Estimation of Similarity in the Qualitative Composition of Humic Substance in Marine Sediments By Means of an Uv-Spectroscopic Library

In this paper a method for the study of the qualitative similarity of extractable humic substance (EHS) in marine sediments based on the realisation of UV spectral library of EHS is described. the spectral library was built including the digitised spectra of humic substance extracted from several marine sediments (46 samples) and two samples of standard materials (lignin sulphonate and humic substance) in a Statistica data file. the data matrix was elaborated by means of different multivariate statistic techniques such as Cluster Analysis (CA), Principal Components Analysis (PCA) and the univariate technique Spectral Correlation Analysis (SCA). This approach allows us to show the contribution of different organic compounds (aromatic, lipid and acid) to the composition of EHS and moreover it evidences also the structural characteristics of EHS in terms of similarities in the qualitative composition of samples such as presence of terrestrial and/or vegetal contributions. the UV library is an objective tool to study the qualitative composition of EHS and it represents a complementary approach to the most common methods based on the application of spectroscopic (IR, ¹³CNMR), potentiometric and chromatographic techniques.     

饮用水中氧化性物质的危害及处理技术研究进展

氧化性物质作为饮用水中一种特殊污染物已对人体健康产生了危害,如何有效地去除这些物质迫在眉睫。对水中氧化性物质的产生、危害及其处理技术进行总结,详述了物化处理和氢自养生物还原处理技术的原理、特点及国内外的研究进展。     

New York City Environmental Justice Alliance Waterfront Justice Project

This paper reviews key challenges and opportunities addressed by the New York City Environmental Justice Alliance's (NYC-EJA) Waterfront Justice Project, a citywide campaign to promote climate resilience and sustainability in urban industrial waterfront communities of New York City. NYC-EJA is a non-profit membership-driven network linking grassroots organisations from low-income neighbourhoods and communities of colour in their struggle for environmental justice. The Waterfront Justice Project is documenting community vulnerability in the context of climate change impacts, sources of industrial pollution, and demographic and socio-economic trends. This campaign is enabling community-based organisations, environmental justice communities, city planners, local and state government agencies, local business-owners, and other stakeholders to work in partnership to achieve community resilience while advocating for local jobs and promoting best practices in pollution prevention. New York City's waterfront policies ease the siting and clustering of public infrastructure, water pollution control plants, waste transfer stations, energy facilities, and heavy manufacturing uses in six areas designated as Significant Maritime and Industrial Areas (SMIAs). The SMIAs are located in environmental justice communities, largely low-income communities and communities of colour, in the South Bronx, Brooklyn, Queens, and Staten Island. New York City's local waterfront land use and zoning policies create cumulative risk exposure not only to residents and workers in the host waterfront communities, but also, in the event of storm surge or sea-level rise, to neighbouring, upland communities.     

Physiologically based pharmacokinetic modeling of perfluoroalkyl substances in the human body

Currently, there are limited data on the levels of perfluoroalkyl substances other than perfluorooctane sulfonic acid and perfluorooctanoic acid in the human body. Most of this information has been extracted from biological monitoring of plasma while the occurrence of perfluoroalkyl substances in other human tissues is rarely studied. The objective of the present study was to develop a physiologically based pharmacokinetic model to assess the concentration of perfluoroalkyl substances in human tissues, based on an existing model previously validated for perfluorooctane sulfonic acid and perfluorooctanoic acid. Experimental data on concentrations of perfluoroalkyl substances in human tissues from individuals in Tarragona County (Catalonia, Spain) were used to estimate the values of some distribution and elimination parameters needed for the simulation. No significant correlations were found between these parameters and the chain lengths. The model was finally validated for five perfluoroalkyl substances.     

纳米氧化锌对大型溞肠道组织毒性效应及机理研究

研究了不同浓度纳米氧化锌（ZnONP）及其在水中释放的对应浓度的Zn²⁺溶液对大型溞（Daphnia magna）肠道组织显微和亚显微结构的影响,探讨了ZnONP对大型溞的肠道组织毒性效应特征和作用机理.结果表明,0.3 mg·L^-1-Zn²⁺组（Zn²⁺浓度0.170 mg·L^-1）和0.3 mg·L^-1 ZnONP溶液皆对大型溞的肠道造成损伤,主要导致大型溞中肠与直肠之间的连接处发生扭曲,其中ZnONP对肠道组织结构弯曲影响最为明显,0.3 mg·L^-1 ZnONP组引起大型溞个体最大肠道弯曲率高达42%.大型溞肠道组织HE染色结果显示,ZnONP暴露会造成大型溞肠道上皮组织断裂、胞间连接空泡化、纹状缘模糊及杯状细胞脱落等,而相对应浓度Zn²⁺组的毒性较弱.电子显微镜下对大型溞肠道组织亚显微结构观察发现,0.3 mg·L^-1 ZnONP处理组大型溞肠道上皮细胞组织出现微绒毛排列紊乱、脱落、溶解,上皮细胞松散,线粒体双层膜结构不完整,嵴溶解消失,核糖体增多等现象.0.3 mg·L^-1-Zn²⁺组大型溞肠道组织上皮细胞有损伤,但整体结构基本完整.从ZnONP和对应的Zn²⁺所产生的毒性效应特征和各组大型溞机体中Zn元素含量的测定分析,ZnONP对大型溞造成的肠道组织损伤不仅与其释放的Zn²⁺引起的毒性有关,更可能与大型溞对颗粒物摄取的方式或ZnONP在体内的积累量、排泄速率和作用的细胞器等有关.因此,ZnONP对肠道组织毒性效应产生的分子机制还需要 进一步研究.     

Extracellular polymeric substance induces biogenesis of vivianite under inorganic phosphate-free conditions

Vivianite is often found in reducing environments rich in iron and phosphorus from organic debris degradation or phosphorus mineral dissolution. The formation of vivianite is essential to the geochemical cycling of phosphorus and iron elements in natural environments. In this study, extracellular polymeric substances (EPS) were selected as the source of phosphorus. Microcosm experiments were conducted to test the evolution of mineralogy during the reduction of polyferric sulfate flocs (PFS) by Shewanella oneidensis MR-1 (S. oneidensis MR-1) at EPS concentrations of 0, 0.03, and 0.3 g/L. Vivianite was found to be the secondary mineral in EPS treatment when there was no phosphate in the media. The EPS DNA served as the phosphorus source and DNA-supplied phosphate could induce the formation of vivianite. EPS impedes PFS aggregation, contains redox proteins and stores electron shuttle, and thus greatly promotes the formation of minerals and enhances the reduction of Fe(III). At EPS concentration of 0, 0.03, and 0.3 g/L, the produced HCl-extractable Fe(II) was 107.9, 111.0, and 115.2 mg/L, respectively. However, when the microcosms remained unstirred, vivianite can be formed without the addition of EPS. In unstirred systems, the EPS secreted by S. oneidensis MR-1 could agglomerate at some areas, resulting in the formation of vivianite in the proximity of microbial cells. It was found that vivianite can be generated biogenetically by S. oneidensis MR-1 strain and EPS may play a key role in iron reduction and concentrating phosphorus in the oligotrophic ecosystems where quiescent conditions prevail.     

Impact of Invasive Cane Toads on Australian Birds

Abstract: The cane toad (Bufo marinus), a large, toxic, American anuran, was introduced to Australia in 1935. Populations of many of Australia's reptiles (snakes, varanid lizards, crocodiles) and carnivorous mammals (dasyurid marsupials) have declined because these predators are killed by the toad's powerful toxins. In contrast to these well‐studied species, little is known about the cane toads impacts on Australian birds. We reviewed published and unpublished data on behavioral interactions between Australian avian predators and cane toads and collated distributional and dietary information to identify avian taxa potentially at risk from cane toad invasion. Cane toads are sympatric with 172 frog‐eating bird species in Australia, and an additional 8 bird species overlap with the predicted future range of the toad. Although many bird species thus are potentially at risk, behavioral observations suggest the risk level is generally low. Despite occasional reports of Australian birds being killed when they ingest cane toads, most birds either ignore toads or survive the predation event. The apparently higher tolerance of Australian birds to toad toxins, compared with Australian reptiles and marsupials, may reflect genetic exchange between Australian birds and Asian populations that encounter other bufonid species regularly and hence have evolved the capacity to recognize or tolerate this toxic prey.     

智能化有害有毒气体污染源监测仪的研究

为了快速寻找有害有毒气体污染源,利用8个红外激光气体传感器,分别安装步进电机驱动旋转的圆盘圆周上在不同的方向上对污染气体进行数据采集。同时与二维热差式风速风向传感器采集到的风速风向数据,一并送入MSC1210单片机进行数据处理和运用智能人工神经网络进行模式训练与模式识别,从而识别出污染源的位置、浓度和种类。通过GPS全球卫星定位系统和GPRS无线传输网络,把监测到的信息发送给相关部门早做处理,并报警,避免污染进一步扩散。实验表明,该智能化追索气体污染源监测仪具有良好的可靠性、安全性和实用性。     

Fe(Ⅱ)活化过硫酸钠深度处理工业园区污水处理厂出水

采用Fe(Ⅱ)活化过硫酸钠(PS)技术对工业园区污水处理厂出水进行深度处理,通过响应曲面法考察了PS/COD、Fe(Ⅱ)/PS和pH对COD和TOC去除率的单独和联合效应.利用紫外-可见扫描、凝胶色谱及三维荧光等手段表征深度处理前后的有机物特性变化.结果表明,PS/COD和Fe(Ⅱ)/PS对COD去除影响极显著;而PS/COD、Fe(Ⅱ)/PS和pH对TOC去除均有显著影响.PS/COD和pH联合效应对COD去除影响显著.最优工艺条件PS/COD比3.47、Fe(Ⅱ)/PS比3.32、pH 6.5时,COD和TOC去除率为50.7%和60.6%.Fe(Ⅱ)-PS氧化能将大分子有机物转化为小分子,削减类蛋白质、类富里酸和类腐殖酸的含量.     

活化过硫酸盐对市政污泥调理效果的影响

常规污泥脱水技术只能将市政污泥含水率降到80%左右,难以满足日益严格的污泥处理处置要求.活化过硫酸盐产生硫酸根自由基SO4·-具有强氧化性,可用于破坏污泥的絮体结构.本研究利用Fe2+活化过硫酸钠(SPS)的方法进行污泥调理,以到达改善污泥的脱水性能的目的.结果表明,当Fe2+与S2O2-8投加量(以绝干污泥计)分别为25.88 mg·g-1、80 mg·g-1(Fe2+与S2O2-8摩尔比为1.1∶1)时,污泥毛细吸水时间CST和污泥比阻SRF降低率最大,滤液中蛋白质和多糖浓度达到最大.进一步的研究表明,污泥Zeta电位值由负向正变化,颗粒比表面积增大,絮体由密集的团状变成结构松散的层状结构,污泥脱水性能提高.