Optimization of UV curable acrylated polyester-polyurethane/polysiloxane ceramer coatings using a response surface methodology

Dual UV and moisture curable acrylated polyester, organic/inorganic hybrid coatings were prepared using a coupling agent and tetraethylorthosilicate (TEOS) oligomers. An acrylated polyester resin based on adipic acid, neopentyl glycol, trimethylolpropane, and acrylic acid was synthesized. TEOS oligomers were prepared through the hydrolysis and condensation of TEOS with water and 3-(triethoxysilyl)propylisocyanate (TEOSPI) was used as the coupling agent between organic and inorganic phases. Trimethylolpropane triacrylate (TMPTA) was used as a reactive diluent. The formulations were cured into films by utilizing UV, followed by moisture curing. The resultant coatings were evaluated in terms of tensile and fracture toughness properties by using ANOVA. Effects of the TEOS oligomers, TEOSPI, and TMPTA on the free radical UV polymerization kinetics were also investigated. The experiments were planned according to the three-factor, three-level Box-Behnken design. Reaction kinetics, fracture toughness, and tensile properties were evaluated in terms of the concentrations of TEOS oligomers, TEOSPI, and TMPTA concentrations. Presented at the 82nd Annual Meeting of the Federation of Societies for Coatings Technology, October 25–27, 2004, in Chicago, IL.     

Optimization of sulfamethoxazole degradation by TiO2/hydroxyapatite composite under ultraviolet irradiation using response surface methodology

A titanium dioxide/hydroxyapatite/ultraviolet (TiO₂/HAP/UV-A) system was used to remove sulfamethoxazole (SMX) from water in a second-order response surface methodology (RSM) experiment with a three-level Box-Behnken design (BBD) for optimization. The effects of both the primary and secondary interaction effects of three photocatalytic reaction variables were examined: the concentration of SMX (X₁), dose of TiO₂/HAP composite (X₂), and UV intensity (X₃). The UV intensity and TiO₂/HAP dose significantly influence the SMX and total organic carbon (TOC) removal (p<0.001). However, the SMX and TOC removal are enhanced with increasing TiO₂/HAP dose up to certain levels, and further increases in the TiO₂/HAP dose result in adverse effects due to hydroxyl radical scavenging at higher catalyst concentrations. Complete removal of SMX was achieved upon UV-A irradiation for 180min. Under optimal conditions, 51.2% of the TOC was removed, indicating the formation of intermediate products during SMX degradation. The optimal ratio of SMX (mg L^?1) to TiO₂/HAP (g L^?1) to UV (W/L) was 5.4145 mg L^?1 to 1.4351 g L^?1 to 18W for both SMX and TOC removal. By comparison with actual applications, the experimental results were found to be in good agreement with the model’s predictions, with mean results for SMX and TOC removal of 99.89% and 51.01%, respectively.     

中心组合设计响应面法优化烟梗提取工艺

为了提高造纸法再造烟叶原料烟梗的提取率,以水为溶剂,以提取时间、提取温度、液料比进行3因素5水平的中心组合设计,采用响应面法优化烟梗提取参数,建立数学模型并进行验证。结果表明,最优工艺条件为：提取温度59℃,提取时间45min,液料比9．1：1,对最佳工艺条件提取率的预测值为38．33％,实测值为38．03％,相对误差仅为0．78％。     

中心组合设计响应面法优化烟叶碎片萃取工艺

为了提高造纸法再造烟叶原料中烟叶碎片的萃取率,以水为溶剂,以萃取时间、萃取温度、液料比进行3因素5水平中心组合设计,采用响应面法优化烟叶碎片萃取参数,建立数学模型,并进行实验验证。结果表明,最优工艺条件为:萃取温度69℃,萃取时间39 min,液料比10.6∶1(mL∶g);得到了数学预测模型,对最佳工艺条件萃取率的预测值为40.46%,与实测值(40.22%)的相对误差仅为0.59%。     

星点设计-效应面优化乳化交联法制备恩诺沙星壳聚糖微球

以平均粒径、载药量、包封率及总评归一值为评价指标,运用星点设计考察芯材比、油水相比、壳聚糖浓度对微球制备的影响,对结果进行二项式拟合,效应面法选取最佳工艺条件并进行预测分析。结果显示,最佳工艺条件为：油水相比为4.2∶1,壳聚糖浓度为2%,交联时间为3.5 h。在此条件下,制得的微球粒径均一,球形圆整,平均粒径为7.21μm,包封率为61.34%,载药量为70.12%。体外释放行为符合Higuchi方程,2 h和24 h时累积释放率分别为32%和84%。     

Optimization of photooxidative removal of p-nitrophenol in a spinning disc photoreactor using response surface methodology

In this article, response surface methodology (RSM) was used to obtain optimum conditions for removal of p-nitrophenol (PNP) by UV/H₂O₂ process using spinning disk photoreactor (SDP). For this purpose, the effect of five independent variables, the initial concentration of PNP, the initial concentration of H₂O₂, pH, solution volume, and irradiation time on the PNP removal percent, was investigated. Central composite design, one of the response surface techniques used for process optimization. The results showed a good agreement between the RSM predicted and experimental data with “R²” and “Adjusted R²” of 0.9692 and 0.9480, respectively. In addition, “Predicted R²” of 0.8909 is in reasonable agreement with “Adjusted R²” of 0.9488. At optimal conditions, that is, PNP concentration of 20.78?mg L^?1, H₂O₂ concentration of 1355.83?mg L^?1, solution volume of 566.08?mL, irradiation time of 12.30?min, and pH of 4.59 the removal percent predicted by RSM is 100% which has good correspondence with its experimental value (98.67%).     

Optimization of CO2 capture process with aqueous amines using response surface methodology

Amine is one of candidate solvents that can be used for CO₂ recovery from the flue gas by conventional chemical absorption/desorption process. In this work, we analyzed the impact of different amine absorbents and their concentrations, the absorber and stripper column heights and the operating conditions on the cost of CO₂ recovery plant for post-combustion CO₂ removal. For each amine solvent, the optimum number of stages for the absorber and stripper columns, and the optimum absorbent concentration, i.e., the ones that give the minimum cost for CO₂ removed, is determined by response surface optimization. Our results suggest that CO₂ recovery with 48 wt% DGA requires the lowest CO₂ removal cost of $43.06/ton of CO₂ with the following design and operating conditions: a 20-stage absorber column and a 7-stage stripper column, 26 m³/h of solvent circulation rate, 1903 kW of reboiler duty, and 99°C as the regenerator-inlet temperature.     

UV、UV/H2O2及UV/O3法去除饮用水中有机残留物的应用效果比较

分别采用UV、UV/H2O2及UV/O3对饮用水进行深度氧化处理,考察水样中药物残留（复方新诺明及碘普罗胺）和燃油添加剂残留（MTBE及TAME）的消解情况。     

响应面法优化凹凸棒土-CoFe2O4磁性复合材料的制备工艺

针对粉末状凹凸棒土在实际应用中难以固液分离的问题,在其表面负载CoFe_2O_4磁性颗粒,以单宁酸吸附量作为指标,借助响应面法优化了凹凸棒土-CoFe_2O_4磁性复合材料(ACMC)的制备工艺。结果表明,各因素对吸附量的影响程度顺序为:CoFe_2O_4与凹凸棒土质量比反应时间 pH值反应温度,最佳制备工艺条件是CoFe_2O_4与凹凸棒土质量比为1.07, pH值为11.66,反应温度为74.11℃,反应时间为4 h。所制备出的最优ACMC对单宁酸的吸附量可达140.54 mg/g,与系统预测值(143.96 mg/g)接近,说明响应面法优化结果可靠。     

Optimization of rotating-jet electrospinning process using response surface methodology

Rotating-jet electrospinning method is one of the efficient techniques for producing aligned nanofibers. This paper reports an accurate investigation on the influence of collector diameter (CD), voltage, polymer concentration (PC), and insulator length (IL) of spinneret on the degree of fiber alignment (DFA), production rate of fiber, and fiber diameter. The polymer solution was a mixture of polyacrylonitrile and N,N-dimethylformamide. The ranges of independent variables were 20–50 cm for CD, 10–22 kV for voltage, 13–19 wt% for PC, and 0.5–3 cm for IL. To minimize the number of required experiments for a complete evaluation, response surface methodology (RSM) and central composite rotatable design were applied by means of Expert Design Software. After defining the upper and lower bounds of the above independent variables in the software, 30 unique experiments were delivered. The recommended operating conditions by the software were exactly applied in the laboratory and the corresponding values for the DFA, production rate, and fiber diameter were measured. The nanofiber morphology was examined by scanning electron microscopy (SEM). By applying the least-squares method in the DX7.0.0 software, well-fitting polynomial correlations to the experimental results were obtained, and using these correlations, the influence of independent variables and responses was comprehensively studied. Finally, the best values of independent variables for optimizing the responses were determined using RSM.     

Application of mesoporous magnetic carbon composite for reactive dyes removal: Process optimization using response surface methodology

Discharging the effluents of textile wastewaters into potable water resources can endanger the ecosystem, due to their reactivity, toxicity, and chemical stability. In this research, the application of powder activated carbon modified with magnetite nanoparticles (PAC-MNPs) as an adsorbent for removal of reactive dyes (Reactive black 5 (RB5) and reactive red 120 (RR120)) was studied in a batch system. The adsorption performance was evaluated as a function of temperature, contact time and different adsorbent and adsorbate concentrations. The levels of factors were statistically optimized using Box-Behnken Design (BBD) from the response surface methodology (RSM) to maximize the efficiency of the system. The adsorption process of both dyes was fit with the pseudo-second order kinetic and Langmuir isotherm models. The identified optimum conditions of adsorption were 38.7 °C, 46.3 min, 0.8 g/L and 102 mg/L for temperature, contact time, adsorbent dose, and initial dyes concentration, respectively. According to the Langmuir isotherm, the maximum sorption capacities of 175.4 and 172.4 mg/g were obtained for RB5 and RR120, respectively. Thermodynamics studies indicated that the adsorption process of the reactive dyes was spontaneous, feasible, and endothermic. After five cycles, the adsorption efficiency was around 84 and 83% for RB5 and RR120, respectively. A high value of desorption was achieved, suggesting that the PAC-MNPs have a good potential in regeneration and reusability, and also can be effectively utilized in industrial applications. PAC-MNPs also show a good anti-interference potential for removal of reactive dyes in dye-industry wastewaters.     

Optimization of biodiesel production process in a continuous microchannel using response surface methodology

We assessed the biodiesel production process in a continuous microchannel through preparation of a heterogeneous catalyst (CaO/MgO) from demineralized water plant sediment. This mixed oxide catalyst was used for transesterification of rapeseed oil as feedstock by methanol to produce biodiesel fuel at various conditions. A microchannel, utilized as a novel reactor, was applied to convert rapeseed oil into biodiesel in multiple steps. The effects of the process variables, such as catalyst concentration, methanol to oil volume ratio, n-hexane to oil volume ratio, and reaction temperature on the purity of biodiesel, were carefully investigated. Box-Behnken experimental design was employed to obtain the maximum purity of biodiesel response surface methodology. The optimum condition for the production of biodiesel was the following: catalyst concentration of 7.875 wt%, methanol to oil volume ratio of 1.75: 3, n-hexane to oil volume ratio of 0.575: 1, and reaction temperature of 70 °C.     

H2O2 / O3, H2O2 / UV And H2O2 / Fe2+ Processes For The Oxidation Of Hazardous Wastes

Activated hydrogen peroxide produces very reactive OH-radicals which destroy hazardous contaminants in water. The principles and different methods of activation are described. Results from laboratory studies show the numerous applications of this new technology. A successful scaleup of laboratory tests to an industrial level is discussed. Finally, a cost estimate for treating different types of water with hydrogen peroxide is presented.     

响应面法优化苦参碱粗品的结晶纯化过程

通过Box-Behnken试验设计,系统地考察了料液比、温度及结晶时间3个因素对苦参碱结晶收率的影响,并运用响应面法对建立的二次回归模型进行了综合分析。结果表明,当料液比为1∶28.78、温度为59.19℃、时间为30min时,苦参碱的结晶收率最大,其值为97.16%。     

Optimization of the n-hexane isomerization process using response surface methodology

Isomerization reactions on commercial zirconium sulfate catalyst are investigated in order to determine influence of hydrogen/feed ratio, space velocity and temperature on n-hexane conversion. Investigated range of inlet parameters includes values that are applied in the industrial practice of the isomerization process. Box–Behnken experimental design was carried out in order to optimize n-hexane isomerization process. Statistical analysis of experimental data was performed to obtain second order polynomial model and the optimum conditions were determined: hydrogen/feed ratio of 6, space velocity of 2 h⁻¹ and temperature of 170 °C. At optimum conditions conversion of n-hexane was 70 wt.%. In addition, temperature dependency of product composition was investigated at optimum values of hydrogen/feed ratio and space velocity. Obtained results show that methylpentanes greatly depend on temperature, unlike dimethylbutanes, in the studied range from 130 to 170 °C. Isomer that was produced in highest quantities was 2-methylpentane, while 3-methylpentane forms in somewhat smaller amounts. 2,2- and 2,3-dimethylbutanes, which contribute the most to the octane number value, are formed in relatively small quantities, amounting to less than 10 wt.% of the total amount of isomers formed.     

Optimization of supercritical carbon dioxide removal of lipid and cholesterol from goat placenta using response surface methodology

Supercritical CO₂ (SC-CO₂) extraction was applied to remove lipid and cholesterol from freeze-dried goat placenta. A response surface methodology (RSM) was employed to optimize the extraction parameters. The effects of pressure, temperature, flow rate of CO₂ and extraction time on the yields of lipid and cholesterol were investigated. Response surface analysis showed that the data were adequately fitted to second-order polynomial model. The independent variables, quadratics of pressure and extraction time, and the interaction between pressure and temperature had significant effects on the yields of lipid and cholesterol, respectively. The optimum parameters within the experimental range of the variables were 34.6 MPa, 35.3 °C, 29.1 min with a CO₂ flow rate of 18.2 L/h. Under such condition, the yields of lipid and cholesterol were predicted to be 21.02% and 8.46 mg/g, respectively. Furthermore, the removal efficiency of cholesterol by SC-CO₂ was higher than those achieved by Soxhlet and Folch extraction methods.     

UV/O3/H2O2化学氧化活性艳蓝KN-R

以商品染料活性艳蓝KN-R为研究对象,利用VC／O3/H2O2技术进行氧化处理。考察了染料溶液在此过程中的pH、电导率、COD、TOC和吸光度的变化。经过70min的氧化过程,结果表明,溶液的pH降低、电导率不断升高、色度去除率达98．9％,溶液的COD和TOC去除率分别为47％和5％。VC／O3/H2O2技术与UV/H2O2氧化法相比,UV／O3/H2O2能显著去除染料溶液的色度。     

Optimization of the activity of CaO/Al2O3 catalyst for biodiesel production using response surface methodology

In this work the response surface methodology (RSM) in conjunction with the central composite design (CCD) were used to optimize the activity of CaO/Al₂O₃ solid catalysts for the production of biodiesel. In order to measure the catalyst activity, we used palm oil as a representative raw material for the conversion to biodiesel. The biodiesel production was carried out in a batch laboratory scale reactor. The results showed that both the calcination temperature and the amount of calcium oxide loaded on the support had significant positive effects on the biodiesel yield. The maximum basicity and biodiesel yield obtained were about 194 μmol/g and 94%, respectively. Overall, the catalyst showed high performance at moderate operating conditions and its activity was maintained after two cycles.     

乙酰甲胺磷UV-TiO_2/类Fenton光催化降解过程的响应面法优化

为提高乙酰甲胺磷农药残留降解效率,在单因素实验的基础上,应用响应面法对乙酰甲胺磷纳米TiO2-UV/类Fenton光催化降解过程中纳米TiO2添加量、农药初始浓度、添加类Fenton试剂及反应时间等因素进行了优化,建立并验证了所得到的预测模型。结果表明,乙酰甲胺磷纳米TiO2-UV/类Fenton光催化降解过程可应用所建立的二次多项回归拟合方程进行预测,模型拟合良好;同时,除类Fenton组成比例与乙酰甲胺磷初始浓度之间无交互作用外,其他各因素之间均存在显著交互作用;计算得到的优化工艺条件为:纳米TiO2添加量0.1 g/L,H2O2∶Cu2+添加比例26.34,乙酰甲胺磷初始浓度23.09 mg/L,光照时间25.42 min,在此条件下,乙酰甲胺磷降解率预测值为100.414%,验证值为99.99%。说明响应面法对筛选光催化降解工艺条件,提高光催化降解效率是十分有效的。     

Optimization of biodegradation of natural fiber (Chorchorus capsularis): HDPE composite using response surface methodology

Deterioration in mechano-chemical properties due to biodegradation of prepared high-density polyethylene and jute eco-friendly polymer composites in soil and pure microbial culture was investigated through a programmed experimental design. The composite was prepared by compression molding process and then subjected to biodegradation. The biodegradation process was studied using face-centered central composite experimental design protocol and the model equations were formulated to assess the effects of jute fiber loading and treatment time on biodegradation (expressed as percentage loss in composite weight and tensile strength) of the composite. The optimal process conditions corresponding to maximum biodegradation were evaluated for both the media using response surface methodology. The maximum weight losses were 25.8924 % for soil medium and 12.4167 % for pure culture medium at 30 wt% jute fiber loading and 6 months of treatment time. At the derived optimal conditions, the effects of biodegradation were also manifested as 84.2621 and 70.9842 % losses in the tensile strength in soil and pure culture media, respectively. The present study, thus, demonstrates that HDPE/jute composite polymer can be appreciably biodegradable and the extent of biodegradation is more pronounced in soil medium compared to pure microbial culture. The analyses of the evolution of chemical composition and microstructure of the composite before and after biodegradation were performed through Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy. FTIR spectra indicated significant changes in chemical composition due to biodegradation, while the ruptured structure of the treated composite revealed notable changes in the morphology due to biodegradation.