Degradation of simulated organic wastewater by advanced oxidation with oxidants generated from oxygen reduction

The degradation capacity of advanced oxidants generated from oxygen reduction was investigated in model effluent containing chlorobenzene, aniline and benzene through the advanced oxidation processes(AOPs). Intermediate products of the degradation process were determined by GC–MS, and they contributed to specify the degradation pathways of monoaromatic compounds. The study particularly focused on the influence of the dosage of the oxidant, pH and the initial concentration of organic compounds on the degradation effectiveness.When the dosage of oxidant was 4 wt% and the pH was 7, the maximum degradation rates of 74.83% chlorobenzene, 70.32% aniline and 37.69% benzene were achieved. Furthermore, microwave was applied to intensify the oxidation process under optimal operation conditions, and the degradation rates were increased to 87.85% chlorobenzene, 89.11% aniline and 39.03% benzene, respectively.     

侧光光纤引导的内源可见光催化降解亚甲基蓝(英文)

The side-glowing optical fibers (SOFs) were chosen as the conducting medium of endogenous light; and 20 mg·L-1 methylene blue was chosen as the target to be degraded. The SOF is made up of quartz core with a silicon cladding, which can emit light through side surface more uniformly and transmit light for longer distance to avoid attenuation of light by liquid medium. The filament lamp was chosen as visible light source. Different reaction conditions, such as the presence of optical fiber or not, the quantity of SOF, light irradiation intensity were tested by measuring the methylene blue degradation of methylene blue. The results show that suitable reaction conditions were 1.167 g·L-1 Ag + /TiO 2 with 7% (by mass) of Ag + doped in TiO 2 , and 500 roots of SOF (30 cm length in solution). The photocatalytic degradation efficiency under 300W lamp irradiation for 8h was about 97%. And the photocatalytic degradation efficiency of methylene blue degradation was proportional to SOF quantity, light irradiation intensity and catalytic dosage within a certain range. Compared with general UV and visible light SOFs could save a huge amount of energy and cost, in the potential applications in dealing with organic pollutants on a large scale.     

β-环糊精水中催化氧化肉桂醛合成天然苯甲醛(英文)

A facile and efficient procedure has been developed systematically for the oxidative cleavage of cinna-maldehyde to benzaldehyde by sodium hypochlorite with water as the only solvent in the presence of β-cyclodextrin (abbreviated as β-CD). Different factors influencing cinnamaldehyde oxidation e.g. reaction temperature, the amount of catalyst and oxidant, have been investigated. The yield of benzaldehyde reaches 76% under the optimum conditions (333 K, 4 h, molar ratio of cinnamaldehyde to β-CD is 1:1). Furthermore, a feasible reaction mecha-nism including the formation of benzaldehyde and the two main byproducts (phenylacetaldehyde and epoxide of cinnamaldehyde) has been proposed.     

Microwave-aided roasting for extraction of vanadium from stone coal

Low recovery rate,high energy consumption and serious pollution are existed in traditional processes of vanadium extraction.To seek a new process with high recovery rate,low energy consumption and less pollution discharge is of great significance.Microwave-aided roasting for vanadium extraction is an environmentally-friendly technology.Non-pollution roasting processes with additives following sodium carbonate and potassium carbonate,under microwave irradiation were investigated with stone coal.The valence variation of vanadium in oxidation roasting of the vanadium bearing stone coal was studied.The results showed that the oxidation process of vanadium was a stepwise process following V(Ⅲ)→V(Ⅳ)→V(Ⅴ).The roasted stone coal was characterized by XRD,SEM.Factors associated with extraction rate were investigated following roasting temperature,roasting time,microwave power,and amount of roasting additive.Comparing with conventional roasting process,the recovery rate was higher without air pollution.     

Microwave-assisted leaching of vanadium from vanadium slag with sulfuric acid

Microwave irradiation was used to investigate vanadium slag in place of traditional heating.Factors associated with vanadium extraction ratio were studied following the concentration of leaching agent,oxidant dosage,microwave power,microwave irradiation time and mass ratio of liquid to solid.Results indicated that leaching ratio based on microwave leaching at atmospheric pressure can get to 68.48% under the conditions following sulfuric acid concentration 30%,mass ratio of liquid to solid ratio 2∶1,mass ratio of vanadium slag to manganese dioxide dosage 25∶1.4,and microwave power 800W for 3.5 h at 95 ℃.While,leaching ratio based on microwave leaching under pressure was up to 45.79% under the conditions following sulfuric acid concentration 20%,mass ratio of liquid to solid ratio 2∶1,mass ratio of vanadium slag to manganese dioxide dosage 25∶0.9,microwave power 800W for 10 min.Results showed leaching based on microwave irradiation under pressure can shorten time 94.44% in comparison with that at atmospheric pressure,and the leaching extraction can improve about 20%.     

Characterization of pyrolytic lignins with different activities obtained from bio-oil

Pyrolytic lignin, the water-insoluble fraction in bio-oil, often shows a high content and has strong intermolecular interactions with other compounds in bio-oil. In order to obtain pure pyrolytic lignin and facilitate the utilization of aqueous phase obtained from water extraction of bio-oil, methanol–water extraction method was employed to further separate the bio-oil water-insoluble phase in this paper. Different technologies, including Fourier transform infrared spectroscopy, gel permeation chromatography, and nuclear magnetic resonance, were adopted to characterize the structures of pyrolytic lignins with different activities obtained through this method. Both the heating value and the polymerization degree of high-molecular-weight pyrolytic lignin were higher than those of low-molecular-weight pyrolytic lignin. The molecular weight distribution of high-molecular-weight pyrolytic lignin was relatively wider, among which the contents of dimers to pentamers all accounted for 12% –18%,while the low-molecular-weight pyrolytic lignin mainly consisted of trimers(75.38%). The pyrolytic lignins had similar basic structures, both of which contained syringyl and guaiacyl units, whereas the low-molecular-weight pyrolytic lignin had more abundant syringyl units, reactive carbonyl groups and hydroxyl groups. Meanwhile,thermogravimetric study revealed that the final char residue yield of low-molecular-weight pyrolytic lignin was lower than that of high-molecular-weight pyrolytic lignin.     

基于黏度的润滑油特性通用关联(英文)

Lubricating mineral base oils are normally extracted from lube-oil cuts with furfural solvent.Aromatic content in the raffinate phase from extraction process is an essential parameter that affects the quality of the lubricating base-oils.For determination of aromatic content by the usual ASTM D3238 method,density,refractive index and molecular weight of the raffinate are required.In this work,a new generalized correlation is developed for de-termination the aromatic content by using only the measured viscosity of lubricating oil.With a mole fraction of aromatic compounds,the kinematic viscosity may be obtained at any temperature between 60-100°C along with their molecular weight and refractive index.     

生物质超临界水部分氧化气化的能量过程分析(英文)

Partial oxidation gasification in supercritical water could produce fuel gases (such as H2, CO and CH4) and signif-icantly reduce the energy consumption. In this work, an energetic model was developed to analyze the partial oxidative gasification of biomass (glucose and lignin) in supercritical water and the related key factors on which gasification under autothermal condition depended upon. The results indicated that the oxidant equiva-lent ratio (ER) should be over 0.3 as the concern about energy balance but less than 0.6 as the concern about fuel gas production. Feedstocks such as glucose and lignin also had different energy recovery efficiency. For ma-terials which can be efficiently gasified, the partial oxidation might be a way for energy based on the combustion of fuel gases. Aromatic materials such as lignin and coal are more potential since partial oxidation could produce similar amount of fuel gases as direct gasification and offer additional energy. Energy recovered pays a key role to achieve an autothermal process. Keeping heat exchanger efficiency above 80%and heat transfer coefficient below 15 kJ·s?1 is necessary to maintain the autothermal status. The results also indicated that the biomass loading should be above 15%but under 20%for an autothermal gasification, since the increase of biomass loading could improve the energy supplied but decrease the efficiency of gasification and gaseous yields. In general, some specific conditions exist among different materials.     

Homopolymerization and copolymerization of phenyltrichlorosilane by sonochemical reductive coupling in the presence of sodium

Summary Soluble polymers have been prepared by the sonochemical reductive coupling of phenyltrichlorosilane in toluene in the presence of sodium. Copolymers of phenyltrichlorosilane with phenylmethyldi-chlorosilane were synthesized. The obtained products are of relatively low molecular weight (ˉM_n<10,000). Investigations by ²⁹ Si NMR, UV and by the kinetic studies of the iodine addition indicate that polymers consist of fused cyclopolysilanes with 40% content of strained rings (probably four-membered). Homopolymerization and copolymerization of n-hexyl-trichlorosilane and methyltrichlorosilane is compared with that of phenyltrichlorosilane. The former monomer yields soluble homopolymer and copolymers of relatively higher molecular weights than phenyltrichlorosilane. Methyltrichlorosilane yields usually insoluble products and only at a concentration below 20%, were soluble copolymers formed.     

用过氧化氢和乙酸对未经氢化处理的煤油进行直接氧化脱硫

The oxidative desulfurization of a real refinery feedstock (i.e., non-hydrotreated kerosene with total sulfur mass content of 0.16%) with a mixture of hydrogen peroxide and acetic acid was studied. The influences of various operating parameters including reaction temperature (T), acid to sulfur molar ratio (nacid/nS), and oxidant to sulfur molar ratio (nO/nS) on the sulfur removal of kerosene were investigated. The results revealed that an increase in the reaction temperature (T) and nacid/nS enhances the sulfur removal. Moreover, there is an optimum nO/nS related to the reaction temperature and the best sulfur removal could be obtained at nO/nS 8 and 23 for the reaction temperatures of 25 and 60&#61616;C, respectively. The maximum observed sulfur removal in the present oxidative desulfurization system was 83.3%.     

微波强化Fenton氧化法降解水中阴离子表面活性剂的研究

采用微波/Fenton氧化法降解水中阴离子表面活性剂十二烷基苯磺酸钠(SDBS).比较了微波辐射、Fenton氧化和微波/Fenton氧化3种方法对SDBS的降解效果;考察了H2O2与Fe2+的摩尔比、Fenton试剂投加量、微波功率、溶液pH、反应时间等因素对SDBS降解效果的影响.结果表明,微波辐射可以强化Fenton试剂对SDBS的氧化作用,明显提高SDBS的降解效率,显著缩短反应时间,并能促进SDBS的矿质化,提高TOC去除率;微波辐射与Fenton氧化对SDBS的矿质化具有明显的协同效应.微波/Fenton氧化法降解SDBS的最佳工艺条件为:pH为3,n(H2O2):n(Fe2+)为195,Fenton试剂投加量为140mmol·L-1,微波功率为500W,反应时间为10min.在此工艺条件下,SDBS和TOC去除率分别可达99%和68%.     

木质素氧化降解制备酚类化合物研究进展

木质素作为可再生资源被认为是最具有潜力的苯酚替代物用于制备酚醛树脂,作为制浆造纸工业副产品,木质素来源丰富且低毒,但是木质素具有三维空间网状结构,分子量大,反应活性低。到目前为止,很多方法(如热化学转化、热裂解、液化、超临界水处理、氧化、还原和水解等)用于将大分子木质素降解为小分子物质,得到的小分子物质中含有重要的化工中间体可以用来制备多种产品。本论文综述了木质素氧化降解得到酚类物质的研究现状,并展望了木质素工业化的应用前景。     

木质素氧化降解制备酚类化合物研究进展（英文）

木质素作为可再生资源被认为是最具有潜力的苯酚替代物用于制备酚醛树脂,作为制浆造纸工业副产品,木质素来源丰富且低毒,但是木质素具有三维空间网状结构,分子量大,反应活性低。到目前为止,很多方法（如热化学转化、热裂解、液化、超临界水处理、氧化、还原和水解等）用于将大分子木质素降解为小分子物质,得到的小分子物质中含有重要的化工中间体可以用来制备多种产品。本论文综述了木质素氧化降解得到酚类物质的研究现状,并展望了木质素工业化的应用前景。     

TiO_2光催化氧化降解高沸醇木质素的研究

高沸醇木质素是利用高沸醇溶剂(HBS)法制备纸浆过程中获得的木质素,具有较高的化学活性。在TiO2光催化条件下,研究紫外光降解高沸醇木质素的结构变化,通过紫外分光光度法测定溶液吸光度来判断不同因素条件下高沸醇木质素降解的程度,包括TiO2加入量、光照强度、光照时间、氧化剂用量等。对降解产物进行红外谱图和GC-MS分析,结果表明木质素本身具有复杂的结构形式,经过降解后可以得到香草醛、愈创木基衍生物等小分子物质。     

SO_4~(2-)/ZrO_2固体酸催化氧化降解木质素的因素分析

以固体超强酸为催化剂,过氧化氢为氧化剂降解高沸醇竹子木质素。探讨了反应时间、溶剂配比、固体酸用量和反应温度等因素对降解程度的影响。结果表明,当反应时间4h,反应温度80℃,DMF与水的体积比为1∶2,酸加入量为木质素的4%时,在硫酸亚铁促催化的情况下,降解效果最佳。并利用红外光谱和气相色谱-质谱联用对降解产物进行分析。可知,固体酸催化降解木质素可以得到小分子产物,含有明显的醛酸类物质。     

微波法处理印染废水的试验研究

文章以刚果红作为处理对象,探讨了初始浓度、活性炭加入量、pH、微波功率和微波照射时间对处理效果的影响。研究结果表明,含氮染料在水溶液中能在粉末活性炭协助下被微波快速降解:投加2.0 g/L的活性炭,对25 mL的50 mg/L微波照射1.5 min,能达到76.33%的去除率;在同样的条件下,降解率随着活性炭投加量和微波照射时间的增加而上升,最高可达91.78%。     

Preparation of Enzymatically Liberated Lignin From Naturally Brown-Rotted Wood

Abstract

Brown rots from various conifer species were sieved (&lt60 mesh) and alcohol and water extracted to yield crude preparations of “naturally enzymatically liberated lignin” (NEL) containing 61.4–91.7Z of Klason plus soluble lignin and 0.5–2.6% ash. The <200 mesh fractions were generally best represented in <60 mesh preparations and contained highest Klason plus soluble lignin percentages (86.6–92.2Z). Carbohydrates varied in these fractions between 3.7 and 8.0% and contained glucose, mannose, galactose, xylose, and arablnose, decreasing generally in that order. Methoxyl contents were lower and oxygen contents higher than in milled wood lignin (MWL) suggesting some oxidative demethylation. Treatment with Cuoxaa increased Klason plus soluble lignin content to 93.0–95.8%, decreased carbohydrates to 1.7–5.0%, increased methoxyl and decreased oxygen contents by removal of a part of cellulose and hemicelluloses and of more degraded lignin fractions. Infrared spectra of the preparations showed a small increase in carboxyls and possibly in phenyl conjugated double bonds and a decrease in aromatic structures, as compared with MWL. In thermo-gravimetric analysis the curves for MWL and Cuoxam treated NEL preparations (CuNEL) were very similar when run in nitrogen. In air, however, MWL lost weight appreciably slower. In differential scanning calorimetry in air and oxygen, MWL exhibited less intensive exotherms below 500°C than NEL and left higher amounts of char. The different behaviour of MWL in thermal analysis in oxidative atmosphere was explained by its lower molecular weight and corresponding low glass transition temperature (Tg). It was concluded that preparation of enzymatically liberated lignin from natural brown rot represents a convenient procedure where larger amounts of lignin are required; such lignins are somewhat more degraded than MWL in terms of functional groups present, but are possibly closer to protolignin in terms of molecular weight.     

微波辅助法合成高分子量聚丙烯酰胺

以丙烯酰胺(AM)为单体,水为溶剂,过硫酸铵(APS)和偶氮二异丁基脒盐酸盐(AIBA)为复合引发体系,采用微波辅助法制备聚丙烯酰胺(PAM)。研究了微波辐照功率、辐照时间、单体浓度、引发剂用量对聚丙烯酰胺分子量和单体残留率的影响,采用红外光谱(FT-IR)表征了聚合物产物结构,最后考察了剪切作用对PAM性能的影响。结果表明:采用微波辅助法制备的PAM反应时间短、能耗低、分子量高、单体残留率低;当微波功率为100 W,辐照时间为8 min,单体浓度为25%,引发剂用量为0.05%时产物分子量可达1050×104,并且单体残余量低;PAM的降解随着剪切时间的延长和剪切速度的加快而加快。     

微波-载铜活性炭催化氧化降解腐殖酸

以粉末活性炭(PAC)和颗粒活性炭(GAC)为载体,采用浸渍焙烧法制备了负载铜氧化物的活性炭催化剂,考察了其表面结构、元素组成及BET参数;以腐殖酸模拟废水为对象,研究了微波?载铜活性炭催化氧化降解腐殖酸的效果和影响因素,探讨了微波?催化氧化协同H2O2降解腐殖酸的机理. 结果表明,载铜活性炭比未负载铜的活性炭对腐殖酸的降解率更高,且Cu/PAC的催化效果远优于Cu/GAC,两种催化剂最佳的微波?催化氧化条件分别为Cu/PAC投加量1 g/L, H2O2投加量0.9 mL/L, pH=3,微波功率400 W,微波时间4 min和Cu/GAC投加量8 g/L, H2O2投加量1.5 mL/L, pH=6,微波功率400 W,微波时间4 min,该条件下腐殖酸的去除率分别为93.91%和91.59%. 微波、H2O2和催化剂协同作用对腐殖酸高效降解有决定性作用.     

Effect of gamma ray irradiation on processability and properties of ultra high molecular weight polyethylene

Ultra high molecular weight polyethylene (UHMWPE) has been widely used in many fields due to its outstanding properties. However, it is virtually impossible to be processed by the conventional method due to its high molecular weight and very tight chain entanglement. To solve this problem, a new method was proposed in this article. Gamma ray irradiation was adopted to cause the oxidation degradation of UHMWPE. The degraded products which generated in situ and dispersed in UHMWPE evenly were utilized as self‐lubricant and heat transfer intermediary. These low molecular weight fractions thus could improve the processability of UHMWPE. The effects of irradiation dose on the structure and properties of UHMWPE were studied by fourier transform infrared (FTIR) spectroscopy, gel content measurement, wide angle x‐ray diffraction (WAXD), Haake torque rheometer, mechanical properties measurements and sliding wear tests. The experimental results showed that gamma ray irradiation caused oxidation degradation of UHMWPE. Under appropriate irradiation condition, the processability of UHMWPE could be improved substantially while most of its excellent properties could be kept. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011