大气压介质阻挡放电降解4-氯酚废水的试验研究

采用大气压介质阻挡放电等离子体技术,对4-氯酚(4-CP)水溶液进行了降解处理,研究了放电参数对4-CP降解效率以及过氧化氢产生量的影响,并对降解动力学进行了分析。结果表明,当电源电压为160 V、电流为0.5 A、介质间距为5 mm时,4-CP的降解效果最好;随着电压、电流的提高,间距的减小,过氧化氢的生成量增加;Fe2+对4-CP的去除有明显的催化作用。动力学研究表明,4-CP的质量浓度低于200 mg·L-1时降解为1级反应,高于400mg·L-1时为0级反应。     

g-C3N4/Bi2MoO6复合光催化剂的制备及性能研究

结合热缩聚法和水热法制备了g-C₃N₄/Bi₂MoO₆复合光催化剂,利用X射线衍射（XRD）、傅里叶红外光谱（FT-IR）、扫描电子显微镜（SEM）、透射电子显微镜（TEM）、氮气吸附-脱附曲线、紫外-可见漫反射光谱（UV-Vis DRS）、光致发光光谱（PL）等分析测试技术对材料的结构和性能进行了表征,研究了材料光催化降解罗丹明B（RhB）的效果。结果表明,与纯Bi₂MoO₆相比,g-C₃N₄/Bi₂MoO₆复合材料提高了对可见光的吸收能力,减小了带隙宽度,在可见光激发下提高了降解RhB的光催化活性。其中,5% g-C₃N₄/Bi₂MoO₆复合材料对RhB的降解率最高,在可见光照射180 min对RhB的降解率为93%;而同样条件下Bi₂MoO₆对RhB的降解率为58%。重复性实验表明,复合材料在RhB光降解过程中是稳定的,具有较好的应用潜力。     

铁酸钴活化过一硫酸盐处理高盐废水中罗丹明B的研究

采用溶胶-凝胶法制备了催化剂铁酸钴（CoFe₂O₄）纳米材料,借助扫描电子显微镜（SEM）和 X 射线衍射仪（XRD）对催化剂进行了表征。配制了质量浓度 10 g/L 硫酸钠,50 mg/L 的罗丹明模拟废水,开展了铁酸钴活化 PMS降解高盐废水中罗丹明 B（RhB）的实验。对比了单独投加 PMS、CoFe₂O₄和同时投加 PMS/CoFe₂O₄对 RhB 的降解效果,探究了 PMS投加量、CoFe₂O₄投加量、初始 pH、硫酸钠含量等因素对过一硫酸盐/铁酸钴（PMS/CoFe₂O₄）体系降解RhB 效果的影响。结果表明,PMS/CoFe₂O₄体系降解高盐废水中 RhB 效果显著;硫酸钠的存在对 RhB 的降解过程有一定的抑制作用;在PMS投加量0.8 mmol/L、CoFe₂O₄投...     

微生物降解硝基苯、酞酸酯类有机物试验研究

利用人工介质富集太湖水中微生物降解梅梁湾水源水中硝基苯、酞酸酯类有机物,经低浓度有机物驯化后．停留时间为2天,4天,8天时,硝基苯的降解率分别为83％、64％及100％;磷苯二甲酸二（2-乙基已）酯（DEHP）的降解率分别为68％、63％、14％,所有出水水样中投有检出磷苯二甲酸二丁酯（DBP）。可见通过人工介质富集微生物的方法对太湖梅梁湾水源水中微量有机物的去除有明显效果。     

高铁酸钾预处理降解污水中有机物的特性研究

研究了高铁酸钾在污水预处理过程中对有机物的降解特性,考察了高铁酸钾投加量、反应时间和p H等因素对有机物降解效果的影响,采用荧光分析的手段,分析了高铁酸钾对水中不同类有机物的降解效果。研究表明,在酸性条件下,高铁酸钾投加量的增加更有助于有机物的降解,投加质量浓度增加到50 mg/L后,COD的降解不再有显著的变化。荧光分析表明,高铁酸钾对水中类酪氨酸、类富里酸类有机物均有较好的去除效果。     

磁性CoFe_2O_4催化PMS降解水体中磺胺甲基嘧啶的研究

针对普通工艺难以降解水中磺胺类抗生素现象,采用CoFe_2O_4/PMS工艺降解水中磺胺甲基嘧啶。磁性纳米铁酸钴(CoFe_2O_4)通过催化分解单过氧硫酸氢钾(PMS)产生具有强氧化性的硫酸自由基(·SO_4^-)降解水中磺胺甲基嘧啶,探讨了溶液中CoFe_2O_4浓度、PMS浓度、温度、反应物初始浓度、pH、无机阴离子和腐植酸浓度等影响因素。结果表明,降解过程符合拟一级动力学模型。一定范围内,CoFe_2O_4、PMS浓度越高,降解速率越快;温度对降解效果影响较大;反应物初始浓度与降解速率呈负相关;pH=9时降解速率最快;一定浓度的HCO_3-)降解水中磺胺甲基嘧啶,探讨了溶液中CoFe_2O_4浓度、PMS浓度、温度、反应物初始浓度、pH、无机阴离子和腐植酸浓度等影响因素。结果表明,降解过程符合拟一级动力学模型。一定范围内,CoFe_2O_4、PMS浓度越高,降解速率越快;温度对降解效果影响较大;反应物初始浓度与降解速率呈负相关;pH=9时降解速率最快;一定浓度的HCO_3^-促进磺胺甲基嘧啶的降解,Cl-则抑制其降解;腐植酸浓度越高,降解速率越慢。     

高活性Cu-MnO2类氧化物酶降解罗丹明B

纳米酶因其优良的催化活性在环境修复领域引起人们的广泛关注。元素掺杂可提升纳米酶催化性能。采用一步水热法制备了高活性铜掺杂二氧化锰（Cu-MnO2）类氧化物纳米酶（简称为类氧化物酶），并探究了Cu-MnO2催化降解罗丹明B（RhB）染料的效果。结果表明，铜掺杂后Cu-MnO2产生了协同效应，增强了Cu-MnO2的类氧化物酶催化活性，当溶液pH=3、RhB初始质量浓度为50 mg/L、Cu-MnO2用量为0.01 g时，30 min内可完全降解RhB，并且催化剂使用5次后RhB降解率仍达75%。此外，对环丙沙星、氧氟沙星、四环素和对苯二酚等难降解的污染物的降解率分别为88.86%、90.47%、92.62%和90.99%。Cu-MnO2类氧化物酶催化降解RhB的机理研究表明，富含氧空位的Cu-MnO2中存在丰富的空穴（h+），有利于吸附和催化溶解氧生成大量的单线态氧（1O2）和少量的超氧自由基（O2·-）等活性氧物种用于快速降解有机污染物。     

表面改性铁刨花活化过硫酸盐降解水体中的对硝基苯酚

以机加工废料铁刨花为原料,采用盐溶液吸氧腐蚀的绿色制备方法,在铁刨花表面原位合成γ-FeOOH层,并用X射线衍射(XRD)对其物象进行表征。以对硝基苯酚(4-NP)为目标污染物,研究γ-FeOOH@Fe复合材料活化过硫酸钾(K₂S₂O₈)降解污染物的性能。结果表明,γ-FeOOH@Fe复合材料活化K₂S₂O₈降解4-NP的效率明显优于单纯的铁刨花,在室温条件下,当pH值为7.0、4-NP初始质量浓度为10 mg/L、K₂S₂O₈质量浓度为40 mg/L、γ-FeOOH@Fe投加量为2 g/L时,反应24 min后,4-NP降解率达到92.3%;水中无机阴离子H₂PO₄-和HCO₃^-对γ-FeOOH@Fe活化K₂S₂O₈降解4-NP表现出不同...     

超声空化效应降解焦化废水中有机物的研究

报道了将超声空化效应应用于降解焦化废水中有机物的方法,考查了饱和气体的存在与否、有机物(CODCr)的初始浓度、超声波的声能密度、废水的初始pH值以及废水的温度对超声空化效应降解废水中有机物效果的影响。通过测定自由基清除剂正丁醇对有机物超声降解过程的影响,提出了废水中有机物超声降解的作用机理可能是由超声空化效应在水中产生的·OH自由基使水中的有机物被氧化的过程,有机物的超声降解过程遵循表观一级反应动力学规律。     

碳基含铁催化剂催化过氧化氢氧化去除对氯苯酚的试验研究

为了考察自研发的一种低成本、制作简便的碳基含铁新型催化剂(简称HACO-P型)的催化氧化性能,以对氯苯酚(4-CP)为对象,研究其催化H2O2降解水中4-CP的效果及影响因素.对HACO-P进行形貌表征,结果表明其表面多孔、具有巨大比表面积.单独考察了HACO-P对4-CP的吸附性能并进行了等温线拟合,发现其最大吸附容...     

Photocatalytic degradation of phenols in aqueous solution under irradiation of 254 and 185 nm UV light

The photocatalytic decomposition and mineralization of 4-chlorophenol (4-CP), hydroquinone and 4-nitrophenol (4-NP) in aqueous solution were investigated using two kinds of low-pressure mercury lamps: one was UV (ultraviolet) lamp emitting at 254 nm and the other was VUV (vacuum ultraviolet) lamp emitting at both 254 and 185 nm. VUV irradiation led to the most efficient degradation of the organics. Different mechanisms of photocatalysis and photolysis under VUV irradiation were observed. The degradation rate was subjected to the molecular structures of the substrates. 4-CP was easy to be decomposed, while hydroquinone was easy to be mineralized. However 4-NP was difficult to be decomposed or mineralized. VUV was efficient for decomposition of refractory compounds, such as nitrophenols, and the catalyst was efficient for TOC removal.     

Rate parameter estimation for 4-chlorophenol degradation by UV and organic oxidants

The main objective of this study was to evaluate the rate parameters of degradation/mineralization of 4-chlorophenol (4-CP) using organic oxidants, viz., peroxy acetic acid (PAA), para nitro benzoic acid (PNBA), and methyl ethyl ketone peroxide (MEKP), in basic media, in combination with UV irradiation at 254 nm. All the experiments were conducted with varying time intervals, under identical conditions of UV irradiation and pH. The reactions were followed by HPLC analysis for residual concentration and GC–MS for mineralization, and intermediates/product identification. In the present investigation, the residual concentration data of 4-CP against time were analyzed for reaction order determination by differential and integral methods. The differential method yielded fractional order of reaction for all organic oxidants under consideration. Initially the profile was observed to be linear in the time span of 0–45 s for all the organic oxidants used and thus, first-order approximation was applied. The curvilinear path, which followed up till 300 s, was approximated to first-order and second-order kinetics. No noteworthy results were observed for pseudo-first order rate equation. The change in the nature of the curves was attributed to the formation of intermediates/reaction products.     

Photocatalytic degradation of model organic pollutants on an immobilized particulate TiO2 layer: Roles of adsorption processes and mechanistic complexity

The kinetics of photocatalytic degradation of four different model organic compounds, formic acid (FA), oxalic acid (OA), 4-chlorophenol (4-CP) and the herbicide monuron (3-(4-chlorophenyl)-1,1-dimethylurea) in a self-constructed batch-mode plate photoreactor with a thin flow of contaminated aqueous solution circulating over an illuminated particulate layer of TiO₂ P25 (Degussa) was compared. Both OA and FA were adsorbed on TiO₂ surface; their mineralization, induced by direct transfer of photogenerated holes, proceeded in a single step, without observable intermediates, following approximately zero order kinetics. Numerical simulations were performed using a newly proposed kinetic model based on the photostationary state assumption. The model allowed an explanation of the observed reaction order as well as the comparison of independent with competitive adsorption of organic compound and oxygen on the photocatalyst surface, yielding a better fit for the case of competition. 4-CP and monuron, which were not adsorbed under the conditions used, were degraded through the action of photogenerated hydroxyl radicals. Their degradation proceeded with lower photoefficiency than for the adsorbed compounds (FA and OA). While the mineralization of both 4-CP and monuron followed zero order kinetics, their degradation was close to first order. The different reaction orders were consistently explained using the photostationary state approach.     

新型铁铈复合氧化物催化臭氧氧化工艺去除对硝基苯酚

对硝基苯酚(4-NP)作为一种难降解的有机污染物,在自然环境中半衰期较长,对水生生物及水体环境均有不利影响.采用水热法制备新型铁铈复合氧化物,将其作为臭氧催化剂用于去除水中的4-NP.采用单因素试验,探究铁铈摩尔比、臭氧浓度、催化剂投加量、初始pH等因素对4-NP去除效果的影响.结果表明:在铁铈摩尔比为10:1、水中臭...     

UVA-LED assisted persulfate/nZVI and hydrogen peroxide/nZVI for degrading 4-chlorophenol in aqueous solutions

Photocatalytic degradation of 4-chlrophenol (4-CP) using UVA-LED assisted persulfate and hydrogen peroxide activated by the nZVI (Nano Zero Valent Iron) in a batch photocatalytic reactor was investigated. The reaction involved a lab-scale photoreactor irradiated with UVA-LED light emitted at 390 nm. The efficiency of the reaction was evaluted in terms of 4-CP degradation and mineralization degree at different pH of solution, initial concentrations of nZVI, persulfate, hydrogen peroxide and 4-CP. In UVA-LED/H₂O₂/nZVI process, complete degradation of 4-CP (>99%) and 75% mineralization was achieved at pH of 3, hydrogen peroxide concentration of 0.75 mM, nZVI dosage of 1mM and initial 4-CP concentration of 25mg/L at the reaction time of 30 min. The optimum conditions obtained for the best 4-CP degradation rate were at an initial concentration of 25mg/l, persulfate concentration of 1.5mM, nZVI dosage of 1mM, pH of 3 and reaction time of 120min for UVA-LED/persulfate/nZVI process. It was also observed that the 4-CP degradation rate is dependent on initial 4-CP concentrations for both processes. The pseudo-first-order kinetic constant at 25mg/L initial concentration of 4-CP was found to be 1.4×10^?1 and 3.8×10^?2 in UVA-LED/H₂O₂/nZVI and UVA-LED/persulfate/nZVI processes, respectively. Briefly, the UVA-LED/H₂O₂/nZVI process enhanced the degradation rate of 4-CP by 3.67-times in comparison to UVA-LED/persulfate/nZVI process at 30min contact time, which serves as a new and feasible approach for the degradation of 4-CP as well as other organic contaminants containing wastewater.     

Photocatalytic degradation of rhodamine B and phenol by solution combustion synthesized BiVO4 photocatalyst

Visible-light-induced BiVO₄ photocatalyst has been successfully synthesized via a solution combustion synthesis (SCS) method. The photocatalytic activities of the as-synthesized sample were evaluated by the photodegradation of rhodamine B (RhB) and phenol under visible-light irradiation (λ > 420 nm). The decolorization of high-concentrated RhB (10^− 4 M) and the variation of the chemical oxygen demand (COD), demonstrated that the BiVO₄ photocatalyst was efficient in aromatic organic compounds degradation. The reduction of total organic carbon (TOC) (about 22.0% after 4.5 h of irradiation) showed that the mineralization of RhB over the BiVO₄ photocatalyst is realized. Additionally, much enhanced photocatalytic performance for phenol degradation was also realized with the assistance of appropriate amount of H₂O₂.     

微波辅助Fe_3O_4/H_2O_2类Fenton法处理罗丹明B废水

采用纳米Fe3O4作为催化剂,H2O2为氧化剂,组成多相类Fenton试剂,与微波联合处理罗丹明B(Rh B)染料废水。反应在300W微波反应器中进行,系统研究了H2O2浓度,Fe3O4用量,反应时间,反应温度及催化剂循环使用等条件对罗丹明B脱色率的影响。结果表明,在pH值为4,罗丹明B浓度为100 mg/L,反应温度为80℃,反应时间为5min,H2O2用量为5.0 mL/L,Fe3O4用量为1.25 g/L时,微波辅助条件下罗丹明B脱色率达到100%。此外,催化剂六次循环实验表明,磁性催化剂非常稳定,可重复使用,且易回收。实验表明微波加热与Fe3O4/H2O2类Fenton反应的联合产生了良好的协同效果,该联合工艺可大大提高废水中有机物的处理效果。     

Degradation characteristic of TiO<Subscript>2</Subscript>-chitosan adsorbent on Rhodamine B and purification of industrial wastewater

Based on biosorption and photodegradation coupling technology, a novel adsorbent, which not only adsorbs the heavy metal ions but also degrades organic compound, was prepared by immobilization of nano-TiO₂ on chitosan matrix. Degradation characteristic of Rhodamine B (Rh.B) was investigated by TiO₂-chitosan adsorbents. The results showed that degradation ratio reached 94.3% by 0.2 g adsorbents under ultraviolet radiation light (UV) at initial Rh.B concentration of 10 mg/L and optimal pH of 9.0. Degradation and adsorption behavior characteristics were discussed in the presence of binary pollutants (Rh.B and Ag⁺). The coexistence of Ag⁺ intensely inhibited the degradation ability of Rh.B. Higher Ag⁺ concentration weakened the degradation ability. However, Rh.B did not affect the adsorption capacity of Ag⁺. Moreover, TiO₂-chitosan adsorbent contributed to a higher degradation ability of organic pollutants in practical wastewater. Degradation capacity of contaminants in paper-making wastewater reached 60.8 mg/g at the initial COD concentration of 2,000 mg/L.     

4—甲酰基4—苯乙烯基吡啶分子聚集行为的光谱研究

苯乙烯基吡啶化合物,由于它可能在医学方面和光电子功能材料方面有实际应用前景,已引起人们的兴趣。苯乙烯吡啶化合物的光化学性质类似于二苯乙烯化合物,在光照下可以发生顺-反异构反应、加成反应和二聚反应等不同的光化学反应。但苯乙烯     

Degradation of 2-chlorophenol by Fenton and photo-Fenton processes

The photodegradation of a specific organic pollutant using the Fenton and the photo-Fenton processes has been examined in aqueous solution. The applications of the Fenton process and the photo-Fenton process to the degradation of 2-chlorophenol (2-CP) were investigated. The dependence on the following experimental conditions had been evaluated: initial pH (1.0–9.0), hydrogen peroxide (0.67–2 mM), ferrous ions (0.1–2 mM), initial concentration of 2-CP (0.1–2 mM). The optimal experimental conditions were 1 mM H₂O₂, 1 mM ferrous ion and pH 3.0. Under the optimal conditions, the degradation efficiency of 2-CP in the photo-Fenton process was enhanced 4% more than that of the Fenton process. Experimental results about the degradation of 2-CP show that UV irradiation improves the degradation efficiency of the Fenton process. The major intermediate formed during the degradation of 2-CP was p-benzoquinone.