Alien plant invasions--incorporating emerging invaders in regional prioritization: a pragmatic approach for Southern Africa

Plant invasions are a serious threat to natural and semi-natural ecosystems worldwide. Most management-orientated research on invasions focuses on invaders that are already widespread and often have major impacts. This paper deals with "emerging" invaders-those alien species with the potential to become important problems without timely intervention. A climate matching procedure was developed to define areas of South Africa, Lesotho and Swaziland that could be invaded by 28 plant species that had previously been classified as emerging invaders. Information on the location of populations of these species in the study area was combined with information on their distributions (as native or alien) in parts of Australia and the United States of America. These two countries had the best available distribution data for this study. They also share many invasive alien plant species with South Africa. Climatic data obtained for weather stations near points of known occurrence in these countries were used to define the climatically suitable areas for each species in the study area. Almost 80% of the remaining natural environment in southern Africa was found to be vulnerable to invasion by at least one of these species, 50% by six or more and 24% by 16 or more species. The most vulnerable areas are the highveld grasslands and the eastern escarpment. The emerging invaders with the greatest potential range included Acacia podalyriifolia and Cortaderia selloana. The globally important invaders Ulex europaeus and Lythrum salicaria had a more limited invasion potential but could still become major invaders. There was no relationship between the extent of the climatically suitable areas for the different species and an expert ranking of their invasion potential, emphasising the uncertainties inherent in making expert assessments based on very little information. The methods used in this analysis establish a protocol for future modelling exercises to assess the invasion potential of other emerging invaders.     

POTENTIALS FOR REUSE OF WASTEWATER IN NORTH CENTRAL TEXAS1

ABSTRACT There are several possible ways in which wastewater from municipalities may be reclaimed and reused so as to minimize the need for imported water in North Central Texas. The rationale for reuse is enhanced by the fact that new water quality requirements in the Trinity River system will necessitate a very high degree of treatment at municipal sewage plants, just for discharge to surface streams. The largest potential market for municipal effluent is the steam-electric power industry. Within the next decade the generating capacity for electric power in North Central Texas will have to be more than doubled to meet increasing demand. Adequate supplies of condenser cooling water for such expansion will be difficult to obtain and assure. New large power stations might advantageously be located adjacent to municipal wastewater treatment plants, to utilize effluent as make-up water for cooling towers. Experience elsewhere has shown that well-treated wastewater can be used for cooling tower make-up with a minimum of trouble, with a considerable saving in overall cost, and with conservation of pristine water for other uses.     

四川省野生观赏植物资源及开发利用

介绍了四川省丰富的野生观赏植物资源,分析了开发前景,针对其开发程度低、开发利用方式落后、资源保护性差的现状,指出四川省在野生观赏植物的保护和开发利用中应重点加强的几方面工作.     

石化装置检维修作业HSE管理

针对检维修作业的风险特点,提出了检维修整个过程中的控制重点和注意事项。     

燃煤机组超低排放改造对汞的脱除效果研究

燃煤烟气中汞污染的控制是目前重要的环保课题之一,燃煤电厂利用现有的脱硝、脱硫、除尘设备去除汞,文章分析燃煤电厂烟气净化设备超低排放改造后汞的排放水平,说明现有废气处理设施超低排放改造,既能有效降低烟尘、二氧化硫、氮氧化物排放浓度,也有利于汞的去除,燃煤机组超低排放改造后汞的排放浓度远低于现行0.03 mg/m3的限值;通过分析燃煤电厂现有烟气净化设备对汞的协同去除效果和脱除汞的原理,提出了未来燃煤烟气汞污染控制措施的建议.     

重庆地区吴茱萸属药用植物资源的调查研究

经调查鉴定，重庆地区吴茱萸属药用植物有9种（含种下等级），首次发现吴茱萸红花品系。重点介绍了它们的生境分布、药材商品与生产经营现状等，并编制了分种检索表，为科研、教学、生产经营及开发利用提供了科学依据。     

南京典型城市湖泊湖滨带不同植物区脱氮过程及其影响因素

氧化亚氮（N₂O）是导致全球气候变化的重要温室气体之一,植物根际微生物介导的反硝化和厌氧氨氧化过程作为重要脱氮途径能够减少湖泊湿地生态系统中氮负荷,而反硝化过程是N₂O的最主要产生途径. 城市湖泊湖滨带是水陆交错带,也是氮素输入和转化的重要区域,关注城市湖泊湖滨带植物-微生物介导的脱氮过程和N₂O排放,对维持湖泊生态系统稳定,加强城市湖泊湿地的氮素管理和控制N₂O排放,实现城市可持续发展具有重要意义. 以典型城市湖泊玄武湖湖滨带为研究对象,结合¹⁵N同位素配对、实时荧光定量PCR和高通量测序技术,比较不同类型湿地植物：莲（Nelumbo nucifera）、芦苇（Phragmites australis）和马蹄金（Dichondra micrantha）覆盖区原位N₂O排放通量、潜在反硝化及厌氧氨氧化速率和功能微生物群落丰度、多样性及组成,探讨城市湖泊湿地不同类型植物-微生物介导的脱氮过程及N₂O排放的驱动因子. 结果表明,玄武湖湖滨带湿地植物区N₂O排放通量为6.20~15.03 μg·（m²·h）^-1,其中马蹄金>莲>芦苇;3种湿地植物根际沉积物反硝化和厌氧氨氧化速率（以N计）分别为（8.92±4.33） nmol·（g·h）^-1和（1.03±1.17）nmol·（g·h）^-1,其中莲>马蹄金>芦苇,并且反硝化作用（65.55%~97.82%）均为主导脱氮过程;3种湿地植物根际沉积物中nirK和nirS群落组成存在显著差异（ANOSIM,P<0.005）,硝化杆菌科（Nitrobacteraceae,28.57%）和食球菌科（Zoogloeaceae,14.63%）分别为nirK和nirS群落中优势科,并且nirS基因丰度（1.09×10⁹ copies·g^-1）比nirK（3.00×10⁷ copies·g^-1）高2个数量级,表明nirS型反硝化菌在湿地N₂O排放中更具重要作用（P<0.05）;此外,pH、C/N、NH₄⁺-N和NO₃^--N含量驱动了玄武湖湖滨带N₂O排放通量的变化,而NO₂^--N、LOI和TN含量是玄武湖湖滨带潜在反硝化和厌氧氨氧化速率的主要驱动因子.     

城镇污水处理厂碳排放核算及减排路径分析：以沈阳市某污水厂为例

目前辽宁省城镇污水处理设施建设发展迅速,但针对污水处理系统产生的碳排放研究较少. 基于沈阳市某污水厂污水处理系统数据,结合相关技术指南对其进行碳排放核算,分析主要碳排放来源及其影响因素,有助于该地区碳减排措施的开展. 结果表明,沈阳市某污水处理厂年碳排放量为5.245万t,导致碳排放的主要影响因素为电力消耗（占39.2%）、聚合氯化铝的使用（占18.7%）以及污水处理造成的N₂O排放（占14.5%）. 使用Sumo软件对沈阳市某污水厂主要碳排放影响参数进行拟合分析,结果显示系统中ρ（DO）可由原来的6.51 mg·L^-1降至1.00~2.00 mg·L^-1,此举将有效减少污水处理单元的直接碳排放;当聚合氯化铝投加量调整为原有的76%时,可使该水厂的年间接碳排放量减少0.223万t;当乙酸钠年消耗量由原有的3 710.0 t削减为2 672.0 t时,可使年间接碳排放量同比减少28.14%. 从减碳和替碳两个角度进行分析,提出了适合该水厂的碳减排路径为优化曝气系统、控制精准投药、实现剩余污泥的及时处置以及开发水源热泵技术,研究对提出适合辽宁地区城镇污水处理行业低碳运行的策略具有重要意义.     

新冠期间河北省典型钢铁企业大气污染影响

基于国家气象局气象预报数据,建立了基于AERMOD的钢铁企业污染预报模型,模拟了新冠疫情管控期(2020年2～3月)及解封后期(2020年4～10月)河北省某钢铁企业对大气污染的影响,并结合空气质量实测数据进行模型验证.结果 显示,不利风向条件下,该钢铁厂大气污染物排放对当地3个国控站点SO2、NOx和PM10的平均浓...