船舶压载水防治措施探讨

船舶压载水是外来海洋生物入侵的重要途径,严重危害水域生态平衡,破坏生物多样性,危害环境,造成严重的经济损失。本文针对压载水污染问题,从压载水的管理、处理技术、无压载舱船舶设计等方面,探讨压载水的预防途径和防治方法。     

船舶压载舱沉积物接收处置现状、问题及履约管理对策

《国际船舶压载水和沉积物控制与管理国际公约(2004)》要求妥善处理和处置压载舱沉积物,以防止有害生物入侵。为研究履约现状,选取13家从事压载水沉积物清理、接收及处理作业的修船厂进行了系统调研,结果表明普遍存在防污染措施不全、接收处理作业不规范、接收设施技术标准缺失、管理要求不明确等问题。在分析压载水沉积物的来源、危害、产生量等特性的基础上,结合公约和国内要求,从标准规范完善、监管部门协作、接收设施配套、公约法规宣贯和科技研发支撑等方面分析提出了履约对策。研究成果为有关压载水沉积物相关标准规范、技术政策的制定提供参考,有助于加强压载舱沉积物防污染管理,提升国际公约履行水平。     

船舶压载水和海洋环保

大部分海洋船舶为保证船舶空载航行的稳定性,都有庞大的压载水系统,装有数量巨大压载海水。文章通过大量的数据,明确阐述了船舶海水压载水对海洋环保带来的危害,并列举了多种消除海水压载水污染的方法。随着海洋船舶运输的发展,船舶压载水的异地装入与排出,使海洋污染迅速漫延,海水压载水的污染问题越来越引起世界各国和航运界的重视。对海水压载水的技术处理必将是未来数年船舶科技发展的一个热点。     

船舶压载水处理技术和监督管理研究

船舶压载水不仅危害海洋环境还会对人类健康、当地经济造成影响,《国际船舶压载水和沉积物控制和管理公约》实施即说明了国际社会对此的重视。压载水处理系统的使用,有效地减小了压载水对环境的危害。然而在实际应用中,仍需要通过提高和改进压载水监控技术,使处理后的压载水进一步符合公约标准。本研究根据我国压载水监控现状,提出完善压载水监督管理的措施,促进我国环境、经济和资源的可持续发展。     

鹏字号散货船船体裂纹分析探讨

文章分析探讨了鹏字号散货船2#舱和3#舱压载舱双层底等船壳裂纹原因,针对典型的三类裂纹形态,给出船底壳裂纹区域结构加强方案,通过某船厂对该船实施解决方案,解决了复杂的航运船舶疲劳设计年限超龄产生的局部船体裂纹引起的安全运营问题。     

港口外来生物入侵与压载水风险评估研究综述

海洋贸易过程中船舶压载水引发的港口外来生物入侵风险,其形成受多方因素影响,监控管理难度大,是当今港口海洋生物入侵领域的研究热点。为了全面了解全球港口外来生物入侵风险评估方面的研究现状和发展趋势,本文采用Histcite文献分析工具,以1998-2018年Web of Science数据库和CNKI中国知网全文数据库中相关文献为研究对象,从文献年份变化情况、类型分布、来源分布、国家研究力量和被引频次计量等方面进行统计分析。研究内容主要围绕外来海洋生物入侵和压载水生物入侵的风险评估方法、风险评价指标体系、海洋生物生态安全数据分析及可视化方法方面,未发现全球标准化风险评估方案。     

基于GIS的我国近海外来生物入侵时空演变数据库系统构建方案研究

海洋生物入侵已成为世界海洋生态环境面临的四大问题之一。我国目前针对海洋外来生物入侵的数据资料缺乏,且未形成时空分布的数据系统。本文通过文献查找、资料收集与历史数据整理,现场调研等多种手段,拟掌握我国近海外来生物入侵时空演变历史及现状,提出基于GIS软件的数据库系统的建设方案。本系统的建设可实现海洋入侵物种查询,外来入侵物种判定、不同时期下,外来生物入侵我国近海海域的发生地点、入侵种类、灾害发生时间、灾害影响的对比分析等功能。     

高寒高海拔地区路域生态修复技术体系研究

路域生态修复技术是降低公路建设环境影响的重要手段。由于高寒高海拔地区的地质环境与植物生长条件差异,导致现有的技术体系无法满足该地区生态修复工程的实施。本文从高寒高海拔地区的环境特点出发,结合工程经验,建立了适应于高寒高海拔地区的生态修复技术筛选体系与物种配置方案,形成了完整的高寒高海拔地区生态修复技术体系,对该地区路域生态修复的实施具有指导意义。     

胶粉/杂多酚复合改性沥青制备与性能分析

将废橡胶轮胎粉（Rubber powder,RP）添加至沥青中制备胶粉改性沥青,既能解决废旧橡胶轮胎对环境带来的黑色污染,又能改善提升沥青路面路用性能。但由于胶粉颗粒在溶胀后与沥青的相容性差,单一胶粉改性沥青的储存稳定性不佳。鉴于此,引入生物废油杂多酚（Heteropolyphenol,HP）对废橡胶粉进行改性。采用相色谱-质谱联用试验和同步热分析试验分析杂多酚作为沥青改性剂的可行性及其适宜改性温度;制备不同复合配比下的RP/HP复合改性沥青,并对其物理-流变性能进行测试分析;通过改性前后沥青三大指标（针入度、软化点、延度）及流变学指标的变化幅度,确定RP/HP复配的最佳掺量。试验结果表明：胶粉和杂多酚颗粒相互接触会形成凝胶膜连接,其与沥青形成的半固态连续结构会促使RP/HP复合改性沥青的物理-流变性能显著提升,且推荐的胶粉与杂多酚的最佳掺量分别为18%和4%。     

船舶压载水处理方法综述

船舶压载水是船舶造成水污染的主要途径。船舶压载水含有的有害水生物主要有水藻、水母、斑马纹贻贝等。目前在航压载水常用的处理方法有的深海置换法、机械法、物理法、化学法。其中深海置换法包括排空法、溢流法和稀释法三种。     

Multiattribute decision analysis of mandatory ballast water treatment measures in the US Great Lakes

Mandatory ballast water management, resulting in an increase of required freight rates on the St. Lawrence Seaway, could induce a modal shift away from marine transportation. Such a shift may cause such side effects as increased air pollution and lower transportation safety. A multinomial logit model is built to predict the changes in market shares of competing transportation modes. Two wheat transportation scenarios are studied. The results show that only a small shift, if at any, will accompany mandatory measures for ballast water treatment. To evaluate the trade-offs between the side effects brought by any modal shifts and the NIS invasion effects, the analytic hierarchy process is used to analyze the preferences of federal and state decision-makers. Analysis of questionnaires shows that among the three alternatives, ballast water exchange, filtration/UV, and heat, ballast water exchange proved to be the favored method.     

Heavy metals and metalloid contamination in Louisiana Lake Pontchartrain Estuary along I-10 Bridge

In this study, HMs concentration in sediments and water from the Lake Pontchartrain estuary along the I-10 Bridge were investigated in two seasons to evaluate the level of contamination and to assess the effect of vehicular traffic. Vehicular traffic has led to HMs such as As, Cd, Cr, Pb, Zn, Ni, and Cu accumulation in sediments along the bridge. The HMs content in water especially in summer increased due to high temperature which led to release of HMs from the sediments. The level of pollution attributed to anthropogenic activities was evaluated using several pollution indicators. The overall HMs bioavailability and EFs was mostly high in summer and the concentration of the HMs in both sediments and water was highly influenced by the season and the distance from the highways. The content of As and Cd in lake sediments were higher than the background values (BGV) for both seasons (spring and summer), and Cr and Pb in sediments were higher than the BGV in most sampling points in the spring. According to Sediments Quality Guidelines (SQGs), heavy metals except for As have low biotoxicity, and As could potentially result in harmful effects on the aquatic organisms. The relationship between As and vehicular traffic is less studied so our finding stress the need for further study on source of As in Lake Pontchartrain sediments.     

Probabilistic risk analysis of flying ballast hazard on high-speed rail lines

Flying ballast is a significant safety concern for high-speed train operations on ballasted tracks. It is the phenomenon of a ballast particle displaced from the track, due to the aerodynamic force induced by a passing train traveling above a certain speed. Flying ballast can potentially damage tracks and rolling stock, thereby posing a risk to high-speed rail operations. This paper develops a Probabilistic Risk Analysis (PRA) model based on the information available from the field and the literature. The model enables a quantitative assessment of the probability of ballast particle displacement at a particular position on the track, as well as the probabilistic distribution of the total number of ballast particles that are expected to move. The model accounts for various risk factors, such as train speed, ballast gradation, and track position. The model application is illustrated using a ballasted track on the Yellow River Bridge on the Beijing-Shanghai high-speed rail line in China. The analysis finds that flying ballast probability increases when train speed increases, in particular, the problem of flying ballast becomes more pronounced when train speed exceeds 350 km per hour (217 miles per hour). Flying ballast probability might be reduced when the ballast profile is lower, given all else being equal. In addition, flying ballast probability is expected to be higher at the center of the track than in other positions. The proposed risk model can be further developed and ultimately be used to evaluate route-specific flying ballast risk, enabling the identification, assessment, and comparison of risk mitigation strategies in order to support emerging high-speed rail operations.     

油罐底板渗漏的修补

某油罐底板发生了渗漏,采用AE声发射技术在油罐在用状态下检测出底板渗漏点的大致位置后,倒空油罐,对油罐内部管壁和底板进行热水循环清洗。用N2置换内部的油气,用轴流风机强制通风,检测罐内气体符合呼吸和防爆要求后,从人孔进入罐内。通过渗透检测和真空箱检测的方法精确找出缺陷位置,采用充N2隔离油气、浇水降温、钻孔等一系列措施挖除缺陷,更换底板下缺陷附件的含油沥青砂层。最后,在缺陷所在位置上焊接补丁钢板,成功地进行了易燃易爆油罐底板渗漏的修补。     

Environmental effect of CI engine using microalgae methyl ester with doped nano additives

Algae are organisms that grow in marine environments and use carbon dioxide and light to create bio-mass. There are two groupings of algae: microalgae and macroalgae. Macroalgae are the large, multi-cellular algae often seen growing in ponds. Microalgae, on the other hand, are tiny, unicellular algae that normally grow in suspension within a body of water. Algae oil from microalgae has the possible to become a sustainable fuel source as biodiesel. Microalgae are produced through photosynthesis by utilizing sunlight, water, carbon dioxide and other nutrients. The Botryococcus braunii algal oil was extracted by mechanical extraction method. The transesterification reaction of Botryococcus braunii algal oil with methanol and base catalyst was used for the production of biodiesel. The samples B20 were prepared for each methyl ester obtained from Botryococcus braunii algal oil separately and then the doping of TiO₂ and SiO₂ nanoparticles were added to the each B20 blend samples at a dosage of 50 ppm and 100 ppm with an aid of ultrasonicator. Moreover, in the absence of any engine modifications, the performance and emission characteristics of those blend samples have been investigated from the experimentally measured values such as density, viscosity, calorific value, etc. while the engine performance was also analyzed through the parameters like BSFC, BTH, exhaust emission of CO, HC, NOx and CO₂. The experimental results reveal that the use of biodiesel blend with nano additives in diesel engine has exhibited good improvement in performance characteristic and reduction in exhaust emissions.     

Evaluation of CO2 emissions from railway resurfacing maintenance activities

This paper is the world first to investigate the CO₂ impact of railway resurfacing in ballasted track bed maintenance. Railway resurfacing is an important routine maintenance activity that restores track geometry to ensure safety, reliability and utility of the asset. This study consisted of an extensive field data collection from resurfacing machineries (diesel-engine tamping machines, ballast regulators and ballast stabilisers) including travel distances, working distances, fuel consumption and construction methodologies. Fuel consumption was converted to a kg CO₂/m using the embodied energies of diesel. Analyses showed that tamping machines emitted the highest CO₂ emissions of the resurfacing machineries, followed by ballast regulators and ballast stabilisers respectively. Tamping machines processed 4.25 m of track per litre of diesel, ballast regulators processed 6.51 m of track per litre of diesel and ballast stabilisers processed 10.61 m of track per litre of diesel. The results were then compared to previous studies and a rigorous parametric study was carried out to consider long-term resurfacing CO₂ emissions on Australian railway track. The outcome of this study is unprecedented and it enables track engineers and construction managers to critically plan strategic rail maintenance and to develop environmental-friendly policies for track geometry and alignment restoration.