Assessment of pesticide availability in soil fractions after the incorporation of winery-distillery vermicomposts

The influence of two vermicomposts from winery and distillery wastes on the distribution of diuron in agricultural soil was studied. Physical soil fractionations at 0, 9, 27, 49 and 77 days, allowed the quantification of pesticide residues in different particle-size fractions, coarse waste (WF), sand-sized (SF), silt-sized (SiF), clay-sized (CF) and dissolved organic matter-sized fraction (DOM). The SiF made a greater contribution to the formation of non-extractable residues in unamended soil, but when vermicomposts were added, new sorption sites in WF appeared, being higher for the more humified vermicompost V2. The dissolved organic carbon (DOC) increased with the addition of vermicompost, but the concentration of the desorbed 14C-radiochemical did not increase. Non-significant increment was observed with time for the non-extractable fraction with amendments. Diuron was transformed in all samples, although less than 0.5% was mineralized. The main effect caused by vermicomposts was a reduction in the availability of diuron in soil.     

脉冲电源电凝聚处理厨房废水的研究

将脉冲电源和直流电源分别作为电凝聚处理废水的外加电源,拟试验探明电源对电凝聚处理废水的电能消耗的影响和相关参数的优化.试验结果表明,脉冲电源相对直流电源能更加有效降低阳极的超电位,减缓电极的极化,从而降低槽电压,进而有效地降低电能消耗.在试验条件下,脉冲频率对处理效果影响不显著,而脉冲占空比对处理效果有明显的影响,较合适的脉冲电源电凝聚处理废水的优化参数是:脉冲频率1 000 Hz、占空比60%.同时,对电解槽沉积絮凝物的处理进行了说明.     

Pesticide Environmental Accounting: a method for assessing the external costs of individual pesticide applications

The Pesticide Environmental Accounting (PEA) tool provides a monetary estimate of environmental and health impacts per hectare-application for any pesticide. The model combines the Environmental Impact Quotient method and a methodology for absolute estimates of external pesticide costs in UK, USA and Germany. For many countries resources are not available for intensive assessments of external pesticide costs. The model converts external costs of a pesticide in the UK, USA and Germany to Mediterranean countries. Economic and policy applications include estimating impacts of pesticide reduction policies or benefits from technologies replacing pesticides, such as sterile insect technique. The system integrates disparate data and approaches into a single logical method. The assumptions in the system provide transparency and consistency but at the cost of some specificity and precision, a reasonable trade-off for a method that provides both comparative estimates of pesticide impacts and area-based assessments of absolute impacts.     

The release of nanosilver from consumer products used in the home

Nanosilver has become one of the most widely used nanomaterials in consumer products because of its antimicrobial properties. Public concern over the potential adverse effects of nanosilver's environmental release has prompted discussion of federal regulation. In this paper, we assess several classes of consumer products for their silver content and potential to release nanosilver into water, air, or soil. Silver was quantified in a shirt, a medical mask and cloth, toothpaste, shampoo, detergent, a towel, a toy teddy bear, and two humidifiers. Silver concentrations ranged from 1.4 to 270,000 microg Ag g product(-1). Products were washed in 500 mL of tap water to assess the potential release of silver into aqueous environmental matrices (wastewater, surface water, saliva, etc.). Silver was released in quantities up to 45 microg Ag g product(-1), and size fractions were both larger and smaller than 100 nm. Scanning electron microscopy confirmed the presence of nanoparticle silver in most products as well as in the wash water samples. Four products were subjected to a toxicity characterization leaching procedure to assess the release of silver in a landfill. The medical cloth released an amount of silver comparable to the toxicity characterization limit. This paper presents methodologies that can be used to quantify and characterize silver and other nanomaterials in consumer products. The quantities of silver in consumer products can in turn be used to estimate real-world human and environmental exposure levels.     

Estimating dissolved reactive phosphorus concentration in surface runoff water from major Ontario soils

Phosphorus (P) loss from agricultural land in surface runoff can contribute to eutrophication of surface water. This study was conducted to evaluate a range of environmental and agronomic soil P tests as indicators of potential soil surface runoff dissolved reactive P (DRP) losses from Ontario soils. The soil samples (0- to 20-cm depth) were collected from six soil series in Ontario, with 10 sites each to provide a wide range of soil test P (STP) values. Rainfall simulation studies were conducted following the USEPA National P Research Project protocol. The average DRP concentration (DRP30) in runoff water collected over 30 min after the start of runoff increased (p < 0.001) in either a linear or curvilinear manner with increases in levels of various STPs and estimates of degree of soil P saturation (DPS). Among the 16 measurements of STPs and DPSs assessed, DPS(M3) 2 (Mehlich-3 P/[Mehlich-3 Al + Fe]) (r2 = 0.90), DPS(M3)-3 (Mehlich-3 P/Mehlich-3 Al) (r2 = 0.89), and water-extractable P (WEP) (r2 = 0.89) had the strongest overall relationship with runoff DRP30 across all six soil series. The DPS(M3)-2 and DPS(M3)-3 were equally accurate in predicting runoff DRP30 loss. However, DPS(M3)-3 was preferred as its prediction of DRP30 was soil pH insensitive and simpler in analytical procedure, ifa DPS approach is adopted.     

Potential application of highly reactive Fe(0)/Fe3O4 composites for the reduction of Cr(VI) environmental contaminants

We describe the use of highly reactive Fe(0)/Fe3O4 composites for the reduction of Cr(VI) species in aqueous medium. The composites were prepared by simple mechanical alloying of metallic iron and magnetite in different proportions, i.e. Fe(0) 25, 50, 75 and 90wt%. While after 3h of reaction pure Fe(0) and pure Fe3O4 showed only a low reduction efficiency of 15% and 25% Cr(VI) conversion, respectively, the composites, in particular Fe(0)(25wt%)/Fe3O4, showed a remarkable activity with ca. 65% Cr(VI) conversion. Kinetic experiments showed a high reaction rate during the first 3h, which subsequently decreased strongly, probably due to a pH increase from 6 to 8. Experiments with composites based on Fe(0)/alpha-Fe2O3, Fe(0)/gamma-Fe2O3 and Fe(0)/FeOOH showed very low activities, suggesting that Fe(oct)2+ in the magnetite structure plays an important role in the reaction. Scanning and high resolution electron microscopies and M?ssbauer spectra (transmission and conversion electron M?ssbauer spectroscopy) indicated that the mechanical alloying process promotes a strong interaction and interface between the metallic and oxide phases, with the Fe(0) particles completely covered by Fe3O4 particles. The high efficiency of the composite Fe(0)/Fe3O4 for Cr(VI) reduction is discussed in terms of a special mechanism where an electron is transferred from Fe(0) to magnetite to reduce Fe(oct)3+ to Fe(oct)2+, which is active for Cr(VI) reduction.     

上海市近16年湿沉降化学特征分析

对上海市1992-2007年湿沉降监测结果进行研究,16年来,上海市湿沉降主要呈现以下特征:pH总体呈现下降趋势,酸雨频率呈现上升趋势;2002年起升幅很大;硫酸根离子和钙离子浓度总体呈下降趋势,2003年后,各离子浓度都有一定程度下降;钙离子在总阳离子中的比例总体上明显下降,铵离子与总阳离子的百分比总体上呈上升趋势;硫酸根离子在总阴离子中的比例有所下降,硝酸根离子与总阴离子的百分比则一直呈上升趋势;硫酸根与硝酸根年均值的比值总体上呈明显的下降趋势,表明硫酸型在逐渐减弱;钙离子与铵离子的比值总体上也呈明显的下降趋势。     

华北地区CO2净排放比较优势时空特性分析

采用显示性比较优势理论,对2005-2010年我国华北地区5个省市人均CO2净排放和单位GDP CO2净排放的显示性比较优势做了分析;同时采用变异系数差异分析,结合空间自相关分析方法,对其空间格局和演变规律做了深入研究.研究发现,华北地区5省市人均CO2净排放高于全国平均水平.北京、天津、河北、山西4个省市出现下滑势头,而内蒙古自治区呈现大幅上升势头.山西单位GDP CO2净排放在全国最高,天津和北京低于全国平均水平.华北地区人均CO2净排放和单位GDP CO2净排放比较优势空间分别呈现负相关和正相关特性.     

基于农副食品加工行业生产特性的排放限值核定方法研究

与传统的简单以行业排放标准、环评报告、国家分配的目标总量等为依据的排污许可限值核定方式不同,本研究从农副食品加工行业产量、废水排放等生产特性出发,筛选控制项目,确定多级许可限值,运用直接数据分析法、间接数据分析法、假设推导法,制定基于不同时间尺度的最大日排放浓度限值（C_MDL）、月平均排放浓度限值（C_AML）、日最大负荷限值（MDL）、月平均负荷限值（AML）,并以河南省某屠宰及肉类加工企业为例,进行基于生产特性的排污许可限值计算示范.结果显示：该企业产量随季节变化率超过20%,氨氮排放量波动明显;制定多级排放限值,COD、总氮和总磷无明显变化,制定统一限值,计算结果均严于传统方法核算的排放限值;在此基础上制定的排放限值,可在有效约束企业排污的同时,为排污许可制度的精细化、差异化管理提供技术支持.