医疗垃圾焚烧底灰重金属特性

本文对医疗垃圾焚烧底灰的重金属含量、重金属形态及其渗沥率进行了研究.结果表明:底灰重金属渗沥浓度低于危险废物规定的阈值,但底灰中Zn和Pb的碳酸盐态(F2)含量较高,仍具有一定的潜在危险性;底灰中zn和Pb的可交换态(F1)主要分布在小颗粒中,Pb的碳酸盐态(F2)基本不随颗粒度变化;Pb的渗沥率随初始pH值的增加近似呈U形变化,先降低后升高.     

Estimation of regional building-related C&D debris generation and composition: case study for Florida, US

Methodology for the accounting, generation, and composition of building-related construction and demolition (C&D) at a regional level was explored. Six specific categories of debris were examined: residential construction, nonresidential construction, residential demolition, nonresidential demolition, residential renovation, and nonresidential renovation. Debris produced from each activity was calculated as the product of the total area of activity and waste generated per unit area of activity. Similarly, composition was estimated as the product of the total area of activity and the amount of each waste component generated per unit area. The area of activity was calculated using statistical data, and individual site studies were used to assess the average amount of waste generated per unit area. The application of the methodology was illustrated using Florida, US approximately 3,750,000 metric tons of building-related C&D debris were estimated as generated in Florida in 2000. Of that amount, concrete represented 56%, wood 13%, drywall 11%, miscellaneous debris 8%, asphalt roofing materials 7%, metal 3%, cardboard 1%, and plastic 1%. This model differs from others because it accommodates regional construction styles and available data. The resulting generation amount per capita is less than the US estimate - attributable to the high construction, low demolition activity seen in Florida.     

Alternate Species Concepts as Bases for Determining Priority Conservation Areas

Abstract: Analysis of geographic concentrations of endemic taxa is often used to determine priorities for conservation action; nevertheless, assumptions inherent in the taxonomic authority list used as the basis for analysis are not always considered. We analyzed foci of avian endemism in Mexico under two alternate species concepts. Under the biological species concept, 101 bird species are endemic to Mexico and are concentrated in the mountains of the western and southern portions of the country. Under the phylogenetic species concept, however, total endemic species rises to 249, which are concentrated in the mountains and lowlands of western Mexico. Twenty-four narrow endemic biological species are concentrated on offshore islands, but 97 narrow endemic phylogenetic species show a concentration in the Transvolcanic Belt of the mainland and on several offshore islands. Our study demonstrates that conservation priorities based on concentrations of endemic taxa depend critically on the particular taxonomic authority employed and that biodiversity evaluations need to be developed in collaboration or consultation with practicing systematic specialists.     

中国农业与工程机械尾气减排控制措施的费效分析

移动源尾气排放已成为我国空气污染的主要来源之一,相比于道路移动源来说,非道路移动源尾气排放的减排控制工作仍处于初级阶段。本研究就非道路移动源尾气减排控制的三种主要措施——整车淘汰、发动机更换以及发动机维修,对中国非道路工程和农业机械进行费效分析,探讨经济可行的控制途径。研究假设农业和工程机械的使用年限分别为15年和10年,同时假设采取减排措施后所有机械均达到国IV排放标准。研究表明,采取减排措施后,农业机械每年可减排NOx 40万～45万t,但PM污染物减排效益不明显;工程机械每年可减排NOx约52万t,且PM污染物每年可减排量约16万t,但费用可高达2000亿～25 000亿元,且不同措施的差别巨大,以整车淘汰费用最高。多数农业机械发动机维修所需费用高于发动机更换,相反,工程机械发动机更换所需费用高于发动机维修。因此,在采用减排措施和制定政策时,需要根据实际情况进行调整。对农业机械,采用发动机更换的减排方式更经济;对工程机械,采用发动机维修的减排措施更实惠。     

变电站监控系统“告警直传、远程浏览”功能的设计

为了减少调控中心主站系统的日常运行维护工作量,全面直观、便捷地对变电站进行监控,利用变电站图形网关服务器的告警采集模块通过规约协议直接收取间隔层中的测控及保护装置数据,通过TCP与调控中心主站告警接收模块建立链接,实现实时数据、实时画面、实时功能的“全网共享”。 应用结果表明:“告警直传、远程浏览”功能可将优化后的监控数据和告警信息接入调度主站系统,实现调控信息分层、分类接入变电站调控信息交互规范,满足“调控一体化”建设要求。     

超声化学法降解水中微量亚甲基蓝的研究

在超声波作用下水中微量亚甲基蓝可有效降解,降解动力学符合一级反应,亚甲基蓝超声降解速率随初始浓度的升高而降低,随介质温度的下降而升高．亚甲基蓝在酸性和碱性条件下的降解速率高于中性条件下的降解速率．能促进OH等自由基形成的自由基促进剂Fe^2 和I^-等可有效加速亚甲基蓝的超声降解．     

土壤改良剂联合间套种技术修复重金属污染土壤:田间试验

在田间条件下,验证通过盆栽试验初步筛选出的几种改良剂在玉米和东南景天间套种修复重金属污染土壤的大田实际应用效果.研究结果表明,施用改良剂蘑菇渣肥、云母和沸石能有效降低玉米籽粒和茎叶中的Cd和Pb,玉米籽粒Cd和Pb含量均达到食用标准.蘑菇渣肥显著增加了东南景天对Cd的提取量,腐植酸显著促进了东南景天对Pb的吸收,因此,蘑菇渣和腐植酸可以应用于玉米和东南景天套种系统.施用云母和沸石可以显著提高土壤pH值,降低土壤可交换态Cd/Pb含量,从而降低二种植物对Cd/Pb的吸收;然而,施用蘑菇渣肥和腐植酸却增加土壤可交换/吸附态Cd/Pb含量.植物根系吸收Cd的稳定常数显示该有机吸附态Cd难于被玉米根系吸收.     

不同时刻污染减排对北京市PM2.5浓度的影响

利用空气质量模式Model-3/CMAQ及京津冀地区高分辨率排放源清单,针对有代表性的污染时段(2012年2月7~16日),设置了5种不同时刻的减排方案(在污染峰值提前4d、提前3d、提前2d、提前1d及当天减排),对比在同样的减排比例下,不同时刻开始减排的效果差异.研究发现,提前采取减排控制措施比污染峰值当天开始减排对降低PM2.5浓度的影响更为明显,而且提前采取应急减排的时间越早,PM2.5浓度下降越明显.提前1d、2d、3d减排海淀站和城六区峰值浓度下降率分别为23%和22%、31%和30%、39%和38%,均明显高于当天减排的峰值浓度下降率10%和9%.但随着提前天数的增加,PM2.5峰值浓度进一步下降的幅度越来越小,减排效益较之前显著降低.提前4d减排海淀站和城六区峰值浓度下降率分别为40%和39%,提前4d减排和提前3d减排对降低污染峰值日PM2.5浓度的效果已没有太大差别.同时针对另一个污染时段(2012年1月11~20日)进行了相似的敏感性试验,得出了类似的结论.因此,针对某些污染事件的应急减排,综合考虑减排成本和减排效果,根据气象条件的预报,在可能引起重污染事件的不利气象条件来临时提前2~3d采取减排措施效果最好,既能有效降低PM2.5浓度,也可以避免因盲目长时间减排造成的成本过大.     

A Retrospective Evaluation of the Global Decline of Carnivores and Ungulates

Assessing temporal changes in species extinction risk is necessary for measuring conservation success or failure and for directing conservation resources toward species or regions that would benefit most. Yet, there is no long‐term picture of genuine change that allows one to associate species extinction risk trends with drivers of change or conservation actions. Through a review of 40 years of IUCN‐related literature sources on species conservation status (e.g., action plans, red‐data books), we assigned retrospective red‐list categories to the world's carnivores and ungulates (2 groups with relatively long generation times) to examine how their extinction risk has changed since the 1970s. We then aggregated species’ categories to calculate a global trend in their extinction risk over time. A decline in the conservation status of carnivores and ungulates was underway 40 years ago and has since accelerated. One quarter of all species (n = 498) moved one or more categories closer to extinction globally, while almost half of the species moved closer to extinction in Southeast Asia. The conservation status of some species improved (toward less threatened categories), but for each species that improved in status 8 deteriorated. The status of large‐bodied species, particularly those above 100 kg (including many iconic taxa), deteriorated significantly more than small‐bodied species (below 10 kg). The trends we found are likely related to geopolitical events (such as the collapse of Soviet Union), international regulations (such as CITES), shifting cultural values, and natural resource exploitation (e.g., in Southeast Asia). Retrospective assessments of global species extinction risk reduce the risk of a shifting baseline syndrome, which can affect decisions on the desirable conservation status of species. Such assessments can help conservationists identify which conservation policies and strategies are or are not helping safeguard biodiversity and thus can improve future strategies. Una Evaluación Retrospectiva de la Declinación Global de Carnívoros y Ungulados