Spatial cost efficiency in waste paper handling: the case of corrugated board in Sweden

This paper analyzes the spatial cost efficiency of the Swedish legislation regarding waste disposal handling. We focus on the case of corrugated board and recognize that the different counties in Sweden possess different economic prerequisites in terms of waste paper recovery and utilization potential. We employ data for six corrugated board mills and 20 counties and a non-linear programming model to identify the least cost strategy for reaching the politically specified recycling target of a 65% recovery rate for corrugated board. That is, the total costs of recovering a minimum of 65% in each county are calculated and compared with the case when the country as a whole recovers 65% of all old corrugated board is collected but there exist no uniform target for each county. The conclusion is that from an efficiency point of view the recovery efforts should be concentrated to the highly populated and urbanized counties, and not be uniformly divided throughout the country. In the base case, the results suggest that the cost efficient county-specific recovery rates should range from 51 to 72%.     

长治市沙尘天气污染特征及传输路径解析

以2018年3次沙尘天气为研究对象,分析了PM_2.5和PM₁₀浓度、水溶性离子组分、气象条件和气溶胶光学特征,研究了长治市沙尘天气的典型污染特征和传输路径.结果表明：长治市2018年共8d为受沙尘天气影响日,其中4月份最多（5d）,这与春季大气环流调整,冷暖空气活动频繁有关.沙尘污染发生前一般受西方或西北方冷空气影响,大气层结不稳定,大气环流转为经向环流,平均风速达4m/s以上;沙尘污染过程中PM_2.5/PM₁₀均低于0.3,环境空气中粗颗粒物占比较大,水溶性离子总浓度在PM_2.5中占比下降,Ca²⁺浓度为沙尘污染发生前的4倍以上.冬季沙尘为近地面扩散传输,春夏季沙尘为高空沉降传输,影响范围大,区域传输贡献明显.长治市沙尘重要潜在源区为蒙古国、哈萨克斯坦中部和新疆中北部的荒漠地区,传输路径主要为西北路径和正北路径,其中西北路径为哈萨克斯坦—新疆中北部—内蒙古西部—长治以及新疆中北部—内蒙古西部—长治两条路径,正北路径为蒙古国—内蒙古中部—山西北部—长治.     

地下土壤、水中DNAPLs污染的修复技术研究进展

综述了国内外地下土壤、含水层DNAPLs污染的迁移机理及其修复技术研究进展,对该领域的研究前景做了展望.     

中国生物入侵现状及对策

生物入侵是当今世界三大难题之一,中国也是世界上遭受生物入侵危害最大的国家之一.入侵中国的生物主要是以陆生植物为主,源地以美洲为主.在地域分布上南方和东部地区比较严重.主要侵入途径是以人类活动影响为主,自然扩散比重比较小.生物入侵对我国造成的危害十分巨大,解决生物入侵的主要对策是加强立法,全民重视.     

Insights into multidimensional transport flux from vertical observation and numerical simulation in two cities in North China

This study represents the first quantitative evaluation of pollution transport budget within the boundary layer of typical cities in the Beijing-Tianjin-Hebei (BTH) region from the perspective of horizontal and vertical exchanges and further discusses the impact of the atmospheric boundary layer (ABL)-free troposphere (FT) exchange on concentration of fine particulate matter (PM_2.5) within the ABL during heavy pollution. From the perspective of the transport flux balance relationship, differences in pollution transport characteristics between the two cities is mainly reflected in the ABL-FT exchange effect. The FT mainly flowed into the ABL in BJ, while in SJZ, the outflow from the ABL to the FT was more intense. Combined with an analysis of vertical wind profile distribution, BJ was found to be more susceptible to the influence of northwest cold high prevailing in winter, while sinking of strong cold air allowed the FT flowing into the ABL influence the vertical exchange over BJ. In addition, we selected a typical pollution event for targeted analysis to understand mechanistic details of the influence of ABL-FT exchange on the pollution event. These results showed that ABL-FT interaction played an important role in PM_2.5 concentration within the ABL during heavy pollution. Especially in the early stage of heavy pollution, FT transport contributed as much as 82.74% of PM_2.5 within the ABL. These findings are significant for improving our understanding of pollution transport characteristics within the boundary layer and the effect of ABL-FT exchange on air quality.     

矿产资源型城市工业路径依赖综合诊断方法——基于改进的柯布-道格拉斯生产函数

将矿产资源和生态环境要素纳入常规的柯布-道格拉斯（C-D）生产函数，构建资源-环境-经济综合诊断方法，并应用于以煤炭经济为主的鄂尔多斯市.结果显示，2001~2015年该市综合产出弹性为0.8158，呈规模报酬递减趋势；全市工业路径依赖于2001~2007年处于综合边际收益（MR_KLME）上升过程，2008~2015年进入MR_KLME下降过程.工业增长的生态环境成本明显升高，对MR_KLME起到显著减降作用，导致MR_KLME曲线拐点较常规C-D函数法提前约2~4a.对此，建议加大生态环境保护与治理力度、实施煤炭资源开发总量和强度“双控”等路径依赖破解措施.该方法可纠正由于未考虑资源和环境效应所产生的诊断偏差，有助于更加合理、准确地诊断特定资源型城市工业发展路径依赖的演化特点，并可据此提出有针对性的破解对策.     

An assessment of how distance and diesel oxidation catalyst will impact thermal decomposition behaviors of particles

Decomposition mass loss and pyrolysis products analyses of particles sampled at various locations along the tailpipe of a Euro-IV diesel engine were performed using a thermogravimetry in conjunction with Fourier transformation infrared spectrometry-mass spectrum. Diesel particles were collected at the same location with and without diesel oxidation catalyst (DOC) mounted on the test engine separately. The three poles in thermal gravity-differential thermal gravity images suggested that the decomposition process of diesel particles could be divided into three stages which correspond to the decompositions of lower boiling substances, higher boiling substances and soot respectively. It is noticed that no matter whether DOC was mounted or not, the further the particles were sampled away from the engine block, the lower the peak temperatures and the heavier the mass losses within the first two stages, which indicated that the soluble organic fraction in the particle samples increased and therefore lowering the activation energy of thermal decomposition. Hydroxyl, ammonia, C_xH_y fragments, benzene, toluene, and phenol were found to be the primary products of particle decomposition, which didn't change with the location of particle sample point. The employment of DOC increased the activation energy for particle oxidation and resulted in a higher peak temperature and lower mass loss within the first-stage. Moreover, the CO stretching bands of aldehyde and ketone at 1771 cm^?1 was only detected without a DOC, while the NO₂ peak at 1634 cm^?1 was solely noticed with the presence of DOC. Compared to the first-stage pyrolysis products, more polycyclic aromatic hydrocarbons and less C_xH_y fragments were seen in the second-stage.     

铁路集装箱空箱安全高效调拨的计算机算法

铁路集装箱安全运输的重要内容是确保集装箱运输的连续性 ,而集装箱空箱的高效率、低成本的调拨是铁路集装箱运输连续性的重要前提。为此 ,笔者提出了一种解决铁路路网上集装箱空箱调拨问题的计算机算法 ,该算法将此类问题视为一种特定的运输问题去求解 ,其目标是使得调拨集装箱的运输费用 (箱·公里 )最小 ,费用系数是两个相关站点的最短运输距离 ,并给出集装箱调拨的算例 ,实例证明了该算法是富有效率且可行性好 ,能够满足铁路集装箱运输的高效、快速、便捷运输要求。     

Incidents in manual handling activities

More than 20000 handling manoeuvres in loading or unloading trailers in a large transportation company were observed. The aim of the study was to determine the frequency and nature of the incidents occurring whilst handling. The incidents were recorded and interpreted from a double perspective, namely as risk factors and as activity regulation factors. The study showed that on average, one incident occurred in every seven handling manoeuvres: 71% of them were related to the environment, and 29% to the activity. While numerous, the environment-related incidents were generally without consequences. In this respect, the activity incidents appeared more risky; also, the majority of these incidents occurred during the load positioning phase. The study also showed that loads are re-handled twice as often in unloading as in loading, the frequency of re-handlings varying widely from one handler to another. The reasons why so few of the observed incidents are reported in accident studies and their significance in the understanding of handling problems are discussed.     

BIOECONOMIC ANALYSIS OF SELECTED CONSERVATION PRACTICES ON SOIL EROSION AND FRESHWATER FISHERIES1

ABSTRACT: Farmers can generate environmental benefits (improved water quality and fisheries and wildlife habitat), but they may not be able to quantify them. Furthermore, farmers may reduce their incomes from managing lands to produce these positive externalities but receive little monetary compensation in return. This study simulated the relationship between agricultural practices, water quality, fish responses to suspended sediment and farm income within two small watersheds, one of a cool water stream and one of a warm water stream. Using the Agricultural Drainage and Pesticide Transport (ADAPT) model, this study related best management practices (BMPs) to calculated instream suspended sediment concentrations by estimating sediment delivery, runoff, base flow, and streambank erosion to quantify the effects of suspended sediment exposure on fish communities. By implementing selected BMPs in each watershed, annual net farm income declined $18,000 to $28,000 (1 to 3 percent) from previous levels. “Lethal” fish events from suspended sediments in the cool water watershed decreased by 60 percent as conservation tillage and riparian buffers increased. Despite reducing suspended sediments by 25 percent, BMPs in the warm water watershed did not reduce the negative response of the fisheries. Differences in responses (physical and biological) between watersheds highlight potential gains in economic efficiency by targeting BMPs or by offering performance based “green payments.”