微波诱导催化技术在水污染治理中的应用

阐述了微波诱导技术的基本原理,讨论了微波诱导催化反应中催化剂和载体,归纳了微波诱导催化技术在水污染处理中的应用状况及实例,总结了微波诱导催化技术目前的发展趋势及存在的问题.     

Remove cooking fume using catalytic combustion over Pt/La-Al2O3

Five monolithic catalysts with low noble metal content were prepared by irnmerge method （Pt/γ=Al2O3, Pt/La-Al2O3, Pt/YSZ-AI203, Pt＋Pd/La-Al2O3 and Pd/La-Al2O3） and their activity measurements were carried out in a conventional fixed-bed flow reactor. The results show that La-Al2O3 can promote activity of the prepared catalysts and can decrease the complete conversion temperature of cooking fume. The Pt/La-Al2O3 catalyst has the highest activity and can be applied in wide range of gas hourly space velocity （GHSV）. Some characterizations （XRD, TPR） were carried out with the objective to explain differences in catalytic behaviors. The prepared catalyst showed a great potential for application.     

Effect of copper on the degradation of pesticides cypermethrin and cyhalothrin

The influence of coexisting copper (Cu) ion on the degradation of pesticides pyrethroid cypermethrin and cyhalothrin in soil and photodegradation in water system were studied.Serial concentrations of the pesticides with the addition of copper ion were spiked in the soil and incubated for a regular period of time,the analysis of the extracts from the soil was carried out using gas chromatography (GC).The photodegradation of pyrethroids in water system was conducted under UV irradiation.The effect of Cu~(2 ) on the pesticides degradation was measured with half life (t_(0.5)) of degradation.It was found that a negative correlation between the degradation of the pyrethroid pesticides in soil and Cu addition was observed.But Cu~(2 ) could accelerate photodegradation of the pyrethroids in water.The t_(0.5) for cyhalothrin extended from 6.7 to 6.8 d while for cypermethrin extended from 8.1 to 10.9 d with the presence of copper ion in soil.As for photodegradation,t_(0.5) for cyhalothrin reduced from 173.3 to 115.5 rain and for cypermethrin from 115.5 to 99.0 min.The results suggested that copper influenced the degradation of the pesticides in soil by affecting the activity of microorganisms.However, it had catalyst tendency for photodegradation in water system.The difference for the degradation efficiency of pyrethroid isomers in soil was also observed.Copper could obviously accelerate the degradation of some special isomers.     

Aromatization of waste polyolefin pyrolysate over H-ZSM-5 zeolite-supported gallium oxide catalysts

H-ZSM-5 zeolite-supported gallium oxides were studied as aromatization catalysts for polyolefin pyrolysate. The catalysts were prepared by a conventional physical mixing method with a gallium content of 1.0 and 4.5 wt% and were reduced in flowing hydrogen at 585°C. To test their activity, a polyolefin sample was pyrolyzed and passed over a heated catalyst layer; the product was analyzed by gas chromatography/mass spectrometry. A continuous-flow fixed-bed reactor was used for aromatization of a model gas of polyolefin pyrolysate. For chlorine-free sources at 450°C, the catalyst with only 1.0 wt% gallium exhibited activity comparable to a gallium silicate catalyst. For chlorine-contaminated sources, the catalyst with 4.5 wt% gallium sustained catalytic activity for long periods. From the activity test results, it was found that zeolite-supported gallium catalysts prepared by the physical mixing method are suitable for converting polyolefin into aromatic hydrocarbons.     

复合催化剂对气相苯和甲苯的光催化降解研究

研究了在无催化剂、纯锐钛矿、纯金红石以及复合催化剂时苯和甲苯的光催化降解情况,考察了反应物初始浓度以及不同催化剂组成时苯和甲苯的光催化降解. 结果表明,使用锐钛矿催化剂,苯和甲苯降解效率都有很大提高,而使用金红石催化剂,苯和甲苯降解效率提高的幅度不大,这主要与锐钛矿和金红石的晶体结构有关. 在无催化剂和以金红石为催化剂时,甲苯比苯更容易降解;以锐钛矿为催化剂时苯比甲苯更容易降解. 初始浓度对苯和甲苯的光催化降解过程有一定的影响,在低浓度时降解速率较快,而在高浓度时降解速率较慢. 在锐钛矿催化剂中掺入一定量的金红石可提高催化剂的光催化活性. 对于苯,锐钛矿80%、金红石20%的复合催化剂光催化活性最高;而对于甲苯,锐钛矿90%、金红石10%的复合催化剂光催化活性最高.     

煤和聚丙烯腈炭化过程中负载铁原子在表面与体相间的质量迁移

采用ＸＰＳ和Ａｒ＾＋离子刻蚀技术，研究了炭化过程中铁原子在煤和聚丙烯腈表面和体相间的质量分布规律。结果发现，随炭化进行铁原子由表面向体相迁移和富集，炭化温度升高，迁移和富集增加，表面浓度逐渐降低，以致铁原子沿粒子径向呈浓度梯度分布。     

用MnSO_4作催化剂测定废水中的COD

介绍了用 Mn SO4代替 Ag2 SO4作催化剂测定废水中 COD的方法。该方法可降低分析成本 ,且使回流时间缩短为 30 m in,方法的变异系数、回收率分别为 0 .6 5 %和 96 .8%～10 0 .8%     

废水催化湿式氧化稀土金属氧化物催化剂的研制

采用共沉淀法制得锰铈复合氧化物催化剂,催化湿式氧化处理高浓度苯酚废水。通过正交实验筛选催化剂制备条件,单因素实验优化制得催化剂。研究了CWAO处理废水条件下的金属离子溶出和催化剂的表征。结果表明,该催化剂在低温低压条件下具有优良的湿式氧化催化活性,且金属离子溶出量低,是一种CWAO处理高浓度有机废水中极具应用前景的新型高效催化剂。     

Reclaiming the spent alkaline zinc manganese dioxide batteries collected from the manufacturers to prepare valuable electrolytic zinc and LiNi0.5Mn1.5O4 materials

A process for reclaiming the materials in spent alkaline zinc manganese dioxide (Zn–Mn) batteries collected from the manufacturers to prepare valuable electrolytic zinc and LiNi_0.5Mn_1.5O₄ materials is presented. After dismantling battery cans, the iron cans, covers, electric rods, organic separator, label, sealing materials, and electrolyte are separated through the washing, magnetic separation, filtrating, and sieving operations. Then, the powder residues react with H₂SO₄ (2 mol L^?1) solution to dissolve zinc under a liquid/solid ratio of 3:1 at room temperature, and subsequently, the electrolytic Zn with purity of ?99.8% is recovered in an electrolytic cell with a cathode efficiency of ?85% under the conditions of 37–40 °C and 300 A m^?2. The most of MnO₂ and a small quantity of electrolytic MnO₂ are recovered from the filtration residue and the electrodeposit on the anode of electrolytic cell, respectively. The recovered manganese oxides are used to synthesize LiNi_0.5Mn_1.5O₄ material of lithium-ion battery. The as-synthesized LiNi_0.5Mn_1.5O₄ discharges 118.3 mAh g^?1 capacity and 4.7 V voltage plateau, which is comparable to the sample synthesized using commercial electrolytic MnO₂. This process can recover the substances in the spent Zn–Mn batteries and innocuously treat the wastewaters, indicating that it is environmentally acceptable and applicable.