2014-151)
文摘Hybrid antioxidants cinnamoyldopamine（2a）, p-coumaroyldopamine（2b）, caffeoyldopamine（2c）, feruloyldopamine（2d） and sinapoyldopamine（2e） were synthesized by conjugation of dopamine（DA） and hydroxycinnamic acids（HCAs）. The stabilities were studied in buffers at p H 1.3, p H 5.0, and p H 7.4 including the human plasma. All the compounds were found highly stable at acidic p H, but underwent hydrolysis at neutral p H. Furthermore, the hydrolysis proceeded much faster in plasma in the following order as indicated by half-life values（t1/2）, 2c（1.21 h）〈2e（1.52 h）〈2d（1.85 h）〈2b（3.38 h）〈2a（3.88 h）, correlating with the number of electron-donating groups. It has been proven by UV spectrum that 2c, 2d, and 2e displayed red shift of more than 50 nm as compared to 2a and 2b, because of the presence of OH and OCH3 groups. In addition, the compounds（2b–e） showed no cytotoxicity on normal HUVEC cells as DA, although 2a displayed a 16% inhibition of proliferation at 40 μM following 48 h incubation. Their free radical-scavenging activities were evaluated using ABTS^＊＋ and superoxide anion assays and the mechanisms were proposed. It was found that they all exhibited higher activities than trolox, a recognized antioxidant. Amazingly, in the case of the hybrids（2a–e）, their activity was higher than that of HCAs while lower or comparable to that of DA, suggesting that there may be a ＂saturation effect＂ with the hybrid molecules in the antioxidant activities.
