Complex interplay between formation routes and natural organic matter modification controls capabilities of C60 nanoparticles (nC60) to accumulate organic contaminants

Accumulation of organic contaminants on fullerene nanoparticles (nC₆₀) may significantly affect the risks of C₆₀ in the environment. The objective of this study was to further understand how the interplay of nC₆₀ formation routes and humic acid modification affects contaminant adsorption of nC₆₀. Specifically, adsorption of 1,2,4,5-tetrachlorobenzene (a model nonionic, hydrophobic organic contaminant) on nC₆₀ was greatly affected by nC₆₀ formation route – the formation route significantly affected the aggregation properties of nC₆₀, thus affecting the available surface area and the extent of adsorption via the pore-filling mechanism. Depending on whether nC₆₀ was formed via the “top-down” route (i.e., sonicating C₆₀ powder in aqueous solution) or “bottom-up” route (i.e., phase transfer from an organic solvent) and the type of solvent involved (toluene versus tetrahydrofuran), modification of nC₆₀ with Suwannee River humic acid (SRHA) could either enhance or inhibit the adsorption affinity of nC₆₀. The net effect depended on the specific way in which SRHA interacted with C₆₀ monomers and/or C₆₀ aggregates of different sizes and morphology, which determined the relative importance of enhanced adsorption from SRHA modification via preventing C₆₀ aggregation and inhibited adsorption through blocking available adsorption sites. The findings further demonstrate the complex mechanisms controlling interactions between nC₆₀ and organic contaminants, and may have significant implications for the life-cycle analysis and risk assessment of C₆₀.     

Chemical characterization and source apportionment of atmospheric submicron particles on the western coast of Taiwan Strait, China

Taiwan Strait is a special channel for subtropical East Asian Monsoon and its western coast is an important economic zone in China. In this study, a suburban site in the city of Xiamen on the western coast of Taiwan Strait was selected for fine aerosol study to improve the understanding of air pollution sources in this region. An Aerodyne high-resolution time-of-flight aerosol mass spectrometer(HR-To F-AMS) and an Aethalometer were deployed to measure fine aerosol composition with a time resolution of 5 min from May 1to 18, 2015. The average mass concentration of PM1 was 46.2 ± 26.3 μg/m~3 for the entire campaign. Organics(28.3%), sulfate(24.9%), and nitrate(20.6%) were the major components in the fine particles, followed by ammonium, black carbon(BC), and chloride. Evolution of nitrate concentration and size distribution indicated that local NOx emissions played a key role in high fine particle pollution in Xiamen. In addition, organic nitrate was found to account for 9.0%–13.8% of the total measured nitrate. Positive Matrix Factorization(PMF)conducted with high-resolution organic mass spectra dataset differentiated the organic aerosol into three components, including a hydrocarbon-like organic aerosol(HOA) and two oxygenated organic aerosols(SV-OOA and LV-OOA), which on average accounted for 27.6%,28.8%, and 43.6% of the total organic mass, respectively. The relationship between the mass concentration of submicron particle species and wind further confirmed that all major fine particle species were influenced by both strong local emissions in the southeastern area of Xiamen and regional transport through the Taiwan Strait.     

南通市重污染过程PM_(2.5)中OC/EC浓度水平及污染特征分析

采用EC/OC在线分析仪连续监测数据,结合空气自动监测站监测的PM_(2.5)浓度数据和气象参数,对南通市几次重污染过程进行了分析。结果表明,OC/EC浓度随PM_(2.5)浓度变化趋势基本一致,重污染过程中明显升高,是导致南通市重污染天气的重要元素之一。重污染过程中存在明显的二次有机碳污染,且重污染程度越高,二次有机污染越严重。单次重污染过程OC/EC来源基本相同,仅凭OC/EC的比值判断污染物来源是不充分的。污染过程中TC(OC+EC)的上升幅度较PM_(2.5)中其他组分低,污染后其下降幅度也相对较低。     

白塔堡河不同粒级有机物的三维荧光特征解析

利用三维荧光扫描(3DEEM)和体积积分法(FRI),分析了辽河流域白塔堡河在春汛期水中溶解性有机物(DOM)、小粒径有机物(0.22~0.7μm)和大粒径有机物(>0.7μm)的分布。结果显示:白塔堡河中有机物以芳香类蛋白质和溶解性微生物代谢产物为主,腐植酸类物质含量极少;5类组分在不同粒径有机物中分布相似,在0.22μm以下的DOM中分布最多;溯源分析显示,DOM来源较单一,表现出较强的内源生物降解特性,而颗粒状有机物则表现出内源和陆源的双重特性;多元统计分析显示,白塔堡河点位有机物分布基本上呈现区域性分布特征。     

Carbon paste electrodes modified with biosolids, soils and biocomposites utilized to study the interaction between organic matter and copper

Carbon paste electrodes (CPEs) modified with a biosolid, two types of soils with different amounts of organic matter (OM), and two biocomposites (soils mixed with a biosolid) were used to assess and compare the Cu(II) ion retention properties of the organic matter contained in the samples. The accumulation of Cu(II) on the surface of the modified carbon paste electrodes (MCPEs) was performed under open-circuit conditions. When comparing the response of the MCPEs while assessing parameters such as pH, preconcentration time, and adsorption/desorption capacity, it was found that the reaction mechanism of the two soils is different between the soils and dissimilar from the biosolid; while the biocomposites show reaction mechanisms that are intermediate between those of the soils and the biosolid. This was proven with the use of infrared spectroscopy, since the FTIR spectra show similarities between the two soils and significant differences between the soils and the biosolid.     

An inverse model for the analysis of the Venice lagoon food web

A steady-state model of the Venice lagoon food web was constructed, based on a comprehensive set of data, which were collected in the years 2001-2005. Energy flows were estimated by means of an inverse methodology of constrained optimization based on the Minimum Norm criterion, i.e. on the minimization of both the sum of squares of the residuals and of the sum of squares of energy flows. The solution was constrained by a set inequalities, which were derived from general eco-physiological knowledge and site specific data on energy flows. The trophic network was represented by thirty-two nodes, including single-species compartments for the species of high economical or ecological relevance. Mass balance equations were weighted, in order to obtain meaningful results in presence of large differences, up to 5 orders of magnitude, among biomasses. A perturbation technique was applied, with the purpose of reducing the risk of finding solutions heavily affected by the set of constraints and of obtaining a more robust representation of the energy flows. The main patterns of energy flow are consistent with those obtained in previous attempts at modelling the Venice lagoon food web. Micro- and macro-phytobenthos account for the largest fraction of the primary production. Energy is then transferred towards higher trophic levels by means of two main pathways: the recycling of dead biomass through the detritus compartment and the direct consumption by grazers. The first pathway is the most important and accounts for approximately two/thirds of the energy transferred to the second trophic level.     

不同饲粮对生猪产污情况的影响

研究了精饲料和精青配合饲料饲养下育肥猪排污量和主要污染物含量的差异.结果表明,与饲喂精饲料相比,饲喂精青配合饲料的生猪产粪量降低18.97%,产尿量降低38.56%.精饲料饲养50d后,生猪体质量仅比精青配合饲料饲养平均增加1.5kg,采用精青配合饲料饲养的生猪体质量每增加lkg饲料成本投入比精饲料饲养减少21.68%.精青配合饲料喂养生猪不仅可减少污染物的排放量,还可节约饲料投入成本,提高养猪效益.     

Use of pine needles as an indicator of atmospheric contamination by pentachlorophenol

The use of pine needles as an inexpensive and natural device for collecting atmospheric organic contaminants was investigated. The widespread existence of pentachlorophenol in the atmosphere was investigated by analyzing pine needle extracts by GC-MS. PCP was found at low ppb levels in all pine needle samples which were analyzed.     

猪粪生产有机复合肥的工艺设计

对南平市种猪场的污染现状进行了分析，提出用堆肥化的工艺路线对其猪粪进行处理，生产有机复合肥，在实际应用中取得良好效果。该技术具有操作简便、能耗低，实用性强等特点。