高铁网络可达性测度及经济潜力分析——以安徽省为例

高速铁路的开通给沿线城市的建设带来了重大影响。基于可达性测度以及修正的经济潜力模型,利用GIS对安徽省高铁可达性以及经济潜力进行深入分析。研究表明:(1)高铁开通后安徽省可达性显著提高,但总体格局保持不变,呈现出以合肥为中心,淮南、芜湖等地为副中心的"多核心"模式。池州、铜陵两城市可达性上升幅度最大,黄山紧随其后,芜湖、滁州变化最小。高铁开通后,滁州可达性排名下降5名,下降幅度最大,合肥、淮南、黄山最为稳定,其他城市均有小幅变化。(2)可达性的提升对城市经济潜力造成了一定影响,总体呈现出以合肥为中心的外围扩展模式。池州、铜陵经济潜力增长最为显著,黄山位列第3,可达性的提升直接影响了池州、铜陵、黄山三市的经济发展。高铁开通后,合肥、芜湖经济潜力排名始终位于前二,传统经济中心地位不变。马鞍山排名上升4名,幅度最大,池州、黄山两市处于末端,经济潜力仍然较为薄弱。(3)高铁开通后,时空收敛效应明显,可达性的提升令城市经济潜力增长显著,但受多方面因素影响,可达性与经济潜力呈现不完全契合关系。     

沈阳市固定燃烧源挥发性有机化合物2007年排放清单研究

挥发性有机化合物(VOCs)与.OH的反应是对流层臭氧形成的重要化学过程,是导致城市光化学烟雾的根本原因。为建立沈阳市固定燃烧源VOCs排放清单,选取了电力热力行业、钢铁行业和秸秆燃烧3个主要排放源进行研究。结果表明:(1)2007年,沈阳市固定燃烧源VOCs排放总量为8 544.539 t,其中排放量最大的是秸秆燃烧,为6 317.115 t;其次是电力热力行业,为2 225.780 t;最小的是钢铁行业,为1.644 t。(2)沈阳市各区县固定燃烧源VOCs排放量由大到小排序依次为新民市、法库县、东陵区、康平县、辽中县、于洪区、苏家屯区、大东区、沈北新区、铁西区、沈河区、皇姑区、和平区;VOCs排放强度由大到小排序依次为大东区、沈河区、铁西区、东陵区、皇姑区、和平区、于洪区、苏家屯区、法库县、康平县、辽中县、沈北新区、新民市。     

香烟燃烧排放的主流烟气中PAHs的含量检测研究

研究10种不同价格香烟燃烧烟气的多环芳烃(PAHs)含量特征,结果表明,每种香烟烟气都含有多环芳烃,但是含量差别较大,平均值为405.405ng/g。在检测出来的多环芳烃中,主要是以2,3环多环芳烃为主,占据的比例达到80%左右。因此香烟烟气中的多环芳烃应该引起人们的广泛关注。     

中国城市温室气体清单研究

介绍城市温室气体排放特征和国际城市温室气体清单研究进展,研究了全球城市化和城市CO2排放的强正相关性,以及中国城市清单方法研究起步较早但发展缓慢的特点。分析了城市温室气体清单相对国家清单的特征,即城市清单编制往往采用消费模式,区别于国家清单的生产模式;国际城市清单中往往包括了由于外调电和供暖产生的CO2排放,同时城市温室气体清单编制灵活性和针对性更强。针对我国城市温室气体清单研究的不足,提出了我国城市温室气体清单方法,强调中国城市采用尺度1+尺度2的范围,暂不考虑尺度3的范围,即生产+消费的混合模式,并且在城市市域温室气体排放研究的基础上,加强狭义城市温室气体排放水平的研究。选择北京市和纽约市,对比分析了两个城市CO2排放特征,结果显示,在确定的清单体系下,北京市和纽约市具有较好的可比性。纽约市的总排放量(尺度1+尺度2)略低于北京市排放量,人均排放量略高于北京市。     

电力行业的节能减排与低碳经济

中国能源结构以煤为主,火电行业是碳排放量的主体,面对低碳经济的发展模式,电力行业势必将成为CO2减排的主力军。目前,火电行业通过"上大压小"政策,实现结构减排;通过提高电力工业的烟气脱硫,实现工程减排;通过扩大清洁能源的比例,减少煤炭消耗总量,实现总量减排。使用清洁能源是实现碳减排的有效途径。指出了电力行业"节能减排"的现状和措施,分析了电力行业在"低碳经济"中所面临的新形势,并对低碳电力技术的研究与运用进行了展望,阐述了通过利用清洁能源促进碳减排的迫切性和必要性。     

Environmental assessment of garden waste management in the Municipality of Aarhus, Denmark

An environmental assessment of six scenarios for handling of garden waste in the Municipality of Aarhus (Denmark) was performed from a life cycle perspective by means of the LCA-model EASEWASTE. In the first (baseline) scenario, the current garden waste management system based on windrow composting was assessed, while in the other five scenarios alternative solutions including incineration and home composting of fractions of the garden waste were evaluated. The environmental profile (normalised to Person Equivalent, PE) of the current garden waste management in Aarhus is in the order of −6 to 8 mPE Mg⁻¹ ww for the non-toxic categories and up to 100 mPE Mg⁻¹ ww for the toxic categories. The potential impacts on non-toxic categories are much smaller than what is found for other fractions of municipal solid waste. Incineration (up to 35% of the garden waste) and home composting (up to 18% of the garden waste) seem from an environmental point of view suitable for diverting waste away from the composting facility in order to increase its capacity. In particular the incineration of woody parts of the garden waste improved the environmental profile of the garden waste management significantly.     

季节性城市生活垃圾成分分析及厌氧消化特性研究

城市生活垃圾的成分及特性随着季节和人类在不同季节的生活习惯而变化，针对我国北方城市研究了一年中不同季节的城市生活垃圾成分特点，对影响厌氧发酵过程的相关成分如总有机碳（TOC）、总氮（TN）、蛋白质、脂肪和还原糖等进行了测定分析。通过厌氧消化实验，测得不同季节城市生活垃圾pH值、日产气量、沼气甲烷含量、甲烷累积量、挥发性脂肪酸（VFAs）和氧化还原电位（ORP）等参数的变化规律，分析相应变化的影响因素。结果表明，二、三季度的含水率分别为64．81％和67．50％，高于一、四季度，一季度发酵原料中蛋白质和脂肪含量分别为12．56％和8．86％，明显高于其他3个季度。一季度甲烷累积量最高，达到17616mL，单位发酵原料的产气量为204．8mL／g，也是4个季度中最高的，说明蛋白质、脂肪等有机成分含量对厌氧发酵过程及结果影响比较明显。为进一步的城市生活垃圾厌氧消化制取生物燃气的工艺条件提供依据。     

Long-term evaluation of coal fly ash and mine tailings co-placement: A site-specific study

This study presents the results of a laboratory investigation conducted to evaluate the efficiency of coal fly ash to control the formation of acid mine drainage (AMD) from mine waste. Site-specific materials, coal fly ash from Atikokan Thermal Generating Station and mine tailings from Musselwhite mine, were mixed at different proportions for the investigation of the drainage chemistry and the optimal mix using static testing (acid–base accounting) and kinetic (column) testing. The acid–base accounting (ABA) results indicated that the fly ash possessed strong alkaline (neutralization) potential (NP) and could be used in the management of reactive mine tailings, thus ensuring prevention of AMD in the long-term. Column tests conducted in the laboratory to further investigate long-term performance of fly ash in the neutralization and prevention of acid mine drainage from tailings similarly showed that mixing fly ash with mine tailings reduces dissolution of many heavy metals from tailings by providing alkalinity to the system. It was found that a fly ash to tailings mass ratio equal to or greater than 15% can effectively prevent AMD generation from Musselwhite mine tailings in the co-placement approach.     

Community participatory landscape classification and biodiversity assessment and monitoring of grazing lands in northern Kenya

In this study, we asked the Ariaal herders of northern Kenya to answer "why, what and how" they classified landscape, and assessed and monitored the biodiversity of 10 km(2) of grazing land. To answer the "why question" the herders classified grazing resources into 39 landscape patches grouped into six landscape types and classified soil as 'warm', 'intermediate' or 'cold' for the purpose of land use. For the "what question" the herders used soil conditions and vegetation characteristics to assess biodiversity. Plant species were described as 'increasers', 'decreasers' or 'stable'. The decreaser species were mostly grasses and forbs preferred for cattle and sheep grazing and the increasers were mostly woody species preferred by goats. The herders evaluated biodiversity in terms of key forage species and used absence or presence of the preferred species from individual landscapes for monitoring change in biodiversity. For the "how question" the herders used anthropogenic indicators concerned with livestock management for assessing landscape potential and suitability for grazing. The anthropogenic indicators were related to soils and biodiversity. The herders used plant species grazing preferences to determine the links between livestock production and biodiversity. By addressing these three questions, the study shows the value of incorporating the indigenous knowledge of herders into classification of landscape and assessment and monitoring of biodiversity in the grazing lands. We conclude that herder knowledge of biodiversity is related to the use as opposed to exclusive conservation practices. This type of knowledge is extremely valuable to conservation agencies for establishing a baseline for monitoring changes in biodiversity in the future.     

Mitigation of eutrophication caused by wastewater discharge: A simulation-based approach

Mitigation of eutrophication, intensified by excessive nutrient load discharge in wastewaters regulated by restrictive legal requirements, remains one of today’s most important global problems. Despite implementation of the Water Framework Directive, the Urban Wastewater Directive and the HELCOM recommendations, the actual condition of surface water is still not satisfactory. In response to the above, the study presents an alternative approach for surface water protection against eutrophication based on the selection of appropriate nutrient removal technologies. An activated sludge model simulation was used to enable the identification of environmentally justified nutrient removal systems with lowest eutrophication potential of treated wastewater conditioned by bioavailable nutrient forms content. Based on the outcome of the study, the 3-stage Bardenpho system was identified as the most efficient for bioavailable phosphorus removal, while the Johannesburg system proved to have the highest efficiency for bioavailable nitrogen removal. The proposed eutrophication mitigation approach underlines the need for a reconsideration of current legal regulations which ignore nutrient bioavailability and key eutrophication limiting factors.