相分离联合层析去除类人胶原蛋白中的内毒素

研究类人胶原蛋白(HLC)中内毒素的去除方法,为规模化制备医用生物材料提供参考。采用Triton X-114双水相分离法作为内毒素去除工艺的第1步,亲和层析法作为工艺的第2步,二者偶联操作从类人胶原蛋白中除去内毒素,并对除去内毒素后的HLC进行了理化性能检测。结果表明:采用Triton X-114双水相分离法,在蛋白质量浓度2.06 mg/m L,作用温度44.71℃,作用时间3 h,溶液pH值为7时双水相分离系数K=9.58,蛋白中内毒素含量由10 000—25 000 EU/mg下降为1.5—2.0 EU/mg,蛋白回收率为95.6%;偶联了多聚赖氨酸亲和配基的亲和层析后,HLC中内毒素含量由1.5—2.0 EU/mg降至0.025—0.25 EU/mg,蛋白回收率可达81.9%;2步操作均不会使蛋白发生相对分子质量及化学结构的改变。此工艺操作简便,可显著降低生产成本。     

响应面法优化过氧化氢强化水力空化去除双酚A

利用响应面法(RSM)对过氧化氢强化水力空化(HC/H_2O_2)去除双酚A(BPA)工艺进行设计,建立拟合二次多项式回归模型。结果表明,多项式模型的3个因素对BPA去除效果的影响顺序:入口压力过氧化氢浓度空化时间。HC/H_2O_2技术去除BPA的优化条件:入口压力为0.31 MPa,过氧化氢质量浓度为10.31 mg/L,空化时间为138.81 min。在此条件下BPA去除率的预测值为36.36%,根据实际情况修正优化参数与预测值仅相差0.12%,说明回归方程拟合性较好,模型得到的工艺参数可靠。     

响应面法优化粉末活性炭去除水中的Cr(Ⅵ)

研究了粉末活性炭(PAC)吸附去除水溶液中的Cr(Ⅵ),利用基于单因素实验的响应面法优化了Cr(Ⅵ)的去除条件。结果表明,模型能很好地拟合实验数据。当Cr(Ⅵ)初始质量浓度为50 mg/L时,由响应面法得到的Cr(Ⅵ)最佳去除条件是:pH=3、吸附时间为21.56 min、PAC投加质量浓度为2.40 g/L,相应的Cr(Ⅵ)的去除率为86.00%。实验值和预测值的相对偏差仅为1.07%,证实模型合理可行。     

紫外/氯耦合处理饮用水中氨氮的响应面优化

基于响应面优化法,研究紫外/氯耦合处理饮用水中氨氮的效能。考察氯氮质量比、紫外辐射时间和pH值3个影响因素及其交互作用对氨氮去除的影响,采用二阶方程进行数学模拟,并优化工艺条件。结果表明,紫外/氯耦合技术能有效去除氨氮,三因素均对氨氮的去除影响显著,各因素的交互作用也显著存在。数学拟合模型的相关系数较高（R²=0.992）,模型回归性好。满足饮用水氨氮出水要求（0.5 mg·L^-1）的最优工艺条件为：氯氮质量比4.00,紫外辐射时间6.00 min和pH值7.5。验证实验结果与预测值的偏差仅为0.64%,响应面拟合方程可用于氨氮去除率的预测和最优工艺条件的确定。紫外/氯耦合技术是一种新型的氨氮去除方法,具有投药量小、去除效率高、操作简单等优点。     

紫外/氯耦合处理饮用水中氨氮的响应面优化

基于响应面优化法,研究紫外/氯耦合处理饮用水中氨氮的效能。考察氯氮质量比、紫外辐射时间和pH值3个影响因素及其交互作用对氨氮去除的影响,采用二阶方程进行数学模拟,并优化工艺条件。结果表明,紫外/氯耦合技术能有效去除氨氮,三因素均对氨氮的去除影响显著,各因素的交互作用也显著存在。数学拟合模型的相关系数较高(R2=0.992),模型回归性好。满足饮用水氨氮出水要求(0.5 mg·L?1)的最优工艺条件为:氯氮质量比4.00,紫外辐射时间6.00 min和pH值7.5。验证实验结果与预测值的偏差仅为0.64%,响应面拟合方程可用于氨氮去除率的预测和最优工艺条件的确定。紫外/氯耦合技术是一种新型的氨氮去除方法,具有投药量小、去除效率高、操作简单等优点。     

富硒酵母发酵废水的处理工艺研究

文章采用铁硒共沉淀法去除富硒酵母发酵废液中的无机硒,对Fe Cl3浓度、温度、搅拌时间、p H和静置时间进行了单因素优化,最后对去除率影响较为显著的Fe Cl3浓度、p H和搅拌时间采用中心组合设计和响应面分析进行了优化。结果表明,最佳条件为Fe Cl3浓度为18mg/L,室温,搅拌时间为26 min,p H为9.7,静置时间为15 min,去除率达到了66.73%,基本达到了排放标准。     

MIEX树脂去除水源中突发性六价铬污染的参数优化

水源水中加入六价铬模拟水源突发性六价铬污染,采用单因素和响应曲面法建立了二次多项式回归模型,研究了磁性离子交换(MIEX)树脂去除水源突发性六价铬污染的可行性,对工艺参数进行了优化.结果表明,MIEX树脂可快速去除六价铬,约40 min时达吸附平衡;六价铬去除率随树脂用量增加而增加,随铬浓度增加而降低,pH为4时达最大值;回归模型可有效预测六价铬在MIEX树脂上的吸附.树脂用量与六价铬初始浓度、树脂用量与溶液pH、六价铬初始浓度与溶液pH间的交互作用对六价铬的去除有显著影响.最优参数下MIEX树脂对六价铬的去除率为99.99%.     

正渗透去除微塑料效能及其响应面法优化

试验选取PET塑料颗粒作为去除目标物，NaCl溶液为汲取液，分别考察正渗透膜通量变化及对PET颗粒的去除影响因素分析。结果表明：增大汲取液浓度、运行温度、膜面流速和PET粒径均能显著提高膜通量，且其总膜比通量也较大，但与膜通量衰减存在一定交互作用；试验周期内，在汲取液中未检测到PET颗粒，去除率可达100%。去除率分别由膜截留率及装置系统吸附率贡献，两者占比在各去除影响因素分析中有所变化，其中汲取液浓度、膜面流速和粒径对吸附率去除贡献比影响较大，而温度对其影响不显著，且相关性不强；最后用响应面法优化汲取液浓度、膜面流速和温度对总膜比通量的影响。回归模型分析表明三种影响因素影响程度为：1）在低膜面流速的条件下汲取液浓度>膜面流速>温度；2）在高膜面流速的条件下汲取液浓度>温度>膜面流速。优化方案模型的模拟预测值与实验测试值基本吻合。     

响应面法优化混凝处理南水北调邯郸段水源水

采用响应面法(RSM)对南水北调邯郸段水源水浊度不达标的问题进行混凝工艺优化处理.设计单因素试验,分析混凝剂投加量、反应搅拌时间及反应搅拌速度对浊度去除率的影响,并进行响应面优化.结果表明:混凝剂投加量对浊度去除率的影响最显著,反应搅拌速度对其影响最弱.经过优化后得出最佳混凝工况:混凝剂投加量为22.78 mg·L-1、反应搅拌时间为25.35 min及反应搅拌速度为61.46 r·min-1,此时的浊度去除率可达到86.82％.经验证,响应面模型预测值与实际值的误差为0.45％.     

响应面法优化吹脱处理垃圾渗滤液

利用响应面学的方法对吹脱处理垃圾渗滤液的影响因素进行了探讨和分析,考察了吹脱时间,气液比值,温度和pH对氧化垃圾渗滤液的影响.以渗滤液中氨氮为模拟污染物,采用单因素法筛选出吹脱时间、pH、气液比3个相对重要的影响因素,利用响应面法在吹脱时间5-7h、气液体积比为2000-4000.pH为10-12范围内探讨了操作条件对氨氮去除率的影响,并分析了这些影响因素之间的相互作用.采用响应面法对试验结果进行了模型拟和,并对模型进行了试验验证.结果表明,响应面法的预测值与试验值吻合较好,在通过响应面法得到的优化工艺条件下(吹脱时间为6.5h,pH为11.5,气液体积比3000)处理垃圾渗滤液,氨氮去除率大于90%.     

Endotoxin Removal during the Purification Process of Human-like Collagen

Interaction between human-like collagen (HLC) and endotoxin makes endotoxin removal from HLC more complicated. In this study, a simple, effective, and low-cost method was developed for endotoxin removal. A 0.4% (volume fraction) TritonX-100 solution was used to dissociate the HLC-endotoxin complexes and Q XL resin was used to remove endotoxin from the HLC solution. Product solution containing 1.2 mg · ml^?1 HLC in Tris-HCl buffer (pH 7.5) and 50 mM NaCl was added to the Q XL resin; the endotoxin removal efficiency was more than 98% and HLC recovery of up to 95% could be obtained; HLC purity was also enhanced after this process. The residual TritonX-100 was removed by using a superdex-200 column. This method greatly reduced the cost of purification but provided high endotoxin removal efficiency and HLC recovery.     

Endotoxin removal from human-like collagen by allantoin

ABSTRACT

Human-like collagen(HLC) has an important role in biomedical field, while endotoxin contamination limits it use. In this study, the saturated allantoin as an adsorbent was applied in adsorbing endotoxins from human-like collagen in Tris-acetate-EDTA(TAE) buffer.Finally, the endotoxins carried by allantoin and soluble allantoin could be removed by centrifugation and ultrafiltration. Treated by 400mg/ml of allantoin, at pH6.5 and 25mM NaCl the endotoxins residual in HLC was decreased to 2.38+0.11EU/mg and protein recovery achieved 98.7% in TAE buffer. Endotoxins could be adsorbed on the surface of allantoin crystal by the hydrogen-bond. At pH8.0, the main force was hydrophobic and bivalent bridge between HLC and endotoxins. When the pH was 6.5, the negative-electron repulsion became the main force. And then, Transmission Electron Microscopy(TEM) was used to observe the ultrastruction of HLC,illustrating the protein ultrastruction had not been affected in TAE buffer. In addition, the method of endotoxins removed by allantoin adsorptoin in TAE buffer was safety and greatly reduced the costs,time consumption in contrast with affinity chromatography. As a whole, this paper provided a good idea to establish a large-scale industrial process to remove endotoxin in biomedical field for its simple operation and low cost.     

表面活性剂复配体系修复芘污染土壤实验

以芘污染土壤为对象,利用阴离子表面活性剂鼠李糖脂和非离子表面活性剂皂素进行复配实验,得出最佳复配比并对污染土壤进行修复处理;其次,研究表面活性剂浓度、pH及CaCl₂、MgCl₂、KCl三种离子浓度、洗脱液的回收次数等单因素对洗脱效果的影响;然后利用响应曲面分析,确定影响洗脱效果的主效应因素及其交互作用强度;最后用Box-Behnken模型优化复配体系处理芘污染土壤的实验条件。结果表明：①当复配比为0.2时,鼠李糖脂-皂素混合溶液的表面张力最低,对芘的协同增溶效果最好;②复配体系处理芘污染土壤的单因素实验中,复配药剂浓度、pH、Mg²⁺浓度分别达到1800mg/L、8、0.1mmol/L时,洗脱效率最高;③环境因素对芘去除效果的影响从大到小依次为pH>表面活性剂浓度>Mg²⁺浓度,表面活性剂浓度与pH对芘的洗脱产生较大的交互影响作用,而pH与盐浓度的交互作用最微弱;④Box-Behnken模型优化后得出最佳组合是混合表面活性剂浓度为1900mg/L、pH为5、Mg²⁺浓度为0.2mmol/L,得到的洗脱效率为89.25%。     

温度/pH双响应硝化菌凝胶球的制备及特性研究

采用包埋法制备了粒径均匀的海藻酸钙(CA)硝化菌小球,并用不同浓度的NaCl溶液处理CA硝化菌小球来改善其扩散传质性能,以N-异丙基丙烯酰胺(NIPAAm)、丙烯酸(AA)为单体材料,形成温度/pH响应层,制得一种新型温度/pH双响应硝化菌凝胶小球。以NH4+?N为指示物考察不同制备条件下硝化菌凝胶小球的氨氮去除性能及对温度、pH的敏感特性,并将其应用于实际废水的脱氮处理。结果表明,经浓度为0.3%的NaCl溶液改性后的CA硝化菌小球的扩散传质性能最佳;15 mL温度响应溶液中NIPAAm为200 mg、MBA为4 mg,10 mL pH响应溶液中AA为200 mg、MBA为4 mg时双响应硝化菌小球的氨氮去除性能最好;当温度低至4℃时,氨氮去除率可达29.45%,当pH为9时,氨氮去除率仍可达35.48%。双响应硝化菌凝胶小球具有良好的温度、pH敏感特性,对实际废水中氨氮的去除也具有良好效果,有利于提高低温及碱性条件下硝化菌的硝化效果。     

电化学氧化降解磺胺嘧啶模拟废水的工艺优化

在无隔膜电解槽中,以NaCl为电解质,利用形稳阳极(DSA)产生的羟基自由基(·OH)和原位电生成的活性氯氧化降解磺胺嘧啶(Sulfadiazine,SD)模拟废水。通过高效液相色谱分析SD及其产物含量变化,水杨酸捕集羟基自由基法测定·OH的浓度,探讨工艺参数对·OH、氯离子、余氯、总氯和总有机碳(TOC)去除率的影响。结果表明,反应10 min后SD去除率达100%,反应4 h后溶液TOC明显下降;反应4 h后,pH=3、4、8、8.5、10和12的反应体系中TOC去除率分别为29%、46%、55%、61%、52%和47%,峰值出现在pH=8.5时;提高电流密度、电解质NaCl浓度及降低SD初始质量浓度可增大TOC去除率。该实验最优工艺条件为:pH=8.5,外加NaCl 0.025 mol/L,电流密度20 mA/cm2,初始质量浓度100 mg/L SD,经4 h的电化学氧化降解,TOC去除率达到66%。     

Statistical optimization of Rhodamine B removal by factorial design using reaction rate constant in electrochemical reaction

This study elucidates the reduction of Rhodamine B (RhB) color through electrochemical oxidation technique. Effects of current density, electrolyte type, electrolyte concentration, air flow rate and pH on the RhB color removal were investigated. The 2⁴ full factorial design was used to investigate the individual and combined effects of the current density, NaCl concentration, air flow rate, and pH. Also, this study tested the reaction constant rate (k) regression models as an alternative response surface model for the optimization of operating conditions. Increase of pH decreased the RhB color removal efficiency. At the same time, the increase of current density, NaCl concentration, air flow rate also increased the RhB color removal efficiency. From the 2⁴ factorial design, it was found that the individual main effects and four interaction effects (combined effects) of the independent variables were statistically significant (p<0.05). Also, the prediction results of the RhB concentration using the k regression models showed a nonlinear pattern which was similar to the actual experimental results. In the RhB color removal reactions, the 1 ^st order k regression model showed a smaller prediction error than the 2 ^nd order k regression model.     

基于响应曲面法的磁性离子交换树脂去除甲基橙和刚果红的优化

选取树脂用量、溶液初始pH值、吸附质浓度和吸附时间四个因素,用Box-Behnken响应曲面法分别建立了甲基橙和刚果红在磁性离子交换(MIEX)树脂上吸附的二次多项式回归模型,使用方差及显著性分析证明了回归方程的可靠性。优化了MIEX树脂去除甲基橙和刚果红的工艺参数,探究了最佳工艺条件下MIEX树脂对甲基橙(刚果红)的去除效果。使用NaCl再生饱和吸附后的MIEX树脂,用扫描电镜对吸附前后的树脂进行表征。结果表明,在最优工艺条件下,MIEX树脂对甲基橙和刚果红的去除率最高可达99.12%和98.29%。溶液初始pH值和树脂用量之间的交互作用对MIEX树脂去除甲基橙和刚果红有显著影响。NaCl溶液对MIEX树脂的再生效果显著。     

Performance,optimization, and mechanism of nitric oxide removal by thiourea dioxide/FeIIEDTA reaction systems

In this work, a new innovative absorption system containing both thiourea dioxide (TD) and Fe^ⅡEDTA was used to NO removal. The independently influences of O₂ volume concentration, TD concentration, original pH value and absorbent temperature on NO removal in bubbling device were examined preliminarily. The results revealed that the NO removal efficiency firstly increased and then decreased with the increasing of the three independent variables (O₂ volume concentration, TD concentration and temperature). However, the NO removal efficiency monotonously increased to some extent with pH value increasing from 6.5 to 10.5. In addition, the respective effects of the four variables and the interactive function of them on NO removal were checked with the response surface methodology (RSM) by central composite design (CCD). The calculative model showed that pH value possessed a main positive independent impact on NO removal. Furthermore, the interactive effects between any two factors were expounded by the 3D surface and counter plots. Finally, the optimum absorption conditions for the maximum NO removal at 94.3% experimentally and 95.8% statistically were obtained in O₂ volume content of 6.0%, TD concentration of 0.02 mol·L^-1, original pH value of 10.5 and absorption temperature of 42 ℃.     

氯化钠对改性沸石微波脱除氨氮效果的影响

通过添加助剂NaCl在微波下对天然沸石进行加热制备环境材料,研究了微波后沸石对再生水中氨氮的去除效果。研究发现,助剂预处理可以大大提高微波沸石的脱氮效果。在沸石与NaCl溶液固液比1:50,NaCl溶液浓度4%,343 W的微波功率加热4 min的条件下,微波沸石环境材料对氨氮的去除效果最好,最佳去除率可达99.70%;单独进行343 W、4 min的微波加热沸石对氨氮的去除率为76.46%;相对于天然沸石,上述两种微波沸石对氨氮去除率分别提高了39%、15.76%。通过SEM、EDS、XRD等表征手段对微波前后的沸石分析发现,在微波加热过程中助剂氯化钠的加入使沸石颗粒表面更加松散,出现了更多的孔道,同时天然沸石Ca、Mg、P、S峰消失,主衍射峰强度有所减弱,出现了部分非晶化特征。