Assessing the chemical and biological accessibility of the herbicide isoproturon in soil amended with biochar

Decamethylcyclopentasiloxane (D5) is a cyclic volatile methyl siloxane (cVMS) commonly found in commercially available products. D5 is expected to enter the terrestrial environment through the deposit of biosolids from sewage treatment plants onto agricultural fields for nutrient enrichment. Little to no information currently exists as to the risks of D5 to the terrestrial environment. In order to evaluate the potential risk to terrestrial organisms, the toxicity of a D5 contaminated biosolid in an agricultural soil was assessed with a battery of standardized soil toxicity tests.D5 was spiked into a surrogate biosolid and then mixed with a sandy loam soil to create test concentrations ranging from 0 to 4074 mg kg⁻¹. Plant (Hordeum vulgare (barley) and Trifolium pratense (red clover)) and soil invertebrates (Eisenia andrei (earthworm) and Folsomia candida (springtail)) toxicity tests were completed to assess for lethal and sub-lethal effects. Plant testing evaluated the effects on seedling emergence, shoot and root length, and shoot and root dry mass. Invertebrate test endpoints included adult lethality, juvenile production, and individual juvenile dry mass (earthworms only). Soil samples were collected over time to confirm test concentrations and evaluate the loss of chemical over the duration of a test. The toxicity of the D5 was species and endpoint dependent, such that no significant adverse effects were observed for T. pratense or E. andrei test endpoints, however, toxicity was observed for H. vulgare plant growth and F. candida survival and reproduction. Chemical losses of up to 50% were observed throughout the tests, most significantly at high concentrations.     

Soil metal concentrations and productivity of Betula populifolia (gray birch) as measured by field spectrometry and incremental annual growth in an abandoned urban Brownfield in New Jersey

A forested brownfield within Liberty State Park, Jersey City, New Jersey, USA, has soils with arsenic, chromium, lead, zinc and vanadium at concentrations above those considered ambient for the area. Using both satellite imagery and field spectral measurements, this study examines plant productivity at the assemblage and individual specimen level. Longer term growth trends (basal area increase in tree cores) were also studied. Leaf chlorophyll content within the hardwood assemblage showed a threshold model for metal tolerance, decreasing significantly beyond a soil total metal load (TML) of 3.0. Biomass production (calculated with RG - Red/Green Ratio Index) in Betula populifolia (gray birch), the co-dominant tree species, had an inverse relationship with the Zn concentration in leaf tissue during the growing season. Growth of B. populifolia exhibited a significant relationship with TML. Assemblage level NDVI and individual tree NDVI also had significant decreases with increasing TML. Ecosystem function measured as plant production is impaired at a critical soil metal load.     

Effects of Grazing Pressure on Succession Process and Productivity of Old Fields on Mediterranean Islands

Poterium spinosum, competitive under conditions of overgrazing and fire, accounted for 70%–85% of the total plant cover in all sites, except Santorini, where participation of spiny species was very low. In the recently abandoned sites, annuals accounted for 50%–60% of the standing biomass, but constituted only a tiny fraction in those abandoned for 30 years or more. This was not paralleled by any remarkable increase of the total plant cover. In fact, the yearly produced green biomass decreased with the years after abandonment. The productivity of old fields abandoned for a long time is insufficient to support the grazing animals present. This shortfall, given the animals' requirements, is most dramatic in Symi. The nonrecovering vegetation in the old fields of these mountainous islands constitutes a severe environmental threat; remedial measures appear imperative.     

火电厂对城市空气质量的影响模拟

运用美国ISC3复合工业源模型模拟高井发电厂大气环境影响 ,结果表明 :该厂大气污染物排放的主要影响地区在石景山西北部和门头沟东部 ,丰台西北部和海淀西北部也受到一定影响 ,对老城区影响较小。SO2 、PM1 0 和NOX 年均浓度最大值分别为 2 4 36、1 35、10 30 μg m3,分别占空气质量二级标准的 4 1%、1 35 %、13%。可见 ,高井发电厂对周边区域SO2 浓度影响较大 ,对NOX 也有一定影响 ,对PM1 0 的影响较小。     

树木健康与病虫草害的关系分析

本文论述了树木健康与病害、虫害、草害的关系。     

珠江三角洲气溶胶中正构烷烃分布规律、来源及其时空变化

珠江三角洲地区主要城市气溶胶中正构烷烃分布可分为３种类型，第一类为前峰型，主要来源于汽车尾气；第二类为后峰型，主要来源于植物蜡；第三类为双峰型，来源于植物蜡，燃料燃烧和尾气。     

Utility participation in a multispecies plan

Single-species listings under provisions of the federal Endangered Species Act (ESA) have caused, or have been accused of causing, significant regional economic impact. In an attempt to avoid such adverse effects on regional economic development, the state of California passed the Natural Communities Conservation Planning Act (NCCP) in 1991. It is a voluntary, consensus-based approach to balancing protection of sensitive biota and biodiversity with regional economic development. The pilot NCCP program for the conservation of several threatened, endangered, and category 1 species, plus an additional 35 coastal sage scrub-related species in southern California, was completed and submitted to the public for review and comment in December 1995. This program proposes the voluntary establishment of a 86,600-ha multispecies reserve system. Once completed, participating landowners will receive ESA Section 10(a) incidental take permits for present and identified future projects. Utility rights-of-way are incorporated into the program as important connective linkages between reserve units and other adjacent important habitat areas. All data and information regarding the proposed results of the NCCP are subject to change pending agency response to public comments on the draft Habitat Conservation Plan and joint EIR/EIS.     

植物体游离脯氨酸对SO_2＋NO_2复合物的反应

以大豆、蕃茄、青菜为试验植物，应用开顶式熏气装置，研究了ＳＯ２＋ＮＯ２复合熏气对３种植物游离脯氨酸的影响及其与伤害程度的关系。结果表明，受ＳＯ２＋ＮＯ２熏气的３种植物体内脯氨酸部有增加。其变比规律因植物种类和处理方式而异；脯氨酸的增加率与叶伤害率呈正相关关系。文章初步认为植物体游离脯氨酸可以作为指示污染物的一项生化指标。     

大连星海湾水质预测

建设马栏河污水处理厂是改善大连市南部沿海环境的重要措施。本文运用浅海潮波方程和平流扩散方程进行海域水质预测,结果表明：该污水处理厂建成后,星海湾海域水质将有很大好转,达到国家二级标准。     

砷矿尾砂污染及其治理研究

调查了广东省连南瑶族自治县寨岗铁屎坪土法炼砷废墟及其周边砷污染状况.发现渗流水含砷高达43.72 mg/L,渗流水随雨水沿山坡、溪流流入下游,对周边的水体、土壤、农作物等造成严重污染.同时发现全缘凤尾蕨、龙船蕨、野苎麻、白芒草和接骨草是耐砷植物.模拟试验证实在炼砷废墟和高砷尾砂上种植这些植物可减少砷的迁移,且不致引起二次污染.1998年对铁屎坪土法炼砷废墟进行治理,经一年多跟踪观察,周边水体中砷含量从原来的约0.048 mg/L下降到0.001 06 mg/L.结果表明用植被治理尾砂的砷污染是一种价廉、有效的方法.