基于O_3/UV法在线COD检测的气体溶解量估计方法

针对臭氧协同紫外方法 (O_3/UV)检测化学需氧量(COD)时存在溶解性气体影响测量精度的问题,提出了一种COD检测过程中气体溶解量的估计方法,用于对COD检测模型的补偿。采集不同浓度的COD标准水样在消解过程中的测量数据和实验分析数据,基于PLS-LSSVMs建立溶解氧量和溶解二氧化碳量的估计模型,将模型的输出作为COD检测模型的补偿项。实验结果表明,基于PLS-LSSVMs建立的模型比PLS或者LSSVMs单独建立的模型估计精度高。采用溶解气体量估计模型进行补偿后的O_3/UV法检测COD与国标法测量结果相对误差均小于5%。对提高O_3/UV法检测COD精度具有重要意义。     

臭氧光催化氧化工艺处理工业废水的对比研究

在pH=3、H₂O₂与硝基酚类化合物物质的量比为3∶1、Fe(Ⅲ)与硝基酚类化合物物质的量比为0.1∶1的条件下，以特征污染物硝基酚类化合物的降解率及TOC去除率为评价指标，对比了UV/O₃、UV/O₃/H₂O₂、UV/O₃/Fe(Ⅲ)3种臭氧光催化氧化工艺处理DDNP生产废水的效果。实验结果表明，反应时间1 h时经3种工艺处理后的DDNP生产废水出水的色度和TOC均可达到《兵器工业水污染物排放标准火工药剂》(GB 14470.2—2002)排放标准；UV/O₃体系中H₂O₂或Fe(Ⅲ)的加入对硝基酚类化合物的降解影响不大，而对TOC去除率具有明显的提升。实验条件下UV/O₃/Fe(Ⅲ)工艺的处理效果最优，反应时间1 h时其出水无色，TOC去除率为96%,m(BOD₅)/m(COD)由0.06提升到0.46，且出水硝基酚类化合...     

Matlab在气相反应动力学实验数据中的应用

基于实验室自行搭建的流动管装置，用于气相反应动力学反应速率常数的测量。选用异戊酸叶醇酯与O₃反应体系，将Matlab软件编写程序用于异戊酸叶醇酯与O₃的气相反应动力学实验数据处理与绘图，根据最小二乘线性拟合得到反应速率常数为1.99×10^-16 cm³·molecule^-1·s^-1,所得结果准确度高，避免了传统数据处理方法所带来的人为误差，具有方便、快速与直观等优点，可以补充和改进物理化学实验的教学。     

磁混凝-UV/O3深度处理诺氟沙星制药废水工艺研究

以某诺氟沙星制药企业生物处理单元出水为试验用水，探究磁混凝-UV/O₃工艺对制药废水深度处理的效果。磁混凝试验中，COD去除方面，聚合硫酸铝铁(PFS)絮凝效果明显优于聚合氯化铝(PAC)和聚合硫酸铝铁(PAFS);COD、色度、浊度去除效果方面，阳离子聚丙酰胺(CPAM)助凝效果明显优于阴离子聚丙酰胺(APAM)及非离子聚丙酰胺(NPAM);48μm磁粉投加量为300 mg/L,PFS投加量为400 mg/L,CPAM投加量为6 mg/L，投加顺序为两段式磁粉+PFS—CPAM。在UV/O₃实验中，调整UV/O₃工艺：臭氧投加量为26 mg/min，初始pH为9，初始温度为20℃，氧化时间为60 min。经磁混凝-UV/O₃联合工艺处理后，出水COD小于30 mg/L，色度小于2倍，浊度低于1 NTU，满足当地《贾鲁河流域水污染物排放标准》(DB 41/908—2014)。     

O3/H2O2催化氧化技术深度处理工业园区印染废水

为了获得一种高效低成本处理印染废水的工艺,采用O₃催化氧化、O₃/H₂O₂催化氧化两组氧化体系处理工业园区印染废水并对比处理效果和成本投入,考察反应时间、H₂O₂投加量、O₃气体流量和O₃气体浓度对工业园区印染废水处理效果的影响。结果表明：采用O₃/H₂O₂催化氧化处理工艺,在进水流量为1.2 m³/h、回流量为2.5 m³/h、O₃气体流量为1.0 m³/h、O₃进气浓度为16 g/m³、反应时间为60 min的运行条件下,COD由42.03 mg/L降至30.23 mg/L,去除率为28.08%;UV₂₅₄由0.497 cm^-1降至0.315 cm^-1     

基于操作域划分的聚丙烯熔融指数软测量

讨论了如何建立聚丙烯熔融指数软测量模型及模型更新问题.首先根据聚丙烯反应器中的氢气浓度划分操作域,对于每个操作域,用一种新的非线性部分最小二乘方法建立熔融指数软测量子模型,然后将各个子模型进行组合,建立全局模型.为了使模型适应过程的变化,提出一种递推非线性部分最小二乘算法,利用新获得的数据对原模型进行更新.同时基于滑动窗方法,提出模型在线估计和更新策略.实际应用结果表明,模型取得了很好的估计性能,计算精度满足工业生产的实际要求.     

不同高级氧化技术降解邻苯二甲酸二甲酯的对比研究

以邻苯二甲酸二甲酯(DMP)为目标污染物,研究了3种高级氧化技术(O₃氧化、UV/H₂O₂、Fenton法)对水中DMP的去除效果,采用单因素研究法考察DMP降解的影响因素,采用响应面分析法优化以寻得每种工艺的最佳工艺条件,并对3种处理技术的最佳去除效果及经济成本进行了对比分析。结果表明,对初始浓度为50 mg/L的DMP, O₃氧化法反应的最佳条件为：O₃浓度15 mg/L、pH值9;UV/H₂O₂反应的最佳条件为：UV功率300 W、H₂O₂投加量为180 mg/L、pH值为5;Fenton法最佳条件为Fe₂SO₄浓度60 mg/L,pH值为3,H₂O₂投加量为180 mg/L。响应面优化分析得出3种高级氧化技术对DMP的降解效果依次为：UV/H₂O₂>...     

基于臭氧与超声氧化降低页岩气压裂返排液COD

针对页岩气压裂返排液化学需氧量（COD）高,难以直接排放的问题,研究了臭氧氧化（O₃）、超声氧化（US）和臭氧与超声联用氧化（O₃+US）三种方式降低页岩气压裂返排液COD的效果。结果表明：O₃+US因能产生更多的自由基而具有更好的降低COD效果。O₃+US联用氧化返排液过程中,首先是臭氧直接氧化有机污染物生成醛酮等物质,然后再是自由基氧化降解,返排液颜色会出现特征变化。另外研究了水样pH、超声波功率、催化剂种类和加量、反应时间等因素对O₃+US联用氧化降低COD的影响,结果表明其降低COD的效率随pH的增大而减小,随超声波功率的增大先增大后减小,随作用时间的延长而增大。综合考虑,推荐降低页岩气压裂返排液COD的氧化条件为：臭氧质量浓度42mg/L、pH为2.5左右、超声波功率800W、催化剂MnO₂加量0.45g/L、反应时间100min,处理后COD降低68.17%。同时,降解动力学拟合分析显示MnO₂催化下O₃+US联用氧化降低页岩气压裂返排液COD的过程更符合二级动力学特征。     

园林废弃物生物炭/O3曝气法预处理亚甲基蓝染整废水

利用多种园林废弃物制备生物炭并联合O₃曝气法预处理亚甲基蓝(MB)染整废水，考察由椰壳、香樟叶、茶叶及狗尾牙草等园林废弃物制备而成的生物炭和O₃的投加量、反应p H值对亚甲基蓝染料废水的去除率影响情况。结果显示，当生物炭投加量选取2g·L^-1的椰壳生物炭、O₃13mg·min^-1、p H值为4时，所得最优COD去除率为61.2%，废水UV₂₅₄最高去除率可达35.15%,BOD₅/COD值最高可升至0.53，发光细菌抑制率最低降至38.1%。本方法可有效地降解废水中的有机物分子不饱和键和芳香环结构，显著提高废水的可生化性且降低其生物毒性，具有一定的实际推广应用价值。     

工业制SO3气体浓度实时检测及多元非线性回归建模

工业接触法制SO₃气体浓度高、腐蚀性强、交叉影响大,高精度实时检测困难,且原料流量与SO₃浓度的关系尚不明确,参数调节依赖经验。针对上述问题,采用AO2电化学氧传感器设计了一种工业制SO₃气体浓度的实时检测系统,并构建了输入空气、SO₂流量与输出SO₃浓度的多元非线性回归模型。SO₃气体浓度实时检测系统主要包括AO2电化学氧传感器、传感器调理电路、AD620放大电路及ADS1256 A/D转换电路,通过检测SO₃发生装置输入空气与输出混合气体中O₂浓度的毫伏级变化,间接测量SO₃浓度,避免了其他敏感气体的交叉影响,实验结果表明检测系统的检测时间为27s,灵敏度为111mV/%,偏差小于0.18%,稳定性良好,证明了检测系统的有效性;利用响应面法建立了预测SO₃浓度的三次多项式非线性回归模型,对该模型进行方差分析后结果显著,测试后均方误差（MSE）为0.0007174,相关系数（R²）为0.9929,拟合度好、预测精度高。     

Integrated ozone–photo–Fenton process for the removal of pollutant from industrial wastewater

The use of hybrid advanced oxidation processes(AOPs) for the removal of pollutants from industrial effluents has been extensively studied in recent literature. The aim of this study is to compare the performance of the photo,Fenton, photo-Fenton and ozone–photo–Fenton processes in terms of color removal and chemical oxygen demand(COD) removal of distillery industrial effluent together with the associated electrical energy per order. It was observed from the experimental results that the O_3/UV/Fe~(2 +)/H_2O_2 process yielded a 100% color and95.50% COD removals with electrical energy per order of 0.015 k W·h·m~(-3) compared to all other combinations of the AOPs. The effects of various operating parameters such as H_2O_2 and Fe~(2+) concentration, effluent pH, COD concentration and UV power on the removal of color, COD and electrical energy per order for the ozone–photo–Fenton process was critically studied and reported. The color and COD removals were analyzed using a UV/Vis spectrometer and closed reflux method.     

光催化辅助高浓度臭氧循环工艺降解对氯苯酚及协同机理

针对臭氧(O3)降解对氯苯酚(4-CP)中效率有限且尾气排放高的问题,采用光催化辅助高浓度臭氧循环工艺并对TiO2浓度、循环气量以及pH值等因素进行研究,结合对苯醌变化及猝灭剂试验分析其协同机理.循环气量为2.0 L·min-1,TiO2投加量为250 mg·L-1时,O3/TiO2/UV体系的降解动力学系数为0.29...     

SIMULTANEOUS REACTIONS OF CO, NO, O2 AND NH3 ON Pt/γA12O3 CATALYST IN A TUBULAR REACTOR

A reliable method to continuously monitor NH₃ in a gas stream containing CO—NO—O₂ and H₂O has been developed. The method is based on a quantitative oxidation of NH₃ to NO on a Pt catalyst. The extent of this reaction is affected by temperature, excess oxygen present, and space-velocity. There is a significant effect of inlet O₂ concentration on extent of various reactions in the CO—NO—O₂—H₂O system on a Pt/γAl₂O₃ catalyst. At fixed space-velocity and catalyst temperature, and for fixed reactor inlet concentrations of CO and NO. there is negligible CO—NO reaction either in the absence of oxygen or in the presence of excess oxygen. However, short of the stoichiometric amount of O₂ required for CO oxidation, there is appreciable CO—NO (and possibly also CO—NO—H₂O) reaction whose extent increases with increasing oxygen concentration. This increase is especially dramatic in a narrow window of O₂: concentrations near the stoichiometric point. Interestingly enough, near the stoichiometric point, self-sustained isothermal oscillations in the outlet CO and NO concentrations are also observed (Subramaniam and Varma. submitted for publication)     

电芬顿-臭氧一体化工艺处理船舶生活污水

高级氧化技术是一种新型、绿色的水处理工艺,通过各种强化技术更快、更多地产生具有强氧化性的羟基自由基,使其与废水中的有机物发生链式反应,从而将废水中的有机物快速高效降解为无害的无机盐。采用两种典型的高级氧化技术：电芬顿和臭氧,一体化处理船舶生活污水,研究结果表明：在电流密度20 mA/cm²,芬顿试剂n（H₂O₂）：n（Fe²⁺）=3：1,C（Fe²⁺）为0.01 mol/L,氧气速率2 L/min,臭氧投加量6 g/L时,电芬顿-臭氧一体化装置能有效降解船舶生活污水中的污染物,当处理时间为120 min时,对COD去除率可达86.4%。     

Catalytic effect of platinum on the kinetics of carbon oxidation by NO2 and O2

The effect of a commercial Pt/Al₂O₃ catalyst on the oxidation by NO₂ and O₂ of a model soot (carbon black) in conditions close to automotive exhaust gas aftertreatment is investigated. Isothermal oxidations of a physical mixture of carbon black and catalyst in a fixed bed reactor were performed in the temperature range 300–450 °C. The experimental results indicate that no significant effect of the Pt catalyst on the direct oxidation of carbon by O₂ and NO₂ is observed. However, in presence of NO₂–O₂ mixture, it is found that besides the well established catalytic reoxidation of NO into NO₂, Pt also exerts a catalytic effect on the cooperative carbon–NO₂–O₂ oxidation reaction. An overall mechanism involving the formation of atomic oxygen over Pt sites followed by its transfer to the carbon surface is established. Thus, the presence of Pt catalyst increases the surface concentration of –C(O) complexes which then react with NO₂ leading to an enhanced carbon consumption. The resulting kinetic equation allows to model more precisely the catalytic regeneration of soot traps for automotive applications.     

A Method to Obtain Gas-PDMS Membrane Interaction Parameters for UNIQUAC Model

The recovery or capture of one or more components from gas mixture by membrane separation has become a research focus in recent years. This study investigates the gas-membrane solution equilibrium, for which Henry’s law is not applicable if the gas phase is a mixture. This problem can be solved by using UNIQUAC model to calculate the activity coefficient of gas dissolved in the membrane. A method was proposed in this study to obtain the gas-membrane interaction parameter for UNIQUAC model. By the experiments of gas permeation through polydimethylsiloxane PDMS membrane, the solubility coefficients of some gases (N₂, CO₂, CH₄) were measured. Through non-linear fitting UNIQUAC model to the experimental results from this study and in literature (H₂, O₂, C₃H₈), the gas-membrane interaction parameters for these gases were obtained. Based on these parameters, the activity coefficients of the dissolved gas were calculated by UNIQUAC model, and their values agree well with the experimental data. These results confirm the feasibility and effectiveness of the proposed method, which makes it possible to better predict gas-membrane solution equilibrium.     

In situ IR and pulse reaction studies on the active oxygen species over SrF2/Nd2O3 catalyst for oxidative coupling of methane

Pulse reaction method and in situ IR spectroscopy were used to characterize the active oxygen species for oxidative coupling of methane (OCM) over SrF₂/Nd₂O₃ catalyst. It was found that OCM activity of the catalyst was very low in the absence of gas phase oxygen, which indicated that lattice oxygen species contributed little to the yield of C₂ hydrocarbons. IR band of superoxide species (O₂⁻) was detected on the O₂-preadsorbed SrF₂/Nd₂O₃. The substitution of ¹⁸O₂ isotope for ¹⁶O₂ caused the IR band of O₂⁻ at 1128 cm⁻¹ to shift to lower wavenumbers (1094 and 1062 cm⁻¹), consistent with the assignment of the spectra to the O₂⁻ species. A good correlation between the rate of disappearance of surface O₂⁻ and the rate of formation of gas phase C₂H₄ was observed upon interaction of CH₄ with O₂-preadsorbed catalyst at 700 °C. The O₂⁻ species was also observed on the catalyst under working condition. These results suggest that O₂⁻ species is the active oxygen species for OCM reaction on SrF₂/Nd₂O₃ catalyst.     

Degradation of neonicotinoid insecticides by different advanced oxidation processes and studying the effect of ozone on TiO2 photocatalysis

Although some studies concerning the effect of pH and ozone dosage on TiO₂ photocatalysis (O₂/TiO₂/UV) have already been published, no complete investigation and explanation of the effects of both parameters on photocatalytic ozonation (O₃/TiO₂/UV) have been carried out. Aqueous solutions of neonicotinoid insecticides (thiacloprid and imidacloprid) were chosen as a degradation medium, since they exhibit a high threat for aquatic systems and it is of great importance to find an effective method for their elimination from the environment. In preliminary stability tests, thiacloprid showed higher photo- and chemical stability compared to imidacloprid, therefore its degradation was studied in detail. To assess the suitability of various treatments for degradation and mineralization of thiacloprid in water at different pH values and ozone dosages, we applied ozonation (O₃) and three different photochemical advanced oxidation processes, namely ozonation, coupled with UV radiation (O₃/UV), O₃/TiO₂/UV and O₂/TiO₂/UV. Light source emitting mainly in UVA range was applied in all three processes. The photocatalytic ozonation (O₃/TiO₂/UV) was found to be the most efficient process irrespective of pH. The synergistic effect of ozone and TiO₂ photocatalysis was noticed at acidic and neutral pH, but the synergism was lost at basic pH, probably due to faster self-decompositon of ozone under alkaline conditions. At acidic pH, also the oxidation of chloride anions to chlorate(V) was noticed in O₃/TiO₂/UV and in O₃/UV processes. By plotting the disappearance rate constants of thiacloprid degradation in O₃/TiO₂/UV and O₃/UV systems as a function of the flow rate of ozone, the synergistic effect of ozone was undoubtedly proven. The slope of the linear fit in case of O₃/TiO₂/UV process was considerably steeper than in case of O₃/UV, which would not happen in absence of synergistic effect. The linearity in O₃/TiO₂/UV system was lost only at very high flow rates of ozone.