影响光催化超滤膜反应器降解Acid Blue 7的因素研究

设计研制了一种光催化超滤膜反应器,并选用一种颗粒状纳米级TiO2作光催化剂,对染料AcidBlue7光氧化降解进行了研究。影响染料降解的因素包括:错流速度、催化剂浓度、染料初始浓度、溶液的pH值以及曝气条件。研究结果发现,光催化超滤反应器对染料废水处理具有较高的处理效果,且颗粒状光催化剂能够实现良好分离。

Photocatalytic degradation of Acid Blue 62 over CuO-SnO_2 nanocomposite photocatalyst under simulated sunlight

The novel CuO-SnO2 nanocomposite oxide photocatalysts were prepared by simple co-precipitation method, and characterized by X- ray diffraction, transmission electron microscopy, N2 adsorption-desorption measurement and UV-Vis diffuse reflectance spectroscopy. The photocatalytic activities of CuO-SnO2, evaluated using the photodegradation of Acid Blue 62 as a probe reaction under the irradiation of Xenon light, were also found to be related to the calcination temperature and the molar ratio of Cu to Sn. The maximum photocatalytic activity of the CuO-SnO2 photocatalyst was observed to be calcined at 500~C for 3 h （the molar ratio of Cu to Sn was 1：1） due to the sample with good crystallization and high surface area. It also showed much higher photocatalytic activity in treatment dye wastewater under simulated sunlight irradiation compared to Degussa P25 TiO2.

Photocatalytic Degradation of Acid Blue 62 over La/I/TiO2 Nanocomposite Photocatalyst under Simulated Sunlight

In order to explore the photocatalytic activity of the lanthanum and iodine co-doped TiO2,the degradation of acid blue 62 as a probe reaction under simulated sunlight irradiattion was investigated.A novel visible-light-activated La/I/TiO2 nanocomposition photocatalyst was prepared using precipitation-diping method,and characterized by X-ray diffraction（XRD）,transmission electron microscopy（TEM）and UV-Vis diffuse reflectance spectroscopy（UV-Vis-DRS）.The photocatalytic efficiency of La/I/TiO2 was evaluated by the photodegradation of reactive acid blue 62 as a probe reaction under simulated sunlight irradiationt.Photocatalytic experiment results shows that the La/I co-doped TiO2 catalyst has higher photocatalytic activity than the standard Degussa P25,La-doped TiO2 and I-doped TiO2 photocatalysts under simulated sunlight irradiation,and the way of La/I co-doping extends the absorption spectra of TiO2 and shifts the absorption edge remarkably toward longer wavelength.

Kinetic analysis of experiment data for the formation of C.I.Acid Blue 9 leuco compound

A systematic study of the synthesis of C.I.Acid Blue 9 leuco compound in water is reported.The kinetic analysis of experimental data for the condensation reaction between 2-formylbenzenesulfonic acid sodium and N-ethyl-N-(3'-sulfonic acid benzyl) aniline obtained at four different temperatures ranging between 85 and 100°C is discussed.It is shown that the reaction followed second-order rate kinetics.The overall rate constant(k) increased with the increase of temperature.On the basis of the value of k,activation energy(E_a) of the reaction was evaluated.Importantly,it is found that reactant concentration has great effect on the formation of C.I.Acid Blue 9 leuco compound,implying that it is not enough to improve the conversion of N-ethyl-N-(3'-sulfonic acid benzyl) aniline by only prolonging reaction time in the late period of the reaction.

Acid Blue 25 adsorption on base treated Shorea dasyphylla sawdust:Kinetic,isotherm,thermodynamic and spectroscopic analysis

The potential of base treated Shorea dasyphylla（BTSD） sawdust for Acid Blue 25（AB 25） adsorption was investigated in a batch adsorption process.Various physiochemical parameters such as pH,stirring rate,dosage,concentration,contact time and temperature were studied.The adsorbent was characterized with Fourier transform infrared spectrophotometer,scanning electron microscope and Brunauer,Emmett and Teller analysis.The optimum conditions for AB 25 adsorption were pH 2,stirring rate 500 r/min,adsorbent dosage 0.10 g and contact time 60 min.The pseudo second-order model showed the best conformity to the kinetic data.The equilibrium adsorption of AB 25 was described by Freundlich and Langmuir,with the latter found to agree well with the isotherm model.The maximum monolayer adsorption capacity of BTSD was 24.39 mg/g at 300 K,estimated from the Langmuir model.Thermodynamic parameters such as Gibbs free energy,enthalpy and entropy were determined.It was found that AB 25 adsorption was spontaneous and exothermic.

Modeling and Thermodynamics of Methylene Blue and Acid Blue 80 Adsorption onto Potato Residue Based Activated Carbon

A study was made on the adsorption kinetics and thermodynamics of methylene blue（MB） and acid blue 80（AB80） onto powder of activated carbon（PAC） prepared by chemical method from dry potato residue（DPR）. The PAC was characterized by N2 adsorption-desorption isotherms analysis and Scanning electron microscopy. The ma- ximum adsorption capacities of PAC for MB and AB80 at 303 K are 532.19 and 156.22 mg/g, respectively. The re- suits indicate that the adsorption kinetics of the selected dyes on PAC is well-described by the pseudo-second order model. And their thermodynamic data were analyzed via the isotherms of Langmuir, Freundlich, Redlich-Peterson, Toth and Sips, and the thermodynamic parameters were calculated. The results show that PAC is a fast and effective adsorbent for removing the cationic dyes from aqueous solutions.

Cu(Ⅱ),Ni(Ⅱ)Complexation with Acid Alizarine Blue B in the Presence of Cetyltrimethylammonium Bromide

The coordination reactions of Cu（Ⅱ） and Ni（Ⅱ） with acid alizarine blue B （AABB） in the presence of cetyltrimethylammonium bromide （CTAB） micelle were investigated using the microsurface adsorptionspectral correction technique （MSASC）. The aggregation of AABB on CTAB followed the Langmuir isothermal adsorption law. The enrichment of AABB on CTAB sensitized the complexation between Cu（Ⅱ） or Ni（Ⅱ）and AABB. The binding ratio of AABB to CTAB was 1：2.5, and monomeric aggregate, AABB2CTAB5, was formed with an adsorption constant of 5.95×10^5 at 20 ℃ or 2.48×10^5 at 40 ℃. In the ternary complexation, the ratio of AABB：Cu and AABB：Ni were 1：1 and 1：2.5, respectively. Two types of aggregates, Cu2.AABB2·CTAB80 and Ni5.AABB2.CTAB80, were formed.

Photo-catalytic decolourisation of toxic dye with N-doped titania:A case study with Acid Blue 25

Dyes are one of the hazardous water pollutants.Toxic Acid Blue 25,an anthraquinonic dye,has been decolourised by photo-catalysing it with nitrogen doped titania in aqueous medium.The photo catalyst was prepared from 15% TiCl 3 and 25% aqueous NH 3 solution as precursor.XRD and TEM revealed the formation of well crystalline anatase phase having particle size in the nano-range.BET surface area of the sample was higher than that of pure anatase TiO 2.DRS showed higher absorption of radiation in visible range compared to pure anatase TiO 2.XPS revealed the presence of nitrogen in N-Ti-O environment.The experimental parameters,namely,photocatalyst dose,initial dye concentration as well as solution pH influence the decolourisation process.At pH 3.0,the N-TiO 2 could decolourise almost 100% Acid Blue 25 within one hour.The influence of N-TiO 2 dose,initial concentration of Acid Blue 25 and solution pH on adsorption-desorption equilibrium is also studied.The adsorption process follows Lagergren first order kinetic

Kinetic Spectrophotometric Determination of Trace Titanium(Ⅳ) Based on Oxidation Discoloration of Acid Chrome Blue K with Hydrogen Peroxide

A simple and sensitive kinetic spectrophotometric method for the determination of trace amounts of titanium(IV),based upon the catalytic effect of Ti(IV) on the oxidation of acid chrome blue K (ACBK) by hydrogen peroxide in 0.002 mol/L sulfuric acid,is described. The reaction rate is monitored spectrophotometrically by measuring the decrease in absorbance of ACBK at 524 nm. The detection limit of the method is 1.01×10?9 g/mL,and the linear range is 0-0.048 mg/L. The influence of acidity,concentration of reactants,reaction time,reaction temperature and for-eign ions is also discussed. The optimum reaction conditions were established and some kinetic parameters determined. The apparent activation energy of the catalytic reaction is 5.32 kJ/mol. The relative standard deviation for the determi-nation of titanium(IV) at the concentration of 0.048 mg/L is calculated to be 1.31% (n = 11). In combination with sol-vent extraction separation,the method has been successfully applied to the determination of trace titanium(IV) in human hair,plant matter,tea and rock samples. The results are in good agreement with the certified values with the relative standard deviations (RSD) of 1.4%-3.5%.

Flow-injection Spectrophotometric Determination of Uric Acid in Urine via Prussian Blue Reaction

A simple and sensitive flow injection（FI） spectrophotometric method was reported for the determination of uric acid based on the reduction of Fe（III）/ferricyanide in the presence of uric acid. The in situ reduced ions reacted with unreduced portion of ferricyanide/Fe（III） to form soluble Prussian blue, which was monitored at an absorption wavelength of 735 nm. The optimized conditions allow a linear calibration graph in a concentration range of 1―100 μmol/L. The relative standard deviation was in a range of 0.5%―2.5%, with a detection limit（3σ blank） of 0.3 μmol/L and a sampling frequency of 60 injection/h was obtained. The effect of common substances present in human physiological fluids on the determination of uric acid was examined. The method was applied to determining uric acid in human urine samples with the recoveries in a range of 96%―105%. The results agree well with those by spectrophotometric reference method at a confidence level of 95%. Spectrophotometric procedures for uric acid determination in clinical samples were reviewed briefly.

Catalytic-kinetic spectrophotometric determination of vanadium (V) based on the Celestine blue-bromate-vanadium (V)-citric acid reaction

A novel sensitive and relatively selective kinetic method is presented for the determination of V（V） based on its catalytic effect on the oxidation reaction of Celestine blue by potassium bromate in the presence of citric acid as an activator. The reaction was monitored spectropho- tometrically by measuring the decrease in absorbance of Celestine blue at a maximum absorption wavelength of 540 nm between 0.5 and 9 min （the fixed-time method） in an H3PO4 medium at 45℃. The effect of various parameters such as concentrations of H3PO4, citric acid, potassium bromate and Celestine blue, ionic strength, reaction temperature and time on the rate of V（V） catalyzed reaction was studied. The method is free from the most interferences, especially from large amounts of V（IV）. The decrease in absorbance is proportional to the concentration of V（V） over the entire concentration range tested （0.025-1.25 lag.mL^-1） with a detection limit of 6.80 tag.L^-1 （according to statistical 3Sblank/k criterion） and a coefficient of variation （CV） of 1.78% （for ten replicate measurements at 95% confidence level）. The proposed method suffers from a few interferences such as Cr（VI） and Hg（Ⅱ） ions. The method was successfully applied to the determination of V（V） in river water, lake water, tap water, natural drinking water samples and a certified standard reference material such as SRM-1640 with satis- factory results. The vanadium contents of natural water samples were detected by using both linear calibration curve and standard addition curve methods. The recoveries of spiked vanadium （V） into the certified standard water sample were found to be quantitative, and the reproducibility was satisfactory. It was observed that the results of the SRM 1640 were in good agreement with the certified value.

Resonance Rayleigh Scattering and Resonance Nonlinear Scattering Methods for Determination of Methylene Blue with 12-Tungstophosphoric Acid

In a pH=0.65―1.5 NaAc-HCl medium, methylene blue（MB） reacts with 12-tungstophosphoric acid （TPA） by virtue of electrostatic attraction and hydrophobic force to form a 3：2 ion-association complex. As a result, the intensities of resonance Rayleigh scattering（RRS）, second-order scattering（SOS） and frequency doubling scatte- ring（FDS） are enhanced greatly. The maximum scattering wavelengths of RRS, SOS and FDS are located at 316, 647 and 311 nm. The increments of scattering intensity（△I） are directly proportional to the concentration of MB in a certain range. The methods exhibited high sensitivity, and the detection limits（3s） for MB are 2.3 ng/mL（RRS method）, 5.6 ng/mL（SOS method） and 6.4 ng/mL（FDS method）, respectively. The effects of coexisting substances have been examined, and the results indicate that the methods have good selectivity. Based on the above researches, a new spectral method for the determination of trace amounts of MB has been developed. It can be applied to the determination of MB in human serum, and the recoveries are 97.5%―105.0%. The results are in good agreement with those obtained by the pharmacopoeia method. In this work, the optimum conditions of the reaction and the influencing factors were investigated. In addition, the reaction mechanism and the reasons of the enhancement of resonance light scattering were discussed.

弱酸性蓝AS 染料排放的废盐制碳基吸附剂及利用

将染料弱酸性蓝AS(AS)生产排放的含盐废水喷雾干燥后制成废盐,再将其有机污染物煅烧制备成类活性炭吸附剂(LAC),用于AS染料生产过程中产生的洗涤废水的吸附脱色净化,同时回收粗盐NaCl可循环用于AS工业生产的盐析过程。对LAC进行吸附过程动力学、热力学研究,并研究AS染料废水溶液初始浓度、温度及pH对吸附性能的影响。在40 mg/L的AS染料废水中,温度为318 K的条件下,平衡吸附量为29.22 mg/g。在酸性及温度较高时吸附能力较强。Langmuir等温线方程能更好拟合吸附实验结果。另外,采用一锅混合法,添加四水合乙酸镁对LAC进行改性,改性后的吸附剂LACMg0.75比表面积较LAC提升了近5倍,饱和吸附量能够达到550.02 mg/g,较LAC提升了接近20倍。

Agent Blue: A Secret Military and Environmental Chemical Weapon Used for Food Denial in South Vietnam during the Vietnam Civil War (1962-1965)

During the last 60 years, the southern Vietnam environment and Vietnamese living in the Mekong Delta have bio-accumulated arsenic from natural and anthropic (Vietnam Civil War (1962-1965)) sources via their drinking water (groundwater from tube wells) and food supply leading to an increasing risk of chronic poisoning over time. A synthesis and analysis of publications and records is presented to document the Republic of Vietnam (RV), the official name of the South Vietnam Government, and United States (US) militaries contribution to arsenic levels and toxic spikes in the Vietnam Mekong Delta groundwater. During the Vietnam Civil War, Agent Blue, in powder form, was shipped to Port Saigon, via the Saigon River, and transported to the Tan Son Nhut Air Force base during the Vietnam Civil War. After the official start of the American-Vietnam War (1965-1973) the tactical herbicides were re-routed to Bien Hoa Air Force base (1965 to 1971). Approximately 3.2 million liters of Agent Blue (468,008 kg As) was sprayed or dumped by the RV military with the assistance and support of the Central Intelligence (CIA), US Army and US Navy, during the 1962-1965 Khai Huang (Hamlet) Program. A portion of an additional 4.6 million liters of Agent Blue (664,392 kg of As) was sprayed between 1962 and 1965 by the US Air Force as part of Operation Ranch Hand and prior to the official start of the American-Vietnam War in August 1964. Operation Rand Hand began in 1962 and ended in 1971. The Institute of Medicine estimated a total of 7.8 million liters (1,132,400 kg As) of Agent Blue was applied to southern Vietnam landscape from 1962 to 1971. This total includes both the 1962 to 1965 RV Khai Huang program with the assistance of the CIA, US Army and US Navy, and the total Agent Blue applied by US Air Force Operation Ranch Hand from 1962 to 1971. The primary objective of this study was to document how Agent Blue, the arsenic-based herbicide, became a secret US military and environmental chemical weapon used by the RV and US militaries in southern Vietnam during the Vietnam Civil War years (1962-1965). This assessment found that the anthropic arsenic, including Agent Blue, added a toxic burden to the Mekong Delta soils, surface water, groundwater, drinking water, food supply, and human health. However, there are missing details regarding political decisions and a full accounting of the geographic locations sprayed and amount of Agent Blue used. Vietnam War Archives have paper correspondence and RV herbicide spray records that shed greater light on this period. These records are over 50 years old and need to be electronically scanned, stored, and made available for additional historical analyses.

Dawson型磷钨酸季铵盐对亚甲基蓝废水的光催化降解

采用共沉淀法制备了一种新的Dawson型磷钨酸十二烷基三甲基铵盐[C_(15)H_(34)N]_(6)P_(2)W_(18)O_(62)·2H_(2)O,通过红外光谱、热重分析、EDS能谱和扫描电镜对其组成、结构及形貌进行了表征,采用BET氮气吸附测定了比表面积。以亚甲基蓝为模拟染料废水,研究其光催化性能和降解亚甲基蓝的动力学行为,研究结果表明:14 mg/L的50 mL亚甲基蓝模拟染料废水在pH为4的条件下,加入20 mg催化剂,35 W紫外灯光照2 h,亚甲基蓝降解率达到95.0%,光催化降解反应符合一级动力学模型,动力学方程为:lnρ0/ρt=0.051 7t,降解速率常数为0.051 7 min-1,半衰期为13.4 min,表明Dawson型磷钨酸十二烷基三甲基铵对亚甲基蓝的降解具有高效的光催化活性,且重复使用催化性能好,循环5次后的降解率达到94.53%。

熊去氧胆酸治疗新生儿高胆红素血症的文献分析

目的Meta分析熊去氧胆酸(ursodeoxycholic acid,UDCA)治疗新生儿高胆红素血症的临床疗效。方法在中国知网、万方、维普、Pub Med/MEDLINE及Scopus等中英文数据库中检索,筛选出2010—2023年期间有关UDCA用于高胆红素血症新生儿治疗的随机对照试验,对文献质量评价,提取相关文献研究资料,采用Review Manager 5.4统计软件对筛选出的文献进行Meta分析,以探讨UDCA联合蓝光治疗新生儿高胆红素血症的临床疗效。结果筛出符合研究的6篇随机临床试验文献,包括1篇中文与5篇英文文献。文献中的对照组新生儿总计371例,均行蓝光照射疗法;试验组总计439例,均行UDCA+蓝光照射疗法。文献的I2值均>50%且P值均<0.10时,表示存在异质性,采用随机效应模型;经Meta分析,试验组新生儿在治疗后不同时间段的总胆红素水平均明显低于对照组(P<0.05);且试验组光疗持续时间也明显短于对照组(MD=-19.15,95%CI:-20.80~-17.50,P<0.01)。结论相较于传统的蓝光疗法,联合UDCA治疗能进一步促进高胆红素血症患儿的胆红素水平下降,缩短光疗时间。

钛白副产硫酸亚铁中镁离子的含量分析

本文研究以酸性铬蓝K为指示剂,以草酸铵为沉淀剂排除Fe^(2+)干扰,用紫外分光光度法测定钛白副产物FeSO_(4)中的Mg^(2+)的含量。实验结果表明,Mg-铬蓝K的最大吸收峰波长为540nm,最佳pH值为9.5,最佳沉淀剂草酸铵的用量为10mL。经加标回收的方法验证了方法的可行性,测出钛白副产物FeSO_(4)中Mg^(2+)含量为1.07%。

改性菠萝皮对水中亚甲基蓝的吸附性能研究

以农业废弃物菠萝皮为原料,使用柠檬酸对菠萝皮粉末分别进行超声波改性和热改性,探究了改性菠萝皮对亚甲基蓝的去除效果。通过扫描电子显微镜(SEM)和傅里叶变换红外光谱(FTIR)对改性前后菠萝皮孔隙和表面结构进行表征,同时考察了改性前后菠萝皮的投加量、pH值、反应时间和染料质量浓度对吸附亚甲基蓝的影响。结果表明:经过柠檬酸改性后的菠萝皮表面引入了羧基官能团,对亚甲基蓝的吸附效果显著增加。在吸附剂用量为1.2 g·L^(-1)、起始p H为6.52、改性时间90 min、起始质量浓度为100 mg·L^(-1)的条件下,柠檬酸超声波改性菠萝皮(PA-US)和柠檬酸热改性菠萝皮(PA-TM)对亚甲基蓝的去除率分别可以达到65%、98%。吸附等温线的研究表明,PA-US和PA-TM吸附过程均符合Langmuir等温模型,说明该吸附过程为单分子层吸附,且对亚甲基蓝的最大吸附量分别为56.05 mg·g^(-1)和333.33 mg·g^(-1),与未改性菠萝皮(PA)的最大吸附量相比,分别提高了1.39、8.08倍。吸附动力学研究表明,PA-US和PA-TM对亚甲基蓝的吸附均符合准二级动力学方程模型。由吸附等温线和动力学模型结果可以推断该吸附过程属于化学吸附。

再生纤维素微球的制备及其吸附亚甲基蓝和叶酸负载

以微晶纤维素(MCC)的尿素/NaOH溶液为分散相,通过乳液法制备了不同粒径的再生纤维素微球(RCM),考察了RCM对亚甲基蓝吸附行为,并探讨了再生纤维素微球对叶酸(FA)的负载性能。扫描电子显微镜(SEM)结果表明,制备的RCM表面结构粗糙,内部呈一定的中空结构;X射线衍射(XRD)和傅里叶变换红外光谱(FT-IR)结果表明,RCM晶型由Ⅰ型变为Ⅱ型,微球的粒径随转速增大而减小,转速由400 r/min提高至转速1200 r/min时,粒径从286μm降至27μm,减小了约90.56%;随水油体积比(V(MCC)∶V(LP))的减小而减小,V(MCC)∶V(LP)从1∶3降至1∶7时,粒径从311μm降至54μm,减小了约82.64%;随乳化剂质量分数(w(span-80))的增加而减小,当w(span-80)为0.5%时,粒径约为276μm,增大w(span-80)至2.5%时,粒径降至52μm左右,减小了约81.16%。RCM用于吸附亚甲基蓝时,72 h,吸附达到平衡;pH值为10时,吸附能力最强,吸附量为6.11 mg/g;当RCM用量为50 mg时,单位吸附量达到最大值,为4.78 mg/g,符合拟一级吸附动力学模型,吸附过程主要为物理吸附。再生纤维素负载叶酸微球(FCM)的具体负载率可达到98.8%,FCM有效提高了叶酸的储藏稳定性,5 d保留率为74.71%,相对于纯叶酸相比提高了34.7%。

P(N-MAAm)水凝胶吸附剂的制备及其对亚甲基蓝染料吸附性能的研究

将N-羟甲基丙烯酰胺引入聚丙烯酸-丙烯酰胺体系,采用“一锅煮”法合成了P(N-MAAm)水凝胶。结果显示,当n(AM)∶n(AA)为1∶4、中和度为60%、交联剂用量为0.4%、n(AM)∶n(N-MA)=9.5∶0.5时,P(N-MAAm)对亚甲基蓝(MB)的实测最大吸附量可达1603.77 mg/g;降低环境温度、盐度,提高pH有利于P(N-MAAm)水凝胶吸附MB;吸附动力学曲线符合准一级动力学模型(R_(1)>0.999),吸附等温线更符合Langmuir模型(R_(L)>0.981),P(N-MAAm)水凝胶对MB的吸附过程更倾向于是物理吸附,并且可能是多分子层吸附。P(N-MAAm)水凝胶通过Langmuir模型拟合计算得到理论最大吸附量为3170.27 mg/g;具有良好的可重复利用性能,5次吸附-解吸循环后对MB的去除率仍高于95%。