The First Attempt for Accounts of Environmental Chemistry and Technology Research

In the field of environmental chemical science and technology,researchers have been publishing high-quality research articles on a specific discovery as well as comprehensive reviews on a broader area.After multiple years of research and publication of individual reports,they are looking for a new venue for scientific communication,which will not only summarize a series of their past achievements but also further extend the discussion without including a comprehensive review of 200+articles.

Comparison of Accelerated Solvent Extraction, Soxhlet and Sonication Techniques for the Extraction of Estrogens, Androgens and Progestogens from Soils

Leaching of hormones from manure amended fields to receive surface water can lead to endocrine disruption in resident fish populations. In order to determine the concentrations of hormones present in manure amended soils, and thus the potential for soils to release hormones to aquatic environments, efficient extraction methods are needed. In this study, the efficacy of three techniques (accelerated solvent extraction [ASE], Soxhlet and sonication) for the extraction of estrogens, androgens and progestogens, as well as their metabolites, from various soil types were evaluated. The stability of hormones spiked into these soils and stored for 30, 90 and 210 days at -20°C was also investigated. Four experimental soil matrices (reagent sand, silt loam, clay and high organic) were spiked with 50 μL of 10 μg·mL-1 (in methanol;final conc. 100 ng·g-1) of a stock mix of hormones and isotopically-labeled standards (ISTDs). After equilibration, triplicate samples of the spiked soils were extracted by ASE, Soxhlet and sonication techniques and analysed, without post extraction cleanup, using HPLC-MS/MS. Sonication and ASE were effective at extracting hormones from all matrices with overall average apparent recoveries, for all 19 extracted analytes, of 71% ± 23% and 73% ± 16%, respectively. Soxhlet was significantly less efficient (p < 0.05) with overall average apparent recoveries of 58% ± 34%. Incorporation of ISTDs resulted in overall average process efficiencies of 108% ± 24%, 102% ± 24% and 180% ± 310% for ASE, Soxhlet and sonication, respectively. The hormones had variable stability in soils stored for at least 30 days, and therefore it recommended that soil samples be analysed within 30 days of sampling.

Influence of Waste Materials Containing Tungsten on Melting and Crystallization of Glass-ceramics

Influences of waste materials containing tungsten on melting and crystallization of glass-ceramics are discussed in this article. High temperature melting, nucleation and crystallization of glass-ceramics were explored by means of DTA, XRD and SEM. The high temperature melting performance of glass-ceramics ingredients can be effectively improved by mixing the right amount of waste materials containing tungsten. But the additive amount should be properly controlled, the mixing content of waste materials containing tungsten should be a range of 0.5 ~ 2.0 %. In the experiment of glass-ceramics ingredients system, the molten softening temperature of base glass powder reduced about 20 ℃ by adding 1 % waste materials containing tungsten, and the nucleation temperature reduced about 15 ℃. The nucleation and crystallization performance of glass-ceramics mineral crystals can be promoted by mixing the right amount of waste materials containing tungsten. That is helpful to improve the quality of glass-ceramics products.

汞同位素地球化学概述

汞同位素是一个新兴的地球化学示踪手段。过去十多年来,随着质谱技术的飞跃发展,汞同位素地球化学研究取得了引人注目的进展,主要体现在如下两个方面。(1)实验及理论地球化学研究表明,汞生物地球化学循环的一系列过程都能导致显著的汞同位素质量分馏。此外,汞还是自然界少数存在同位素非质量分馏的金属元素之一。汞同位素非质量分馏对识别某些特殊地球化学过程(如光还原作用、挥发作用等)具有重要指示意义。(2)自然样品的汞同位素测试表明,自然界汞同位素组成(δ202 Hg和Δ199 Hg)变化可达>10‰。目前,汞同位素地球化学已被应用于汞污染源示踪、汞生物地球化学过程判别等领域,并有望在不久的将来在汞的大气化学、生物地球化学等领域得到更为广泛的应用。

Effects of soil properties on production and bioaccumulation of methylmercury in rice paddies at a mercury mining area,China

Rice paddy soil is recognized as the hotspot of mercury（Hg） methylation, which is mainly a biotic process mediated by many abiotic factors. In this study, effects of key soil properties on the production and bioaccumulation of Hg and methylmercury（MeHg） in Hg-contaminated rice paddies were investigated. Rice and soil samples were collected from the active Hg smelting site and abandoned Hg mining sites（a total of 124 paddy fields） in the Wanshan Mercury Mine, China. Total Hg（THg） and MeHg in soils and rice grains, together with sulfur（S）,selenium（Se）, organic matter（OM）, nitrogen（N）, phosphorus（P）, mineral compositions（e.g., SiO2, Al2O3 and Fe2O3） and pH in soils were quantified. The results showed that long-term Hg mining activities had resulted in THg and MeHg contaminations in soil-rice system. The newly-deposited atmospheric Hg was more readily methylated relative to the native Hg already in soils, which could be responsible for the elevated MeHg levels in soils and rice grains around the active artificial Hg smelting site. The MeHg concentrations in soils and rice grains showed a significantly negative relationship with soil N/Hg, S/Hg and OM/Hg ratio possibly due to the formation of low-bioavailability Hg–S（N）–OM complexes in rhizosphere. The Hg–Se antagonism undoubtedly occurred in soil-rice system, while its role in bioaccumulation of MeHg in the MeHg-contaminated rice paddies was minor. However, other soil properties showed less influence on the production and bioaccumulation of MeHg in rice paddies located at the Wanshan Mercury Mine zone.

Sources, evolution and impacts of EC and OC in snow on sea ice： a measurement study in Barrow, Alaska

Based on the field measurements in Barrow, Alaska within the period of April-May 2015, we investigate the sources and variations of elemental carbon(EC) and organic carbon(OC) in the surface layer of snowpack on sea ice, and estimate their effects on the sea ice albedo. Results show that the snow OC in Barrow are from natural sources(e.g. terrestrial higher plants and micro-organisms) mainly, as well as biomass burning(e.g. forest fires and straw combustion) as an important part. Both EC and OC can accumulate at the snow surface with snow melt. The variations in EC and OC and liquid water content in the snow layer are well consistent during the snow-melting period. A higher rate of snow melt implied a more efficient enrichment of EC and OC. In the last phase of snow melt, the concentration increased to a maximum of 16.2 ng/g for EC and 128 ng/g for OC, which is ~10 times larger than those before snow melt onset. Except for the dominant influence of melt amplification mechanism, the variation in concentrations of EC and OC could be disturbed by the air temperature fluctuation and snowfall. Our study indicates that the lightabsorbing impurities contributed 1.6%-5.1% to the reduction in sea ice albedo with melt during the measurement period. The significant period oflight-absorbing impurities influencing on sea ice albedo begins with the rapid melting of overlying snow and ends before the melt ponds formed widely, which lasted for about 10 days in Barrow, 2015.

Coordination geometry of Zn^(2+) on hexagonal turbostratic birnessites with different Mn average oxidation states and its stability under acid dissolution

Hexagonal turbostratic birnessite,with the characteristics of high contents of vacancies,varying amounts of structural and adsorbed Mn^（3＋）,and small particle size,undergoes strong adsorption reactions with trace metal（TM）contaminants.While the interactions of TM,i.e.,Zn^（2＋）,with birnessite are well understood,the effect of birnessite structural characteristics on the coordination and stability of Zn^（2＋）on the mineral surfaces under proton attack is as yet unclear.In the present study,the effects of a series of synthesized hexagonal turbostratic birnessites with different Mn average oxide states（AOSs）on the coordination geometry of adsorbed Zn^（2＋）and its stability under acidic conditions were investigated.With decreasing Mn AOS,birnessite exhibits smaller particle sizes and thus larger specific surface area,higher amounts of layer Mn^（3＋）and thus longer distances for the first Mn／O and Mn／Mn shells,but a low quantity of available vacancies and thus low adsorption capacity for Zn^（2＋）.Zn K-edge EXAFS spectroscopy demonstrates that birnessite with low Mn AOS has smaller adsorption capacity but more tetrahedral Zn（^（IV）Zn）complexes on vacancies than octahedral（^（VI）Zn）complexes,and Zn^（2＋）is more unstable under acidic conditions than that adsorbed on birnessite with high Mn AOS.High Zn^（2＋）loading favors the formation of^（VI）Zn complexes over^（IV）Zn complexes,and the release of Zn^（2＋）is faster than at low loading.These results will deepen our understanding of the interaction mechanisms of various TMs with natural birnessites,and the stability and thus the potential toxicity of heavy metal pollutants sequestered by engineered nano-sized metal oxide materials.

Understanding the sources and composition of the incremental excess of fine particles across multiple sampling locations in one air shed

Well-designed health studies and the development of effective regulatory policies need to rely on an understanding of the incremental differences in particulate matter concentrations and their sources. Although only a limited number of studies have been conducted to examine spatial differences in sources to particulate matter within an air shed, routine monitoring data can be used to better understand these differences. Measurements from the US EPA Chemical Speciation Network （CSN） collected between 2002-2008 were analyzed to demonstrate the utility of regulatory data across three sites located within 100 km of each other. Trends in concentrations, source contribution, and incremental excesses across three sites were investigated using the Positive Matrix Factorization model. Similar yearly trends in chemical composition were observed across all sites, however, excesses of organic matter and elemental carbon were observed in the urban center that originated from local emissions of mobile sources and biomass buming. Secondary sulfate and secondary nitrate constituted over half of the PM2.5 with no spatial differences observed across sites. For these components, the excess of emissions from industrial sources could be directly quantified. This study demonstrates that CSN data from multiple sites can be successfully used to derive consistent source profiles and source contributions for regional pollution, and that CSN data can be used to quantify incremental differences in source contributions of across these sites. The analysis strategy can be used in other regions of the world to take advantage of existing ambient particulate matter monitoring data to better the understanding of spatial differences in source contributions within a given air shed.

Surface-enhanced Raman spectroscopy for emerging contaminant analysis in drinking water

Emerging contaminants(ECs)in drinking water pose threats to public health due to their environmental prevalence and potential toxicity.The occurrence of ECs in our drinking water supplies depends on their physicochemical properties,discharging rate,and susceptibility to removal by water treatment processes.Uncertain health effects of long-term exposure to ECs justify their regular monitoring in drinking water supplies.In this review article,we will summarize the current status and future opportunities of surface-enhanced Raman spectroscopy(SERS)for EC analysis in drinking water.Working principles of SERS are first introduced and a comparison of SERS and liquid chromatography-tandem mass spectrometry in terms of cost,time,sensitivity,and availability is made.Subsequently,we discuss the strategies for designing effective SERS sensors for EC analysis based on five categories—per-and polyfluoroalkyl substances,novel pesticides,pharmaceuticals,endocrine-disrupting chemicals,and microplastics.In addition to maximizing the intrinsic enhancement factors of SERS substrates,strategies to improve hot spot accessibilities to the targeting ECs are equally important.This is a review article focusing on SERS analysis of ECs in drinking water.The discussions are not only guided by numerous endeavors to advance SERS technology but also by the drinking water regulatory policy.

大气汞均相和非均相化学反应过程研究进展

作为环境中汞传输的最重要通道,大气在汞的全球生物地球化学循环和传输扩散中起着极其关键的作用.大气环境成分复杂,汞在随大气环境传递过程中会经历复杂的化学反应,并导致不同形态之间相互转化,这也成为影响大气汞远距离传输尺度的关键因素.本文主要对大气汞在不同相界面之间的分配过程和主要影响因素(包括相界面的物理化学性质和外部环境条件等)进行了总结;对大气Hg0主要氧化反应过程(卤族元素氧化和O_3、OH·氧化)进行了阐述;对大气Hg^(2+)还原反应过程,尤其是光致还原反应等进行了梳理.如何综合运用野外监测分析和室内模拟等,利用微观分子表面分析等新技术明确大气汞均相、非均相反应过程,并将反应机理与大气汞传输过程模拟系统融合,将是未来大气汞研究的重要内容之一.

Study of the Properties of Polyurethane-waste Rubber Granulate Composites

1 Results The production of rubber is very high and rises every year. Among other things it is directly connected with the growth of car production. Therefore, the processing of waste rubber and its management must be treated as a global problem. Used rubber may replace conventional fuel and, owing to its low price, can improve the economic effectiveness of combustion. Energy recovery by combustion of car tyres allows for rapid management of rubber waste. However, it is well-known that all kinds of wast...

Study of Dynamics of the Cross-linkinc Process of Hyperbranched Polymers

1 Results The description of the relaxation properties of polymers is the way to characterizate the influence of the polymer structure on its useful properties: stability and persistence. Synthesis and investigation of model compounds are needed to perform the physico-chemical characteristics of polymers. Instrumental methods as NMR and dielectric spectroscopy, thermogravimetric analysis and mechanical spectroscopy are used to this goal[1,2]. Dynamic mechanical thermal analysis (DMTA) is one of the most...