酸碱对剩余活性污泥中氮磷类物质破解研究

污水处理过程中产生的剩余活性污泥量大,难以被处理处置,目前已成为污水厂自身的严重污染源。用不同浓度的HCl溶液、NaOH溶液分别对城市污水厂剩余活性污泥进行处理后,对其中溶解性氮、磷物质的破解释放规律进行了对比研究。实验结果表明,在泥水体积比相同的条件下,同浓度NaOH溶液对污泥NH4＋－N的释放效果好于HCl溶液,但对溶解性PO43－－P的释放质量浓度低于HCl溶液;两种方法中NH4＋－N的最大释放质量浓度分别是106．0、153．4 mg/L ,PO43－－P的释放质量浓度分别是133．5、126．3 mg/L。研究为进一步污泥资源化应用提供了理论依据。     

混合药膜包膜系统释放动力学研究

存储混合型是目前研究较多的控制释放体系 ,但由于其机理较为复杂 ,目前尚未建立合理实用的动力学模型 .以混合药膜包膜体系为研究对象 ,建立了释放动力学的简化模型并获得了解析解 .实验数据表明 ,该模型适用于描述药物装填量大于饱和溶解度的药物释放动力学行为 (相对偏差小于 3 % ) .根据该模型还从理论上分析了两种限定条件 (Dm Df和 Dm Df)下药物的释放特征 :当 Dm Df时 ,释放速率变为常数 ,达到零级释放 ,其释放速率与药膜无关 ,这为零级释放缓释体系如何控制释放速率和药物释放量提供了理论依据 :当 Dm Df时 ,药物的释放速率与药膜中的释放系数、溶解度和药物的装填量有关 ,与包膜过程无关 ,其释放过程类似于混合药膜缓释体系     

钩藤总碱凝胶骨架片的研制及释放度考察

以羟丙甲基纤维素(HPMC)为骨架材料，采用湿法制粒，制备钩藤总碱缓释片。以体外释放度实验研究了缓释片的释药机理及其影响因素。结果表明：钩藤总碱凝胶骨架片的释放符合Higuchi方程，其释放速度受多种因素的影响，如HPMC、乳糖、微晶纤维素的用量，附加剂的调节和控制。     

MATHEMATICAL ANALYSIS OF DRUG RELEASE FROM A MONOLITHIC MATRIX WITH AN INITIALLY LINEAR CONCENTRATION DISTRIBUTION

将化学工程学原理应用到药物释放这一多学科领域，研究了初始浓度分布为线性的平板混合药膜体系释放动力学模型，该模型可用来描述高装填量平板混合药膜的释放后期，并可简化为无限渗阱时的特定情况．根据该模型，计算了混合药膜内的浓度－距离分布和浓度－时间分布曲线，研究了释放介质体积对释放过程的影响．     

水窖底泥中氨氮释放动力学模拟

在不同温度和振荡速度的影响下,水窖底泥中氨氮解吸至上覆水中,会对上覆水造成影响。通过实验分析并探讨了温度和振荡速度对水窖底泥中氨氮释放的影响并进行动力学模拟。实验结果表明：温度和振荡速度增大能够促进水窖底泥中氨氮释放,且氨氮解吸平衡浓度增大;通过准一级动力学方程和准二级动力学方程拟合,两种动力学方程对氨氮释放过程的拟合效果较为接近,且温度影响下两种动力学拟合效果较振荡速度影响好一些（不同温度下其氨氮释放动力学拟合 R2在0．91～0．97,而振荡速度 R20．72～0．94）;因此,窖水的水质可能受到上述因素的影响。实验结果可为窖水水质维护,窖水水质处理等提供理论依据。     

室温下有机化合物水溶性的一个简单判据

有机化合物的溶解性是研究有机物性质以及应用过程中的一个重要问题,有时从溶解性还会获得有关分子结构的一些信息,而水作为一种重要溶剂来讲,找出一个简单地判别有机物水溶性的方法是很有用的。笔者查阅了大量有机物在水中的溶解度数据,发现许多有机物在水中的溶解情况有这样     

pH对蒙溪河底泥氮磷释放影响的研究

分析了不同pH值对蒙溪河底泥总氨(TN)、总磷(TP)释放特性的影响。结果表明,底泥中的TN在整个释放过程中,呈“单峰曲线”变化,pH越大,TN净释放量越大：底泥中的TP在酸性范围内,呈负释放状态,且pH越小,“负释放强度”越大：在碱性范围内,pH越大,TP释放量越大。pH在4．00～6．02范围内,水体中TN、TP在第1d开始负释放,TN在第2d回升到最大值,然后又下降,到第4d基本达到平衡,而TP到第2d负释放量达到最大值,而后基本保持平衡：pH在7．81～10．98范围内,水体中TN、TP释放量在第3d达到最大值,然后,TN又下降,到第4d基本达到甲衡,而TP释放量较小；pH为12．00时,水体中TN、TP释放量在第2d达到最大值,然后,TN有所下降,到第4d基本达到平衡,TP释放量倍增,其释放量为前者的3～8倍。说明底泥N、P营养物质对蒙溪河水质存在着潜在的危险性。     

十六烷基壳聚糖纳米微球的制备及其药物负载

采用对低分子量壳聚糖经十六烷基改性的方法制得纳米微球 ,所得微球粒径主要分布在 10 0nm左右 .其红外谱图表明 ,烷基的取代主要发生在壳聚糖的氨基上 .以扑热息痛为模型药物在磷酸缓冲液 (pH =7.4)中进行了体外释放研究 ,结果表明 ,随着取代度的增加 ,扑热息痛在磷酸缓冲溶液中达到平衡时的浓度降低 ,降低投料量 ,可有效地降低药物释放的平衡浓度 .     

聚（N-异丙基丙烯酰胺）水凝胶的制备及其溶胀动力学研究

以N-异丙基丙烯酰胺（NIPAAM）为单体,偶氮二异丁腈（AIBN）为引发剂,分别采用疏水性的1,2-二乙烯苯（DVB）和水溶性的N,N,-亚甲基双丙烯酰胺（BIS）为交联剂制备了温度敏感水凝胶聚（N-异丙基丙烯酰胺）（PNIPAAM）。制得的PNIPAAM水凝胶的低临界溶解温度（LCST）在32℃附近。通过测定水凝胶在不同温度下达到溶胀平衡时的溶胀比和水凝胶的去溶胀动力学及千凝胶的再溶胀动力学过程,讨论了交联剂用量及其性质（疏水性和水溶性）对水凝胶性能的影响。结果表明,随着温度的逐渐升高,水凝胶的溶胀比下降,在其LCST附近下降最为显著。水凝胶在25℃时的再溶胀速率比50℃下的收缩过程要慢得多。在同样的实验条件下．交联剂用量低的样品对温度响应更为敏感。     

水溶性苯胺蓝的热氧降解过程与动力学

用差热分析方法（ＤＴＡ）、热重分析法（ＴＧ）和微分热重分析法（ＤＴＧ）研究水溶性苯胺蓝在空气中流中的热氧降解过程和动力学,发现水溶性苯胺蓝热氧降解过程由３个紧连步骤组成．用ＣｏａｔｓＲｅｄｆｅｒｎ方程进行动力学处理,确定水溶性苯胺蓝热氧降解的表观反应级数分别为１７,２０,０９和活化能为２５４６,３３１５,５９７７ｋＪ／ｍｏｌ．     

Biosynthesis of (<Emphasis Type="Italic">R</Emphasis>)-2-hydroxy-3-phenylpropionic acid using whole recombinant <Emphasis Type="Italic">Escherichia coli</Emphasis> cells in an aqueous/<Emphasis Type="Italic">n</Emphasis>-octane biphasic system

(R)-2-hydroxy-3-phenylpropionic acid (PLA) is an ideal antimicrobial compound with broad-spectrum activity against a wide range of Gram-positive bacteria, some Gram-negative bacteria, and fungi. We studied the bioconversion of phenylpyruvate (PPA) to PLA using whole recombinant Escherichia coli cells in a series of buffer/organic solvent systems. Octane was found to be the best organic solvent. The optimum volume ratio of the water phase to the n-octane phase, conversion temperature, substrate concentration, and cell concentration were 6:4, 40 °C, 12.5 g/L, and 30 g/L wet cells, respectively. Under the optimized conditions, the average PLA productivity in the aqueous/n-octane system was 30.69% higher than that in the aqueous system, and 32.31 g/L PLA was obtained with the use of a stirred reactor (2-L scale). Taken together, our findings indicated that PLA biosynthesis was more efficient in an aqueous/n-octane biphasic system than in a monophasic aqueous system. The proposed biphasic system is an effective strategy for enhancing PLA yield and the biosynthesis of its analogues.     

一种黄酮磺酸盐的合成与表征

以5-甲基-7-甲氧基异黄酮为先导化合物在浓硫酸中进行磺化,得到其磺化产物:5-甲基-7-甲氧基异黄酮-4’-磺酸钠,极大的改善了水溶性。采用1H NMR、13C NMR和元素分析对磺化产物的结构进行了表征,并对磺化条件进行了优化。确定了其磺化反应的最佳实验条件是:5-甲基-7-甲氧基异黄酮与浓硫酸比值(g/mL)为1:6,反应时间为10h,反应温度为100℃。     

Effects of Surfactant on Solubility and Microbial Conversion of Steroid

Enhancing the dispersion and dissolution of substrate particles in substrate water suspension is a feasible way to improve steroid bioconversion. The aim of the present study is to investigate the effects of applying surfactant to microbial conversion system on the dispersion, solubilization and in turn bioconversion of steroid substrate. The model system is hydroxylation of substrate 19α- 17α-epoxy- 4-pregnene- 3.2It-dine by microbial enzymes from Rhizopus nigricanl. The results show that the presence of substrate leads to an increase in critical micelle concentration （ CMC） of surfactant PSE compared with the normal CMC of PSE in aqueous solution. The grinding time during substrate suspension preparation affects the substrate aqueous solubility differently with the varied surfactant concentrations while barely making any difference in substrate solubility in the absence of surfactant. The properly prolonged grinding time can make up for the loss in substrate solubility arising from the reduction in surfactant concentration. The surfactant complexes composed of surfactants PSE and MGE at appropriate ratios are screened out with orthodoxy experiment method. the interaction between PSE and MGE exerts the most prominent effects on substrate bioconversion, and the surfactant complexes show more beneficial effects on steroid bioconversion than the surfactant PSE used alone.     

笋壳基活性炭对铜离子和亚甲基蓝的共吸附性能研究

以笋壳为原材料,经过NaOH活化、碳化后制得笋壳基活性炭,研究了其对重金属及有机污染物的单独和共吸附性能。选取Cu(Ⅱ)和亚甲基蓝（MB）作为复合污染水体的特征污染物,探讨活性炭对两者的单独和共吸附性能,并从动力学角度探讨了吸附机理。结果表明,不同类型的污染物单独存在时,笋壳基活性炭对Cu(Ⅱ)和MB的吸附量分别是6.55 mg/g和 18.26 mg/g;而当上述两种污染物共存时,吸附量均明显下降,这说明Cu(Ⅱ)和MB存在竞争吸附。准二级动力学方程很好地描述了笋壳基活性炭对Cu(Ⅱ)和MB的吸附行为。吸附速率的控制步骤是内扩散,吸附速率还受膜扩散的控制。     

聚二乙烯基苯/聚丙烯酸IPN的合成及性能研究

采用分步聚合法合成了两网质量比不同,第二网交联度均为30%的聚二乙烯基苯/聚丙烯酸甲酯互穿聚合物网络（PDVB-PMA IPN）,将它们分别用20%的NaOH/甲醇溶液碱解,合成了一网疏水、一网亲水的聚二乙烯基苯/聚丙烯酸互穿聚合物网络（PDVB-PAA IPN）。测定了两网质量比对树脂的比表面积、平均孔容、孔径以及弱酸交换量的影响。比较了不同树脂对水溶液中苯酚的吸附性能差别,测定了此类树脂的热力学数据,探讨了此类树脂的吸附机理,建立了一种通过溶胀致孔合成吸附树脂的方法。     

Biotreatment of oily wastewater by rhamnolipids in aerated active sludge system

Oily wastewater generated by various industries creates a major ecological problem throughout the world. The tra-ditional methods for the oily wastewater treatment are inefficient and costly. Surfactants can promote the biodegradation of pe-troleum hydrocarbons by dispersing oil into aqueous environment. In the present study, we applied rhamnolipid-containing cell-free culture broth to enhance the biodegradation of crude oil and lubricating oil in a conventional aerobically-activated sludge system. At 20 ℃, rhamnolipids (11.2 mg/L) increased the removal efficiency of crude oil from 17.7% (in the absence of rham-nolipids) to 63%. At 25 ℃, the removal efficiency of crude oil was over 80% with the presence of rhamnolipids compared with 22.3% in the absence of rhamnolipids. Similarly, rhamnolipid treatment (22.5 mg/L) for 24 h at 20 ℃ significantly increased the removal rate of lubricating oil to 92% compared with 24% in the absence of rhamnolipids. The enhanced removal of hydrocarbons was mainly attributed to the improved solubility and the reduced interracial tension by rhamnolipids. We conclude that a direct application of the crude rhamnolipid solution from cell culture is effective and economic in removing oily contaminants from wastewater.     

Enhancement of solubility and mass transfer coefficient of salicylic acid through hydrotropy

This study deals with the effect of hydrotropes on the solubility and mass transfer coefficient of salicylic acid. The solubility and mass transfer studies were performed using the hydrotropes, i.e., sodium acetate, sodium salicylate, citric acid, and urea at concentrations of 0-3.0 mol/L and system temperatures of 303-333 K. It was found that the solubility and mass transfer coefficient of salicylic acid increases with increase in hydrotrope concentration and also with system temperature. All hydrotropes used in this work showed an enhancement in solubility and mass transfer coefficient to different degrees. The maximum enhancement factor values were determined for all hydrotropes used in this study. The highest value was 28.08 for solubility studies and 10.42 for mass transfer studies. The performance of hydrotropes was measured in terms of the Setschenow constant （Ks）. The highest value observed was 0.696.     

Retroactive revaluation of an odor-taste association

Rats showed an increase or decrease in preference for an aqueous odor conditioned stimulus (CS) presented in compound with a palatable (sucrose) or unpalatable (quinine) taste unconditioned stimulus (US), respectively. Four experiments then studied the consequences for odor preference of presenting water in the context where the odor-taste compound had previously occurred (i.e., no-CS-no-US experience). Exposure to that context increased the preference for the odor associate of sucrose and decreased preference for the odor associate of quinine. The increased preference for the odor associate of sucrose was contingent on reexposure to the context where the odor-sucrose compound had occurred (i.e., retroactive revaluation) and was reduced by preexposure to the context where the odor-sucrose compound was to occur (i.e., latent inhibition of the context). The retroactive revaluation of within-event learning caused by exposures to the associated context is discussed in terms of (1) the modified version of the SOP model (Wagner, 1981) proposed by Dickinson and Burke (1996) and (2) the comparator model (Miller & Matzel, 1988).     

Effects of two medicinal plants Psidium guajava L. （Myrtaceae） and Diospyros mespiliformis L. （Ebenaceae） leaf extracts on rat skeletal muscle cells in primary culture

Crude decoction, aqueous and ethanolic extracts of two medicinal plants （Psidiura guajava and Diospyros raespiliformis）, widely used in the central plateau of Burkina Faso to treat many diseases were evaluated for their antagonistic effects on caffeine induced calcium release from sarcoplasmic reticulum of rat skeletal muscle cells. These different extracts showed a decrease of caffeine induced calcium release in a dose dependent manner. Comparison of the results showed that Psidiura guajava leaf extracts are more active than extracts of Diospyros mespiliformis and that crude decoctions show better inhibitory activity. The observed results could explaine their use as antihypertensive and antidiarrhoeal agents in traditional medicine, by inhibiting intracellular calcium release.