Heterogeneous photocatalytic oxidation of cyprodinil and fludioxonil in leaching water under solar irradiation

The efficiency of ZnO and TiO₂ suspensions in the photocatalytic degradation of two fungicides (cyprodinil and fludioxonil) in leaching water was investigated. The experiments were carried out at pilot plant scale using compound parabolic collectors under natural sunlight. The blank experiments for both irradiated compounds solutions showed that both oxides strongly enhanced the removal of the fungicides. The addition of an oxidant (Na₂S₂O₈) to the ZnO or TiO₂ increased the rate of photooxidation. The degradation of cyprodinil and fludioxonil followed first order kinetics according to the Langmuir-Hinshelwood model. Complete degradation of both fungicides was achieved within 4 h (t_30W = 18 min) when treated with illuminated ZnO. The disappearance time (DT₇₅), when referred to the normalized illumination time (t_30W), was lower than 40 and 550 min (t_30W = 2 and 40 min) for both fungicides using ZnO or TiO₂, respectively. ZnO appeared to be more effective in cyprodinil and fludioxonil oxidation than TiO₂ probably due to its nonstoichiometry.     

微波辐射技术在聚乙烯醇降解反应中的应用

考察了微波功率、pH值、H2O2用量和反应时间对聚乙烯醇降解反应的影响.实验表明,在微波辐射条件下,微波功率为800W,辐射时间为1min,pH值为3, H2O2用量为22g H2O2·100g-1 PVA时,5ml聚乙烯醇(7%)的平均聚合度能够在1min内降至67.与常规油浴加热相比,反应速度提高10-20倍.     

污水紫外消毒微生物光复活原理及其控制技术

紫外消毒技术因其具有操作简单、无有害副产物、经济高效等优势,在污水处理中越来越广泛被应用.但其无剩余消毒能力,微生物在光照条件下进行修复而实现复活,从而导致出水微生物数量增多.综述了国内外紫外消毒出现的光复活现象,阐述了污水紫外消毒微生物光复活原理和控制技术.     

用微波辐照消除磺基水杨酸污染物

介绍了利用微波辐照去除废水中磺基水杨酸污染物的技术。处理废水时,先用活性炭吸附污染物,然后,将滤出的活性炭用微波幅照,使其再生,即可有效地消除废水中有机物的污染。实验表明,对废水中磺基水杨酸的去除率可达 ９７ ４％。     

微波辐照制备花生壳活性炭研究

以花生壳为原料通过微波辐照制备了具有高比表面积并含有大量中孔的活性炭。讨论了活化剂类型、浸渍时间、浸渍比、活化剂浓度、微波功率和辐照时间对花生壳活性炭制备的影响。结果表明:相较磷酸和氢氧化钠,采用氯化锌活化剂制备的花生壳活性炭有更好的碘吸附性能;在浸渍浓度为40%,浸渍比为1∶6,浸渍时间为48 h,微波功率为500 W,辐照时间为6 min的条件下,制备的花生壳活性炭碘吸附值和亚甲基蓝吸附值分别为(898.6±12.8)mg/g和(46.2±3.8)mg/g;微波辐照工艺制备的活性炭,其碘吸附与亚甲基蓝吸附能力均优于马弗炉工艺;花生壳活性炭的碘吸附与亚甲基蓝吸附能力均优于市售活性炭。     

TiO2对水溶液中4-氯酚电子束辐照降解和矿化的影响

以电子加速器为辐照手段,在4-氯酚水溶液中添加TiO2纳米粒子,通过对溶液辐照前后4-氯酚浓度、GC/MS、总有机碳(TOC)、氯离子浓度、辐照前后的紫外-可见光谱过程和溶液pH值的测定分析,研究4-氯酚水溶液在TiO2纳米粒子存在下的辐照降解和矿化特性.结果表明,TiO2纳米粒子的加入对4-氯酚的辐照降解效果没有明显影响,但改变了4-氯酚的降解途径并可以较大地提高4-氯酚的矿化.     

吸附剂-无机/有机脱附体系微波场中的温度响应

主要研究介电常数不同的物质以及吸附剂/脱附剂体系在微波场中的温度响应规律,为日后系统研究微波热效应对吸附剂再生的影响作一铺垫。研究发现,液体物质在微波场中的温度响应与其介电常数有关;不同的吸附剂/脱附剂体系在微波场中也表现出不同的温升行为。     

活性炭-微波辐射法去除苯酚的机理研究

通过微波辐射前后水样的紫外分光扫描分析,以及微波辐射后水样中的苯酚浓度和COD浓度之间线性相关性分析表明,活性炭-微波辐射强化除酚效率的主要机理是微波使反应体系温度升高导致的活性炭加速吸附作用,而不是微波诱导催化氧化作用。通过对微波辐射前后活性炭的SEM扫描电镜分析说明,活性炭在微波场中由于“微域爆炸”导致其表面及内部孔隙结构的变化, 吸附性能得到改善,是强化苯酚去除的另一原因。 研究还表明,在较短的作用时间内,活性炭-微波辐射法的除酚效率高于常温吸附,但低于沸腾条件下的高温吸附。活性炭-微波辐射去除苯酚的规律遵循其吸附特性,温度越高,吸附反应速度越快。     

我国东南沿海车辆装备涂层环境试验设计

目的研究我国东南沿海环境对我军车辆装备涂层的影响。方法根据近海试验场所提供的温湿度、氯离子浓度、辐照总量等相关数据,当量转化为光照、温度、湿度、化学介质四种环境因子,依据GJB150A—2009《军用装备实验室环境试验方法》裁剪制定了依次进行湿热辐照试验、中性盐雾试验和酸性盐雾试验的实验室模拟方法。结果相同试片在实验室模拟环境与实际环境中表现出的电化学特征较为一致。结论该试验设计能较好模拟当地实际环境影响,为在该地区服役的车辆装备有机涂层的使用寿命预测、涂层防护与防腐蚀保养等技术研究提供了重要依据。     

Ultraviolet irradiation induced oxidative stress and response of antioxidant system in an intertidal macroalgae Corallina o cinalis L.

The response of the antioxidant defense system of an intertidal macroalgae Corallina officinalis L. to different dosages of UV-B irradiation was investigated. Results showed that superoxide dimutase (SOD) and peroxidase (POX) increased and then maintained at a relatively stable level when subjected to UV-B irradiation. Catalase (CAT) activity under medium dosage of UV-B irradiation (Muv) and high dosage of UV-B irradiation (Huv) treatments were significantly decreased. Ascorbate peroxidase (APX) activity first remained unaltered and then increased in Huv treatment. In addition, the assay on isozymes was carried out using non-denaturing polyacrylamide gel electrophoresis (PAGE). The activities of some SOD isoforms were altered by UV-B. Two new bands (POX V and POX Ⅶ) appeared upon exposure to all three UV-B dosages. CAT Ⅲ activity was increased by low dosage of UV-B irradiation (Luv),whereas CAT Ⅲ and CAT Ⅳ disappeared when the alga was exposed to Muv and Huv. Two bands of APX (APX Ⅵ and APX Ⅶ)were increased and a new band (APX X) was observed under Huv exposure. H2O2 and thiobarbituric acid reacting substance (TBARS)increased under Muv and Huv treatments. Overall, UV-B protection mechanisms are partly inducible and to a certain extent sufficient to prevent the accumulation of damage in C officinalis.