Distribution,characteristics and daily fluctuations of microplastics throughout wastewater treatment plants with mixed domestic–industrial influents in Wuxi City,China

• MPs were analyzed throughout three WWTPs with mixed domestic–industrial influents. • White polyethylene granules from plastic manufacturing were the most dominant MPs. • MPs abundance in random grab-sampling was lower than that in daily dense sampling. • The production of MPs such as microbeads need to be restricted from the source. In wastewater treatment plants (WWTPs), microplastics (MPs) are complex, especially with mixed domestic–industrial influents. Conventional random grab sampling can roughly depict the distribution and characteristics of MPs but can not accurately reflect their daily fluctuations. In this study, the concentration, shape, polymer type, size, and color of MPs were analyzed by micro-Raman spectroscopy (detection limit of 0.05 mm) throughout treatment stages of three mixed domestic–industrial WWTPs (W1, W2, and W3) in Wuxi City, China, and the daily fluctuations of MPs were also obtained by dense grab sampling within 24 h. For influent samples, the average MP concentration of 392.2 items/L in W1 with 10% industrial wastewater was much higher than those in W2 (71.2 items/L with 10% industrial wastewater) and W3 (38.3 items/L with 60% industrial wastewater). White polyethylene granules with a diameter less than 0.5 mm from plastic manufacturing were the most dominant MPs in the influent of W1, proving the key role of industrial sources in MPs pollution. In addition, the daily dense sampling results showed that MP concentration in W1 influent fluctuated widely between 29.1 items/L and 4617.6 items/L within a day. Finally, few MPs (less than 4.0 items/L) in these WWTPs effluents were attributed to the effective removal of wastewater treatment processes. Thus, further attention should be paid to regulating the primary sources of MPs.     

背景溶液对纳米氧化铁吸附病毒的影响

以噬菌体X174为病毒替代,通过等温静态批量吸附实验,研究了4种纳米氧化铁(α-Fe2O3、γ-Fe2O3-B、γ-Fe2O3-N、Fe3O4)对病毒在不同背景溶液中的吸附行为及其影响因素.结果表明,在模拟地下水中,4种纳米氧化铁对病毒均具有较高的吸附比例,其中α-Fe2O3对病毒吸附比例最高,在病毒初始浓度比较低(约1E+03PFU.mL-1)时可达100%.经Langmuir和Freundlich吸附等温线方程对上述吸附结果进行拟合表示,纳米氧化铁对病毒的吸附均为有利吸附(favorable adsorption),并可能存在多层吸附,吸附比例均随着病毒初始浓度的增加而减少.纳米氧化铁对病毒的吸附比例随着背景溶液离子强度的增加而降低,表示其吸附行为以电性吸附为主.背景溶液中阴离子存在显著降低了病毒的吸附量,这可能与阴离子竞争病毒吸附位点有关,其中HPO24-比HCO3-表现得更为明显.结果同时显示背景溶液中多价阳离子的存在(比如Ca2+和Mg2+)比单价阳离子(比如Na+和K+)更有利于纳米氧化铁对病毒的吸附.综上可知,纳米氧化铁是一种潜在的病毒净化理想材料,应用时需考虑其环境因素的影响.     

Monitoring of air pollution by polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans of pine needles in Korea

The atmospheric contamination levels of polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) were evaluated from the analysis of pine needles in South Korea. Pine needles were collected from 30 sampling points at five main cities in South Korea (Busan, Daegu, Gwangju, Changwon and Jeju island). The highest concentrations of PCDDs/DFs (2.19–26.88 pg I-TEQ/g of dry weight) were measured at Busan, where is the city of the highest population density and traffic volume among five cities. The lowest concentration was detected at Jeju with 0.62 pg I-TEQ/g dry weight, suggesting Jeju could be an environmental background area in Korea. The dominant homologues of PCDDs/DFs in pine needles were the lower chlorine-substituted compounds such as tetra CDDs and CDFs, and the distribution ratios of PCDDs/DFs decreased with increase of the number of chlorine substituents. Homologue profiles of pine needle samples were similar to PCDDs/DFs profiles of the vapor phase in the ambient air, and thus the pine needles absorbed the vapor phase of PCDDs/DFs from air. Results suggested that pine needles could be used as an indicator of the atmospheric contamination for PCDDs/DFs in Korea.     

Exploring the impact of new particle formation events on PM2.5 pollution during winter in the Yangtze River Delta, China

New particle formation（NPF） events are an increasingly interesting topic in air quality and climate science. In this study, the particle number size distributions, and the frequency of NPF events over Hefei were investigated from November 2018 to February 2019. The proportions of the nucleation mode, Aitken mode, and accumulation mode were 24.59%,53.10%, and 22.30%, respectively, which indicates the presence of abundant ultrafine particles in Hefei. Forty-six NPF events occurred during the obser...     

Study on Residential Water Use in North China:Analysis of Nationwide Statistical Data and Case Study of Taiyuan City

Residential water use is gradually becoming the focus in China‘s municipal water supply planning and management in recent years. Little is known, however, about the residential water use in modem China due to the transition of economy and enhancement of management on water conservation. In order to better understand the characteristics of residential water use in North China, a model for identifying the determinants of residential water use was established and analyzed by using panel data and cross-section data methodologies. Then Taiyuan city, the capital city of Shanxi Province in Northern China was selected as a case study. Both the analyses and field investigation indicate that the relatively slow increase of residential water use in recent years may result from the implementation of strict laws and regulations on water conservation. And through the investigation,first-hand information about water consumption pattern, water reuse/conservation, people‘s attitude toward water quantity and quality, etc. have been obtained.     

浮游植物群落结构季节变化研究——以太湖梅梁湾和东太湖为例

为了解太湖浮游植物群落结构的特征,2017年7月至2018年6月对太湖梅梁湾(藻型湖区)和东太湖(草型湖区)浮游植物群落结构和理化因子进行了调查.结果发现:梅梁湾氮磷浓度显著高于东太湖,梅梁湾浮游植物年平均数量是东太湖4.94倍,梅梁湾浮游植物年平均生物量是东太湖的2.16倍;梅梁湾微囊藻数量占比为68.52％～99....     

采煤区覆岩与地表沉陷控制技术研究及展望

煤矿开采引起覆岩及地表沉陷的控制理论与技术研究是涉及全球性灾害学科的研究内容之一。笔者通过对采动覆岩破坏特征的分析，提出了覆岩破坏与移动的“竖四带”的分区模式；并在评述传统控制技术及效果的基础上，介绍了覆岩与地表沉陷控制的新技术——离层注浆技术的原理、特点及应用前景     

An integrated methodology for estimation of forest fire-loss using geospatial information

These days, wildfires are prevalent in almost all areas of the world. Researchers have been actively analyzing wildfire damage using a variety of satellite images and geospatial datasets. This paper presents a method for detailed estimation of wildfire losses using various geospatial datasets and an actual case of wildfire at Kang-Won-Do, Republic of Korea in 2005. A set of infrared (IR) aerial images acquired after the wildfire were used to visually delineate the damaged regions, and information on forest type, diameter class, age class, and canopy density within the damaged regions was retrieved from GIS layers of the Korean national forest inventory. Approximate tree heights were computed from airborne LIDAR and verified by ground LIDAR datasets. The corresponding stand volumes were computed using tree volume equations (TVE). The proposed algorithm can efficiently estimate fire loss using the geospatial information; in the present case, the total fire loss was estimated as $5.9 million, which is a more accurate estimate than $4.5 million based on conventional approach. The proposed method can be claimed as a powerful alternative for estimating damage caused by wildfires, because the aerial image interpretation can delineate and analyze damaged regions in a comprehensive and consistent manner; moreover, LIDAR datasets and national forest inventory data can significantly reduce field work.     

Pyrrolidinium Imides: Promising Ionic Liquids for Direct Capture of Elemental Mercury from Flue Gas

A new approach to vapor phase elemental mercury capture has been explored; this approach exploits an ionic liquid coating layer to oxidize elemental mercury for subsequent immobilization by chelating ligands. The room temperature ionic liquid 1-butyl-1-methyl pyrrolidinium bis(trifluoromethane sulfonyl)imide (P₁₄) was selected for study based on its oxidation potential window, thermal stability, and low vapor pressure. Tests were also completed in which KMnO₄ was added to P₁₄ to form a new ionic liquid, P₁₄–KMnO₄, with a higher oxidation potential. In room-temperature bulk liquid phase capture experiments, 59% of the elemental mercury in the inlet gas was captured using P₁₄ alone; mercury capture using P₁₄–KMnO₄ was quantitative. P₁₄ and P₁₄–KMnO₄ coatings were successfully applied to mesoporous silica substrates and to silica substrates functionalized with mercury chelating ligands. The coating layers were found to be thermally stable up to 300°C. Fixed-bed tests of nonfunctionalized silica coated with P₁₄ showed an elemental mercury uptake of 2.7 mg/g adsorbent at 160°C; at the same temperature, functionalized silica coated with P₁₄–KMnO₄ showed an elemental mercury capacity of at least 7.2 mg/g adsorbent, several times higher than that of activated carbon. The empty bed gas residence time in these tests was 0.04 s. A chelating adsorbent incorporating P₁₄ in the coating layer, may be capable of simultaneous removal of elemental and oxidized mercury from coal combustion flue gases.