响应曲面法优化电催化降解PNP废水运行条件

针对废水高毒性、可生化性差等特点,采用三维电催化氧化法处理PNP废水,重点考察电压、初始pH和反应时间对废水COD去除率的影响,并采用BBD响应曲面法优化运行条件.结果表明:运行条件的显著顺序为反应时间＞电压＞初始pH,其中反应时间和电压之间的交互作用显著.在电压为26.32 V、反应时间为80.63 min、pH为4...     

响应曲面法优化电化学耦合体系预处理焦化废水

针对焦化废水有机负荷高、生物抑制性强等特点,采用电化学耦合体系进行预处理研究。以原厂污泥制备污泥活性炭（AC）粒子电极,并表征其表面含有羟基、醚基、羰基、羧基等多种含氧官能团,有利于催化反应。考察阴极曝气对预处理的影响及降解机理分析,结果表明曝气有利于开环反应。基于Central-Composite响应曲面法考察外加电压、初始pH、曝气量、AC填充比等因素对预处理的单独影响及交互作用,并以COD去除率为评价指标。结果表明：各因子的影响显著性顺序为AC填充比 > 初始pH > 曝气量 > 外加电压,其中初始pH和曝气量的交互作用较显著。最佳运行条件为外加电压15 V,初始pH 5.8,曝气量12.4 ml·min^-1,AC填充比50%,反应时间45 min,此时COD去除率达46.8%。废水COD由4700 mg·L^-1降至2500 mg·L^-1,色度去除率为50%,B/C由0.05增至0.37,可生化性明显提高,且能耗较低为0.971 kW·h·（kg COD）^-1。研究表明,采用电化学技术能有效预处理焦化废水,并提高可生化性。     

响应曲面法对纳滤膜分离废水中山梨醇的研究

为同时研究多个试验变量对NT102纳滤膜分离血液制品废水中山梨醇的影响,并得到最优试验条件,利用响应曲面法对NT102纳滤膜分离废水中山梨醇的试验进行设计,以温度、压力和回收率作为影响因素,将截留率作为响应指标,采用Box-Behnken组合设计法建立数学模型,研究温度、压力和回收率对山梨醇截留率的影响.模型优化所得的...     

响应曲面设计优化混凝处理乐果农药废水

采用Design Expert 7.1软件设计分析实验数据,通过中心复合试验设计和响应面分析法研究复合絮凝剂聚合氯化铝锌(PAZC)和聚合氯化铝(PAC)混凝处理乐果农药废水。以溶液pH值和絮凝剂用量为考察因素,分别以COD和总磷去除率为考察指标,选用最佳数学模型描述考察指标和考察因素之间的数学关系,得到了二次响应曲面模型,模型具有较高的回归率(R20.98),与实验结果吻合程度较高在其最佳pH值分别为11.80和11.79,PAZC和PAC投加量分别为11.97和12.27mg?L-1的反应条件下,COD去除率(63.1%和43.5%)及总磷去除率(89.3%和79.3%)达到最高值。     

响应曲面法优化锡酸钠合成工艺

以锡为原材料,温度、碱质量分数、氧化剂质量分数和氧化剂滴速为考察因素,采用Box-Behnken的中心组合试验设计和响应曲面分析法对锡酸钠合成工艺进行研究,并建立关于锡转化率的预测模型。结果表明：锡反应转化率(Y)=16.02-1.53A+1.58B-6.91C+2.64D-0.0067AB-0.021AC+0.021AD+0.085BC-0.014BD+0.047CD+0.0022A²-0.022B²+0.21C²-0.019D²,模型决定系数R²=0.7291,拟合度较为显著。锡酸钠合成最佳反应工艺参数为温度79℃、碱质量分数17%、氧化剂质量分数16%、氧化剂滴加速度4mL/min,此条件试验锡转化率达到99.17%。因素分析表明：温度和碱质量分数对锡酸钠合成锡的转化率影响较为显著。     

FST复合型光催化剂降解普施安染料——响应曲面法优化操作条件

根据中心组合实验设计原理,在单因素试验的基础上,采用三因素三水平的响应曲面分析法,建立了FST复合型光催化剂降解普施安染料的二次多项数学模型,并以普施安染料脱色率为响应值作响应面和等高线,考察了pH值、催化剂投加量和光照时间对普施安染料降解的影响。结果表明,光催化剂降解普施安染料的优化工艺条件为：pH值1.3、催化剂投加量O．57g·L^-1、光照时间49．9min。在此工艺条件下,理想普施安染料脱色率达到99．47％以上。     

染料废水的电催化降解特性研究

采用三维电催化氧化法降解结晶紫（CV）、亚甲基蓝（MB）和罗丹明B(RhB)3种染料废水,通过紫外可见光谱和傅立叶红外光谱初步探究染料的降解特性,并拟合动力学方程。结果表明：MB的COD去除率最大,其次是CV和RhB。各染料分子的苯环、杂环、共轭体系等特征结构均可不同程度地被破坏,且RhB的分子更易被破坏。MB、RhB废水的COD质量浓度符合二级动力学方程,CV废水的COD质量浓度符合一级动力学方程,且MB的COD去除速率比RhB的更高。     

响应曲面法优化硝酸分解磷矿工艺

采用响应曲面法优化硝酸法生产磷酸工艺,探讨硝酸浓度、液固质量比、反应温度对磷矿分解率的影响,对优化实验结果进行多项回归拟合分析,建立反映硝酸浓度、液固质量比、反应温度及三者之间交互作用对磷矿分解率影响的二次多项回归模型。结果表明,优化后的最佳工艺条件为反应时间1.5 h、硝酸w(HNO3)45%、液固质量比14、反应温度65℃,此条件下磷矿分解率的模型预测值与验证实验平均值的偏差很小,说明模型预测与优化的可信度高。     

微波干燥MgO涂层响应曲面法优化工艺研究

对初始含水率70%的MgO涂层进行微波干燥实验,采用响应曲面法中心组合设计对工艺参数进行优化,实验结果表明:料功比、干燥时间、初始含水率对微波干燥涂层的相对脱水率都有影响。影响的显著程度顺序为:干燥时间料功比初始含水率。结合响应曲面优化及产品质量评分的方法得到了第一阶段干燥的最佳工艺条件:微波功率280 W,干燥时间30 min,涂层厚度2.0 mm干燥效率最高,预测的相对脱水率为37.87%,而实测的相对脱水率为37.55%,实验值与预测值偏差为-0.32%,响应曲面优化有效。     

响应曲面法优化混合菌HJ8-1降解水中原油污染物

采用响应曲面法优化混合菌HJ8-1修复原油污染水体的条件,以原油浓度、氮浓度、磷浓度和表面活性剂(SDBS)浓度为自变量、原油降解率为因变量,运用Box-Behnken(BB)设计研究了各自变量及其交互作用对水中原油污染物降解效果的影响.以二次多项式回归方程预测模型为基础,得到含油量为2 g·L-1、11g·L-1和2...     

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％。     

响应面法优化餐饮废水混凝工艺研究

餐饮废水是一种污染严重、成分复杂的高浓度有机废水。为了降低生化处理的负荷,采用混凝沉淀工艺对餐饮废水进行预处理,利用响应面法优化混凝工艺条件。通过扫描电子显微镜（SEM）、X射线能谱（EDS）及X射线衍射（XRD）分析絮体组成结构的变化,采用三维荧光光谱对比餐饮废水处理前后有机物成分的变化,探究餐饮废水的降解机理。结果表明：在初始pH 7.75,FeCl₃投加量为101.84 mg/L,搅拌及沉降时间分别为42.05 s和25.99 min的条件下,响应面法预测COD去除率为45.34%,与实测值仅相差0.02%（<2%）。由SEM、EDS及XRD分析可知,混凝前原水的悬浮物表面相对平整,混凝后的沉淀物颗粒表面粗糙,且表面呈空间网状结构;混凝前后废水的絮体主要含有C、Cl、Na、O、N、P等元素;混凝后的絮体表面附着铁的氢氧化物。通过三维荧光分析可知,混凝沉淀工艺能有效地去除可溶性微生物副产物和腐殖酸类物质。     

Modeling and optimization of lipase‐catalyzed synthesis of dilauryl adipate ester by response surface methodology

BACKGROUND: Adipate esters are used as low‐temperature and low‐viscosity plasticizers for polyvinyl chloride and its copolymers. In this work, optimization of lipase‐catalyzed production of dilauryl adipate was carried out using response surface methodology (RSM) based on a four‐factor‐five‐level central composite rotatable design (CCRD). Immobilized lipase from Candida antarctica (Novozym 435) was used as catalyst in this reaction. Various reaction parameters affecting the synthesis of adipate ester, including alcohol/acid molar ratio, amount of enzyme, temperature and reaction time, were investigated. RESULTS: Statistical analysis showed that the amount of enzyme was less significant than the other three factors. The optimal conditions for the enzymatic reaction were obtained at 5.7:1 substrate molar ratio using 0.18 g of enzyme at 53.1 °C for 282.2 min. Under these conditions the esterification percentage was 96.0%. CONCLUSIONS: The results demonstrated that response surface methodology can be applied effectively to optimize the lipase‐catalyzed synthesis of adipate ester. The optimum conditions can obtained be used to scale up the process. Copyright © 2008 Society of Chemical Industry     

Removal of malachite green from aqueous solution by sorption on hydrilla verticillata biomass using response surface methodology

In the present study, the effect of adsorbent dose, pH, temperature, initial dye concentration and contact time on malachite green removal from an aqueous medium using hydrilla verticillata biomass has been investigated. The central composite face-centered experimental design (CFCD) in respons surface methodology (RSM) was used for designing the experiments as well as for full response surface estimation. The optimum conditions for maximum removal of malachite green from an aqueous solution of 75.52 mg/L were as follows: adsorbent dose (11.14 g/L), pH (8.4), temperature (48.4°C) and contact time (194.5 min). This was evidenced by the higher value of coefficient of determination (R ²= 0.9158).     

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 and modeling of UV-TiO2 mediated photocatalytic degradation of golden yellow dye through response surface methodology

In this article, heterogeneous photocatalysis of golden yellow (GY) dye by Evonik p25 titanium dioxide (PTD) and UV radiations was optimized by using central composite design of response surface methodology. The GY dye photocatalysis was expressed as the function of amount of PTD loading (X₁), GY dye initial concentration (X₂), and UV irradiance intensity (X₃). The optimization of degradation conditions was done by measuring two different responses, that is, color removal (Y₁) and chemical oxygen demand removal (Y₂). The effect of X₁, X₂, and X₃ were studied in the range 0.5–1.5?g/L, 15–35?W/m², and 10–30?mg/L, respectively. The quadratic model was suggested for Y₁ and Y₂. The numerical optimization of results was done via Design Expert software. The predictive results obtained were verified by performing actual experiments. The photodegradation kinetics, total organic carbon disappearance, effect of inorganic salts, and H₂O₂ concentration on GY dye photodegradation were also studied.     

Optimisation of reaction conditions for the synthesis of single‐walled carbon nanotubes using response surface methodology

The effects of three preparation variables, i.e. reaction temperature, reaction time and reaction gas (methane/nitrogen) flow rate, on the ratio of the intensity of the Raman D band to the intensity of the G band (I_D/I_G), carbon mass and the presence of radial breathing mode (RBM) peaks were investigated by using a central composite design to develop two linear models. The most influential factor in each experimental design‐response was identified using the analysis of variance. The predicted I_D/I_G ratio, carbon mass and presence of RBM peaks determined during the process optimisation were found to agree satisfactorily with the experimental values. The optimum conditions for synthesising single‐walled carbon nanotubes were determined to be a reaction temperature of 900°C, a reaction time of 59 min and a reaction gas flow rate of 54 mL/min. © 2011 Canadian Society for Chemical Engineering     

Optimization and analysis of nickel adsorption on microwave irradiated rice husk using response surface methodology (RSM)

BACKGROUND: The removal of heavy metals using adsorption techniques with low cost biosorbents is being extensively investigated. The improved adsorption is essentially due to the pores present in the adsorbent. One way of improving the porosity of the material is by irradiation of the precursor using microwaves. In the present study, the adsorption characteristics of nickel onto microwave‐irradiated rice husks were studied and the process variables were optimized through response surface methodology (RSM). RESULT: The adsorption of nickel onto microwave‐irradiated rice husk (MIRH) was found to be better than that of the raw rice husk (RRH). The kinetics of the adsorption of Ni(II) from aqueous solution onto MIRH was found to follow a pseudo‐second‐order model. Thermodynamic parameters such as standard Gibbs free energy (ΔG°), standard enthalpy (ΔH°), and standard entropy (ΔS°) were also evaluated. The thermodynamics of Ni(II) adsorption onto MIRH indicates that it is spontaneous and endothermic in nature. The response surface methodology (RSM) was employed to optimize the design parameters for the present process. CONCLUSION: Microwave‐irradiated rice husk was found to be a suitable adsorbent for the removal of nickel(II) ions from aqueous solutions. The adsorption capacity of the rice husk was found to be 1.17 mg g^?1. The optimized parameters for the current process were found as follows: adsorbent loading 2.8 g (100 mL)^?1; Initial adsorbate concentration 6 mg L^?1; adsorption time 210 min.; and adsorption temperature 35 °C. Copyright © 2008 Society of Chemical Industry     

Application of response surface methodology to optimize the operation process for regeneration of acid and base using bipolar membrane electrodialysis

BACKGROUND: Bipolar membrane electrodialysis (BMED) has been widely used for desalination, concentration, separation, and purification in many fields. The purpose of this study is to optimize the operation conditions using response surface methodology (RSM) for the regeneration of sulfuric acid and ammonia from ammonium sulfate solution by BMED coupled with ammonia in situ stripping. RESULTS: A three‐factor central composite design of RSM was used to analyze the effect of operation conditions (current density, flow rate, initial acid concentration) on average current efficiency (ACE) and establish the optimal operation conditions. The ACE was 76.7 ± 2.2% under optimal operation conditions (current density 23.8 mA cm^?2, flow rate 27.3 L h^?1, initial acid concentration 0.09 mol L^?1). CONCLUSION: A suitable regression model for predicting ACE within the ranges of variables used was developed based on experimental results. The operation conditions were optimized by RSM and the ACE obtained under the optimal operation conditions was in good agreement with the value predicted by the regression model (78%), which proved the validity of the model. Copyright © 2007 Society of Chemical Industry