道路交通噪声预测模式预测结果的比较

为了分析实际环境影响评价中常用的各种公路交通噪声预测模型预测结果之间存在的差异,并验证各预测方式与实测值之间的相符性,通过对选取的高速公路和市政快速公路采用各种预测模型计算比较,并用实际监测值对各模型预测结果进行验证,结果发现,不同的预测方式会造成预测结果之间昼间4～9 dB、夜间5～10 dB的差异,采用2006版规范计算车速和单车噪声源强,距离衰减考虑车流量大小的预测方式得到的预测结果与实测值最为接近。     

道路交通噪声预测的研究进展

为评价道路交通噪声影响情况,以美国联邦公路管理局(FHWA)噪声预测模型为主,各国相继开发了基于当地实际情况的道路交通噪声预测模型,中国也以导则和规范等形式相继发布了各种交通噪声预测模型。中国进行噪声环境影响评价中,用得较多的主要有《环境影响评价技术导则声环境》(HJ 2.4—2009)、《公路建设项目环境影响评价规范》(JTG B03—2006)推荐的噪声预测模型,此外也有部分评价工作采用了德国的Cadna A软件。通过对比分析,HJ 2.4—2009的衰减及修正因素在综合考虑FH-WA噪声预测模型及JTG B03—2006基础上更加全面,而JTG B03—2006和Cadna A软件在源强和车速确定方面则均较成熟。有必要根据区域道路特点,选择适合特征区域的道路交通噪声预测模型,并结合实际情况对模型参数进行合理修正,最终形成一些可供区域参考的统一的模型修正参数,积极推动中国的声环境评价工作的发展。     

公路交通噪声预测模型FHWA与RLS90的比较

为了了解我国长期以来使用的两种公路交通噪声预测模型,即美国联邦公路局(FHWA)模型和德国RLS90模型的预测精确性,通过理论分析,比较了RLS90分段模型、RLS90长直线模型、FHWA模型的差异,并通过实际测量值对3种模型的计算结果进行了验证,表明RLS90模型在高速公路交通噪声预测中略优于FHWA模型。     

广东省道路交通噪声预测统计模型

为了建立符合广东省的道路交通噪声预测模型,在国内学者相关研究成果的基础上,对FHWA模型进行了深入分析,并根据道路交通噪声预测模型原理,引入等效车流量等概念建立了理论噪声预测统计模型.在此基础上,对广东省市政路和高速路的交通噪声实测数据进行多元线性回归分析,确定广东省交通噪声预测统计模型.经验证,在广东省交通噪声预测评价中该模型预测精度非常高.该研究思路与方法值得在全国各地区处理交通噪声环境问题的工作中加以推广与应用.     

Microbial metagenomics in the Baltic Sea: Recent advancements and prospects for environmental monitoring

Metagenomics refers to the analysis of DNA from a whole community. Metagenomic sequencing of environmental DNA has greatly improved our knowledge of the identity and function of microorganisms in aquatic, terrestrial, and human biomes. Although open oceans have been the primary focus of studies on aquatic microbes, coastal and brackish ecosystems are now being surveyed. Here, we review so far published studies on microbes in the Baltic Sea, one of the world’s largest brackish water bodies, using high throughput sequencing of environmental DNA and RNA. Collectively the data illustrate that Baltic Sea microbes are unique and highly diverse, and well adapted to this brackish-water ecosystem, findings that represent a novel base-line knowledge necessary for monitoring purposes and a sustainable management. More specifically, the data relate to environmental drivers for microbial community composition and function, assessments of the microbial biodiversity, adaptations and role of microbes in the nitrogen cycle, and microbial genome assembly from metagenomic sequences. With these discoveries as background, prospects of using metagenomics for Baltic Sea environmental monitoring are discussed.     

Monitoring a changing Arctic: Recent advancements in the study of sea ice microbial communities

Sea ice continues to decline across many regions of the Arctic, with remaining ice becoming increasingly younger and more dynamic. These changes alter the habitats of microbial life that live within the sea ice, which support healthy functioning of the marine ecosystem and provision of resources for human-consumption, in addition to influencing biogeochemical cycles (e.g. air–sea CO₂ exchange). With the susceptibility of sea ice ecosystems to climate change, there is a pressing need to fill knowledge gaps surrounding sea ice habitats and their microbial communities. Of fundamental importance to this goal is the development of new methodologies that permit effective study of them. Based on outcomes from the DiatomARCTIC project, this paper integrates existing knowledge with case studies to provide insight on how to best document sea ice microbial communities, which contributes to the sustainable use and protection of Arctic marine and coastal ecosystems in a time of environmental change.Supplementary InformationThe online version contains supplementary material available at 10.1007/s13280-021-01658-z.     

广州市内环路交通噪声模拟与降噪措施评估研究

基于单车辆噪声排放模型,考虑距离衰减及声屏障的遮挡作用,建立了高架道路交通噪声模拟模型,计算了广州市内环路的交通噪声分布,并基于地理信息系统(GIS)绘制了内环路的交通噪声地图。同时,以环市东路路段为例,评估了限速、限行及加装声屏障等降噪措施的降噪效果。结果表明:(1)内环路昼间的噪声污染较严重,靠近道路的第1排建筑物大部分处于65～70dB的噪声环境之下,面对路面的建筑物的开窗位置,噪声达到70～75dB。噪声较严重的地区为环市东路路段、火车站路段、中山一路路段、南岸路路段、环市西路路段等,这些地区都可能成为内环路噪声投诉事件的高发地区。相同地区的噪声在夜间下降了一个级别,能够达到《城市区域环境噪声标准》(GB 3096—93)的限值要求(55dB)。(2)加装声屏障的措施,能够在不影响现有路面行车状态的情况下达到降噪要求,是比较推崇的方法。     

道路交通噪声影响人体心电指标的规律研究

借助多功能动态生理检测仪、现场道路交通噪声信号采集系统及室内道路交通噪声信号回放系统等精密仪器设备,研究了道路交通噪声对人体心电的短时影响,并运用统计学、时间序列理论对噪声影响心电指标的规律进行了分析,提出了一种解释道路交通噪声影响人体心电指标规律及确定噪声安全阈值的理论方法。结果表明,不同噪声声压级对心电低频(LF)、高频(HF)之比(LF/HF)时间序列的自相关系数衰减速率影响不同,声压级越高,LF/HF时间序列的自相关系数衰减到0.500时的速率越慢,经历的延迟期越长;当道路交通噪声超过43dB时,有可能对人体心电状态造成潜在的影响。     

Recent advances in the breakdown of microplastics: strategies and future prospectives

Microplastics pollution is becoming a major environmental issue, and exposure to microplastics has been associated with numerous adverse results to both the ecological system and humans. This work summarized the state-of-the-art developments in the breakdown of microplastics, including natural weathering, catalysts-assisted breakdown and biodegradation. Characterization techniques for microplastic breakdown involve scanning electron microscopy, Fourier infrared spectroscopy, X-ray photoelectron spectroscopy, etc. Bioavailability and adsorption capacity of microplastics may change after they are broken down, therefore leading to variety in microplastics toxicity. Further prospectives for should be focused on the determination and toxicity evaluation of microplastics breakdown products, as well as unraveling uncultivable microplastics degraders via cultivation-independent approaches. This work benefits researchers interested in environmental studies, particularly the removal of microplastics from environmental matrix.

     

铁路噪声预测模式的监测验证与误差分析

为了验证列车通过的等效声级、等效时间及预测模式的正确性,选择了一个开阔的场所,在距离铁路外轨中心线30 m处采用两种不同的方式记录列车通过时的源强及持续时间,然后利用监测值预测60 m处的1h等效连续A声级,并与60 m处的1h等效连续A声级监测值进行对比.结果表明,列车经过身边到离开时的持续时间作为等效时间,经过身边时的最大噪声级作为源强,所得到的预测值与监测值的误差范围在-0.3～0.9 dB(A),方差为0.229,离散度较小,预测值与监测值较吻合,可用于指导设计与规划工作.同时,在分析误差产生原因的基础上,提出了提高预测准确性的建议.     

常青道路景观配置对交通噪声的衰减效果

选取重庆市主城区常见的3种道路景观植物——石楠(阔叶类植物)、小叶黄杨(中等叶子类植物)和雪松(针叶类植物),研究常青道路植物对交通噪声的衰减效果。结果表明:(1)在相同排列条件下,3种植物的降噪能力依次为石楠>小叶黄杨>雪松。对单一植物种,植物间交叉排列的绿化带对交通噪声的衰减效果比平行排列好。(2)不同种类植物对噪声的插入损失峰值所处的频段不同。针叶类植物对低频(<500Hz)噪声有很好的衰减效果,阔叶类植物对高频(>2 000Hz)噪声有很好的衰减效果,中等叶子类植物对中频(500～2 000Hz)噪声有很好的衰减效果。(3)选择针叶类植物和较大冠幅的阔叶类植物搭配种植,如雪松和石楠,可有效地提高绿化带对各频段的交通噪声的吸收能力。     

A comparison of chemical mechanisms used in atmospheric models

Four chemical mechanisms used in current photochemical models are compared in detail. Isopleths of the maximum hourly average concentrations of O₃, NO₂ and PAN were constructed for the EPA, FSM, CBII and ELSTAR mechanisms in atmospheric simulations employing the same meteorological conditions and representation of the pollutant mix for all mechanisms. The four mechanisms differ substantially in their predictions of maximum hourly average O₃ and PAN concentrations. However, the mechanisms agree well in their NO₂, predictions, and all show NO_x inhibition of O₃ formation. Using the Empirical Kinetic Modeling Approach, the NMOC (nonmethane organic compounds) reductions necessary to meet the O₃ standard were determined for various O₃, design values and NMOC/NO_x ratios. These calculated NMOC reductions are very sensitive to the chemical mechanism employed, the ELSTAR mechanism requiring the largest NMOC reductions and the EPA and FSM mechanisms the smallest. Simulations of two smog chamber experiments used in developing the mechanisms show that some of the differences between the predictions of the mechanisms are due to different assumptions on aldehyde photolysis rates and radical sources in the chambers.     

Comparison of models used for the determination of odor thresholds

Several methods of data analysis used for the evaluation of odor detection thresholds have been examined through application to two samples of n-butanol. Panels of seven-ten people, working with a six level, IITRI, ternary forced choice olfactometer, were presented with initial concentrations of 99.5 and 52.1 ppm n-butanol during three trials. The ranking-plotting and ASTM E-679 methods were applied to the evaluation of discrimination-recognition thresholds of the odorous samples. It was found that single evaluations of detection or discrimination-recognition thresholds by either method were always ± 50%of the mean of six trials.The effects of successful guessing on the magnitudes of detection thresholds were examined in terms of a model based on the principle of maximum likelihood estimation of one, two and three trials of panel response. The magnitude of the discrimination threshold obtained by this method always fell between the detection and discrimination-recognition thresholds evaluated by the currently used models. The mean discrimination threshold of n-butanol for six trials was found to be 0.65 ± 0.25 ppm. It appears that the magnitude obtained from one trial with seven panel members would be sufficiently reliable for regulatory purposes when only one field sample is available, since any subsequent trials did not produce threshold values better than ± 40 % of the mean of six tests involving seven and ten panel members exposed to two different initial concentrations.     

Generalized models for prediction of pentachlorophenol dissipation dynamics in soils

Dissipation of pentachlorophenol (PCP) in soil was investigated and the chemical relationships with soil properties were addressed. The results indicate that the dissipation of extractable PCP residues can be described using first-order kinetics equations, with a half-dissipation time (T(1/2)) ranging from 6.5 to 173.3d. The sharply different patterns of PCP dissipation in different soils were closely related to soil properties. Correlations of stepwise regression equations obtained were significant at 0.01 probability level between soil parameters and extractable PCP residues (R(2)=0.974**) as well as T(1/2) values (R(2)=0.882**). Using pH together with organic carbon content (OC) and soil particle size distribution, the dissipation dynamics of PCP in soil could be accurately predicted.     

Future-year ozone prediction for the United States using updated models and inputs

The relationship between emission reductions and changes in ozone can be studied using photochemical grid models. These models are updated with new information as it becomes available. The primary objective of this study was to update the previous Collet et al. studies by using the most up-to-date (at the time the study was done) modeling emission tools, inventories, and meteorology available to conduct ozone source attribution and sensitivity studies. Results show future-year, 2030, design values for 8-hr ozone concentrations were lower than base-year values, 2011. The ozone source attribution results for selected cities showed that boundary conditions were the dominant contributors to ozone concentrations at the western U.S. locations, and were important for many of the eastern U.S. locations. Point sources were generally more important in the eastern United States than in the western United States. The contributions of on-road mobile emissions were less than 5 ppb at a majority of the cities selected for analysis. The higher-order decoupled direct method (HDDM) results showed that in most of the locations selected for analysis, NOx emission reductions were more effective than VOC emission reductions in reducing ozone levels. The source attribution results from this study provide useful information on the important source categories and provide some initial guidance on future emission reduction strategies.

Implications: The relationship between emission reductions and changes in ozone can be studied using photochemical grid models, which are updated with new available information. This study was to update the previous Collet et al. studies by using the most current, at the time the study was done, models and inventory to conduct ozone source attribution and sensitivity studies. The source attribution results from this study provide useful information on the important source categories and provide some initial guidance on future emission reduction strategies.     

Enhancing the performance of data-driven models for monthly reservoir evaporation prediction

Environmental Science and Pollution Research - The accuracy level for reservoir evaporation prediction is an important issue for decision making in the water resources field. The traditional...     

Comparison of artificial neural network and regression models in the prediction of urban stormwater quality.

Urban stormwater quality is influenced by many interrelated processes. However, the site-specific nature of these complex processes makes stormwater quality difficult to predict using physically based process models. This has resulted in the need for more empirical techniques. In this study, artificial neural networks (ANN) were used to model urban stormwater quality. A total of 5 different constituents were analyzed-chemical oxygen demand, lead, suspended solids, total Kjeldahl nitrogen, and total phosphorus. Input variables were selected using stepwise linear regression models, calibrated on logarithmically transformed data. Artificial neural networks models were then developed and compared with the regression models. The results from the analyses indicate that multiple linear regression models were more applicable for predicting urban stormwater quality than ANN models.     

Modelling dispersion of traffic pollution in a deep street canyon: Application of CFD and operational models

In this study, numerical modelling of the flow and concentration fields has been undertaken for a deep street canyon in Naples (Italy), having aspect ratio (i.e. ratio of the building height H to the street width W) H/W = 5.7. Two different modelling techniques have been employed: computational fluid dynamics (CFD) and operational dispersion modelling. The CFD simulations have been carried out by using the RNG k–? turbulence model included in the commercial suite FLUENT, while operational modelling has been conducted by means of the WinOSPM model. Concentration fields obtained from model simulations have been compared with experimental data of CO concentrations measured at two vertical locations within the canyon. The CFD results are in good agreement with the experimental data, while poor agreement is observed for the WinOSPM results. This is because WinOSPM was originally developed and tested for street canyons with aspect ratio H/W ≌ 1. Large discrepancies in wind profiles simulated within the canyon are observed between CFD and OSPM models. Therefore, a modification of the wind profile within the canyon is introduced in WinOSPM for extending its applicability to deeper canyons, leading to an improved agreement between modelled and experimental data. Further development of the operational dispersion model is required in order to reproduce the distinct air circulation patterns within deep street canyons.     

Recent progress and challenges on the removal of per- and poly-fluoroalkyl substances (PFAS) from contaminated soil and water

Environmental Science and Pollution Research - Currently, due to an increase in urbanization and industrialization around the world, a large volume of per- and poly-fluoroalkyl substances (PFAS)...