碳纳米管表面等离子体改性活化过一硫酸盐性能研究

将简单高效的等离子体刻蚀方法应用于碳纳米管(CNTs)的表面改性,通过扫描电子显微镜(SEM)、透射电子显微镜(TEM)、X射线衍射(XRD)、X射线光电子能谱(XPS)和拉曼光谱(Raman)等对改性后的催化剂进行表征分析,结果表明经刻蚀得到的CNTs缺陷程度和氧含量均有较大提升。研究发现改性后的CNTs催化剂可有效提升过一硫酸盐(PMS)活化性能,在降解水中2,4-二氯苯酚(2,4-DCP)的性能研究中反应速率为未改性CNTs的3.2倍,30min内2,4-DCP去除率可达到97%,同时在实际水体和放大实验中也展现出良好的性能。淬灭实验和电子顺磁共振实验结果表明体系中主要的活性物质为单线态氧(^(1)O_(2))。本研究提供了一种简单制备高性能非金属活化PMS催化剂的方法,并在水体中有机污染物的去除中展现出良好的应用前景。

工业有机危险废物气化激冷废水特性及处理工艺技术研究

高温气化炉协同处理工业有机危险废物(IOHW)是近年来实现资源化利用的热门技术之一。由于IOHW来源的多元性、复杂性和不确定性,对高温气化炉气化IOHW时产生的激冷废水特性及其相应处理工艺技术方面的研究相对较少。探究了激冷废水的来源、特性及元素迁移分配规律,结果显示激冷废水呈现高盐、高磷、高有机物、高氨氮污染等特点。研发了以板框过滤法、磷酸铵镁结晶法、磷酸盐沉淀法、臭氧氧化法和电渗析法为主体的组合工艺技术,在激冷废水处理量为1m^(3)·h^(-1)的中试规模工艺流程中实现了激冷废水资源化和循环利用,并评价了其主要经济指标。结果表明,激冷废水中主要污染物浓度的持续波动会影响该工艺处理效率的稳定性,氨氮、总氮、总磷、有机污染物的去除率分别为44.6%~67.4%、33.9%~60.1%、91.9%~96.1%和43.1%~72.9%,处理1 m^(3)激冷废水的总工艺成本约6元,副产品收益为6元,基本可实现收支平衡。

Inactivation of Bacteria in Oil Field Injected Water by a Pulsed Plasma Discharge Process

Pulsed plasma discharge was employed to inactivate bacteria in the injection water for an oil field. The effects of water conductivity and initial concentration of bacteria on elimination efficiency were investigated in the batch and continuous flow modes. It was demonstrated that Fe2＋ contained in injection water could enhance the elimination efficiency greatly. The addition of reducing agent glutathione （GSH） indicated that active radicals generated by pulsed plasma discharges played an important role in the inactivation of bacteria. Moreover, it was found that the microbial inactivation process for both batch and continuous flow mode well fitted the model based on the Weibull＇s survival function.

Fabrication of visible-light responsive S-F-codoped TiO_2 nanotubes

Fabrication and S-F-codoping of TiO2 nanotubes were carried out by a one-step electrochemical ano-dization process to extend the photoresponse of TiO2 to the visible-light region. The prepared samples were annealed in air and detected by SEM,XRD,XPS and UV-vis DRS spectrophotometer. The results showed that the average tube diameter of the nanotubes was 150 nm and the average tube length was 400 nm. The doped TiO2 nanotubes exhibited strong absorption in visible-light region. Photoelectro-catalytic degradation efficiency of 4-CP over S-F-codoped TiO2 nanotubes was 39.7% higher than that of only-F-doped sample. Moreover,sulfur and fluorine codoped into substitutional sites of TiO2 had been proven to be indispensable for strong response and high photocatalytic activity under visible light,as assessed by XPS.

Polycyclic aromatic hydrocarbons in the centralized wastewater treatment plant of a chemical industry zone:Removal,mass balance and source analysis

Increased attention has been given to the fate of pollutants such as polycyclic aromatic hydrocarbons (PAHs) introduced to the wastewater treatment plants.Dissolved and adsorbed PAHs were detected in the centralized wastewater treatment plant of a chemical industry zone in Zhejiang Province,China.The most abundant PAHs were the low molecular weight PAHs (e.g.,Acy,Ace,Flu and Phe),accounting for more than 80% of the total 16 PAHs in each treatment stage.Phase partitioning suggested that the removal of PAHs in every treatment stage was influenced greater by the sorption of particles or microorganisms.The removal efficiencies of individual PAHs ranged between 4% and 87% in the primary sedimentation stage,between 1% and 42% in anaerobic hydrolysis stage,between <1% and 70% in aerobic bio-process stage,between 1.5% and 80% in high-density clarifier stage,and between 44% and 97% in the whole treatment process.Mass balance calculations in primary stage showed significant losses for low molecular weight PAHs and relatively good agreements for high molecular weight PAHs as well as in anaerobic hydrolysis,high-density clarifier stage and sludge stream for most PAHs.Great gains of 60%-150% were obtained for high molecular weight PAHs in aerobic bio-process stage due to biosorption and bioaccumulation.Our investigations found that PAHs entering the wastewater treatment plant (WWTP) could be derived from the dyeing chemical processes as the byproducts,and the contribution supported by the largest dyeing chemical group was up to 48%.

Preparation of TiO_2/ITO film electrode by AP-MOCVD for photoelectrocatalytic application

Titanium dioxide （TiO2） thin films were grown onto Indium tin oxide （ITO） glass under atmospheric pressure by chemical va- por deposition （AP-MOCVD） using titanium tetraisopropoxide astitanium precursor. The as-prepared TiOe/ITO films were characterized using X-ray diffraction （XRD）, scanning electron microscopy （SEM）, transmission electron microscopy （TEM）, X-ray photoelectron spectroscopy （XPS） and photoelectrochemical measurements. Their photocatalytic （PC） and photoelec- trocatalytic （PEC） activities were evaluated based on the results of methyl orange dye （MO） degradation experiments in aque- ous solution. The difference between the front side （EE, electrolyte/electrode interface） and the back side （SE, sub- strate/electrode interface） illumination was evaluated in both photocurrent and MO degradation experiments. The effect of the film thickness on degradation rate by PEC under the two illumination directions was also studied. Stability of TiO2/ITO film electrode was investigated in repetitive degradation experiments. Overall, the TiO2/ITO film with thickness ranging from 321 to1440 nm deposited by MOCVD method is an effective photoelectrode for MO degradation under SE illumination in PEC reaction system.