Mn的氧化价态对Mn/γ-Al2O3催化剂催化臭氧氧化气相低浓度甲苯的影响

采用共沉淀法,以Al₂O₃为载体制备Mn/γ-Al₂O₃和Mn-Ce/γ-Al₂O₃催化剂,并分别在N₂气氛和O₂气氛下焙烧。采用固定床连续流动反应器,研究所制备催化剂在室温条件下催化臭氧氧化甲苯的性能。通过XRD、XPS和FTIR等手段对催化剂的结构和组成进行表征。结果表明,Mn/γ-Al₂O₃催化剂具有良好的催化臭氧氧化甲苯和催化臭氧自身分解的性能,共沉淀法制备催化剂的最佳Mn负载量为20%。O₂气氛焙烧和Ce的加入,可以有效提高催化剂的活性和寿命。原因是O₂气氛焙烧和Ce的加入可以提高Mn的氧化价态。催化剂失活的主要原因是有机副产物在催化剂表面吸附堆积,失活催化剂在550℃、空气气氛下焙烧可恢复催化性能。     

二氧化氯催化氧化—曝气生物滤池法深度处理造纸废水

采用二氧化氯催化氧化法—BAF法深度处理造纸废水,实验结果表明:在二氧化氯加入量为150mg/L,催化氧化时间为40min时,可生化性BOD5/COD最高达到0.316;二氧化氯氧化后出水经曝气生物滤池深度处理后,BOD5低于20mg/L,COD低于90mg/L,TSS低于30mg/L,处理后水质完全达到国家新的排放标准(GB3544—2008)。     

改进钒基SCR脱硝催化剂的抗碱金属中毒性能

以锐钛矿型二氧化钛和钛钨粉(5%WO3-TiO2)为载体,制备了系列钒和钨负载量不同的钒钛催化剂,考察碱金属和碱土金属(钾、钠和钙)对催化剂在氨选择性催化还原(NH3-SCR)氮氧化物反应中催化活性的影响。钾、钠和钙对钒钛催化剂的中毒影响大小顺序为钾钠钙。提高钒钛催化剂中钒的含量可显著提高催化剂的SCR活性和抗碱金属中毒性能,但高钒负载量(4.5%V2O5)造成催化剂氮气选择性明显下降,氧化亚氮生成显著增加。钨的添加有利于提高钒钛催化剂的低温活性和抗碱金属中毒性能,对氮气选择性无明显影响。     

Chemometric approach to evaluate element distribution in muscle,liver and fish bone of roach (Rutilus rutilus), silver bream (Blicca bjoerkna) and crucian carp (Carassius carassius) from Swarzędzkie Lake (Poland) using ICP-MS and FIAS-CVAAS techniques

The content of elements in fish tissues and organs from Swarz?dzkie Lake was investigated in order to evaluate the possible risk associated with their consumption by animals as well as humans. Samples of muscle, liver and fish bone of three fish species; roach (Rutilus rutilus), silver bream (Blicca bjoerkna) and crucian carp (Carassius carassius) were collected from seine catches undertaken as part of the biomanipulation of Swarz?dzkie Lake. Element concentration (Al, As, Cd, Co, Cr, Cu, Hg, Ni, Pb, Zn) was determined by inductively coupled plasma mass spectrometry (ICP-MS), with the exception of Hg where the flow injection analysis system cold vapour atomic absorption spectrometry (FIAS-CVAAS) was applied. The study indicated a large variation in the occurrence of the investigated elements in different parts of the fish body. The highest content of Al and Zn was stated in all fish organs for each fish species. The majority of the applied statistical and chemometric methods (e.g., PCA, CA) refer to roach since we had a large number of data for this species. The obtained results were assessed in terms of their accuracy and precision using certified reference material of Fish Muscle ERM BB422.     

烟气脱硫脱硝一体化技术的研究进展

煤炭资源作为现阶段我国的主要资源,所造成的环境问题日益严重。随着我国对环境问题的不断重视,烟气脱硫、脱硝催化剂的研究也在不断的发展。总结了目前应用较为广泛的脱硫脱硝一体化技术,并展望活性炭用于烟气脱硫脱硝一体化的发展前景。     

铁铈钛复合氧化物催化剂的制备及其选择性催化还原NO的性能

采用共沉淀法制备了一种新型催化剂——铁铈钛复合氧化物催化剂,研究了Fe掺加量、体积空速以及H2O和SO2的加入对其选择性催化还原NO性能的影响;采用XRD和SEM等手段对催化剂的结构和形貌进行了表征。表征结果显示,Fe的掺加使催化剂表面的颗粒更均匀,提高了催化剂的分散度。实验结果表明：以Ce（NO3）3,Fe（NO3）3?9H2O,TiOSO4?2H2O为原料、按n（Ce）∶n（Fe）∶n（Ti）=0.2∶0.8∶1配比制得的Ce0.2Fe0.8TiOx为催化剂,在反应温度250 ℃、反应时间3 h、体积空速25 000 h-1的条件下,NO去除率为99.8%,N2选择性为100%;Fe的掺加显著提高了Ce0.2Fe0.8TiOx催化剂的抗H2O和SO2的能力。     

锌、铁等离子对氧化锌烟气脱硫工艺中亚硫酸锌氧化的影响

在氧化锌法脱除烟气SO2工艺中,脱硫产物亚硫酸锌的氧化是实现锌、硫资源回收的关键环节。在pH为4～5,25℃等条件下,考察了锌、铁、镉离子对亚硫酸锌氧化过程的影响。结果发现,铁离子对亚硫酸锌氧化过程有较强的催化作用,锌离子有一定的催化作用,而低浓度的镉离子几乎不影响氧化过程。进一步的研究表明,锌、铁离子的独自催化氧化速率对各自的浓度均为0．5级响应,但在混合状态下,锌离子对铁离子的催化过程有抑制作用。     

Cu-SBA-15催化湿式过氧化氢氧化水溶液中罗丹明B

采用水热晶化法合成了不同含铜量的Cu—SBA-15介孔分子筛,并且用XRD、N2吸附、TEM以及uV—vis对所合成的样品进行表征。以Cu—SBA-15为催化剂,H2O2为氧化剂,催化湿式过氧化水溶液中的罗丹明B,主要考察H2O2浓度、催化剂用量、处理温度、初始pH等因素对罗丹明B氧化效果的影响。结果表明,在同样的处理条件下罗丹明的脱色率明显高于TOC去除率,处理温度、初始pH对罗丹明B的脱色与氧化有重要影响。在罗丹明B初始浓度100mg／L,H2O2初始浓度1．8g／L,催化剂量0．3g／L,温度60℃,pH为7．0,处理时间100min时,罗丹明B的脱色率为98．6％,TOC去除率为62．8％。     

Triclosan in Fresh Water Fish Gibelion Catla from the Kaveri River,India, and Its Consumption Risk Assessment

Triclosan is a common antimicrobial agent that is found in significant levels in the aquatic environment and may elicit effects on aquatic organisms through unexpected modes of action. In this study, triclosan was quantified in fish from the Kaveri River, India, by using the gas chromatography and mass spectrometry technique and it was found in the range of 0.73–50 ng/g wet weight (ww). The mean bioaccumulation factor based on water (BAF_w 820) and sediment (BAF_s 2.12) in the Kaveri River showed that triclosan is accumulative in fish, and reflects its feeding behavior. The bioaccumulation indicates triclosan's persistence or prevalence throughout the river stretch. Human risk assessment through dietary intake demonstrated that the triclosan exposure is five orders of magnitude lower than the acceptable daily intake (50 μg/kg bw) and US EPA reference dose (300 μg/kg bw/day). This investigation is the first to report the bioaccumulation of triclosan in freshwater fish from India. Further, the results indicate that this fish acts as a biomarker of exposure for triclosan and thus shall be used to report triclosan pollution in the future.     

BiVO_4催化剂的离子液体辅助水热合成及其可见光催化活性

采用溴化1-丁基-3-甲基咪唑([Bmim]Br)离子液体辅助水热合成法制备了光催化剂Bi VO4。以高压氙灯作为可见光源,亚甲基蓝为目标污染物,考察反应温度、p H、反应时间和离子用量等制备条件对Bi VO4的可见光催化活性的影响,确定了最佳制备条件。并采用XRD、SEM和UV-Vis漫反射等分析手段对催化剂的晶相、形貌和光学特性进行了表征。结果表明,在离子液体加入量为2 m L、p H=4、反应温度为180℃、反应时间为4 h的条件下,制得的Bi VO4催化剂的可见光光催化活性最高。制得的Bi VO4为单斜相,呈分散的、大小均匀的片状,在200~500 nm范围有一个较宽的强吸收平台,具有良好的可见光催化活性,在可见光照射下对浓度为5 mg/L的亚甲基蓝的光催化脱色率达97%以上。