建筑物披上“护身衣”

不久前,化学工程师们发现了一个如何利用二氧化钛使建筑物免受脱色污染的方法。为推广该项成果而进行的技术改进正在进行中,不久的将来, 以二氧化钛为主要组成成分的自动清洁产品会进军国内市场。另外,有关研究人员宣称二氧化钛市场潜力巨大。     

电气石球负载纳米二氧化钛光催化剂的制备及其对水中邻苯二甲酸酯的降解作用

以电气石微球为载体,采用溶胶–凝胶法制备电气石负载纳米二氧化钛(TiO_2)光催化材料。用X射线衍射分析、扫描电镜对微球负载TiO_2光催化剂的晶型结构和形貌进行了表征。以6种邻苯二甲酸酯为降解对象,考察了热处理温度、辐射强度对TiO_2光催化活性的影响。发现TiO_2以纳米颗粒的形式牢固负载在电气石微球表面;以天然电气石微球为载体所制得的TiO_2光催化剂对于6种邻苯二甲酸酯具有较好的光催化降解效果。     

土壤中有机磷农药的测定及光催化降解的研究

本文以建立加速溶剂萃取-固相萃取小柱净化-气相色谱法测定土壤中有机磷农药的方法及其光降解为主要研究目的。通过条件优化摸索出更为优越的土壤有机磷农药前处理方法,利用高灵敏度、高选择性的FPD检测器进行定性、定量分析。使用溶胶凝胶法自制纳米二氧化钛粉体,讨论土壤中乐果光催化降解的影响因素。研究结果显示硅胶小柱的净化效果好;敌敌畏由于本身的性质,回收只有30%左右。催化剂剂量、反应时间、光照强度对乐果的光催化降解均有较大的影响。     

TiO2光催化氧化法处理有机废水实验分析与改进

介绍光催化氧化的基本原理及其对有机物的光催化氧化过程,对二氧化钛光催化氧化法处理有机废水的实验实例进行了分析,提出了提高二氧化钛光催化氧化活性的方法和研究趋势。     

提高凹凸棒粘土脱色力的新措施

本文介绍一种提高凹凸棒粘土脱色力的新方法。该方法能制得脱色力与活性炭相当的活性凹凸棒粘土;这种活性凹凸棒粘土可在某些领域代替活性炭作脱色剂、除臭剂,取得显著的经济效益。     

阳离子淀粉-双氰胺-甲醛絮凝剂的合成及其絮凝性能

以阳离子淀粉、双氰胺、甲醛为主要原料,以硫酸铝为催化剂,并引入添加剂合成了阳离子淀粉 双氰胺 甲醛脱色絮凝剂。探讨了阳离子淀粉用量、甲醛用量、催化剂用量、反应温度、反应时间及添加剂对阳离子淀粉 双氰胺 甲醛树脂混凝脱色性能的影响,并对印染废水进行了混凝脱色试验。实验结果发现,当双氰胺23 5g、阳离子淀粉5 6g、甲醛57 8g、硫酸铝4 8g、添加剂12 5g、反应温度(70±1)℃、反应时间为1 5小时。试验表明产品的混凝脱色性能良好,CODCr去除率≥91%,脱色率≥99%。并对制得的产品进行了絮凝性能试验,结果表明该产品具有良好的絮凝性能。     

无花果曲霉菌丝球对活性艳蓝KN-R的脱色研究

生物吸附法是染料废水处理中很有前途的一种方法。本文将培养的无花果曲霉菌丝球用于蒽醌染料活性艳蓝KN-R的脱色，研究了培养时间、温度、转速、pH值及盐浓度、不同碳源、不同氮源对菌丝球脱色的影响；比较了活菌与死菌的脱色效果；探讨了菌丝球重复利用对脱色率的影响。结果表明：培养时间为72h，温度为33℃，转速为150rpm，pH值为6．0，盐浓度为0.5％，以乳糖为碳源、硝酸钠为氮源时，菌丝球对活性艳蓝KN-R的脱色效果最好：活菌对染料的吸附性能比死菌好；菌丝球在重复利用了四次后，脱色率仍达85．7％。     

固定化酵母菌对活性艳蓝KN-R的脱色研究

采用海藻酸钙加活性碳的方法对酵母菌进行固定化。正交试验结果表明，三者合适配比为海藻酸钠3％，活性碳10％，氯化钙4％。此方法制得的凝胶颗粒机械强度好、经久耐用。固定化酵母菌凝胶小球最适条件为：培养时间为48h，培养温度为37℃，培养基pH为3．0，凝胶量为10g。固定化细胞经多次脱色后能重复使用，4次脱色后其脱色率还达79．2％。     

活性炭吸附法去除印染工业废水色度的试验与研究

通过试验初步研究活性炭直接吸附去除印染工业废水色度中吸附剂投加量、吸附时间等对色度去除率的影响。通过混凝沉淀法与活性炭吸附法结合、搅拌电解法与活性炭吸附法结合、脱色氧化法与活性炭吸附法结合等试验初步探讨了活性炭吸附与其它处理方法结合去除印染工业废水色度的可行性。同时，讨论了以上几种处理方法对水样中CODCr的去除、水样pH值变化等的影响。     

KN—R活性兰生化脱色方法研究

传统的生化处理印染废水的脱色效果很不理想,但本试验通过对已驯化的活性污泥脱色有效菌株进行诱变、筛选、培养和优化,使生化法处理印染废水的脱色效果得到明显的提高。     

茄子秸杆活性炭对染料废水的吸附性能研究

以茄子秸秆为原料,ZnCl2为活化剂制备粉末状活性炭,主要研究了活性炭对染料废水的吸附性能;以活性红X-3B和酸性蓝RL为模型染料,考察了染料初始浓度、pH值、活性炭投加量和吸附时间等对染料脱色率的影响。结果表明,染料初始浓度和活性炭投加量对染料脱色率影响较大。初始浓度为300mg／L时,活性炭的最佳投加量分别为1g／L和1．4g／L;在最佳工艺条件下,脱色率分别在93％和98％以上,COD去除率分别为94．5％和86．4％,出水水质达到国家一级《纺织染整工业水污染物排放标准》（GB 4287—1992）。     

Photocatalytic degradation of para-hydroxybenzoic acid: Relationship between substrate adsorption and photocatalytic degradation

Dark adsorption and photocatalytic degradation of para-hydroxybenzoic acid (PHBA) was studied in the presence of Degussa P-25 titanium dioxide photocatalyst under concentrated solar radiation. This work includes the study of the effect of pH, and of the presence of different anions and cations on dark adsorption and photocatalytic degradation (PCD) of PHBA on titanium dioxide. The results obtained clearly indicate that there is a link between the extent of adsorption of PHBA and its PCD. Conditions that favor greater adsorption of PHBA also favor a greater PCD. This points to the possibility that the mechanism of PCD involves a surface reaction between adsorbed PHBA and OH ° radical. Anions were generally found to have a detrimental effect on the photocatalytic degradation of PHBA. Cl^- caused the greatest decrease in the PCD followed by NO₃^-, HCO₃^- and SO₄^2-. Cations Cu²⁺ and Fe²⁺ were not found to assist the degradation of PHBA, possibly due to the anions associated with them.     

P-25纳米TiO2在含酚废水处理方面的应用

采用室内模拟研究,以P-25纳米TiO2作为光催化剂进行了苯酚水溶液的光催化降解性能探讨,初步考察了溶液的pH、P-25纳米TiO2用量对光催化降解苯酚过程的影响,以获得P-25纳米TiO2光降解含酚废水的较好反应条件.实验结果表明,当溶液pH=8时,降解水体中苯酚效果最佳,强酸和强碱条件均不利于苯酚的降解;在pH 8的反应体系中,当光催化剂用量为0.4g/L时,催化水体中苯酚降解的效果最好.     

Heterogeneous photocatalysed degradation of a herbicide derivative, isoproturon in aqueous suspension of titanium dioxide

Heterogeneous photocatalysed degradation of a herbicide derivative, N-(4-isopropylphenyl)-N',N'-dimethylurea (Isoproturon, 1) was investigated in aqueous suspensions of titanium dioxide by monitoring the change in absorption intensity and depletion in Total Organic Carbon content as a function of irradiation time. The degradation kinetics was studied under different conditions such as pH, catalyst concentration, substrate concentration, different types of TiO(2) and in the presence of electron acceptors such as hydrogen peroxide (H(2)O(2)), potassium bromate (KBrO(3)) and potassium persulphate (K(2)S(2)O(8)) besides molecular oxygen. The degradation rates were found to be strongly influenced by all the above parameters. The photocatalyst Degussa P25 was found to be more efficient as compared with other photocatalysts. An attempt was made to identify the degradation product through GC-MS analysis technique.     

沸石负载型TiO2处理炼化反渗透浓缩水的研究

利用沸石负载型二氧化钛对炼化企业的反渗透浓缩水进行研究,考察了催化剂对浓缩水的处理效果及影响降解的因素。由实验结果可知:沸石负载型二氧化钛对反渗透浓缩水TOC降解率达到67.4%,降解浓缩水的最佳条件为:pH值为4～6,温度30～40℃,光照时间2.5h,催化剂投加量为1.5g/L。实验为浓缩水处理技术的发展提供了新的依据。     

Photocatalytic degradation of organic wastes by electrochemically assisted TiO2 photocatalytic system

Photocatalytic degradation of organic wastes with nanosized titanium dioxide particles has been studied for a long time in order to offer an appropriate method for wastewater treatment, but its practical application is greatly limited by the slow process. In this work, an electrochemically assisted TiO2 photocatalytic system was set-up by combining a TiO2 photocatalytic cell with a three-electrode potentiostatic unit. The composite system revealed high photocatalytic activity towards organic wastes mineralization. After continuous treatment for 0.5 h, the maximum absorption of rhodamine 6G (R-6G) was reduced by more than 90%; chemical oxygen demand (COD) and biochemical oxygen demand (BOD5) of textile dye wastewater (TDW) were decreased by 93.9 and 88.7%, respectively. The biodegradability of TDW was also improved because the COD/BOD5 ratio decreased from 2.1 to 1.2. All these results indicated that the composite system could be used for effective organic wastes mineralization or as a feasible detoxification and color removal pretreatment stage for biological post treatment.     

Heterogeneous photocatalysed degradation of two selected pesticide derivatives, triclopyr and daminozid in aqueous suspensions of titanium dioxide

Heterogeneous photocatalysed degradation of two selected pesticide derivatives, triclopyr (1) and daminozid (2), has been investigated in aqueous suspensions of titanium dioxide by monitoring the change in substrate concentration employing the UV Spectroscopic analysis technique and depletion of Total Organic Carbon (TOC) content as a function of irradiation time. The degradation kinetics were studied under different conditions such as reaction pH, substrate and catalyst concentration, different types of TiO2 and in the presence of electron acceptors such as hydrogen peroxide (H2O2), potassium bromate (KBrO3) and ammonium persulphate (NH4)2S2O8 in addition to molecular oxygen. The degradation rates were found to be strongly influenced by all the above parameters. The photocatalyst Degussa P25 was found to be more efficient as compared with other photocatalysts. The pesticide derivative triclopyr (1) was found to degrade faster as compared to daminozid (2). An attempt was also made to identify the intermediate products formed during the photooxidation process using GC/MS analysis. Probable pathways for the formation of products have been proposed.     

阳离子染料废水处理的工艺研究

首先采用两级物化－电解－吸附工艺对高浓度阳离子染料生产废水进行预处理,再与低浓度生产废水、生活污水混合生化处理,总脱色率和CODcr去除率均可达到99．9％以上,达标排放。     

Synthetic endocrine disruptors in the environment and water remediation by advanced oxidation processes

The present study is an overview of the literature on classes and types of compounds described as "endocrine disruptors" and their treatability in water by advanced oxidation processes, which generate hydroxyl radicals in water. The review is limited to details of the destruction of three classes of endocrine disruptors, namely bisphenols, alkylphenols and phthalates, which are among the most highly suspected endocrine disrupting compounds that interfere with the hormonal system of wildlife. It was found that photocatalysis with titanium dioxide was the most frequently tested advanced oxidation method most likely due its potential to render complete mineralization. There is sufficient research also with direct and indirect photolysis and ozonation, which were less effective for the overall mineralization but more representative of the conditions existing in real water treatment plants.     

染料废水脱色的物理化学处理技术

染料废水目前主要的脱色方法有吸附、混凝、氧化还原和生化法.活性炭吸附适用于低浓度的染料废水处理.聚硅硫酸铁混凝效果与Fe/SiO4摩尔比和pH值相关.氢氧化镁可有效去除印染废水中的直接红染料.有机絮凝剂往往需要和其它药剂复配.氧化法脱色率大,但成本高昂,且受染料废水的组成、氧化性及pH值影响.还原法药剂价格低廉,但还原降解产物具有毒性,必须经过二次处理.生物法成本较低,又受制于染料的生物降解性.因此发展多种手段联合应用已是当前染料废水处理的研究方向.