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.     

Lipase‐catalyzed ethanolysis of soybean oil in a solvent‐free system using central composite design and response surface methodology

BACKGROUND: In this work we describe the synthesis of ethyl esters, commonly known as biodiesel, using refined soybean oil and ethanol in a solvent‐free system catalyzed by lipase from Thermomyces lanuginosus. Central composite design and response surface methodology (RSM) were employed to optimize the biodiesel synthesis parameters, which were: reaction time, temperature, substrate molar ratio, enzyme content, and added water, measured as percentage of yield conversion. RESULTS: The optimal conditions obtained were: temperature, 31.5 °C; reaction time, 7 h; substrate molar ratio, 7.5:1 ethanol:soybean oil; enzyme content, 15% (g enzyme g⁻¹ oil); added water, 4% (g water g⁻¹ oil). The experimental yield conversion obtained under these conditions was 96%, which is very close to the maximum predicted value of 94.4%. The reaction time‐course at the optimal values indicated that 5 h was necessary to obtain high yield conversions. CONCLUSION: A high yield conversion was obtained under the optimized conditions, with relative low enzyme content and short time. Comparison of predicted and experimental values showed good correspondence, implying that the empirical model derived from RSM can be used to adequately describe the relationship between the reaction parameters and the response (yield conversion) in lipase‐catalyzed biodiesel synthesis. Copyright © 2008 Society of Chemical Industry     

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%。     

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％。     

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%).     

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%。     

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。     

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.     

Optimization of acrylonitrile removal by activated carbon‐granular using response surface methodology

A statistical Box–Behnken design of experiments was performed to evaluate the effects of individual operating variables and their interactions on the acrylonitrile (AN) removal of C₀ = 100 mg/L as fixed input parameter. The variables examined in this study included activated carbon‐granular (AC) dosage, w, temperature, T, and time of contact, t. The significant variables and optimum conditions were identified (w = 4 g/L, T = 30°C, and t = 120 min with AN uptake of 23.97 mg/g of AC) from statistical analysis of the experimental results using response surface methodology (RSM).     

响应面法优化微生物诱导碳酸钙沉积培养基

通过响应面法对微生物诱导CaCO3沉积的培养基组分进行优化。结果表明,最适宜培养基配方为葡萄糖30g/L、大豆蛋白胨10g/L、尿素50g/L、硝酸钙0.5mol/L、吐温80体积分数0.05%以及氯化镍250μmol/L。葡萄糖浓度和尿素浓度、葡萄糖浓度和硝酸钙浓度、葡萄糖浓度和吐温浓度、硝酸钙浓度和吐温浓度以及尿素浓度和氯化镍浓度,对微生物诱导CaCO3沉淀量的影响有着比较显著的双因子效应。沉淀物CaCO3含有少量有机质,形成方解石型或方解石和球霰石混合晶型的CaCO3,其形貌和堆积密度随外界条件改变而不同。     

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。     

Preparation of mullite ceramic microfilter membranes using Response surface methodology based on central composite design

In this paper effect of free silica removal from mullite microfilter membranes using different sodium hydroxide (NaOH) concentrations at different temperatures and for different removal times was studied. The prepared membranes were subjected to XRD, SEM, porosity analysis, and mechanical strength measurement. Response surface methodology (RSM) based on central composite design (CCD) was used to design the experiments and analyze three operating parameters including; NaOH solution concentration, NaOH solution temperature and removal time. The optimum porosity of 49.4 was obtained with NaOH solution concentration of 35 wt% at temperature 75 °C and removal time equal to 8 h.Water flux and mechanical strength as important characteristics were measured for all the membranes. For the membrane with the optimum porosity, water flux, mechanical strength, and free silica removal percentage were 61.7 kg/m² h, 21.6 MPa, and 28.2%, respectively. The maximum rejection percentage was 97.2% and emulsion flux for this state was 15.6 kg/m² h at temperature 25 °C and cross flow velocity of 1.5 m/s.     

Optimization of mechanical properties of PP/Nanoclay/CaCO3 ternary nanocomposite using response surface methodology

Response surface method of experimental design was applied to optimize the mechanical properties of polypropylene (PP)/nanoclay/CaCO₃ hybrid ternary nanocomposite using three different levels of melt flow index (MFI) of PP, nanoclay, and CaCO₃ contents. The samples were prepared by melt mixing in a lab scale corotating twin screw extruder. The main effect of each parameter on the tensile modulus, tensile strength, and impact strength was extensively discussed. The structure of obtained nanocomposite was studied using X‐ray diffraction (XRD), atomic force microscopy (AFM), and scanning electron microscopy (SEM) techniques. Tensile modulus and impact resistance of prepared ternary nanocomposite were correlated to considered parameters using a second‐order polynomial model. Also, the optimum values of studied variables were determined using contour plots. The obtained results show that increasing the nanoclay and CaCO₃ contents improve the tensile modulus up to 45%, whereas the optimum value of impact strength, about 54%, is achieved at low concentrations of nanoclay (2 wt %) and CaCO₃ (8 wt %). © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

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.     

响应面分析法优化2-巯基苯并噻唑的合成

采用单因素考察和响应面分析法相结合,对高压下苯胺、CS2和硫磺合成2-巯基苯并噻唑的工艺条件进行优化。首先单因素考察法优化了搅拌、催化剂两个因素,再采用响应面分析法对升温速率、保温时间、原料配比3个关键因素进行优化分析,得到了合成2-巯基苯并噻唑的收率计算模型,并得到合成优化条件：反应在高温高压无搅拌条件下,以水杨酸为催化剂,水杨酸用量为苯胺质量的5%,原料摩尔配比为n(苯胺)∶n(S)∶n(CS2)=1∶1.05∶1.11,升温速率为1.93℃/min,保温时间为2.0 h,2-巯基苯并噻唑收率高达92.08%,使得反应时间缩短1.0 h,升温速率降低了0.77℃/min,收率提高了6.2%。     

Application of O3 and O3/H2O2 as post-treatment processes for color removal in swine wastewater from a membrane filtration system

This study was aimed to evaluate the use of ozone (O₃) alone and peroxone (a combination of ozone and hydrogen peroxide; O₃/H₂O₂) as post-treatment processes for color removal in swine wastewater from a membrane filtration system. Results showed that the application of ozone-alone process or the peroxone process could reduce both capital and operating costs compared to reverse osmosis (RO) treatment. Of the two oxidation processes, the ozone-alone process was the most effective for treating nanofiltration (NF)-filtered wastewater, while the peroxone process was the most effective for treating ultrafiltration (UF)-filtered wastewater.     

Arsenite removal from groundwater in a batch electrocoagulation process: Optimization through response surface methodology

In this study, influences of seven process variables such as initial pH (pH_i), applied current (i), operating time (t_EC), initial As(III) concentration (C_o), diameter of Fe ball anode (d_p), column height in the electrocoagulation (EC) reactor (h) and airflow rate (Q_air) for removal of As(III) from groundwater by a new air-fed fixed-bed EC reactor were evaluated with a response surface methodology (RSM). The proposed quadratic model fitted very well with the experimental data for the responses. The removal efficiencies and operating costs were determined to be 99% and 0.01 $/m³ at the optimum operating conditions (a pH_i of 8.5, 0.05 A, 4.94 min, d_p of 9.24 mm, h of 7.49 cm, Q_air of 9.98 L/min for 50 µg/L). This study clearly showed that the RSM in the EC process was a very suitable method to optimize the operating conditions at the target value of effluent As(III) concentration (10 µg/L) while keeping the operating cost to minimal and maximize the removal efficiency.