Preparation and photocatalytic properties of porous C and N co-doped TiO2 deposited on brick by a fast, one-step microwave irradiation method

A one-step microwave irradiation method was used to deposit carbon and nitrogen co-doped TiO_2((C, N)-TiO_2) on commercial brick((C, N)-TiO_2/brick). The as-prepared samples were characterized by X-ray diffraction, ultraviolet–visible(UV–vis) diffuse reflectance spectroscopy, photoluminescence spectroscopy, X-ray photoelectron spectroscopy, and scanning electron microscopy(SEM). A selective technique was also used to investigate the concentration of hydroxyl radicals during UV–vis irradiation of the Methyl Orange solution with the as-prepared samples. The C and N dopants enhanced visible light absorption and provided a longer lifetime for the photo-generated electron–hole pairs. The SEM images showed that the as-prepared sample is porous. The dark adsorption and photodegradation test for(C, N)-TiO_2/brick showed good photodegradation and good recyclability. The best photodegradation rate was 94% after 2 hr. The maximum degradation rate was maintained even after the 6th cycle. The good photocatalytic properties are attributed to the enhanced visible light absorption, enhanced pollutant adsorption arising from the porous structure of the(C, N)-TiO_2 thin film, and longer lifetime of the photo-generated electron–hole pairs.(C, N)-TiO_2/brick should have potential commercial applications in photodegradation processes because of its low cost, good photodegradation, and excellent recyclability.     

European regulations to reduce lead emissions from automobiles – did they have an economic impact on the German gasoline and automobile markets?

Environmental protection policies in the automobile market were not implemented until the motorisation of the masses in the 1960s caused an increasing environmental burden. The rising air pollution was considered a latent danger to humans, animals and plants. In the years up to 1985 the EU passed several regulations to limit the mass pollutants CO, CxHy and NOx. Germany was the first EU-member nation to also be concerned with lead in gasoline, passing reduction regulations as early as 1971. In 1986, several EU-member nations implemented the supply of unleaded gasoline. This decision was predominantly based on information about widespread forest damage. The reduction of lead emissions due to these regulations could be verified in different environmental systems. An example of this was the decline of atmospheric lead concentrations and human blood lead levels in Germany. With regard to industries, the German mineral oil and automobile markets were affected mostly. The price trend of gasoline was no longer only influenced by varying crude oil prices but also by tax discrimination between leaded and unleaded fuel. With regard to the distribution system, the market positions particularly of the medium-sized traders and the independent importers were weakened. In the automobile market, favourable terms of competition were experienced by producers who had already gained experience with catalyst systems in the US market. The Gasoline Lead Content Regulations had no significant effects on further economic indicators, except for competition. Electronic Publication     

应用生物制剂修复黑臭河涌试验研究

应用固定化生物催化剂(IBC)对江门市某河涌进行生物修复。结果表明:向底泥投加IBC能增加底泥中有益微生物量,优化底泥微生物群落,使河涌底泥中有机质逐渐降解;同时能抑制硫酸盐还原菌(SRB)繁殖,降低底泥中硫化物含量。试验进行4个月后,底泥有机质去除率达到54.7%⁶3.7%,底泥中SRB数量减少了92.8%63.7%,底泥中SRB数量减少了92.8%⁹4.5%,底泥硫化物含量降低了81.9%94.5%,底泥硫化物含量降低了81.9%⁸7.5%,河涌黑臭现象基本消除;向上覆水体投加IBC,在IBC中微生物和多种酶的协同作用下,水中有机污染物被快速降解,上覆水体的COD和氨氮浓度逐渐下降,试验进行4个月时,去除率分别达到20.0%87.5%,河涌黑臭现象基本消除;向上覆水体投加IBC,在IBC中微生物和多种酶的协同作用下,水中有机污染物被快速降解,上覆水体的COD和氨氮浓度逐渐下降,试验进行4个月时,去除率分别达到20.0%³5.2%和32.9%35.2%和32.9%⁴4.1%,提高了河涌的生物自净能力。     

聚酯废气在Cu-Mn催化剂上的催化燃烧

在30Nm^3／h中试装置上研究了聚酯生产废气在Cu—Mn催化剂上的催化燃烧。研究表明，应用催化燃烧工艺能够连续平稳处理聚酯生产废气。其适宜操作条件是：催化燃烧反应器进口温度250℃，空速20000h^-1。经此条件处理后。总烃去除率达97．1％-99．6％，净化排气中总烃和乙醛浓度均小于100μL／L，符合国家排放标准。     

丙酮在Pt/NM,Fe-Cu-Mn/NM催化剂上深度氧化反应动力学研究

采用积分反应器分别考察了Pt/NM,Fe-Cu-Mn/NM催化剂上丙酮深度氧化反应的活性和动力学。结果表明,Fe-Cu-Mn-NM催化剂对丙酮的氧化活性高于Pt/NM催化剂,深度氧化反应的速度方程可用幂函数表达式r=Ae~(△EIRTC)#来表示,相应的动力学参数Fe-Cu-Mn/NM为:n=0.5,△E=145.8(kJ/mol),A=3.63×10~(10);Pt/NM为:n=1,△E=93.3,A=4.91×10~4。     

用MnSO4-NiSO4取代Ag2SO4协同催化快速测定CODCr

在标准重铬酸钾法中，提出用MnSO4-NiSO4组合催化剂取代Ag2SO4催化剂，快速测定废水的CODcr。其最佳实验条件为质量之比MnSO4:NiSO4=1:1.5，MnSO4-NiSO4总量为0．15g,加热回流时间为5min。通过对8种不同浓度的标准邻苯二钾酸氢钾样品和5种废水样分析，经统计检验表明，本方法与标准重铬酸钾法无显著性差异，两者具有较好的可比性。     

铁矿石催化剂催化氧化CO性能的研究

在大气治理各方法中，催化转化法越来越得到人们的重视．本文论述了铁矿石（催化剂）对ＣＯ催化转化的实验研究过程，并制得一种优化催化剂，实验结果表明其具有很好的催化氧化性能：空速２×１０４ｈ－时，１５０℃ＣＯ转化率达９０％，２００℃ＣＯ转化率为９９％以上．     

非均相光催化氧化研究进展

光催化氧化技术是一种新兴的高效节能现代水处理技术,本文从半导体光催化氧化的机制,各类污染物光催化降解的现状,光催化剂活性的研究现状,固定相光催化氧的进展,光催化氧化技术发展中存在问题等方面进行综述     

光降解制药废水的试验研究

研究了紫外光催化氧化法对制药废水的降解机理。考察了 Ti O2 投加量与污染物初始浓度的关系 ,并经初步估算其量子效率为 6.1 %     

柴油机尾气净化用的钙钛矿型催化剂的研究

用浸渍法制备了多种ABO_3型催化剂,考察了多种因素对其活性的影响及作用机制。柴油机台架实验结果表明,在A位掺杂Sr可提高催化剂的活性;稀土在最后一次浸渍液中浸渍,以二次浸渍为宜;堇青石陶瓷蜂窝状催化剂的性能优于γ-Al_2O_3球状催化剂。蜂窝状催化剂上CO的起燃温度T_(50)％=110℃,而T_(90)％=157℃;在温度仅为200℃,而空速高达70000h~(-1)的条件下CO的净化率仍达90％;积碳起燃温度为323℃,优于Pt族贵金属催化剂;热稳定性和对CO浓度的适应性较好,且具有抗SO_2中毒能力。