CoPcS/TiO2/beads及TiO2/beads光催化降解水面浮油

以钛酸四丁酯为原料,空心玻璃微珠(beads)为载体,采用溶胶一凝胶法制备出TiO2/beads光催化剂,用浸渍法制备出CoPcS/TiO2/beads新型光催化剂.研究了利用TiO2/beads及CoPcS/TiO2/beads光催化剂降解水面漂浮植物油的最优条件.结果表明:(1)溶胶-凝胶法制备TiO2/beads的最佳条件为:空心玻璃微珠浸渍3次,450～550℃下焙烧2 h.用CoPcS对TiO2/beads进行改性时,TiO2/beads的最1圭浸渍时间为30 min.(2)在中性或酸性条件下,375 W中压汞灯光照2～3 h,TiO2/eads与CoPcS/TiO2/beads的最佳用量分别为3 g和1 g(植物油3 g),在此条件下,植物油的去除率都高达90%.(3)微量H2O2对TiO2/beads和CoPcS/TiO2/beads的光催化活性都有很大的提高.对于TiO2/beads催化剂,H2O2的最佳用量为5～11 mmol/L;对于CoPcS/TiO2/beads催化剂,H2O2的最佳用量为5～30 mmol/L.(4)新型光催化剂CoPcS/TiO2/aeads比TiO2/beads具有更好的除油性能.     

TiO2溶胶光催化降解亚甲基蓝

以钛酸四正丁酯[Ti(OC4H9)4]为前驱体,乙醇为溶剂,盐酸为催化剂,在20℃制备了有光催化活性的TiO2溶胶.在40 W紫外灯光照条件下,通过对亚甲基蓝的降解试验,研究了溶胶制备条件、溶胶用量、光照时间和亚甲基蓝溶液初始质量浓度与光催化效果的关系.试验结果表明:当Ti(OC4H9)4与H2O量比为1:100,20℃下陈化7 d,制得的TiO2溶胶对0.20g/L亚甲基蓝溶液的降解率达到97.5%,具有较好的光催化性能.     

织物负载S-N共掺杂TiO2薄膜的光催化降解活性染料研究

采用溶胶-凝胶法制备S-N共掺杂改性纳米TiO2溶胶,通过浸溃工艺对棉织物进行整理,制备出织物负载S-N共掺杂TiO2薄膜.探讨了在日光灯照射下,其对活性红MS模拟活性染料废水的光催化活性.结果表明,在日光灯照射下,织物负载S-N共掺杂TiO2薄膜的光催化降解率大大高于织物负载TiO2薄膜的降解率;对活性红MS的光催化降解效果随染液中氯化钠浓度的升高而降低,随碳酸钠浓度的升高而提高.     

Photocatalytic oxidation using a new catalyst--TiO2 microsphere--for water and wastewater treatment

Since the suspended TiO2 powder enjoys free contact with UV irradiation in a photoreactor system, it can generally achieve better efficiency than the immobilized TiO2 catalysts. However, the separation and reuse of this catalyst powder from treated water often limit its application in practice. In this study, a new type of TiO2 catalyst called TiO2 microsphere was prepared by a sol-spraying-calcination method, which can easily settle in its aqueous suspensions under gravity. The SEM image of the TiO2 microsphere samples demonstrated that they had an almost spherical shape with a particle size of 30-160 microm, while the XRD analysis indicated that these TiO2 microspheres still had a crystal size of 8.1 nm. Since these TiO2 microspheres had a porous structure with higher specific surface area and pore volume than normal TiO2 powders, they appeared to have strong adsorption ability in its aqueous suspensions. The photocatalytic activity of the TiO2 microspheres was evaluated in the photodegradations of salicylic acid (SA) and sulfosalicylic acid (SSA). The experimental results showed that the reaction rate using the TiO2 microspheres was similar to that using the TiO2 powders in the SA suspensions and even higher than that in the SSA suspensions. Chemical and physical properties of the TiO2 microspheres and powders that are attributed to photoactivity were discussed based on the Langmuir-Hinshelwood kinetic model. The prepared TiO2 microsphere samples were reused in the photooxidation reaction more than 50 times. It was found that there was no significant weakening in their photoactivity and no change in their particle shape. This TiO2 microsphere catalyst can be simply used to conduct an effective photooxidation in its suspension for water and wastewater treatment with ease of recovery from treated water.     

TiO2光催化降解橡椀栲胶的研究

通过CODcr表征,利用悬浮态TiO2对溶液中橡椀栲胶光催化降解作用进行了研究。结果发现,碱性条件下,紫外灯光直接照射,栲胶溶液的浓度为0.5 g/L,TiO2用量为1.0 g/L,降解效果较好;外加H2O2对橡椀栲胶的光催化降解有极大的促进作用,但这种促进作用会因为光生电子效率的影响而有一个极限值。     

掺氮纳米ZnO／TiO2粉体对印染废水的处理

以Ti(SO4)2和Zn(NO3)2为原料,CO(NH2)2为沉淀剂,采用均匀沉淀法制备了掺杂氮和不同质量分数ZnO的纳米TiO2复合粉体,通过XRD、XPS和TEM等进行表征,并测定了其对印染废水的光催化性能.结果表明,掺杂产生Ti-P-Zn键和Ti-O-N键,复合粉体的激发波段从紫外光扩展到可见光波段,催化活性大大提高,具有较强的可见光催化性能;ZnO掺杂质量分数为2%时,复合粉体对印染废水的太阳光催化性能最高,太阳光照射5 h,脱色率达86.5%,COD降解率达67.3%.     

Design of a photocatalyst for bromate decomposition: surface modification of TiO2 by pseudo-boehmite

The rate of BrO3- reduction by a commercial TiO2 photocatalyst under UV illumination in an aqueous solution was increased by lowering the pH from 7 to 5. The effect is attributable to an enhancement of the electrical interaction between BrO3- and the positively charged surfaces of the TiO2 photocatalyst. The surface charge can be controlled by a surface modification of the TiO2 photocatalyst without controlling the pH of the water. In fact, the isoelectric point of surface-modified TiO2 was higher than that of the unloaded TiO2 photocatalyst, resulting in an increase in the rate of the photocatalytic reduction of BrO3- at a neutral pH. This increase is explained by an increase in the amount of adsorbed BrO3- on the photocatalyst surface.     

用吸附相反应技术制备弱光响应的铈掺杂TiO2复合光催化剂

为拓展多相光催化的实际应用和满足环境治理的严格要求,利用吸附相反应技术设计并制备了弱紫外光响应高效的TiO2 多组分催化剂。借助透射电子显微镜、高分辨率透射电子显微镜和X 射线衍射分析了不同焙烧温度下铈离子掺杂量对催化剂形貌的影响,并结合光致发光光谱和弱光降解甲基橙过程,探索了催化剂结构变化对光生载流子复合率和弱光催化活性的影响。结果表明,当掺杂量较低（小于0.10%）时,铈离子掺入引起TiO2 晶格膨胀,从而引入光生载流子的浅能级捕获中心,提升了催化活性;在较高掺杂量（0.20% 以上）时, 铈离子掺入抑制了TiO2 结晶,催化剂中大量无定形TiO2 严重抑制了其活性;焙烧温度越高,铈离子掺杂量对催化剂结构和活性的影响越显著;降解高浓度甲基橙时,催化性能最好的催化剂的活性是商用P 25 的2 倍多。     

Survey of bisphenol A in bottled water products in Canada

A method based on isotope dilution headspace solid-phase microextraction and gas chromatography/mass spectrometry was used to assess levels of bisphenol A (BPA) in 56 samples of bottled water products sold in Canada. Levels of BPA in samples of all 51 non-polycarbonate (PC) bottled water products were lower than the method detection limit (0.50 µg l^–1). Levels of BPA in most bottled water products in PC carboys were low, ranging from <0.50 to 1.4 µg l^–1 with an average of 0.75 µg l^–1. However, BPA was detected at levels of 8.8 and 6.5 µg l^–1 in two bottles of the bottled water products in PC carboys from the same product analysed over a 5-week period, likely due to accidental or careless exposure of the products to heat (e.g. under the sun) during storage and/or transportation for extended periods of time.     

PET非织造基溅射TiO_2/Nd/TiO_2及其抗菌性

利用磁控溅射技术,在室温条件下将纳米稀土Nd及光催化型抗菌材料TiO2以TiO2/Nd/TiO2方式沉积在PET非织造布表面,以制备纳米结构稀土激活TiO2复合抗菌材料。由于宽化了纳米TiO2的吸收光谱,制备的材料在可见光照射的情况下具有较好的抗菌效果。通过正交试验,获得最佳的溅射制备条件,即TiO2溅射功率75 W,Nd溅射功率40 W,Ar气体流量15 mL/min,反应压强1 Pa,所制备的复合抗菌薄膜抗菌效果最好。     

TiO2-ZnO复合水溶胶对纯棉织物的抗紫外线整理

采用溶胶-凝胶技术制备TiO2-ZnO水溶胶,通过浸轧、烘干、焙烘等工序对纯棉织物进行整理,然后对整理前后织物的抗紫外线性能进行比较,评价其抗紫外线等级,对整理后未皂洗织物和皂洗30次织物的抗紫外线性能进行比较,以评价抗紫外线性能的耐久性.结果表明,经整理的织物UPF等级为50＋,皂洗30次后的UPF等级为35,即经过此法整理的纯棉织物具有很好的紫外线防护性能和良好的耐久性.     

Co掺杂TiO2纳米晶光催化降解制浆黑液

用溶胶-凝胶法制备Co掺杂TiO2纳米晶,利用X-射线衍射(XRD)和紫外-可见光谱(UV-Vis)对样品进行表征.结果表明400℃时,粒子平均粒径为10nm左右,适量Co掺杂抑制TiO2晶粒的成长,掺Co使TiO2纳米晶的光谱响应范围向可见光拓展.在紫外光照射下,掺杂Co的TiO2能有效促进光催化降解制浆黑液,显著提高制浆黑液中CODCr的去除效果,反应8h后,CODCr由反应前的480mg/L降至144mg/L,色度去除率可达到86.9%.     

纳米TiO2光催化氧化技术在造纸废水处理中的应用

TiO2光催化氧化是一种新兴的高效水处理技术，其在处理废水中的难降解毒性有机污染物等方面具有广阔的应用前景。文章介绍了纳米TiO2光催化氧化技术的原理、影响因素及其在制浆造纸废水处理方面的研究进展，并对存在的问题作了探讨。     

Photocatalytic oxidation of arsenite in TiO2 suspension: kinetics and mechanisms

Arsenite [As(III)] and arsenate [As(V)] are highly toxic aquatic contaminants. Since arsenite is more mobile in natural waters and less efficiently removed in adsorption/coagulation processes than arsenate, the oxidation of arsenite to arsenate is desirable in water treatment. We performed the photocatalytic oxidation of arsenite in aqueous TiO2 suspension and investigated the effects of pH, dissolved oxygen, humic acid (HA), and ferric ions on the kinetics and mechanisms of arsenite oxidation. Arsenite oxidation in UV-illuminated TiO2 suspension was highly efficient in the presence of dissolved oxygen. Homogeneous photooxidation of arsenite in the absence of TiO2 was negligibly slow. Since the addition of excess tert-butyl alcohol (OH radical scavenger) did not reduce the rate of arsenite oxidation, the OH radicals should not be responsible for As(III) oxidation. The addition of HA increased both arsenite oxidation and H2O2 production at pH 3 under illumination, which could be ascribed to the enhanced superoxide generation through sensitization. We propose that the superoxide is the main oxidant of arsenite in the TiO2/UV process. The addition of ferric ions also significantly enhanced the arsenite photooxidation. In this case, the addition of tert-butyl alcohol reduced the arsenite oxidation rate, which implied thatthe OH radical-mediated oxidation path was operative in the presence of ferric ions. Since both Fe3+ and HA that were often found with the arsenic in groundwater were beneficial to the photocatalytic oxidation of arsenite, the TiO2/UV process could be a viable pretreatment method. This can be as simple as exposing the arsenic-polluted water in a TiO2-coated trough to sunlight.     

超高效液相色谱-四级杆串联质谱法检测饮用水中双酚A和双酚F及其氯化消毒副产物

目的建立饮用水中双酚A(BPA)、双酚F(BPF)及其9种氯化消毒副产物的超高效液相色谱-四级杆串联质谱(UPLC-MS/MS)检测方法。方法 500 ml饮用水样品经PLEXA固相萃取柱富集净化后,通过BEH C_(18)色谱柱(2.1 mm×100 mm,1.7μm)分离,以乙腈-水作为流动相梯度洗脱,采用四极杆串联质谱仪电喷雾负离子模式进行检测,外标法定量。结果 11种目标物质在给定的浓度范围内具有良好的线性关系(r~20.99),方法定量限(LOQ)为0.01~4.00 ng/L,加标回收率为78.8%~99.6%,相对标准偏差(RSD)均小于12.2%。利用该方法分析40份实际饮用水样品,BPA、BPF和四氯双酚A(4Cl-BPA)3种目标物质在样品中的检出率分别为45.0%(18/40)、40.0%(16/40)和32.5%(13/40),检出浓度分别为0.60~9.40、LOQ~106.20和LOQ~0.02 ng/L。结论本方法具有良好的灵敏度、回收率和重复性,适合饮用水样品中BPA、BPF及其氯化消毒副产物的测定。     

Photocatalytic degradation of acid blue 80 in aqueous solutions containing TiO2 suspensions

The photocatalytic degradation of the anthraquinonic dye Acid Blue 80 in aqueous solutions containing TiO2 dispersions has been investigated. The process has been monitored by following either the disappearance of the dye (via HPLC) and the formation of its end-products (via IC, GC, and TOC analysis). Although a relatively fast decolorization of the solutions has been observed, the mineralization is slower, and the presence of residual organic compounds was evidenced even after long term irradiation, confirming the relevant stability of anthraquinone derivatives. The identification of various unstable intermediates formed after low irradiation times was performed by HPLC-MS, allowing us to give insight into the early steps of the degradation process which mainly involve C-N bonds breaking and substrate hydroxylation. Complete and relatively fast mineralization of the substrate was achieved by irradiating the semiconductor dispersions in the presence of added K2S2O8.     

TiO2光催化降解印染废水的工艺研究

用悬浮法光催化氧化实际印染废水，并与不加催化剂的光降解处理废水的结果进行比较，结果表明：采用TiO2为催化剂可以显著加快光催化氧化过程。探讨了处理时间、处理温度、TiO2催化剂用量等因素对废水的去除和脱色的影响。实验结果表明，光催化处理该染料废水的最佳工艺条件为：处理时间6h，温度30℃，TiO2用量为1mg／mL。     

固相萃取-超高效液相色谱-串联质谱法测定瓶装饮用水中双酚A、双酚S

目的建立固相萃取(solid phase extraction,SPE)结合超高效液相色谱-串联质谱法(ultra performance liquid chromatography-tandem mass spectrometry,UPLC-MS/MS)测定瓶装饮用水中双酚A(bisphenol A,BPA)、双酚S(bisphenol S,BPS)的方法。方法利用BPA-D_4和BPS-~(13)C_(12)混合同位素内标,经Waters Oasis系列的HLB固相萃取柱富集样品,以甲醇-水为流动相,经Waters BEH C_(18)色谱柱分离,采用UPLC-MS/MS在负离子电离(electron spray ionization,ESI-)模式和多反应监控(multiple reaction monitoring,MRM)模式下检测。结果用该方法测定时,BPA在1~50μg/L范围内线性良好,BPS在0.2~10μg/L范围内线性良好,相关系数r均为0.9999,BPA的平均回收率为99.5%~100.7%,相对标准偏差为0.8%~4.6%;BPS的平均回收率为95.9%~102.1%,相对标准偏差为1.3%~2.5%,BPA的最低检出浓度为20 ng/L,BPS的最低检出浓度为5 ng/L。结论此方法操作简单、灵敏度高、重现性好,适用于瓶装饮用水中双酚A、双酚S的检测。     

Determination of bisphenol A in foods using GC/MS

An analytical method using GC/MS was developed for bisphenol A (BPA) in foods and BPA was determined in canned foods and fresh foods such as vegetables, fruit and meat. BPA was extracted with acetone from the samples and the extract was concentrated at under 40 degrees C in vacuo to afford an aqueous solution, which was washed with hexane after alkalization and extracted with 50% diethyl ether-hexane after acidification. Extracts were cleaned up on a PSA and/or a C18 cartridge column, and BPA was derivatized with heptafluorobutyric anhydride and determined by GC/MS (SIM). This method was applicable to the detection and determination of BPA residues in food samples at the level of 1 ng/g. Among canned foods, BPA was found in 6 corned beef, 1 chicken, 9 sweet corn and 3 bean samples at the levels of 17-602 ng/g, 212 ng/g, 2.3-75 ng/g and 3.5-26 ng/g, respectively. BPA was also detected in 1 retort soup and 1 retort pack product at the levels of 11 ng/g and 86 ng/g, respectively. As for dairy products, BPA was not detected in butter and milk. Among fresh foods, BPA was detected in 2 fish and 3 liver samples at the levels of trace (tr)-6.2 ng/g and tr-2.2 ng/g, respectively. In vegetables, fruits and chocolates, a trace level of BPA was detected in only 1 chocolate. Traces of BPA were also detected in 3 samples of 6 boxed lunches.