High performance of multi-layered alternating Ni–Fe–P and Co–P films for hydrogen evolution

Judiciously engineering the electrocatalysts is attractive and challenging to exploit materials with high electrocatalytic performance for hydrogen evolution reaction. Herein, we successfully perform the interface engineering by alternately depositing Co–P and Ni–Fe–P films on nickel foam, via facile electroless plating and de-alloying process. This work shows that there is a significant effect of de-alloying process on alloy growth. The electronic structure of layered alloys is improved by interface engineering. The multilayer strategy significantly promotes the charge transfer. Importantly, the Co–P/Ni–Fe–P/NF electrode fabricated by interface engineering exhibits excellent electrocatalytic hydrogen evolution activity with an overpotential of 43.4 mV at 10 mA cm-2 and long-term durability for 72 h in alkaline medium (1 mol L-1 KOH). The innovative strategy of this work may aid further development of commercial electrocatalysts.     

催化湿式氧化乐果农药废水及催化剂的研究

通过共沉淀法制备了用于湿式氧化乐果农药废水的Cu/Mn复合氧化物催化剂,研究了沉淀剂种类、沉淀温度、焙烧温度和活性组分配比等因素对Cu/Mn复合氧化物催化剂的活性及稳定性的影响,确定了最佳制备条件,利用BET比表面积测定和XRD对催化剂进行了表征。结果表明:优化条件制备的Cu/Mn复合氧化物催化剂催化湿式过氧化氢氧化处理乐果农药废水时,具有较高的催化活性和稳定性。催化剂用量以6 g/L,反应温度80℃,过氧化氢加入量为12.0 g/L,反应时间60 min,COD去除率为89.5%,活性组分溶出量较小。     

日光/H2O2/草酸铁络合物光解水溶液中的直接耐酸大红

以H2O2/草酸铁络合物作光氧化剂,利用太阳光对水溶液中的直接耐酸大红进行了光氧化降解试验研究。结果表明,在日光照射下,H2O2/草酸铁络合物能使溶液中直接耐酸大红迅速光解,晴天光照15min或阴天光照30-40min,溶液（直接耐酸大红的质量浓度为50mg/L）可褪至无色;溶液的初始pH对染料光解有显著影响;pH为2-4时光解效果最佳;提高H2O2浓度可以提高光解速率,但H2O2的利用率会降低。     

深度氧化技术处理有机废水的研究进展

利用深度氧化技术处理有机废水是目前国内外废水处理的新技术,在美国和欧洲等发达国家,该技术已应用于各种废水和饮用水处理过程。针对我国石油、石化企业在外排废水中所含有毒有害有机物质大多难以降解的特点,经过调研,详细介绍了深度氧化技术处理有机废水的研究进展,并着重探讨了在光催化氧化技术、超声降解技术、超临界水氧化技术、湿式氧化技术等方面所做的工作及深度氧化过程除去水中有机污染物的原理。     

Modelling of stem biomass accumulation in Pinus densiflora seedlings exposed to aqueous-phase OH radicals generating mist

The present study aimed to evaluate the short-term biomass accumulation of forest trees exposed to wet acidic depositions. A hierarchical Bayesian model of tree growth was developed based on the data of a short-term experiment in which 2-year-old Japanese red pine (Pinus densiflora Sieb. et Zucc.) seedlings were exposed to aqueous phase OH radicals generated by an iron-oxalate-H₂O₂ mist (a pseudo-polluted dew) over two growing periods. We conducted a statistical comparison of tree growth between the control and pollution treatment groups by using the growth model incorporated the random effects due to the unknown characteristics of each seedling. The variability among seedlings is expressed in this model by the posterior probabilistic distributions of unobserved dry weight of a stem cohort before exposure treatment. The analysis of the effects of pollution treatment on the stem growth revealed that this treatment decreases the biomass allocation in the current year stems. However, the effects on the relative growth rate of pre-existing stems were unclear. Based on these results, we can speculate that in a polluted environment, the short-term growth of the young stems in the seedlings inhibited by pollution treatment, thereby resulting in the slowdown of long-term biomass accumulation. This can explain the patterns observed in the declining Japanese red pine forests that are subjected to OH-generating dews in the polluted area of western Japan.     

负压二次曝气二氧化氯发生器的研制与应用

以氯酸钠和工业盐酸为基本原料,采用独特的负压二次曝气工艺,在催化剂作用下,经氧化还原反应产生以二氧化氯为主的混合消毒气体,经吸收后形成一定浓度的二氧化氯混合消毒液,与待处理水充分混合,达到杀菌消毒的目的。     

无过氧化氢添加Fenton氧化法降解有机物的可行性研究

Fenton反应可以氧化分解有机物,在反应中的关键氧化剂羟基自由基(HO·)是通过亚铁离子与过氧化氢作用生成的,因此,传统的Fenton氧化必须由外部添加过氧化氢.研究了一种新的方法,即采用Nafion膜固定化亚铁离子,并通过光催化反应提供Fenton氧化所需的过氧化氢,使得Fenton反应在不添加过氧化氢的条件下也能够连续进行.结果表明,以甲酸为代表有机物,该方法可以在不添加过氧化氢的条件下起到分解甲酸的作用.而且,通过对负载亚铁离子Nafion膜的再生,可以使该方法的降解能力保持在稳定的范围.     

Degradation of 2,4-dichlorophenoxyacetic acid in water by ozone-hydrogen peroxide process

IntroductionAt present, several types of organic pollutantsreferred to as environmental endocrine disruptors(ED) have been suggested to be associated withabnormal sexual development (Hu, 2000). It wasreported that the ED led to the decline of reproductive…     

Effects of nitrogen and carbon dioxide on hydrogen explosion behaviors near suppression limit

By varying inert gas content, equivalence ratio and initial pressure, this study is aimed at investigating flame propagation behaviors and explosion pressure characteristics near suppression limit. For carbon dioxide, the weakest flame floating phenomenon is observed at Φ = 1.5 and the buoyant instability is enhanced when the equivalent ratio deviates to the rich and lean sides. For nitrogen, the buoyant instability decreases with increasing equivalent ratio. Both maximum explosion pressure and maximum pressure rise rate increase firstly and then decrease with the increase of equivalence ratio, and they decrease significantly with increasing content of carbon dioxide and nitrogen. For carbon dioxide, the critical suppression ratio of Φ = 0.6, 0.8, 1.0, 1.5 and 2.0 is 7.50, 7.18, 5.74, 3.83, and 2.87. For nitrogen, the critical suppression ratio of Φ = 0.6, 0.8, 1.0, 1.5 and 2.0 is 15.83, 11.87, 9.50, 6.33 and 4.75. Compared to nitrogen, the carbon dioxide is more effective on suppressing hydrogen explosion pressure. The adiabatic flame temperature, thermal diffusivity and mole fraction of active radicals continue to decrease with increasing content of carbon dioxide and nitrogen, which contributes to the decrease of laminar burning velocity.     

石油化工企业含苯胺消防污水处理技术研究

针对石油化工企业含苯胺的消防污水,利用基于过氧化氢和氯化铁为氧化剂的深度氧化技术,通过氧化、絮凝、过滤和吸附对消防污水进行处理。实验确定氧化剂的投加量为理论投加量,氧化时间1.0h,消防污水pH值为6.86时,絮凝剂最佳使用浓度约为2%,消防污水中苯胺和COD去除率达到99.5%以上,达到了消防污水处理效果。