Reuse of Fenton sludge as an iron source for NiFe2O4 synthesis and its application in the Fenton-based process

The potentially hazardous iron-containing sludge from the Fenton process requires proper treatment and disposal, which often results in high treatment cost. In this study, a novel method for the reuse of Fenton sludge as an iron source for the synthesis of nickel ferrite particles(NiFe_2O_4) is proposed. Through a co-precipitation method followed by sintering at 800°C, magnetic NiFe_2O_4 particles were successfully synthesized, which was confirmed by powder X-ray diffraction(XRD), scanning electronic microscopy(SEM), energy dispersive spectroscopy(EDS), Fourier transform infrared spectroscopy(FT-IR) and Raman spectroscopy. The synthesized NiFe_2O_4 could be used as an efficient catalyst in the heterogeneous Fenton process. In phenol degradation with H_2O_2 or NiFe_2O_4 alone, the phenol removal efficiencies within the reaction time of 330 min were as low as 5.9% ± 0.1% and 13.5% ±0.4%, respectively. However, in the presence of both NiFe_2O_4 and H_2O_2, phenol removal efficiency as high as 95% ± 3.4% could be achieved, indicating the excellent catalytic performance of NiFe_2O_4 in the heterogeneous Fenton process. Notably, a rapid electron exchange between_Ni II and_Fe III ions in the NiFe_2O_4 structure could be beneficial for the Fenton reaction. In addition, the magnetic catalyst was relatively stable, highly active and recoverable, and has potential applications in the Fenton process for organic pollutant removal.     

压电智能骨料动态拉应力标定试验研究∗

为了监测混凝土内部受拉开裂损伤,提出了混凝土内部拉应力监测压电智能骨料,并对其进行了动态拉应力标定试验研究。首先,制备4个压电智能骨料受拉试件,建立拉应力监测系统;其次,对压电智能骨料施加往复拉应力,标定得到其灵敏度系数;然后,对压电智能骨料试件施加单调荷载直至其受拉破坏,得到其抗拉强度及输出的电压信号,对比了破坏过程的实际与监测荷载。结果表明,往复荷载作用下,SA输出与输入荷载呈良好的线性关系,SA的灵敏度系数一致性较好;单调荷载作用下,各SA抗拉强度均高于混凝土抗拉强度。综上,压电智能骨料有潜力应用于混凝土内部的拉应力监测。     

活性炭纤维吸附-催化燃烧装置处理有机废气

介绍一种处理有机废气的吸附－催化燃烧新型装置，以活性炭纤维为吸附剂，结合多单元分流组合式中附床，采用PLC电脑来实现整个系统的连续运行。实验运行结果表明，对于处理大风量，低浓度的有机废气，该技术与其他技术相比具有净化效率高，节能降耗，自动化水平高等优点。     

高羊茅对微牛物强化修复石油污染土壤影响的研究

进行了石油污染土壤在外源微生物菌剂和高羊茅协调作用下的强化修复试验，对外源微生物菌剂在不同植被条件下的去除特征进行了分析。分别进行了没有植物、高羊茅草坪、高羊茅草种新育草坪3种不同情况下的降解试验。结果表明，微生物菌剂对石油污染土壤有着良好的降解效果，去除率为36％-43％，而没有微生物菌剂和植被作用下的对照组的去除率仅为5．74％～6．0％；高羊茅草坪能够提高微生物进一步降解的能力，在直接铺草坪的情况下，去除率可以达到51％～62％；在播种高羊茅草种，形成新嫩草坪的情况下，去除率为48％～54％。结果表明，在直接铺高羊茅草坪条件下，微生物菌剂的强化分解作用可以提高41．6％-44．2％，在新嫩草坪作用下能够提高27．9％-30．6％，可以认为高羊茅草坪对于提高微生物菌剂的强化分解有一定的促进作用。在试验过程中还对不同修复的土壤pH值变化特性进行了分析。     

Nitrogen transfer from one plant to another depends on plant biomass production between conspecific and heterospecific species via a common arbuscular mycorrhizal network

Environmental Science and Pollution Research - The formation of a common mycorrhizal network (CMN) between roots of different plant species enables nutrient transfers from one plant to another and...     

山地土壤—植物系统中汞污染问题的初步调查

调查研究表明：在山地大气、水体质量较好的环境中,柑橘（含汞量）有超标问题,其土壤汞有超背景值现象;而蔬菜土壤则无此问题,其原因可能是由于多年生植物从大气和土壤中富积微量汞的时间较一年生植物长,以及土壤中砂粒结合汞粘粒结合汞具有更高的生物活性     

英语电影教学与英语综合应用能力的培养

英语电影教学是走在前端的一项多媒体教学尝试。语言学习轻松、直观,内容生动、丰富,在减轻学生语言学习焦虑及培养学生语言的应用能力,了解西方社会文化、历史等方面起到了有效的促进作用。     

老港填埋场新鲜渗滤液性质研究

用系列滤膜对老港填埋场2003年3月份新鲜渗滤液进行了梯度分离．并研究了其CODcr、氨氮、TOC、IC、TC、TS、FS、电导率、pH、色度,浊度的变化趋势与不同孔径膜之间的关系。结果表明,随着膜孔径的减小,CODcr、氨氮、TOC、IC、TC、TS、FS、色度、浊度等都有不同程度的降低,但降低不大,说明可溶性部分物质对新鲜渗滤液的污染性贡献最大;电导率、pH则先增大后减小。     

Origin of hydrogen sulfide in coal seams in China

In recent years, coal mines in China have seen accidents caused by sudden release of hydrogen sulfide (H₂S), with higher severity. Based on recent local and overseas research on the origin of hydrogen sulfide and the comparative analysis of isotopes, the paper presents three formation models of hydrogen sulfide: bacterial sulfate reduction (BSR), thermo-chemical sulfate reduction (TSR) and igneous activity, as well as the characteristics for identification. This paper analyzes and categorizes the formation models of some hydrogen sulfide in coal seams in China. Some suggestions were put forward for future research of H₂S in coal mines in China.     

北京城区雨水径流水质及其主要影响因素

掌握城区雨水径流水质及其主要的影响因素是有效地利用城区雨水资源和控制城市非点源污染的基础。根据北京 1998— 2 0 0 0年大量的降雨径流水质数据 ,本文分析了城区屋面和道路雨水径流的水质变化规律及其主要影响因素城市雨水径流的水质很差 ,初期径流的污染程度甚至超过城市污水。除了空气质量的影响外 ,最重要的影响因素是屋面材料、道路类型及路面污染状况、气温、降雨强度、降雨量和降雨间隔时间等