Understanding and addressing the environmental risk of microplastics

Over the past decades, the plastic production has been dramatically increased. Indeed, a category of small plastic particles mainly with the shapes of fragments, fibers, or spheres, called microplastics (particles smaller than 5 mm) and nanoplastics (particles smaller than 1 μm) have attracted particular attention. Because of its wide distribution in the environment and potential adverse effects to animal and human, microplastic pollution has been reported as a serious environment problem receiving increased attention in recent years. As one of the commonly detected emerging contaminants in the environment, recent evidence indicates that the concentration of microplastics show an increasing trend, for the reason that up to 12.7 million metric tons of plastic litter is released into aquatic environment from land-based sources each year. Furthermore, microplastic exposure levels of model organisms in laboratory studies are usually several orders of magnitude higher than those found in environment, and the microplastics exposure conditions are also different with those observed in the environment. Additionally, the detection of microplastics in feces indicates that they can be excreted out of the bodies of animal and human. Hence, great uncertainties might exist in microplastics exposure and health risk assessment based on current studies, which might be exaggerated. Policies reduce microplastic emission sources and hence minimize their environmental risks are determined. To promote the above policies, we must first overcome the technical obstacles of detecting microplastics in various samples.     

Analytical methods for microplastics in the environment: a review

Environmental Chemistry Letters - Microplastic pollution is a recently discovered threat to ecosystems requiring the development of new analytical methods. Here, we review classical and advanced...     

Prediction of half-life for adsorption kinetics in a batch reactor

Environmental Science and Pollution Research - Besides adsorption rate constant, the half-life was also a basic factor that described the characteristics of adsorption kinetics. However, the direct...     

绍兴城区夏季大气挥发性有机物特征、来源及大气反应活性

研究了2019年夏季(8月)绍兴城区的烷烃、烯烃、炔烃、芳烃、卤代烃、含氧挥发性有机物(VOCs)、腈7类共98种VOCs的特征、来源及大气反应活性。结果表明,7类VOCs的平均质量浓度由大到小依次为烷烃(24.29μg/m3)卤代烃(17.17μg/m3)芳烃(15.89μg/m3)含氧VOCs(14.72μg/m3)烯烃(4.06μg/m3)炔烃(1.23μg/m3)腈(0.27μg/m3)。烃、腈和卤代烃白天浓度低,夜间浓度高,含氧VOCs基本上终日保持稳定。白天交通排放的贡献较为显著;夜间除交通排放外,挥发性有机溶剂的使用对绍兴城区夏季VOCs也有重要影响。此外,VOCs在一定程度上受到了长距离气团传输的影响,也存在一定的老化现象。烯烃、芳烃是绍兴城区夏季最具大气反应活性的VOCs。     

提高GPS定位精度的群调度滤波算法*

为解决现行安全生产科技领域中全球定位系统（GPS）/惯性导航系统（INS）融合系统容易产生较大时变误差的关键问题，满足GPS定位信号的精度和信号数据处理时间的要求，提出1种群调度滤波算法，通过实验仿真，分别与模糊算法、机器学习算法及卡尔曼滤波网络算法进行比较研究。结果表明:群调度滤波算法兼顾了定位精度与数据处理时间，具有较大优势，可在航空安全、船舶安全、应急监测、灾后抢险等安全科技领域广泛应用。     

Effect of pressure and atmosphere during hydrothermal treatment on the properties of sewage sludge-derived solid fuel

Journal of Material Cycles and Waste Management - Efforts to improve the performance of hydrothermal treatment (HT) in producing high-quality solid fuel from sewage sludge were carried out by...     

都市边缘区田园综合体建设能力测算——以南京市高淳区为例

从田园综合体概念出发，量化评价乡镇田园综合体建设能力，为农地综合利用提供理论支撑。该研究以南京市高淳区为例，构建了涵盖现代农业、休闲旅游、田园社区的评价指标体系定量测算，以镇级尺度，综合运用GIS空间分析、TOPSIS、障碍度模型等探析田园综合体建设能力及其阻碍因素，在此基础上提炼差异化的发展路径。结果表明：（1)现代农业、休闲旅游、田园社区建设能力空间差异显著；（2)休闲旅游、田园社区、现代农业等3个维度对田园综合体建设作用程度和方向不一；（3)影响各乡镇田园综合体建设能力主要障碍因子互有差异，各因子间具复合制约功效；(4）研究针对东部慢城生态区、中南部环湖湿地区、西部水乡圩网区、中北部中心老城区的土地利用提出相应的建设路径。     

升金湖湿地景观格局变化对越冬鹤类地理分布的影响

升金湖湿地是安徽省内的唯一以越冬鹤类为保护对象的国家级自然保护区。研究湿地景观格局变化对越冬鹤类地理分布的影响在恢复湿地生态系统、保护鹤类种群等方面具有重要参考价值。该文对升金湖湿地的白头鹤、白鹤、灰鹤及白枕鹤越冬鹤类的地理分布特征进行了分析,结合升金湖湿地1986～2017年间的8期遥感影像分析景观格局变化特征,并探讨了景观格局变化对越冬鹤类地理分布特征的影响。结果表明:1986～2017年间,升金湖湿地景观格局变化显著,斑块数量增加,景观破碎化严重。泥滩地、草滩地、建设用地、水田面积总体呈增加态势,旱地、林地、芦苇滩地及水域面积总体呈减少态势;4种鹤类数量总体呈减少趋势。鹤类主要地理分布区域为水域、水田、芦苇滩地、泥滩地及草滩地;升金湖湿地景观破碎化不断加剧,鹤类地理分布区域面积整体上在逐渐减少,适宜鹤类生境面积减少,直接导致近30年来鹤类数量逐渐减少。     

鄂西长江小流域土地利用方式对土壤团聚体稳定性的影响

探究土地利用方式对长江中游小流域土壤团聚体稳定性的影响,为鄂西地区土地合理利用与管理以及土壤结构改良提供借鉴.以下牢溪小流域5种不同土地利用方式(柏树林、蔬菜地、石坎农田、撂荒地、天然林)土壤为研究对象,对比分析各土地利用方式间土壤团聚体粒径组成及稳定性差异.结果 表明:(1)柏树林、石坎农田、撂荒地和天然林土壤团聚体以＞2 mm为优势粒级,平均为57.66％,蔬菜地以＜0.25 mm微粒径团聚体为主,均值为60.86％;(2)林地(柏树林和天然林)土壤稳定性和抗蚀性要优于农用地(石坎农田和蔬菜地),耕地撂荒提升团聚体稳定性;(3)分形维数D与破坏率PAD、可蚀性K呈正相关,与团聚体直径(MWD和GMD)和水稳性大团聚体WR0.25呈负相关,分形维数较好反映小流域土壤团聚体的稳定性和抗侵蚀性.对流域内林区的封育是提升土壤结构稳定性的最优管理方式.