原位聚合法制备纳米凹凸棒土/聚乳酸复合材料

将凹凸棒土（AT）进行提纯和有机改性后, 采用原位聚合法制备了OAT质量分数为1%、 3%、 5%的纳米凹凸棒土/聚乳酸复合材料（OAT/PLA-x）。采用红外、 扫描电镜、 X射线衍射等对复合材料进行了表征, SEM结果表明, 凹凸棒土粒子在复合材料中实现了均匀稳定分散。复合材料的力学性能和综合热性能测试表明: OAT/PLA-3复合材料的拉伸强度、 弹性模量分别比纯PLA增加98.6%和130.0%; 复合材料的热稳定性明显提高。同时, 复合材料的溶液降解速率也明显加快。      

有机改性凹凸棒土/聚氨酯弹性体纳米复合材料的制备与性能

采用插层复合法制备有机改性凹凸棒土/聚氨酯弹性体纳米复合材料。用傅里叶变换红外光谱(FT-IR)测试技术对凹凸棒土的有机改性进行表征。研究了纳米复合材料的力学性能、耐热性能及纳米填料在复合材料中的分散形态。结果表明,当改性凹凸棒土质量分数达到2%时,复合材料的拉伸强度为55.91MPa,扯断伸长率为559.45%,300%定伸应力为31.69 MPa,硬度几乎保持不变,综合力学性能达到最佳,同时其热稳定性也有所提高;改性凹凸棒土的加入量低于2%时,在聚氨酯基体中分散较为均匀,随着含量的增加出现团聚现象。     

多孔吸附光催化复合材料在含汞废水治理中的应用研究

以凹凸棒土和活性污泥为材料制备多孔载体,采用溶胶-凝胶法制备光催化剂TiO2和多孔吸附光催化复合材料。通过单因素实验,探究降解汞离子(Hg2+)的最优条件,研究TiO2光催化剂降解汞污染物的机制。结果表明:多孔吸附光催化复合材料质量浓度为20g/L,当pH=7.0时,在紫外光源照射10min,Hg2+的还原率达最大,Hg2+的去除率可达71.58%。最后,考察了利用多孔吸附光催化复合材料处理含甲基汞(CH3-Hg+)废水的可行性。     

纳米AT/NBR复合材料的制备与研究

纳米凹凸棒土(AT)是一种天然纳米填料,对其性质和改性方法的研究直接关系到它的应用性能和工业前景。采用熔融共混法制备了纳米凹凸棒土/丁腈橡胶(AT/NBR)复合材料,并进行了力学性能测试。具体考察了增塑剂、硅烷偶联剂、不同凹凸棒土填充量、改性方法等对复合材料力学性能的影响。结果表明,经Si-69改性的AT可以显著提高NBR的力学性能。     

聚吡咯/凹凸棒纳米复合材料对Cr6+的吸附性能

以FeCl3为氧化剂和掺杂剂用原位聚合法制备了聚吡咯/凹凸棒纳米复合材料,用以吸附溶液中高毒性的Cr6+。研究表明,该吸附剂在10min内即可达到吸附平衡,吸附效果优异,同时考察了吸附剂用量、Cr6+的初始浓度和pH值对吸附效果的影响。吸附过程等温线数据符合Langmuir等温吸附方程式,饱和吸附量为48.45mg/g,计算得到的热力学数据ΔH、ΔG、ΔS均为负值,说明该吸附过程是一个放热的自发过程。吸附动力学符合准二级动力学方程,说明吸附过程属于化学吸附反应过程。用傅里叶变换红外光谱和扫描电镜对复合材料的结构进行表征,发现聚吡咯微球包覆在棒状的凹凸棒表面形成纳米复合材料,其红外谱图与聚吡咯基本一致。     

聚丙烯酸/蒙脱土纳米复合材料的性能及保水行为动力学

利用高温快速反应法成功制备了聚丙烯酸/蒙脱土高吸水性纳米复合材料。考察了交联剂质量分数对纳米复合材料吸水倍率的影响规律,并利用SEM等表征发现,当交联剂用量为0.225%时,可获得很好的结果,所得纳米复合材料吸水倍率为372 mL/g。在20℃~70℃的范围,研究了聚丙烯酸/蒙脱土纳米复合材料的保水行为动力学。结果表明,20℃时聚丙烯酸/蒙脱土10 g水凝胶干燥时间为128 h,在高温条件下该复合材料仍具有优异的保水性能;其保水过程为零级反应;复合材料保水反应的反应速率常数为k=3.7967×107exp(-Ea/RT),其保水过程的表观活化能Ea=43.19kJ/mol。     

聚碳酸亚丙酯/凹凸棒纳米复合材料制备与热稳定性研究

通过溶液共混法制备了聚碳酸亚丙酯/凹凸棒纳米复合材料。利用FT-IR、XRD和SEM表征手段研究了复合材料的结构。研究表明有机改性的凹凸棒在聚碳酸亚丙酯中分散均匀,平均粒径为70nm。利用TG研究了聚碳酸亚丙酯/凹凸棒纳米复合材料的热稳定性,结果发现纳米尺寸凹凸棒的引入能够显著提高聚碳酸亚丙酯的热稳定性,其中凹凸棒含量为0.5%的复合材料热稳定性最好,其5%、50%和最大热分解温度分别为273℃、291℃和289℃,相比PPC分别提高了63℃、53℃和52℃。     

有机酸掺杂的聚苯胺/凹凸棒复合材料的制备及性能表征

以磺基水杨酸为掺杂剂,采用化学原位聚合法合成了聚苯胺/凹凸棒土(PANI/ATP)纳米导电复合材料,并通过SEM、XRD和FT-IR技术对样品的形貌、结构进行表征。同时考察了苯胺(Ani)与凹凸棒土(ATP)质量比对复合材料体积电阻率的影响。结果表明:苯胺单体在凹凸棒土的表面发生原位聚合,并以非晶态形式包覆在凹凸棒土的表面,形成有机包覆层。随着苯胺用量的增多,纳米复合材料的电导率逐渐增大,当Ani/ATP质量比超过20∶80时,电导率增加缓慢并趋于稳定。     

聚丙烯/凹凸棒土纳米复合材料的制备、结构与性能

采用超声波分散方法将凹凸棒土(简称凹土AT)在水中进行分散,然后用硅烷偶联剂KH570对凹凸棒土纳米棒晶进行表面处理,采用X射线光电子能谱(XPS)对表面结构进行了表征.将经上述表面处理的凹凸棒土与PP复合制备纳米复合材料,研究了纳米复合材料的结晶行为与力学性能.     

原位聚合制备LDPE/凹凸棒土纳米复合材料

利用超声波分散处理凹凸棒土,分别采用硅烷偶联剂KH570对其进行表面修饰和溶液聚合法在修饰后的凹土表面原位接枝聚合MMA单体,将经上述处理的凹土与LDPE(低密度聚乙烯)复合制备LDPE／AT纳米复合材料。结果表明,通过超声波分散的方法可以得到凹凸棒土纳米棒晶,凹凸棒土对MMA无阻聚作用,表面包覆的聚甲基丙烯酸甲酯(PMMA)能有效地解决复合材料的界面粘接,提高复合材料的性能。     

炭纤维阳极氧化对活性污泥固着性能的影响

通过炭纤维电化学表面改性及动态固着代替静态固着,发现好氧池中处理后的聚丙烯腈(PAN)基炭纤维固着能力更好。对改性后炭纤维的表面形貌、表面官能团的种类和含氧官能团的含氧量进行了表征,并根据动、静态固着效果,分析了影响活性污泥固着的关键因素。SEM表面形貌观察表明经过电化学刻蚀后,炭纤维表面粗糙度的增加有利于形成活性污泥的固着。XPS分析显示,电化学表面改性后,C-C键、羧基、羰基等官能团影响活性污泥的表面固着效果,其中羧基的影响最为显著,另外,表面化学吸附氧对活性污泥固着有促进作用。     

Sorption and degradation of bisphenol A by aerobic activated sludge

Laboratory-scale batch experiments were conducted to investigate the sorption and degradation of bisphenol A (BPA) at μg/L range in an aerobic activated sludge system. The sorption isotherms and thermodynamics indicated that the sorption of BPA on sludge was mainly a physical process in which partitioning played a dominating role. The values of sorption coefficient K_oc were between 621 and 736 L/kg in the temperature range of 10–30 °C. Both mixed liquor suspended solid (MLSS) and temperature influenced BPA sorption on sludge. The degradation of BPA by acclimated activated sludge could be described by first-order reaction equation with the first-order degradation rate constant of 0.80 h⁻¹ at 20 °C. The decrease of initial COD concentration and the increase of MLSS concentration and temperature enhanced BPA degradation rate. The removal of BPA in the activated sludge system was characterized by a quick sorption on the activated sludge and subsequent biodegradation.     

Influence of pH, curing time and environmental stress on the immobilization of hazardous waste using activated fly ash

The current work is related to inorganic species in sludge generated from Common Effluent Treatment Plant contaminated with hazardous wastes at relatively high concentration. The environmental sensitive metals studied in the sludge are Pb, Fe, Ni, Zn and Mn. The solidification/stabilization (S/S) of heavy metals within fly ash-cement-based matrix was conducted for low cost treatment and reuse of sludge. The study examines the strength of the S/S product by predicting the effect of supplementary cementing material from efficiency factor (k) at 60 degrees C curing temperature. The leaching test was performed at two different pH 7 and 4 to determine the efficiency of heavy metal immobilization. It was observed that replacing 76% OPC by 56% fly ash and 20% sludge for 28 days curing period shows increase in strength as well as rate of stabilization for zinc, iron and manganese at pH 7, lead and nickel were stabilized by 79 and 82%, respectively. Environmental stress test was performed to evaluate the tolerance of extreme adverse environmental condition.     

Removal of o-xylene using biofilter inoculated with Rhodococcus sp. BTO62

Rhodococcus sp. BTO62 was isolated from activated sludge from a wastewater treatment plant as an o-xylene-degrading microorganism. BOT62 degraded not only o-xylene, but also benzene, toluene, ethylbenzene, m- and p-xylenes and styrene (BTEXS). A laboratory scale biofilter packed with Biosol as packing material, which is made from foamed waste glass mixed with corrugated cardboard, was inoculated with strain BTO62 and operated to remove relatively high loading of o-xylene at different space velocities under non-sterile and sterile conditions. The o-xylene elimination capacity to maintain more than 90% removal efficiency was 41g/m3/h under sterile condition, but it enhanced to 160g/m3/h under non-sterile condition. This indicates possibilities of the role of other contaminants for degradation of o-xylene and the degradation of intermediate products of o-xylene by contaminants. Quick recovery of o-xylene degradation was observed after shutdown of o-xylene gas supply and mineral medium circulation for 10-30 days.     

超声挤出制备聚丙烯/纳米碳酸钙复合材料及其结晶和分散形态

采用超声挤出制备了聚丙烯/纳米碳酸钙(PPCA s)复合材料,考察了加入纳米碳酸钙前后的结构演变和结晶行为的变化。结果表明,超声辐照能促进n-C aCO3粒子在聚合物基体中的分散,使其分散尺寸减小,分布更均匀。由于纳米粒子的成核效应,PPAC s的结晶温度和结晶度都有所提高,施加超声使结晶温度又有所提高,使结晶度相对于未施加超声辐照的纳米复合材料的低。     

改性玄武岩纤维的制备及其挂膜性能

以不同表面活性剂作为分散剂,采用物理涂覆法对玄武岩纤维（BF）进行表面改性处理,得到3种改性玄武岩纤维（MBF）。以FTIR、光学接触角分析仪和SEM分别研究了BF和MBF的表面官能团、亲水性和微观形貌的变化。计算了载体的挂膜率和残余挂膜率,以光学显微镜和扫描电子显微镜观察了BF和MBF的生物膜生长情况,讨论了不同表面处理对BF挂膜性能的影响。结果表明：经表面改性处理后,MBF的表面亲水性和水中分散性得到有效改善,其中经阳离子型表面活性剂（十六烷基三甲基氯化铵,CTAC）改性的玄武岩纤维（MBF-C）具有最佳亲水性和水中分散效果,接触角由133.57°（BF）下降至62.52°（MBF-C）。挂膜实验结果表明,3种表面活性剂对BF的表面改性处理均有助于增加微生物的附着量和提升附着强度,其中改性后的MBF-C挂膜率为256.25%,残余挂膜率为41.28%,具有最优的挂膜效果。     

有机铁改性玄武岩纤维及其对微生物的附着行为

以草酸和FeSO₄7H₂O为原料,利用液相沉积法对玄武岩纤维（BF）进行表面改性,以SEM、EDS、XPS、接触角分析仪和Zeta电位测试仪研究BF改性前后的微观形貌、元素组成、表面亲水性和电负性等性能。以枯草芽孢杆菌在不同的生长环境中的生长曲线来判断BF改性前后的生理毒性,以纯菌吸附实验和活性污泥固定实验考察有机铁改性玄武岩纤维（MBF）对微生物附着行为的影响。结果表明:MBF的亲水性和电负性得到明显改善,MBF的水接触角由89.71°降至为56.74°,表面Zeta电位由-18.53 mV提升至-5.03 mV; MBF对细菌的生长无抑制作用,不存在生理毒性;在12 h后MBF表面固定的微生物量可达27.91 gm-2,表明有机铁改性BF有助于促使更多的生物量附着在载体表面,进而有利于提高载体的污/废水处理效果。      

Determination of estrogens in sludge and sediments by liquid extraction and GC/MS/MS

Two methods have been developed that enable the determination of estrogens down to 2 ng/g in digested and activated sludge from domestic sewage treatment plants (STPs) and down to 0.2 ng/g in freshwater sediments. The method for sludge analysis consists of solvent extraction; a gel permeation chromatography (GPC) cleanup step, a 1 g silica gel column; and finally, detection by GC-ion trap MS/MS of the silylated estrogens with MSTFA. For sediments, the solvent extraction was successively followed by silica gel cleanup, solid phase enrichment (SPE), and a HPLC cleanup before derivatization and GC/MS/MS detection. Mean recoveries of the estrogens mainly exceeded 70% in sludge and 90% in sediments. In activated and digested sewage sludge, estrone and 17beta-estradiol were detected up to 37 ng/g and 49 ng/g, respectively, and 17alpha-ethinylestradiol up to 17 ng/g. The occurrence of estrogens in digested sludge indicates that estrogens can be persistent during sludge digestion. In river sediments, estrone and 17beta-estradiol were detected up to 2 ng/g (estrone), and the contraceptive 17alpha-ethinylestradiol was found with a maximum of 0.9 ng/g. Mestranol, a prodrug for 17alpha-ethinylestradiol, was not detected either in sludge or in sediments.     

智能凝胶对水流量自适应控制的仿生研究

制备了多孔聚乙烯醇缩甲醛凝胶(PVFM),研究了其对水流量控制的自适应性能.结果表明,多孔聚乙烯醇缩甲醛凝胶具有很快的吸水/脱水速度和膨胀应力变化的灵敏响应性.结合弹性水管受压变形的控制结构,研究了材料感知土壤含水量的变化和对滴灌流量进行动态调节的智能特性,发现止水/放水周期可控制在1 h以内.     

Treatability and kinetics studies of mesophilic aerobic biodegradation of high oil and grease pet food wastewater

In this work, batch activated sludge studies were investigated for the treatment of raw pet food wastewater characterized by oil and grease concentrations of 50,000-66,000 mg/L, COD and BOD concentrations of 100,000 and 80,000 mg/L, respectively, as well as effluent from an existing anaerobic digester treating the aforementioned wastewater. A pre-treatment process, dissolved air flotation (DAF) achieved 97-99% reduction in O&G to about 400-800 mg/L, which is still atypically high for AS. The batch studies were conducted using a 4-L bioreactor at room temperature (21 degrees C) under different conditions. The experimental results showed for the DAF pretreated effluent, 92% COD removal efficiency can be achieved by using conventional activated sludge system at a 5 days contact time and applied initial soluble COD to biomass ratio of 1.17 mg COD/mg VSS. Similarly for the digester effluent at average oil and grease concentrations of 13,500 mg/L, activated sludge affected 63.7-76.2% soluble COD removal at 5 days. The results also showed that all kinetic data best conformed to the zero order biodegradation model with a low biomass specific maximum substrate utilization rate of 0.168 mg COD/mg VSS day reflecting the slow biodegradability of the wastewater even after 99% removal of oil and grease.