Effect of pretreatment temperature on volatile fatty acids production by activated sludge

考察了预处理温度对剩余污泥水解酸化生产挥发性脂肪酸(VFAs)的影响。分别在70、80、90、100℃下处理剩余活性污泥2 h,考察其水解酸化情况。结果表明:热处理可提高溶液中的SCOD及碳水化合物含量,提高效果随温度升高而增大;预处理温度对污泥产酸的促进效果为:90℃>80℃>100℃>70℃。经加90℃处理的活性污泥在缺氧条件下水解酸化30 h后,VFAs的产酸量达到最大,为946 mg/L。VFAs包括乙酸、丙酸、丁酸和戊酸,其中乙酸和丙酸为主要产物,热预处理污泥可提高VFAs中乙酸的含量。The effect of thermal pretreatment temperature on solubilization an acidification of waste sludge(WAS) was investigated.Pretreatment temperatures of WAS ranged from 70℃ to 100℃ and holding time was 2 h.The results showed that COD solubilization was found to increase with treatment temperature.Whereas,total volatile fatty acid(TVFAs)concentration was found to be in the following order:90℃>80℃>100℃>70℃.The optimal pretreatment temperature was 90℃.The VFAs concentration of WAS pretreated under 90℃ was 946 mg/L after 30 h of fermentation.The VFAs consisted of acetic,propionic,butyric and valeric acids,but acetic and propionic acids were the two main products.The proportion of acetic acid was increased by thermal pretreatment.福建省科技重点项目(2008Y0060);; 厦门市科技计划项目(3502Z20073005);; 新加坡厦大校友会研发与学术交流基金项

Analysis of the nutrient distribution features and affecting factors in the Jiulongjiang estuary

根据2009、2010年“丰水期“和“枯水期“四航次九龙江河口混合区的调查资料,且结合历史资料对营养盐含量及分布特征、周日变化特征进行了统计和相关分析,研究了九龙江流域营养盐输入海洋的变化过程,探讨九龙江河口营养盐伴随潮汐变化,以及河口混合过程中的生物地球化学行为。调查期间溶解无机氮、硅和磷含量的平面分布呈现出由径流冲淡水高值向河口外海端递减的变化趋势;在涨潮时,河口区感潮段高溶解无机氮、硅、磷营养盐的陆源冲淡水与低溶解无机氮、硅、磷营养盐外海水相遇,随着外海水的侵入,外海水的作用逐渐加强,在稀释混合过程中呈现出无机营养盐逐步降低的变化趋势,退潮时则相反;营养盐在这复杂的河口过程中往往表现出在水动力的作用下稀释混合是主要过程,无机氮和活性硅酸盐在河口稀释混合过程中呈现保守性特征,活性磷酸盐在河口转移(补充)过程的行为复杂化,呈现缓冲作用为主。Based on the historical data and the data from four surveys in the wet season and dry season of 2009 and 2010 in the Jiulongjiang estuary,the concentration and distribution of nutrient were discussed in the mixing process.Furthermore,the daily variation of nutrient concentration with the tide was also discussed.The results showed that:(1) the concentration of total dissolved inorganic nitrogen,silicate and phosphate all decreased gradually from the river runoff to seawater;(2) in high tide,in the mixing process of the runoff with high nutrient concentration and the seawater with low concentration of nutrient,the concentration of nutrient decreased due to seawater.On the contrary,during the ebb,the concentration of nutrient increased due to the runoff;(3) in the mixing process in Jiulongjiang estuary,nitrogen and silicate were both conservatively diluted,but phosphate was buffered because of the complicated transfer and complement of phosphate.国家海洋局公益性项目(200805064);国家海洋局第三海洋研究所基本科研业务费项目(海三科2009021);海三科200900

Separation and purification of catalpol from Radix Rehmanniae

An ultrasonic extraction technology of preparing catalpol from Radix Rehmanniae was optimized by a uniform experimental design.The optimum conditions for ultrasonic extraction were thus established: 68% (vol) ethanol aqueous solution as extraction solvent,the volume(ml) to mass(g) ratio of extraction solvent to feed of 5∶1,the ultrasonic treatment time of 36 min.The crude catalpol obtained from the optimized ultrasonic extraction technology was further purified by selective adsorption with macroporous resin.The adsorption capacities and desorption yields of ten kinds of macroporous resins for catalpol were investigated.The results showed that H103 resin possessed the best performance.The properties of dynamic adsorption and desorption of H103 resin for catalpol were subsequently investigated on adsorption column.The optimum conditions for adsorption and desorption were determined.The concentration of catalpol in the loaded sample solution was 6.15 mg·ml-1,the flow rate was 1.0 ml·min-1,the volumetric percentage of ethanol in the eluting solvent was 75%,the elution flow rate was 0.5 ml·min-1 and the elution volume was 3.33 BV(bed volume).Under the above conditions,the purity of catalpol product eluted from the column packed with H103 resin reached 62.39% while that of the crude catalpol was only 10.01%

Biosynthesis of Silver Nanoparticles from Various Medicinal Plant Extracts and Their Antibacterial Properties

作者简介:林源(1985－)，女，硕士研究生。联系人:李清彪(1963－),教授，博士生导师，电话:0592－ 2189595，E－mail:kelqb@xmu．[中文摘要]分别以中草药丁香、山茱萸、地榆和乌梅的提取液为还原剂和保护剂合成银纳米颗粒,利用紫外-可见吸收光谱(UV-vis)、透射电镜(TEM)以及X射线粉末衍射(XRD)对产物进行了表征。结果表明,所得银纳米颗粒呈近球形,提高提取液的pH有利于获得粒径较小、分散性好、稳定性高的银纳米颗粒。进一步考察制得的银纳米颗粒的抗菌性能,结果表明,其对大肠杆菌和金黄色葡萄球菌有很强的抑制作用,最小抑菌质量浓度(M IC)分别可达1.69和3.38 mg/L。[英文摘要]Quasi-spherical silver nanoparticles(AgNPs) were synthesized from the extracts of different medicinal plants including Syzygium aromaticum,Cornus officinalis,Prunus mume and Sanguisorba officinalis,and were subsequently characterized by means of UV-visible spectroscopy,transmission electron microscopy and X-ray diffraction.When pH values of the extracts were adjusted to 10,the biosynthesized AgNPs were well-dispersed,highly stable,and relatively small in size.Thus obtained AgNPs were found to demonstrate good antibacterial activity against Escherichia coli and Staphylococcus aureus，with minimum inhibitory concentrations of 1.69 and 3.38 mg /L required，respectively．国家自然科学基金重点项目(21036004);国家自然科学基金面上项目(20976146);福建省科技计划重点项目(2009H0041

空气中so2对直接甲醇燃料电池性能影响

直接甲醇燃料电池(DMFC)通常采用空气中氧气作为氧化剂,但空气中硫化物、氮化物等污染物会对电池性能造成影响.本文采用恒流放电曲线、极化曲线、循环伏安扫描(CV)和电化学阻抗谱(EIS)等方法,研究SO2对DMFC电池性能影响,分析其毒化作用机制.研究表明,SO2毒化导致催化剂电化学活性面积(ECSA)减小,氧还原反应(ORR)电荷转移电阻增大,从而造成DMFC电池开路电压和工作电压加速衰减,峰值功率密度减小.进一步探究了三种恢复策略,空气吹扫与I-V变载操作都只能实现电池性能的部分恢复,CV扫描可完全恢复电池性能

铜基催化剂上甲苯深度氧化的机理分析

运用浸渍法制备了一系列CuO／γ—Al2O3催化剂，利用FTIR、MS、XRD等技术研究了甲苯在该催化剂上的深度氧化的性能及反应机理。初步讨论了活性氧化铝上铜的最佳负载量，铜在催化剂中的作用，以及甲苯在该催化剂上不同条件下反应的中间产物和最终产物及其产生机理

Orthogonal Arrays and Covering Design

去牙痛复方中药药液的研制和疗效探讨1周海虹彭德宁孙若琳（厦门大学海外教育学院厦门361005）牙痛是口腔疾病中的常见症状，也是人们最受困扰的病痛之一.为了寻找一种安全、高效、方便、快捷的止牙痛药物以适应临床需要，我们研制出以两面针为主的去牙痛复方中药...In this paper,the algebraic structure of orthogonal design is given.The covering design and degree of separation are introduced ,and the properties of greatest covering For an orthogonal design are proved