Rheological properties of sMBR sludge under unsteady state conditions

The aim of this work is to investigate the rheological behaviour of MBR sludge for prolonged sludge retention time and during unsteady state conditions. The role of the total suspended solids and of the soluble organic matter is specifically studied through two running periods characterized by different organic loads and/or solid retention times. Diverse rheological parameters are examined. They are obtained from flow measurements carried out for an extent range of shear stress values.The obtained results show clearly that operating conditions capable of changing the total suspended solid (TSS) and soluble organic compound (COD) concentrations modify the rheological behaviour of the sludge.In comparison with the TSS concentration, the soluble organic compounds greatly affect the cohesion and the rigidity of the sludge three dimensional network. On the other hand, the COD concentration and the TSS content have equivalent quantitative influence on the rheological parameters characterizing the flow of the sludge.The results obtained are of great importance because operating conditions leading to the modification of the soluble microbial product concentration, and of the sludge rheological characteristics in the reactor, can strongly modify not only the mixing and aeration performances but also the membrane fouling of the MBR unit.     

木薯淀粉-VAc接枝共聚生物降解材料性能的研究

以过硫酸铵为引发剂,接枝聚合制成木薯淀粉-醋酸乙烯酯(VAc)接枝共聚物.将该共聚物增塑、交联处理,制备可生物降解材料;研究了此材料的力学性能、热性能及生物降解性能等.结果表明,木薯淀粉-VAc接枝共聚降解材料的拉伸强度、撕裂强度及断裂伸长率分别为23.29 MPa、89.48 kN/m及225%,实验室微生物及土埋方式能快速地促进材料降解,材料60 d内的最大失重率为55.68%.     

Experiences with Ozone Treatment Of Drinking Water in Yugoslavia

Ozone currently is being used in several drinking water treatment plants in Yugoslavia. The new Belgrade water treatment plant “Makis” is the largest one with 42 kg/h of installed ozone generating capacity and has been in operation since 1987. This paper describes the main features of ozone application in drinking water treatment. The experimental results of “Makis” pilot-plant investigations and a few examples of ozone application in Yugoslavia are presented.     

羊栖菜褐藻糖胶的分离纯化和组成性质研究

对羊栖菜褐藻糖胶的7种组分进行了分离纯化和性质研究。首先以羊栖菜为原料,通过CaCl2法和酸法抽提褐藻糖胶,然后经DEAE-Cellulose52离子交换柱层析和SephadexG-100凝胶柱层析,分离得到了7个组分,经纸层析和紫外扫描证实均为单一组分。其次对7个组分的性质进行了研究,经GPC凝胶排阻色谱、气相色谱和红外光谱对各组分的相对分子质量、单糖组成、结构性质等进行了测定;经HIO4氧化法和比浊法对各组分的岩藻糖和硫酸根含量进行了测定;最后通过MTT法,研究了各组分对DU-145和SPC-A1细胞的作用,结果表明各组分对该二种癌细胞的增殖均有抑制作用。     

有机膨润土的改性及其在生物废水处理中的应用

以新疆乌兰陵格膨润土为原材料,添加阴-阳离子表面活性剂制得一系列阴阳离子有机膨润土。对原土和有机土进行XRD、SEM及粘度表征。XRD结果表明,改性后蒙脱石层间距由1.337 nm增加到2.538 nm;SEM结果表明,阴-阳离子表面活性剂已经插层进入蒙脱石层间。将阴-阳离子有机膨润土作为吸附剂去除生物废水中谷氨酸。当pH=5.6,阴-阳离子有机膨润土的用量为2 g/L时,谷氨酸的去除率可达到40.09%。     

2003年～2015年金黄色葡萄球菌食物中毒事件特征分析

为了解2003年～2015年金黄色葡萄球菌引起的食物中毒事件发生规律,对中国知网收录的2003年～2015年金黄色葡萄球菌食物中毒暴发资料进行统计与分析。结果为共收集到发生在2003年～2015年间的金黄色葡萄球菌食物中毒事件86起,累计发病2 431人,死亡0人。肠毒素A（enterotoxin,sea）所引起的食物中毒事件最多,其次为肠毒素C（enterotoxin C,sec）。金黄色葡萄球菌所引起的食物中毒事件大多发生在夏、秋两季,然而食物中毒人数以春季最多,其次为夏季和秋季,冬季中毒人数最少。发生在集体食堂的食物中毒事件最多。肉及其制品引起的食物中毒事件数最多。因此,应针对重点人群、重点场所开展主动监测,指导合理加工或保藏食物,防止食物交叉污染或腐败变质,从而防止食物中毒事件的发生。     

Synthesis, radiolabeling and animal studies of [131I]MPPI: A 5-HT1A imaging agent

The synthesis and biological evaluation of serotonin (5-HT1A) imaging agent [131I]-4-iodo-N-{2-[4-(2-methoxyphenyl)-piperazin-1-yl]-ethyl}-N-pridin-2-yl-benzamide ([131I]MPPI) are reported. The chemical structure of aimed compound and intermediates were confirmed by IR, 1HNMR, and MS. Radiochemical purity was above 99% determined by TLC. Biodistribution of [131I]MPPI in rats displayed high uptake in hippocampus and low uptake in cerebellum. The ratio of the uptake of [131I]MPPI in hippocampus to that in cerebellum was 2.90 at 30 min post injection. The radioactivity in thyroid was 0.069 and 0.128% ID/g organ at 5 min and 120 min,respectively, and it was increased with time, which suggests that in vivo deiodination may be the major route of metabolism. Ex vivo autoradiography of brain section displayed significant decrease of radioactivity in hippocampus when pretreated with 8-OH-DPAT, a selective 5HT1A agonist, compared with control. These findings strongly suggested that 131I-MPPI could be used as an in vivo marker for studies of pharmacology of the 5-HT1A receptor system in animals.     

激光加电场处理辣椒种子的生物效应研究

用ＣＯ２激光加静电场处理的辣椒种子，在生育期各阶段表现出的生物性状明显优于对照。     

基于MatLab的三种群Volterra模型数值求解

建立三种群间相互依存又相互制约的Volterra微分方程模型和改进模型,并结合模型的MatLab数值解,对模型的稳定性进行了说明.     

Kinetics of Phosphorus Release and Uptake in a Membrane-Assisted Biological Phosphorus Removal Process

A long-term comparative study on the kinetics of enhanced biological phosphorus removal (EBPR) was carried out in pilot scale membrane-assisted and conventional biological phosphorus removal processes, by monitoring system performance, phosphorus mass balances, and maximum specific rates in off-line batch tests. The two systems exhibited similar performance in the removal of soluble phosphorus (P) from the influent wastewater, in the specific P release observed in the anaerobic zone, and in the maximum specific P release and volatile fatty acid (VFA) uptake rates. However, when the VFA in the influent was limiting, the conventional EBPR (CEBPR) process performed significantly better than the membrane (MEBPR) counterpart, and this behavior was also reflected in the kinetics of P release. Denitrifying dephosphatation was observed to be significant in both processes during periods of satisfactory P removal. When the aerobic recycle ratio was reduced to a minimum level, the anoxic P uptake activity in the CEBPR sludge was lower than that of the MEBPR sludge. Finally, the biomass decay rates of the two sludge types were estimated to be comparable, with significant reduction of the decay under unaerated conditions.