Distribution and persistence of carbaryl in some terrestrial and aquatic components of a forest environment

Abstract

An oil‐based formulation of carbaryl (1‐naphthyl N‐methyl‐carbamate) (Sevin‐2‐Oil) was applied twice by a fixed‐wing aircraft at a dosage rate of 280 g of A.I./ha/application to a coniferous forest near Allardville, New Brunswick. The highest concentrations of the chemical in fir foliage, litter and forest soil 1 h after application were respectively 4.20, 1.21 and 0.59 ppm (fresh weight). The residues dissipated rapidly and the DT50 values obtained from the depletion curves were 2.3 d for foliage and 1.5 d for litter and soil samples. Very low levels (<0.1 ppm) of carbaryl persisted in foliage and litter beyond the 10 d sampling period. The maximum residue level found in stream water was 0.314 ppm and more than 50% of it had dissipated within 1 h. Low but detectable levels (0.001 ppm) of the chemical persisted in water until the end of the 10 d sampling period. Sediment samples contained a maximum level of 0.04 ppm, which dissipated below the detection limit within 5 h. Brook trout and slimy sculpins captured in the stream 1 d after the spray contained on average about 0.04 ppm of carbaryl and none of it was found in 3 d postspray samples.     

Large-scale risk assessment of polycyclic aromatic hydrocarbons in shoreline sediments from Saudi Arabia: Environmental legacy after twelve years of the Gulf war oil spill

A large-scale assessment of polycyclic aromatic hydrocarbons (PAHs) from the 1991 Gulf War oil spill was performed for 2002-2003 sediment samples (n = 1679) collected from habitats along the shoreline of Saudi Arabia. Benthic sediment toxicity was characterized using the Equilibrium Partitioning Sediment Benchmark Toxic Unit approach for 43 PAHs (ESBTU_FCV,43). Samples were assigned to risk categories according to ESBTU_FCV,43 values: no-risk (≤1), low (>1-≤2), low-medium (>2-≤3), medium (>3-≤5) and high-risk (>5). Sixty seven percent of samples had ESBTU_FCV,43 > 1 indicating potential adverse ecological effects. Sediments from the 0-30 cm layer from tidal flats, and the >30-<60 cm layer from heavily oiled halophytes and mangroves had high frequency of high-risk samples. No-risk samples were characterized by chrysene enrichment and depletion of lighter molecular weight PAHs, while high-risk samples showed little oil weathering and PAH patterns similar to 1993 samples. North of Safaniya sediments were not likely to pose adverse ecological effects contrary to sediments south of Tanaqib. Landscape and geomorphology has played a role on the distribution and persistence in sediments of oil from the Gulf War.     

Comments on current environmental events in Kuwait

This article describes and assesses the impact of oil spillage and oil well fires on Kuwait and its surroundings. The marine ecology of the Arabian Gulf is shown to be relatively resistant to damage from oil spillage. The risks of the contamination of thermal desalination plants by oil and oil products are assessed, and remedies are suggested. Air pollution from burning oil wells is described and its consequences are predicted. Editor’s note: Professor Hosny Khordagui worked as a research scientist at the Environmental and Earth Science Department of the Kuwait Institute for Scientific Research. The Iraqi invasion of Kuwait on August 2, 1990, led to the permanent loss of most of his data, research reports, and laboratory equipment, and Prof. Khordagui was constrained to live under the Iraqi occupation for a few weeks. His article “A Conceptual Approach to the Selection of a Control Measure for Residual Chlorine Discharge in Kuwait Bay” will appear in a forthcoming issue ofEnvironmental Management.     

水力旋流除砂器处理油田采出砂技术

我国部分油田原油生产出砂严重，经常造成集输处理系统的严重磨损和堵塞，储油罐严重积砂，不能实现密闭。储油罐清砂完全靠人工完成，劳动强度大，而且造成环境污染。在海上平台，若采出砂含油量不达标排入海洋，则会给海洋带来严重的污染，因此，采出砂处理是急待解决的问题。文章根据国内外采出砂处理技术调研，介绍了水力旋流器除砂技术原理及工艺和在国外应用实例以及该技术在我国油田的开发应用情况。     

石油工业废弃物处置及其生物治理趋势

鉴于我国石油工作者对石油工业废弃物的普遍关注，现在介绍生物治理的基本概念及ＳＰＥ石油工程师协会中有关含油污泥生物处置的途径及其突出优越性。生物液／固处理工艺（ＬＳＴ）是目前含油污泥处置现场最经济可行的处置方案。这种好氧的ＬＳＴ工艺过程，能够比较充分地代谢和降解石油污泥中的油和脂并大量除去多环芳烃类（ＰＡＨ）化合物及其它有机化合物，明显地降低了石油废弃物对人、畜的毒害程度。其工艺较简单，操作也简易，凡经此工艺处理后的废弃物不留残毒和后患，因此早已被世界上先进国家的炼油业视为处理含油污泥的有效选择了。石油工业废弃物的生物防治和生物降解工艺较大程度地领先于目前我国现场正在执行的各种处理含油废弃物的处理工艺。     

The boiling liquid expanding vapour explosion

The boiling liquid expanding vapour explosion (BLEVE) has existed for a long time and for most of this time it has been cloaked in mystery. Several theories have been put forward to explain this very energetic event but none have been proven. This paper describes a series of tests that have recently been conducted to study this phenomenon.

The study involved ASME code automotive propane tanks with nominal capacities of 400 litres. The tanks were exposed to a combination of pool and/or torch fires. These fire conditions led to thermal ruptures, and in some cases these ruptures resulted in BLEVEs. The variables in the tests were the pressure-relief valve setting, the tank wall thickness, and the fire condition.

In total, 30 tests have been conducted, of which 22 resulted in thermal ruptures. Of those tanks that ruptured, 11 resulted in what we call BLEVEs. In this paper, we have defined a BLEVE as the explosive release of expanding vapour and boiling liquid following a catastrophic tank failure. Non-BLEVEs involved tanks that ruptured but which only resulted in a prolonged jet release.

The objective of this study was to investigate why certain tank ruptures lead to a BLEVE rather than a more benign jet-type release. Data are presented to show how wall temperature, wall thickness, liquid temperature and fill level contribute to the BLEVE process.     

用水力旋流器净化油田采出水

水力旋流器是近１０年来用于油田采出水处理系统的新型设备，它具有体积小、重量轻、分离性能好、运行安全可靠等优点，在世界各地的海上和陆地油田得到了广泛的使用。本文对具有代表性的Ｖｏｒｔｏｉｌ水力旋流器的基本结构、工作原理、影响分离性能的诸因素、应用和优点等进行了介绍。     

交流电凝聚技术及其在油田污水处理方面的应用研究

交流电凝聚（ACE）技术能有效地从稳定的悬浮液和乳浊液中凝聚并分离出固相、重金属和油。电压缩和电絮凝促进凝结、快速沉淀及脱水，且不使用昂贵的高分子电解质和化学药品，也不需使用复杂且易于被超细微粒堵塞的过滤系统。木文介绍了ACE技术的初步原理及其在国外油田污水处理方面的应用，并与传统的污水净化方法进行了比较。     

石脑油罐硫铁化合物自燃原因分析

对一起石脑油罐硫化铁化合物自燃事故的经过和原因进行了分析 ,推断出发生在石脑油罐硫铁化合物自燃并非为FeS自燃 ,并提出了预防同类事故的防范措施。     

杨沸火灾监测预报方法研究（I）－理论基础

本文针对在扬沸前期征兆中表现出显著燃烧微爆噪音,提出了通过监测扬沸前兆噪音、联合温度信息,对扬沸火灾进行诊断、预报的方法。本文的第一部分主要讨论了该方法的理论基础,阐明了其基本原理和技术途径。