Review on synthesis of three-dimensional graphene skeletons and their absorption performance for oily wastewater

Water pollution is a global environmental problem that affects the ecosystem severely. Treatment of oily wastewater and organic pollutants is a major challenge that waits to be solved as soon as possible. Adsorbing is one of the most effective strategies to deal with this problem. Three-dimensional (3D) porous adsorbents made of graphene or graphene-based nanomaterials skeletons had attracted more attention in wastewater treatment because of their large surface area, high porosity, low density, high chemical/thermal stability, and steady mechanical properties, which allow different pollutants to easily access and diffuse into 3D networks of adsorbents. This work presents an extensive summarization of recent progress in the synthesis methodologies and microstructures of 3D graphene foams and 3D graphene-based foams and highlights their adsorption performance for oils and organic solvents. Advantages and disadvantages of various preparation strategies are compared and the corresponded structures of these skeletons are studied in detail. Furthermore, the effects of the structures on oil-adsorption properties are analyzed and some data and parameters of the oil-adsorption properties are listed and studied for easier comparison. At last, the future research directions and technical challenges are prospected, which is hoped that the researchers will be inspired to develop the new graphene-based adsorbents.

     

Effects of two polybrominated diphenyl ethers (BDE-47, BDE-209) on the swimming behavior,population growth and reproduction of the rotifer Brachionus plicatilis

Polybrominated diphenyl ethers(PBDEs) are new kinds of persistent organic pollutants(POPs) and their potential threats to the equilibrium and sustainability of marine ecosystems have raised worldwide concerns. Here, two kinds of PBDEs, tetra-BDE(BDE-47)and deca-BDE(BDE-209) were applied, and their toxic effects on the swimming behavior,population growth and reproduction of Brachionus plicatilis were investigated. The results showed that:(1) The actual concentrations of BDE-47 and-209 in the seawater phase measured by GC–MS(Gas Chromatography-Mass Spectrometer) were much lower than their nominal concentrations.(2) In accordance with the 24-hr acute tests, BDE-209 did not show any obvious swimming inhibition to rotifers, but a good correlation did exist between the swimming inhibition rate and BDE-47 concentration suggesting that BDE-47 is more toxic than BDE-209.(3) Both BDE-47 and-209 had a significant influence on the population growth and reproduction parameters of B. plicatilis including the population growth rate, the ratio of ovigerous females/non-ovigerous females(OF/NOF), the ratio of mictic females/amictic females(MF/AF), resting egg production and the mictic rate, which indicate that these parameters in B. plicatilis population were suitable for monitoring and assessing PBDEs. Our results suggest that BDE-47 and-209 are not acute lethal toxicants and may pose a low risk to marine rotifers at environmental concentrations for short-term exposure. They also accumulate differently into rotifers. Further research data are needed to understand the mechanisms responsible for the effects caused by PBDEs and to assess their risks accurately.     

Effects of two polybrominated diphenyl ethers (BDE-47, BDE-209) on the swimming behavior, population growth and reproduction of the rotifer Brachionus plicatilis

Polybrominated diphenyl ethers (PBDEs) are new kinds of persistent organic pollutants (POPs) and their potential threats to the equilibrium and sustainability of marine ecosystems have raised worldwide concerns. Here, two kinds of PBDEs, tetra-BDE (BDE-47) and deca-BDE (BDE-209) were applied, and their toxic effects on the swimming behavior, population growth and reproduction of Brachionus plicatilis were investigated. The results showed that: (1) The actual concentrations of BDE-47 and -209 in the seawater phase measured by GC-MS (Gas Chromatography-Mass Spectrometer) were much lower than their nominal concentrations. (2) In accordance with the 24-hr acute tests, BDE-209 did not show any obvious swimming inhibition to rotifers, but a good correlation did exist between the swimming inhibition rate and BDE-47 concentration suggesting that BDE-47 ismore toxic than BDE-209. (3) Both BDE-47 and -209 had a significant influence on the population growth and reproduction parameters of B. plicatilis including the population growth rate, the ratio of ovigerous females/non-ovigerous females (OF/NOF), the ratio of mictic females/amictic females (MF/AF), resting egg production and the mictic rate, which indicate that these parameters in B. plicatilis population were suitable for monitoring and assessing PBDEs. Our results suggest that BDE-47 and -209 are not acute lethal toxicants and may pose a low risk to marine rotifers at environmental concentrations for short-term exposure. They also accumulate differently into rotifers. Further research data are needed to understand the mechanisms responsible for the effects caused by PBDEs and to assess their risks accurately.     

零价铁-过二硫酸盐连续运行体系去除水中硝基苯

水中硝基苯(NB)的高毒性对人体健康具有极大的危害,因此,本文建立了零价铁-过二硫酸盐(Fe0-PS)连续运行体系以降解水中NB.研究结果表明,单独Fe0柱可还原降解NB,Fe0对不同浓度NB的还原效果均较好,随着流速的减慢及初始pH的降低,NB还原效果变好;但还原体系中总有机碳(TOC)基本没有去除,只是生成了中间产物苯胺(AN).Fe0-PS联合体系中,随着PS的投加,产生的Fe2+活化PS,发生了类Fenton反应,从而使还原产物AN得以氧化降解,TOC去除率可达54.8%;随着Fe0填充量的增加,氧化产物Fe2+随之增加,还原产物AN随之减少.可见,Fe0-PS连续运行体系,以Fe2+为媒介巧妙结合还原与氧化作用,能有效去除NB.     

A new intelligent electronic nose system for measuring and analysing livestock and poultry farm odours

This paper introduces a new portable intelligent electronic nose system developed especially for measuring and analysing livestock and poultry farm odours. It can be used in both laboratory and field. The sensor array of the proposed electronic nose consists of 14 gas sensors, a humidity sensor, and a temperature sensor. The gas sensors were especially selected for the main compounds from the livestock farm odours. An expert system called “Odour Expert” was developed to support researchers’ and farmers’ decision making on odour control strategies for livestock and poultry operations. “Odour Expert” utilises several advanced artificial intelligence technologies tailored to livestock and poultry farm odours. It can provide more advanced odour analysis than existing commercially available products. In addition, a rank of odour generation factors is provided, which refines the focus of odour control research. Field experiments were conducted downwind from the barns on 14 livestock and poultry farms. Experimental results show that the predicted odour strengths by the electronic nose yield higher consistency in comparison to the perceived odour intensity by human panel. The “Odour Expert” is a useful tool for assisting farmers’ odour management practises. Supported by Ontario Pork, Natural Sciences and Engineering Research Council (NSERC), and Ontario Ministry of Agriculture and Food (OMAF) of Canada.     

基于一维卷积神经网络的燃气管道泄漏声发射信号识别*

为保障燃气管道系统安全运行,及时诊断管道故障,基于VGG-16模型提出基于一维卷积神经网络的燃气管道故障诊断模型,提取原始声发射信号特征参数,有效诊断燃气管道故障。结果表明:基于一维卷积神经网络的燃气管道故障诊断模型,能够有效解决燃气管道故障诊断过程中数据预处理复杂、特征提取困难以及识别准确率低等问题,可为燃气管道故障诊断提供技术支撑。     

钻井噪声特性分析与噪声治理

通过对钻井井场噪声源的分布及特性进行现场勘察分析得知:井场区域内各种设备产生的高强度噪声在70～110dB(A)之间,以中低频噪声为主,主要以柴油发电机房为中心,以球面波形式向四周辐射,对井场作业人员及周围250m范围内的居民和环境产生不同程度的噪声危害。为了有效控制噪声对作业人员及井场周围环境的危害,提出了对重点噪声源、噪声传播途径采取隔声、吸声、消声等降噪措施来降低噪声污染。     

Electrophysiological responses of Dendroctonus armandi (Coleoptera: Curculionidae: Scolytinae) to volatiles of Chinese white pine as well as to pure enantiomers and racemates of some monoterpenes

To better understand the attractiveness of host tree, Chinese white pines (Pinus armandi Fr.) to Chinese white pine beetle (Dendroctonus armandi Tsai and Li), the antennal responses of D. armandi to the host volatile, as well as the pure enantiomers and racemates of some monoterpenes, were examined using an electroantennogram (EAG). EAG responses of male and female D. armandi to blended volatiles extracted from the host and some synthetic terpenes (α-phellandrene, (−)-β-pinene, (+)-α-pinene, (−)-α-pinene, (−)-camphene, β-myrcene, (S)-(−)-limonene, (+)-camphene and (R)-(+)-limonene) showed significant variation due to different compound concentrations and sex of the beetles. EAG responses to extracted blended volatiles were significantly greater in females than in males, but the EAG response was not always proportional to the volatile concentration. At lower concentrations, females responded strongly to α-phellandrene and males to (−)-β-pinene, while at higher concentrations, females responded most strongly to α-phellandrene and males to (+)-α-pinene. Females were significantly responsive to (−)-α-pinene, α-phellandrene and (−)-camphene, while males were more responsive to (S)-(−)-limonene, (+)-α-pinene and (R)-(+)-limonene. The EAG responses of the female D. armandi to the volatile oil were significantly higher than that of the males, and the infested pine volatiles could evoke higher EAG response. Most of the test compounds elicited similar responses, which suggested that several of the compounds may be used in combination by D. armandi in habitat and/or host community location at the Qinling forest ecosystem.     

1971-2010年河南省夏季高温日数的变化趋势分析

基于河南省109个气象站1971-2010年夏季(6-8月)逐日最高气温和平均气温资料,采用气候统计学分析方法,分析了近40年河南省夏季≥35℃、≥38℃和≥40℃高温日数的时空特征及可能的变化趋势.结果表明:1971-2010年河南省夏季3个等级高温日数在空间上呈现出豫西北高海拔和豫东南低海拔地区较多,其它地区较少的分布特征,高值中心位于豫西地区的偃师附近,在时间上无显著的线性变化趋势,但是在年代间呈现出“多-少-多”的变化特征,最近10年夏季高温日数最多;从各台站趋势变化的空间分布看,豫西北海拔较高地区台站呈增加趋势的较多,豫东和豫西南台站呈减少趋势的较多.夏季平均气温和≥35 ℃(r =0.58,n=4360)、≥38℃(r=0.39,n=4360)以及≥40℃(r=0.27,n=4360)高温日数均呈显著正相关.在全球气候变暖背景下,未来河南省高温日数将可能进一步增加,特别是≥35℃的高温日数.