新型钯-银联合活化电磁屏蔽材料的工艺初探

将贵金属化合物溶液与特定的高聚物单体混合,在氨水、乙胺溶液的存在下,络合形成均匀稳定的分散体,再浸渍涤纶织物表面。升温过程中,高分子单体聚合以形成连续的网状结构限制了金属钯团聚。所生成的氨气对Pd2+与Ag+进行还原,原位生成了贵金属聚合物催化层。与传统的前处理工艺相比,无须使用SnCl2敏化,使此法无毒更简便易行。同时,减少了钯盐的用量,降低了成本。在织物上进行化学镀铜,并对其工艺参数进行了初步的研究。实验表明研制的电磁屏蔽材料表面电阻较小,厚度较薄,各方面的性能优良。     

纳米TiO2改性丝素膜中的纳米颗粒粒径分析

为了进一步改善丝素蛋白膜的结构性能,尝试用溶胶凝胶法制备纳米TiO2改性丝素复合膜。测得用溶胶--凝胶法在丝素溶液中直接生成的纳米粒子粒径在76 nm左右,用AFM、有效质量近似模型估算出纳米改性再生丝素膜中纳米粒子粒径在80 nm左右; 当TiO2含量小于1.2 %时,生成的纳米粒子的尺寸小于100 nm;纳米粒子尺寸随着溶液pH的增加而增大。研究表明用溶胶-凝胶法制备纳米再生丝素膜方法可行,成膜前后纳米粒子没有发生团聚,都处于纳米级别。     

纳/微米纤维膜的吸油性及油水分离效果

油水污物是影响环境清洁性的重要因素之一,为此,分析了纳/微米纤维膜对大豆油、液体石蜡和白油3类油的吸油性和油水分离效果,并与市场用针织超细纤维洁净布、非织造超净无尘布进行比较,综合评价其去油污效果。结果表明,纳/微米纤维膜的吸油性和油水分离效果明显好于2种市场用洁净布,纳米级纤维膜对大豆油、液体石蜡、白油的饱和吸油率分别高达15.1、14.9、15.0 g/g,对油水乳液中油的去除率接近50%,其次是微米级纤维膜,针织超细纤维洁净布的效果最差。     

响应曲面法优化纳米氯化钙/PVDF杂化膜制备工艺的研究

利用热致相变法制备了纳米氯化钙/PVDF杂化膜,研究了不同添加量的纳米氯化钙粒子对PVDF微孔膜的膜形态、截留率、水通量以及膜强度的影响。采用响应曲面的分析方法,以PVDF膜的水通量以及膜强度为响应值,确定了最佳的纳米CaCl2粒子的添加量、PVDF的质量分数以及凝固浴温度。结果表明:纳米氯化钙的添加能显著改变PVDF膜的形态结构,随着纳米氯化钙含量的增加,海绵状孔逐渐消失,膜表面出现了大量的界面孔,膜通量以及膜强度先上升后下降,而其对截留率的影响较小,在其质量分数为5%时,截留率以及水通量达到最大值。确定的高强度膜制备工艺条件:CaCl2以及PVDF的质量分数分别为4.7%、44%,凝固温度为49.5℃,该条件下,膜截留率达到了75%,水通量达到了174L·m-2·h-1,膜强度则为29.8MPa。      

Comparison performances of membrane bioreactor and conventional activated sludge prcesses on sludge reduction induced by Oligochaete

Pilot-scale experiments were carried out to compare sludge reduction induced by Oligochaete in a submerged membrane bioreactor (MBR) and a conventional activated sludge (CAS) reactor for 345 d. Worm growth in the CAS reactor was much better than in the MBR. The average worm density of the aeration tank in the CAS reactor was 71 total worms/mg of volatile suspended solids (VSS), much higher than that in the MBR (10 total worms/mg of VSS). Worms did not naturally produce in the MBR, and the dominant worm type in the MBR depended on sludge inoculation from the CAS reactor. Only two types of worms were found in the MBR, Aeolosoma hemprichicii and Nais elinguis. Worm presence and disappearance in the MBR alternated. Worms in the CAS reactor occurred nearly throughout the operating period and were continuously maintained at over 30 total worms/mg of VSS in the aeration tank for 172 d. Three types of worm were found in the CAS reactor, A. hemprichicii, Pristina aequiseta, and N. elinguis, but P. aequiseta was present only occasionally. The alternating dominance of worm types in both reactors changed between Aeolosoma and Nais, and the time of Aeolosoma dominance was longer than that of Nais dominance. Worm growth in the MBR contributed to neither sludge reduction nor improvement of sludge settling characteristics because of low density. But worm presence and bloom in the CAS reactor greatly decreased sludge yield and improved sludge settling characteristics at high density. Both the average sludge yield (0.17 kg of suspended solids (SS)/kg of chemical oxygen demand removed (CODremoved)) and sludge volume index (60 mL/g) in the CAS reactor were much lower than those in the MBR (0.40 kg of SS/kg of CODremoved and 133 mL/g). Nais had more potential for sludge reduction than Aeolosoma. Worm growth had little impact on effluent quality in the MBR but affected effluent quality very much in the CAS reactor.     

Elimination of selected acidic pharmaceuticals from municipal wastewater by an activated sludge system and membrane bioreactors

The elimination of six acidic pharmaceuticals (clofibric acid, diclofenac, ibuprofen, ketoprofen, mefenamic acid, and naproxen) in a real wastewater treatment plant (WWTP) using an activated sludge system and membrane bioreactors (MBRs) was investigated by using a gas chromatography/mass spectrometry (GC/MS) system for measurement of the compounds. Limited information is available for some of the tested pharmaceuticals at present. Solid retention times (SRTs) of the WWTP and the two MBRs were 7, 15, and 65 days, respectively. The elimination rates varied from compound to compound. The MBRs exhibited greater elimination rates for the examined pharmaceuticals than did the real plant. Dependency of the elimination rates of the pharmaceuticals on SRTs was obvious; the MBR operated with a longer SRT of 65 days clearly showed better performance than did the MBR with a shorter SRT of 15 days. The difference between the two MBRs was particularly significant in terms of elimination of ketoprofen and diclofenac. Measurements of the amounts of adsorbed pharmaceuticals on the sludge and aerobic batch elimination experiments were carried out to investigate the elimination pathways of the pharmaceuticals. Results of the batch elimination tests revealed that the sludges in the MBRs had large specific sorption capacities mainly due to their large specific surface areas. Despite the sorption capacities of sludges, the main mechanism of elimination of the pharmaceuticals in the investigated processes was found to be biodegradation. Biodegradation of diclofenac, which has been believed to be refractory to biodegradation, seemed to occur very slowly.     

Fate of surfactants in membrane bioreactors and conventional activated sludge plants

Two membrane bioreactors (MBRs) were operated at high sludge retention time (SRT) (between 30 and 75 d) in parallel to a conventional activated sludge plant (CASP) conducted at SRT = 10 d. The fate of linear alkylbenzene sulfonate (LAS), nonylphenol ethoxylates (NP(n)EO, n = 1-15), nonylphenoxy carboxylates (NP(n)EC, n = 1-2), and nonylphenol (NP) in these systems was investigated. All systems were very efficient in the removal of LAS (around 99%). The analysis of variance showed that the difference in the removal efficiency of LAS in the CASP and the MBR operated at SRT = 65-75 d (respectively 99.0 ± 0.43 and 99.8 ± 0.11) were significant (p < 0.05), confirming the importance of SRT in the removal of LAS. Comparison between the CASP and the MBRs in the removal efficiency of nonylphenolic compounds were conducted considering NP(3-15)EO, the sum of NP(1-15)EO, NP(1-2)EC, and nonylphenol (NP). In all cases MBRs were more efficient than the CASP. In the case of NP the removal was about 76 ± 7.5% for the CASP and 90% ± 12.1 and 82 ± 8.7% for the MBRs. Better performance of MBRs in the removal of nonylphenolic compounds can be attributed to a better degradation. For example, if the sum of NP(1-15)EO and NP(1-2)EC is considered, estimated biodegradation was about 48% for the CASP and 72% for MBRs.     

纳米TiO2/丝素复合膜整理对织物上染率的影响

将粘胶织物和棉织物作为被整理材料，研究经纳米TiO2／丝素复合膜整理前后织物上染率的变化，并借助于AFM(原子力显微镜)观察被整理后织物表面的形状结构。试验结果表明，经复合膜整理后，织物表面的纳米TiO2分散均匀、粒径较小，且上染率有所提高。     

碳纳米生物传感检测金黄色葡萄球菌

目的建立一种基于碳纳米材料的适配体传感器快速检测金黄色葡萄球菌的方法。方法利用核酸适配体与其靶标之间的特异性结合能力以及碳纳米管的荧光猝灭特性,构建一种新型快速的金黄色葡萄球菌检测方法。结果该方法特异性良好,与非目标菌株无交叉反应。同时,该方法对金黄色葡萄球菌的检出限为10~5 CFU/mL,线性范围为10~5～10~9 CFU/mL,而且在此浓度范围之间呈现良好的线性关系,线性方程为Y=53.22X-39.99,线性相关系数r~2=0.992。结论该方法具有检测速度快、操作简便、检测成本低等特点,为金黄色葡萄球菌的快速检测提供了一种有效手段。     

纳米TiO2/丝素复合膜整理对织物色牢度的影响

研究粘胶织物和棉织物经纳米TiO2 /丝素复合膜整理前后色牢度的变化。试验结果表明,经复合膜整理后,无论用酸性橙7、活性红KD 8B,还是直接红F染色的两种织物,色牢度特别是日晒牢度均有较大改善。