Ecological risk of pesticide residues in the British Columbia environment: 1973–2012

An updated ecological risk assessment was conducted to re-evaluate and review the overall risk of pesticide residues to certain aquatic life. The focus was the impact on offsite non-target, freshwater organisms of pesticide operational sprays in British Columbia from 1973 until 2012. The values of risk quotients for pesticides of selected indicator organisms were determined to measure the effect. When compared with organophosphorus, carbamate, and other miscellaneous pesticides, this risk assessment analysis suggests that the historical use of persistent and highly toxic organochlorine pesticides posed, and continue to pose, a deleterious ecological risk. The risk is both short-term acute and long-term sub-acute, chronic toxicity to offsite, non-target aquatic invertebrates and juvenile salmonid fish. Data indicated that these organisms were, and remain, subjected to harmful effects of pesticide residues to varying degrees. Most vulnerable were, and also are, benthic organisms inhabiting bottom sediments. This substrate is the natural sink for persistent pesticide residues, predominantly organochlorine pesticides from historical use, as well as dioxins, furans, and polycyclic aromatic hydrocarbons from wood preservatives, and other sources. Environment Canada's main aquatic protection strategy was a 10 metre no-treatment buffer zone, augmented with an additional appropriate setback along shorelines of fishery and wildlife resource-sensitive water bodies. This study discusses why this guideline was necessary, useful and effective, but was only partially successful. The physical-chemical properties of pesticide residues, from either an individual compound or different compounds in combination, also influence the nature of biological impacts on non-target, aquatic organisms. Few studies have been conducted in British Columbia aquatic environments to investigate the significance of this aspect.     

某铁矿破碎车间除尘系统改造方案的比较与选择

结合气候特点,提出了既经济又可行的除尘方案。     

External benefits of environmental regulation: Resource recovery and the utilisation of effluents

Summary Since 1977, stringent environmental regulation has been progressively imposed on Malaysia's most polluting industry, the palm oil mills. The impact of the regulation on international trade and producer welfare has been quite small compared to the relative benefits to society in terms of changes in the levels of dissolved oxygen in the industrial effluents. External benefits from pollution abatement have been derived. This paper presents a preliminary evaluation of the derived benefits which have a long- term potential of recycling valuable resources while maintaining competitiveness in the international palm oil trade.Dr Khalid Abdul Rahim is a member of faculty in the Department of Natural Resource Economics at the Universiti Pertanian Malaysia. Wan Mustafa Wan Ali is a research assistant in the Department. This paper is based on part of the "Intensification of Research in Priority Areas" (IRPA) project 1991–95, funded by the Government of Malaysia.     

我国职业病防治现状分析及评价报告优化思考

分析和总结了我国职业病危害现状及防治工作中存在的问题,从危害项目界定、危害因素识别、评价因子确定、评价结论合理性探讨以及评价报告编制等方面提出了相关思考和优化性建议,为进一步提升我国职业病防治工作成效提供参考。     

珠三角地区经济与环境协调发展政策研究

研究珠三角地区经济与环境协调发展状况,对于实现该区经济增长与环境保护协调可持续发展具有重要的现实意义。因此,运用协调度(C)和协调发展度(D),分析了2005年-2015年珠三角地区经济与环境协调发展关系。结果表明:珠三角地区整体经济与环境的协调度先升后降,协调发展度明显逐年提升;环境管理体制能促使珠三角地区污染产业转移,实现产业升级。     

菏泽市秋冬季PM2.5水溶性离子化学特征分析

为深入研究菏泽市秋冬季PM_2.5中水溶性离子污染特征,于2017年10月15日-2018年1月31日对菏泽市3个监测点同步进行PM_2.5的采集和分析,分析探讨了不同污染程度下ρ（PM_2.5）及水溶性离子化学特征.结果表明:①菏泽市秋冬季PM_2.5呈区域污染特征.②整个观测期间,ρ（PM_2.5）范围为26.72~284.10 μg/m3,平均值为103.27 μg/m3,其中水溶性离子对ρ（PM_2.5）贡献率较大,为44.65%~49.87%;SNA（NO₃-、NH₄+、SO₄2-的统称）的占比较高,SNA占总水溶性离子质量浓度的86.88%,说明二次气溶胶为菏泽市大气PM_2.5中的重要组成部分.③SNA三角图解和水溶性离子相关性结果表明,采样期间大气中NO₃-、SO₄2-可能以NH₄NO₃、（NH₄）₂SO₄形式存在;ρ（Cl-）与ρ（K+）相关性较高（清洁天和污染天的相关系数分别为0.79和0.81）,由此推测Cl-与K+具有同源性,二者主要源于生物质燃烧.④重度及以上污染天的SOR（硫氧化率）和NOR（氮氧化率）分别为0.54和0.37,分别是清洁天的2.08和2.06倍;轻/中污染天的SOR和NOR分别为0.37和0.29,分别是清洁天的1.42和1.61倍.随着污染程度的加重,SO₂和NO₂向SO₄2-和NO₃-的二次转化增强.重污染日SOR、NOR和相对湿度均大于清洁天和轻/中度污染天,而温度则未表现出相似的变化趋势,说明非均相反应是菏泽市秋冬季SO₄2-和NO₃-形成的重要原因.研究显示,菏泽市污染呈区域性污染特征,二次气溶胶是菏泽市大气PM_2.5的重要组成部分,污染天ρ（NO₃-）、ρ（SO₄2-）、ρ（NH₄+）均与相对湿度呈显著正相关（P < 0.05）,均与温度呈负相关,表明在污染天高湿低温对SO₂、NO₂转化为SO₄2-、NO₃-有推动作用.      

热修复过程中重质非水相液体(DNAPL)共沸实验

本研究开展单组分和多组分DNAPL加热实验,旨在建立热处理过程中温度与DNAPL去除之间的联系.结果表明,单组分DNAPL实验中可以观察到明显的共沸温度平台,而多组分DNAPL实验则是一段温度逐渐上升的共沸区域,两组实验中共沸时间均与初始DNAPL饱和度呈正相关.仅根据局部温度数据判断热修复进程可能会导致错误的结论,当温度结果显示共沸结束后,体系内仍残留有饱和度0.94%~1.60%的DNAPL.温度数据会受到DNAPL组成和温度监测点位置影响,它通常仅能反映局部加热情况,修复时可结合气体和土壤样品中污染物组分变化情况辅助判断修复进程.     

Overview of key operation factors and strategies for improving fermentative volatile fatty acid production and product regulation from sewage sludge

In recent years, volatile fatty acid (VFA) production through anaerobic fermentation of sewage sludge, instead of methane production, has been regarded as a high-value and promising roadmap for sludge stabilization and resource recovery. This review first presents the effects of some essential factors that influence VFA production and composition. In the second part, we present an extensive analysis of conventional pretreatment and co-fermentation strategies ultimately addressed to improving VFA production and composition. Also, the effectiveness of these approaches is summarized in terms of sludge degradation, hydrolysis rate, and VFA production and composition. According to published studies, it is concluded that some pretreatments such as alkaline and thermal pretreatment are the most effective ways to enhance VFA production from sewage sludge. The possible reasons for the improvement of VFA production by different methods are also discussed. Finally, this review also highlights several current technical challenges and opportunities in VFA production with spectrum control, and further related research is proposed.     

Prediction of Soil and Nutrient Losses in A Highland Catchment

Highland catchments in tropical regions are frequently subjected to soil erosion and the transport of chemicals downstream. Any drastic changes in land use will increase the severity of these processes of land degradation. A simulation study using GLEAMS (Groundwater Loading Effects of Agricultural Management Systems) was conducted at a catchment presently under tea farming in Cameron Highlands, Malaysia. Soil, water and nutrient transport associated with several alternative land uses was studied. In addition, the effect of a disruptive form of land clearing on soil, water and nutrient losses was also investigated. Modelling with GLEAMS required information from field measurements and observations, laboratory analyses, guide tables, industry records, maps and reports published by soil survey and meteorological departments. The most critical step in simulating soil and water movement using GLEAMS is the identification of a representative flow sequence. In the catchment under study, the representative flow sequence was overland flow–channel 1–channel 2. Input data on soil erodibility, porosity and surface roughness were manipulated to represent various degrees and forms of disturbance to the surface soil layer. For all land uses studied, the highest soil loss was predicted for the overland flow area where slope gradient is high and the soil friable. The variations in soil loss, runoff and nutrient loss between landscape elements and between land uses were consistent with soil erosion features observed in the field. Soil and nutrient losses were substantial for crops such as cabbage that required land shaping activities and frequent ploughing of the soil. Predicted data on enrichment ratio of specific surface (ERSS) are consistent with nutrient enrichment processes in the field and could prove to be useful in studies on chemical transport in highland catchments.     

WATER QUALITY CHARACTERISTICS OF STORM WATER FROM MAJOR LAND USES IN SOUTH FLORIDA1

ABSTRACT: Starting in 1998, a study was conducted to characterize storm water quality from predominant land use types in a coastal watershed along the south central coast of Florida, namely citrus, pasture, urban, natural wetland, row crop, dairy, and golf courses. Sixty‐three sampling sites were located at strategic points on drainage conveyances for each of seven specific land use areas. Runoff samples were collected following storm events that met defined rainfall criteria for a period of 30 months. Nitrogen (N), phosphorus (P), heavy metals, pesticides, and other water quality parameters were determined, and the results were analyzed to compare and characterize land uses as relative sources for these constituents in runoff. Results showed that runoff from most land use types had low dissolved oxygen concentration and that sediment and nutrient concentrations were closely related to land use, particularly to the amount of fertilizer applied in each land use. Among the eight heavy metals tested, copper was the most frequently detected and was mostly associated with runoff from citrus and golf course land uses. High levels of arsenic were also detected in golf course runoff. The most frequently detected pesticide was simazine from citrus. The information and methodologies presented may facilitate pollution source characterization and ecological restoration efforts.