纳米TiO2光催化技术在工业废水处理中的应用

介绍纳米TiO2的光催化特性,概述纳米TiO2光催化技术在降解印染废水、农药废水、造纸废水、表面活性剂废水以及含苯酚类、石油类和重金属污染物废水处理中的应用研究进展,总结了纳米TiO2应用于废水工业化处理所存在的问题,认为该技术研究领域近期内的主要发展方向为:大力开展纳米TiO2的改性技术、固定化技术和纳米TiO2光催化降解实际工业有机废水的试验研究及其高效、多功能、集成式光催化反应器的研制。     

苯酚废水的高级氧化处理技术

以催生·OH自由基为主要氧化剂来氧化处理废水中难降解有机物的高级氧化技术正成为国内外研究的热点课题.分析了多种高级氧化技术对苯酚废水处理的共同作用机理,阐述了催化湿式氧化法、光催化氧化法、电催化技术、超声声化学氧化、超临界水氧化等在含酚废水高级氧化处理中的研究进展及发展趋势.     

高效菌在废水处理中的应用

高效荫(EM)在废水处理方面具有广阔的发展前景.该文简要介绍了高效菌的微生物组成,处理废水的机理及应用于废水处理的优势.重点概述了其在含酚废水、重金属废水、农药废水处理中的应用实例.对其在废水处理的应用,实现工业化、规模化的推广应用,提出了展望.     

水解——好氧生物处理工艺在屠宰废水处理工程中的应用

屠宰废水是常见的一种食品加工废水，一秀废水有机污染物浓度较高。且含有脂肪，蛋白质等大分子有机物和毛发、动物内脏等杂物，探索水解－－好氧联合处理工艺处理肉鸡屠宰废水的机理。影响处理效率的因素和运行管理条件。在兴民从鸡屠间废水处理工程应用中，取得了较为显著的效果，具有工程投资少，操作简单，便于管理的特点，易于在同类食品加工废水处理中推广应用。     

PTA废水生物处理工艺综述

PTA废水是由对二甲苯(PX)生产PTA过程中产生的排水。废水成分复杂,含大量芳香烃有机物,包括难降解有机物TA和甲基苯甲酸。分析了PTA废水中的芳香烃有机物好氧降解、厌氧降解机理以及TA降解机理。分析结果表明:芳香烃有机物好氧降解速率明显高于厌氧降解速。目前,对于PTA废水处理研究集中在好氧处理和厌氧处理工艺上,重点介绍了PTA废水厌氧、好氧及厌氧-好氧处理的几种工艺及其处理效果。综合投资、能耗、污泥量、操作、处理效率等多种因素,总结出PTA废水处理的最优工艺为厌氧-好氧处理工艺,常用工艺组合包括上旋流厌氧反应器+两级好氧、水解+A/O、两级A/O等。并讨论分析了重金属钴、锰,营养物质N,P,Mg,Fe等以及温度、pH对PTA废水处理效率的影响。同时,展望了PTA废水的研究发展趋势。     

城市供水与废水处理自动化控制技术

将光催化反应装置应用于水处理自动化控制技术,可以达到对城市供水与废水处理的水量、水质实施监控,确保水质符合要求的目的.该技术具有催化效率高、处理废水能力和降解深度可调节综合成本低、适用范围广等特点,具有广泛的社会经济效益和广阔的市场前景.     

废水处理光催化反应器研究进展

综述近年来在废水处理过程中光催化反应器的研究现状。根据光催化反应器中的光催化剂存在形式及应用情况,将反应器分成悬浮式、负载式和耦合式三类,并系统地介绍了这三类反应器的结构、性能及其在应用中的优缺点,提出了废水处理中光催化反应器研究与设计所面临的问题及发展方向。     

水利水电工程施工废水处理工艺与实践

水利水电工程施工废水处理是水电工程项目环境影响评价的重要环节,也是水环境保护的重要措施。从水电工程施工废水污染的危害、水电工程施工废水的特性和水电工程施工废水处理的常用方法等几个方面,结合工程实例对水利水电工程施工废水处理工艺进行了研究,并提出了切实可行的水利水电工程施工废水处理方法。     

喷淋式TiO_2膜光催化反应器处理染料废水的研究

采用溶胶-凝胶法制备了Ti基TiO_2膜光催化剂,X-射线衍射(XRD)分析表明TiO_2主要为锐钛矿。将Ti基TiO_2膜组装成喷淋式光催化反应器,以活性艳红X-3B(RBR)为目标污染物,15W低压汞灯为激发光源进行光催化性能的研究。考察了影响光催化氧化效率的主要因素废水喷淋流量和溶液初始pH,确定最佳喷淋流量为8.8 L/h,pH为3.12。在最佳条件下,处理50 mg/LRBR模拟染料废水2 h的脱色率和COD_(Cr)去除率分别达到98%和80%。结果表明,由于同时加强了溶液的传质效率和提高了激发光源的利用率,喷淋式TiO_2膜光催化反应器可高效地降解染料废水。     

纤维废水处理的管式接触氧化法

一、前言除去水中可溶性有机物。一般采用活性污泥法或生物滤池法,这两种方法对处理以染色整理为主的废水是不充分的,它产生污泥膨胀而造成处理不稳定或恶化,BOD为100毫克/升以下的废水处理效率低以及维护管理麻烦等缺点。管式接触氧化法是在东京都玉川水厂研究成功的,现已在17处建成该设备,并投产运行,特别是对低BOD废水,取得了满意的效果。对纤维废水处理的实际运用结果,认为该法有弥补上述两法不足而取其待点的     

Photocatalytic removal of cyanide with illuminated TiO(2)

Effects of TiO(2) dosage, pH and initial cyanide concentration on the removal efficiency of cyanide from aqueous solutions with illuminated TiO(2) have been investigated. Adsorption and oxidation were recognized as significant processes for the elimination of cyanide. From the Langmuir isotherm, the maximum adsorption capacity was determined as 17.24 mg/g at pH 7. Adsorbed amount of cyanide slightly increased as the TiO(2) dosage increased. However, as no significant increase was observed above 1 g/L TiO(2), an optimum TiO(2) dosage was determined as 1 g/L. Photocatalytic oxidation efficiency of cyanide was greatly affected by the solution pH. It increased as the solution pH decreased. The photocatalytic oxidation efficiency after 120 min was 80.4% at pH 3 while it was only 20.4% at pH 11. Photocatalytic oxidation of cyanide was well described by the second-order kinetics. Photocatalytic reaction with illuminated TiO(2) can be effectively applied to treat industrial wastewater contaminated with cyanide.     

二氧化氯催化氧化降解铬黑T试验研究

在常温常压下,对Fe2O3/γ—A12O3+H2O2和ClO2+TiO2两种催化氧化体系处理铬黑T废水的效果进行了分析。试验结果表明,处理甲基橙废水效果较好的Fe2O3/γ—Al2O3+H2O2组合对铬黑T的降解效果非常有限,而ClO2+TiO2组合的处理效果较好:以500 mg/L的铬黑T溶液为模拟废水,当pH为4,C102投加量为200 mg/L,TiO2投加量为500 mg/L,反应时间为90 min时,脱色率达89.96%,CODCr的去除率可达45.36%。     

Photocatalytical polishing of paper-mill effluents.

Photocatalytic oxidation (PCO) is a promising technology for purification of biological pretreated wastewater or destruction of non-biodegradable compounds. For this reason PCO has been investigated as a last step of purification of biologically pre-treated paper-mill effluents. The influence of the parameters pH, TiO2-modification, TiO2-concentration, catalyst re-use, concentration of substances to be oxidised (wastewater quality) has been determined. The TOC of the biologically pretreated wasterwater was up to 55 mg L(-1). This wastewater was treated with a previously presented aerated cascade photoreactor which was modified for batch experiments. A high specific oxidation rate of up to 0.76 g TOC m(-2) h(-1) as well as a complete TOC mineralization has been achieved after the optimisation of the process parameters. The complete destruction of recalcitrant compounds will offer the opportunity to reuse the wastewater in the production process. The increase of the BOD5/TOC ratio after a short irradiation period indicates the transformation of recalcitrant organic compounds to better biodegradable intermediates. The use of PCO as a pre-treatment step for the enhancement of the biodegradability of wastewater, containing recalcitrant or inhibitory compounds is an alternative to a long and energy-intensive total pollutant mineralization.     

Phosphorus removal and recovery from wastewater by tobermorite-seeded crystallisation of calcium phosphate.

Investigations were focused on the development of a technology for phosphorus (P) recovery straight from wastewater. Facing the finiteness of the natural resources of this essential nutrient, the declared goal must be the sustainable use of available phosphorus sinks such as wastewater treatment plants (WWTP) for the generation of P rock substitutes. A feasible method for simultaneous elimination and recovery of phosphorus from wastewater proved to be the P-RoC process - the phosphorus recovery from wastewater by induced crystallisation of calcium phosphate, applying tobermorite-rich waste compounds of the construction industry. The experiments were performed in fixed bed-, stirred- and expanded bed reactors in laboratory--as well as in pilot-scale experiments. The efficiency and longevity of the P-RoC process was determined by the supply of Ca ions and the initial P concentration. Total P (P-tot) contents in the generated crystallisation products of up to 13% P-tot (30% P2O5) were achieved. Mineralogical investigations proved the formation of a hydroxy-apatite-(HAP)-like coating onto the seed material's surface. Reuse options for the generated crystallisation products, such as substitute for phosphate rock or as new fertiliser, were assessed.     

The use of catalyst to enhance the wet oxidation process.

Wet oxidation tests were performed on two pure compound streams: acetic acid and ammonia; and on two wastewater streams: acrylic acid wastewater and sulphide laden spent caustic. Test results showed that Mn/Ce and Pt/TiO2 were effective catalysts that greatly enhanced acetic acid, ammonia and acrylic acid wastewater destruction. However, the Mn/Ce catalyst performance appears to be inhibited by concentrated salts dissolved in solution. This could limit the applicability of this catalyst for the treatment of brackish wastewaters. Zr, Ce and Ce nanoparticles were also shown to exhibit some catalytic activity, however not to the extent of the Mn/Ce and the Pt/TiO2.     

Simultaneous photocatalytic oxidation of pharmaceuticals and inactivation of Escherichia coli in wastewater treatment plant effluents with suspended and immobilised TiO(2)

Simultaneous Escherichia coli inactivation and oxidation of pharmaceuticals in simulated wastewater treatment plant effluents has been investigated using a photocatalytic treatment with TiO(2) in suspension and immobilised onto a fixed-bed reactor. Non-photocatalytic reference experiments of dark adsorption and photolysis showed a higher sensitivity of E. coli towards the chemical composition of water in comparison with the concentration of pharmaceuticals that remains unaffected. Moreover, it must be underlined that the presence of pharmaceuticals (including antibiotics) did not seem to affect the bacterial viability at such low concentrations. Concerning photocatalytic experiments, both suspended and immobilised TiO(2) were able to simultaneously inactivate and oxidise both kinds of pollutants (bacteria and pharmaceuticals). The fixed-bed reactor showed similar activity to that of the slurry without deactivation after several cycles of reuse. That makes TiO(2) photocatalysis a quite interesting technology for the treatment of drinking water supplies or wastewater plant effluents, allowing the removal of emerging contaminants such as pharmaceuticals during the disinfection treatment.     

催化湿式氧化法处理高浓度对氯苯基异氰酸酯生产废水的研究

在固定床鼓泡式反应器连续反应装置上对对氯苯基异氰酸酯生产过程中产生的高浓度实际废水进行催化湿式氧化处理。实验表明:制备的复合负载型催化剂CuO-ZrO2-CeO2/TiO2在处理该废水时具有较好的催化活性。通过对反应温度、反应压力、反应空速、气液比和进水pH等工艺条件的考察,得出最佳的工艺条件为:反应温度T=240℃,反应压力P=6.5MPa,空速=2.0 h-1,V(气)∶V(水)=230∶1,进水pH=8,在此条件下CODCr去除率达到96.9%。     

13X分子筛负载TiO_2对偶氮染料活性艳红的光催化降解

采用熔融-浸渍法和溶胶-凝胶法将TiO_2负载在13X分子筛上,制成了具有吸附性和光催化性的TiO_2/13X分子筛复合材料,并用XRD、BET比表面积、SEM分析技术对合成材料进行表征.然后将复合材料用于光催化降解偶氮染料活性艳红X-3B的实验,考察了反应时间、催化剂用量、废水pH值对染料光催化降解率的影响.结果表明:熔融-浸渍法制备的TiO_2/13X复合材料对染料的去除率高于溶胶-凝胶法制备的复合材料.当染料的初始浓度为50 mg/L,废水pH为6,复合材料投加量为0.75 g/L时,光照120 min,染料的去除率达到99%.反应过程符合一级动力学方程.     

Novel tiO2 nanocatalysts for wastewater purification: tapping energy from the sun.

Water treatment using TiO2 semiconductor as a durable heterogeneous photocatalyst has been the focus of environmentalists in recent years. Currently, we developed an inexpensive and highly efficient approach for synthesizing nitrogen-doped TiO2 with lower band-gap energy that can respond to visible light. Doping on the molecular scale led to an enhanced nitrogen concentration of up to 21.8%. Reflectance measurements showed the synthesized N-doped TiO2 nanoparticles are catalytically active with the absorbance that extends into the visible region up to 600 nm. The water purification potential of this new class of compound was evaluated by studying the photodegradation of Acid Orange 7 (AO7) and E. coli. Experiments were conducted to compare the photocatalytic activities of N-doped TiO2 nanocatalysts and commercially available Degussa P25 power under identical solar light exposure. N-doped TiO2 demonstrated superior photocatalytic activities in both chemical compound degradation and bactericidal reactions. The result of this study shows the potential of applying new generations of catalyst for wastewater purification and disinfection.