系列混合碳源在EBPR系统颗粒化进程中的影响研究

在SBR反应器中接种富含聚磷菌的活性污泥,以一系列不同比例的丙酸与乙酸混合为碳源条件,进行了EBPR系统颗粒化培养,考察了混合碳源中丙酸所占质量分数(以COD质量浓度计)的提高对EBPR系统颗粒化进程中颗粒粒径生长、污泥沉降性能、系统除磷效率等宏观特性的影响规律.结果表明,EBPR系统污泥颗粒生长速率随碳源中丙酸所占质量分数的增加而提高;碳源中丙酸所占质量分数较高的反应器污泥SVI值相对较高.经90 d培养,碳源中丙酸所占质量分数分别为0%、25%、50%、75%及100%的系统中成熟颗粒体积平均粒径分别为550.64、599.41、642.38、680.99和745.08μm,污泥SVI值分别稳定在30、40、50、60及75 mL.g-1左右.在相同的磷处理负荷下,各试验系统除磷性能产生了显著性差异.0%、25%、50%、75%及100%丙酸碳源系统平均净除磷能力(以MLSS计)分别为0.78、2.29、2.96、3.23及3.77 mg.g-1,平均除磷效率分别为31.5%、56.5%、77.4%、85.9%及97.0%.     

水体微型生物群落参数与水质指标相关性的研究

利用聚氨酯泡沫塑料块(简称PFU)对清华园内某一连续水体中的微型生物群落的变化进行了观测.所研究的微型生物主要包括细菌、真菌、藻类和原生动物,此外也包括一些小型的后生动物,如轮虫等.所考察的水质指标主要有:水温,pH值,DO,COD_Mn,TN,TP以及叶绿素a含量等,并对水体的富营养化程度进行评价,采用层次分析-主要成分分析营养度法(AHP-PCA法)计算出综合营养指数TLI_c值.试验结果表明水体微型生物群落参数(如S_ep,G,T_90%和HI)和水质指标(如TLI_c)之间具有良好的相关性.      

聚苯乙烯泡沫资源化关键技术研究

介绍了废旧聚苯乙烯（PS）泡沫塑料的回收概况、来源与分类、回收工艺和方法、回收技术瓶颈,重点讨论了熔融造粒法回收和改性废旧聚苯乙烯（Ps）泡沫塑料的工艺与进展,不同造粒回收工艺适合的原料种类,资源化利用的方向等,并对不同回收工艺的聚苯乙烯粒子性能作出了比较。     

泡沫聚合物保温材料的研究进展及其应用

综述了以聚氨酯泡沫、聚乙烯泡沫和酚醛泡沫塑料为代表的轻质聚合物泡沫保温材料的发展状况。     

碳化泡沫负载Co3O4活化过硫酸盐降解罗丹明B

Co₃O₄具有优良的活化过硫酸盐的性能而受到人们的重视,但Co₃O₄粉体易团聚、使用过程中难以分离、易流失和重复利用率差等问题严重制约了其实际应用．通过水热法制备碳化三聚氰胺泡沫负载Co₃O₄非均相催化剂．采用X-射线衍射仪（XRD）和扫描电子显微镜（SEM）对催化剂的结构和表面形貌进行分析．研究不同因素对催化剂活化过硫酸氢钾（PMS）降解罗丹明B（RhB）的性能．其最优催化工艺参数：催化剂投加量为35 mg·L^-1、PMS质量浓度为50 mg·L^-1和pH为7、RhB初始质量浓度为10 mg·L^-1,30 min反应后对RhB降解率为98%．结果表明,增大碳化泡沫负载Co₃O₄非均相催化剂投加量和PMS质量浓度能明显提高对RhB的降解率;而增加RhB初始质量浓度和提高pH值会明显抑制RhB的降解率．催化反应过程符合准一级动力学方程．温度对RhB降...     

Prediction of future disposal of end-of-life refrigerators containing CFC-11

The objective of this study was to predict the number of refrigerators containing CFC-11 blown isolation foam and the amount of CFC-11 banked in these refrigerators. By using a Weibull-based survival function, the number of CFC-11 containing and still-functioning refrigerators was estimated to be approximately 1.6 million in 2013 in Turkey. In order to determine the amount of CFC-11 in the isolation foam of these refrigerators, polyurethane (PU) foam samples were taken from a refrigerator manufactured in 1993 and the quantity of CFC-11 was analyzed by a GC-MS. It was determined that 113–195 mg CFC-11/g PU remains in the PU foam depending on the location such as door, sides, top and bottom. Knowing that a mid-sized refrigerator contains 4 kg PU on average, the total amount of PU foam to be disposed of is 6344 tons when the CFC-11 containing refrigerators in Turkey become obsolete in the near future. Furthermore, 717–1237 tons of CFC-11 are expected to be banked in the PU foam of these refrigerators which will exert an equivalent amount of ozone depleting potential (ODP). In addition, the global warming potential will vary between 3.4 and 5.9 million tons of CO₂.     

糠醛废水制备醋酸钙镁工艺中活性炭最佳吸附条件的试验研究

为了提高糠醛废水中和法生产醋酸钙镁(CMA)的纯度,采用活性炭对含CMA约30%的浓缩液进行预处理,结果表明活性炭吸附的最佳工艺条件为:活性炭使用量占液体质量的10%,加入少量硅藻土为助滤剂,温度为60℃,充分混合吸附30 min,反复过滤6次CMA含量可达29.19%.     

Development of heat transfer and evaporation model of LNG covered by Hi-Ex foam

Natural gas is a kind of clean, efficient green energy source, which is used widely. Liquefied natural gas (LNG) is produced by cooling natural gas to −161 °C, at which it becomes the liquid. Once LNG was released, fire or explosion would happen when ignition source existed nearby. The high expansion foam (Hi-Ex foam) is believed to quickly blanket on the top of LNG spillage pool and warm the LNG vapor to lower the vapor cloud density at the ground level and raising vapor buoyancy. To identify the physical structure after it contacted with LN₂ and to develop heat transfer model, the small-scale field test with liquid nitrogen (LN₂) was designed. In experiment, three layers including frozen ice layer, frozen Hi-Ex layer and soft layer of Hi-Ex foam were observed at the steady state. By characterizing physical structure of the foam, formulas for calculating the surface of single foam bubble and counting foam film thickness were deduced. The micro heat transfer and evaporation model between cryogenic liquid and Hi-Ex foam was established. Indicating the physical structure of the frozen ice layer, there were a certain number of icicles below it. The heat transfer and evaporation mathematical model between the frozen ice layer and LNG was derived. Combining models above with the heat transfer between LNG, ground and cofferdam, the heat transfer and evaporation mathematical model of LNG covered by Hi-Ex foam was developed eventually. Finally, LN₂ evaporation rate calculated by this model was compared with the measured evaporation rate. The calculated results are 1.2–2.1 times of experimental results, which were acceptable in engineering and proved the model was reliable.     

β-环糊精/醋酸纤维素纳米纤维的制备及对染料废水的处理

制备了不同β-环糊精(β-CD)含量的醋酸纤维素(CA)纳米纤维膜,并对纤维膜的结构形貌、尺寸分布、孔隙率、比表面积以及纤维膜的力学性能进行表征分析。随后研究了不同β-CD含量、初始浓度、吸附时间下,纳米纤维膜对甲基红染料的截留性能和吸附性能。结果表明:过量(≥30%)的β-环糊精会使纳米纤维产生珠节,纤维的形貌和力学性能变差;吸附试验表明,β-CD的加入提高了CA纳米纤维膜对染料的吸附,MR吸附率可达93.48%,最大平衡吸附量可达181.74 mg/g,比纯CA纳米纤维膜提高了将近40%;此外,染料的截留实验表明,纳米纤维膜对染料的截留效果较差,最大截留率为50.35%。     

电子供体对地下水中高氯酸盐生物去除的影响研究

通过静态实验,考察了电子供体类型及用量对厌氧条件下微生物去除地下水中高氯酸盐的影响.结果表明,电子供体醋酸盐和H₂的加入,可以明显提高ClO₄^-的去除率,驯化后的微生物去除ClO₄^-的速率比未加入电子供体时提高约1.4~3倍.Monod动态模型能很好地拟合两种电子供体环境下ClO₄^-的微生物去除过程,分别以醋酸盐和H₂作为电子供体时,基质半饱和常数K_s为12.6 mg·L^-1和2.2 mg·L^-1,最大比基质消耗速率V_m为0.45 d^-1和0.08 d^-1.动力学参数表明,本实验条件下,异养型混合菌去除ClO₄^-的效果明显优于自养型混合菌;在少数受高浓度ClO₄^-污染的地下水环境中,为了提高ClO₄^-的去除速率只有通过增加菌体浓度或提高微生物酶的活性来实现.随着电子供体醋酸盐用量增加,ClO₄^-的(比)消耗速率逐渐增大.当初始CH₃COO^-与ClO₄^-的比例为3.80 mg(COD)/mg(ClO₄^-)时,比消耗速率v最大(0.27 d^-1).