Volatility of TCDD and PCB from soil

Volatilisation fluxes of 2,3,7,8-tetrachlorodibenzodioxin and Aroclors 1242, 1254 and 1260 were estimated from the model of Jury et.al., developed for compounds with similar physical properties. The influence of soil water content, soil organic matter and water evaporation was investigated. Increasing soil organic matter decreased the volatilisation flux of all four chemicals. Water evaporation was accompanied by increased fluxes, implying that the chemicals were susceptible to wicking. The trends observed were in qualitative agreement with field and laboratory studies. The predicted fluxes serve as a basis for comparing their volatilisation behaviour against pesticides and other homologues, and for the construction of models describing the environmental fate of these compounds.     

Removal of lead and zinc ions from aqueous solution using Amasya zeolites from Turkey

A 3-D Eulerian-Lagrangian approach to moving vehicles is presented that takes into account the traffic-induced flow rate and turbulence. The method is applied to pollutant dispersion in an individual street canyon and a system of two street canyons forming a perpendicular intersection. The approach is based on computational fluid dynamics (CFD) calculations using a Eulerian approach for continuous phase and a Lagrangian approach for moving vehicles. The wind speed was assigned values of 4, 7 and 12 m/s. One-way and two-way traffic with different traffic rates per lane is considered. In the case of the intersection, a longitudinal wind direction was assumed. Predictions show differences in the pollutant dispersion in the case of one-way and two-way traffic.     

Release of vanadium from oxidized sediments: insights from different extraction and leaching procedures

Although the attention for vanadium (V) as a potentially harmful element is growing and some countries adopted threshold values for V in soils, sediments, groundwater, or surface water, V is generally of little importance in environmental legislation and the knowledge about the behavior of V in the environment is still limited. In the present study, the release of V from oxidized sediments, sediment-derived soils, and certified reference materials was investigated by means of several types of leaching tests and extractions that are frequently used for soil and sediment characterization. The pH_stat leaching tests and single and sequential extractions applied in this study show that V generally displays a very limited actual and potential mobility in sediment. “Mobile” V concentrations, as estimated by the amount of V released by a single extraction with CaCl₂ 0.01 mol L^?1, were low, even in the most contaminated sediment samples. Only under strongly acidifying conditions (pH 2), such as in the case of ingestion of soil or sediment or in accidental spills, a substantial release of V can be expected.     

Emissions from charbroiling and grilling of chicken and beef

Emission rates for fine particle (<2.5 microm) mass (PM2.5), carbon (organic/elemental), inorganic ions (SO4(2-), NO3-, NH4+), elements (primarily metals), and speciated organic compounds are reported for charbroiling hamburger, steak, and chicken. The PM2.5 rates for charbroiling meats ranged from 4.4 to 11.6 g/kg of uncooked meat in this study. No mass-emission rates are available from grilling, but the speciated organic data are available for these samples. Emission rates varied by type of appliance, meat, meat-fat content, and cooking conditions. High-fat hamburger cooked on an underfired charbroiler emitted the highest amount of PM2.5. The emissions were almost exclusively composed of organic carbon, with small amounts of elements and inorganic ions. Water-soluble K+ and Cl-, which are used as indicators of wood smoke in source apportionment studies, were also present in meat-cooking emissions. The speciated organic compounds that were measured include polycyclic aromatic hydrocarbons (PAHs), cholesterol, and the long-chain gamma-lactones. Charbroiling emissions yielded an average of approximately 3-5 times more PAHs, approximately 20 times more cholesterol, and approximately 10 times more lactones than grilling. These data were utilized in the ambient source apportionment analysis for the 1997 Northern Front Range Air Quality Study source apportionment.     

Effective and reusable nano-silica synthesized from barley and wheat grass for the removal of nickel from agricultural wastewater

Environmental Science and Pollution Research - In the present study, a comparative analysis was performed on the extraction of nickel ions (Ni2+) from agricultural wastewater using nanosilica (NS)...     

电镀污泥中铜镍回收方法及工艺的研究

研究了电镀污泥中铜、镍的回收方法及工艺,采用硫酸浸出,浸出液在电压为2.4 V时电解3.5 h,铜的总回收率在99%以上,同时将Fe2 氧化成Fe3 ,电解余液(电解铜之后的溶液)加热至90℃,用磷酸盐调节pH至3.0,磷酸钠投加倍数为形成磷酸盐沉淀理论用量的1.4倍,99%的铁、铝、铬被去除.镍的总回收率约在97%以上.     

微囊藻毒素-RR的提取和臭氧氧化降解

在对采自云南滇池水华蓝藻细胞中的微囊藻毒素-RR(microcystin-RR,MC-RR)提取并发现其含量达到0.19mg/g(干重)的基础上,重点研究了臭氧氧化降解所提取的MC-RR。结果表明,当反应体系中臭氧浓度为5.7 mg/L时,初始浓度1.9 mg/L的MC-RR在15 min内被完全降解。利用HPLC/ESI/MS对提取的MC-RR及其氧化降解产物质荷比测定发现,降解前MC-RR的质谱图中出现特征离子m/z=1 038.7、m/z=519.8以及m/z=135.0。而降解后的产物质谱图中只有Adda基团中带苯环结构化合物(C9H10O)的特征离子峰m/z=135.0存在,其他2个离子峰完全消失。由此推断反应体系中MC-RR(m/z=1 038.2)在大量臭氧及其.OH自由基全面攻击下,分子结构中Adda基团以及单环结构中的不饱和双键直接被氧化而发生断链,最终形成小分子的有机物。     

Comparison of residue levels of persistent organochlorine compounds in butter from Spain and from other European countries

Abstract

Commercially available butter from Spain (n=36) and from other European countries (n=20) has been analyzed by high resolution gas chromatography with an electron capture detector for organochlorine contaminants. The results showed that both groups of samples have a similar pattern of these pollutants, but in all cases where significant differences in concentrations were found, Spanish samples presented higher values. This was especially notable for lindane (median values 11.6 vs. 3.0 ng/g wet weight), hexachlorobenzene (6.4 vs. 0.5) and ß‐hexachlorocyclohexane (3.1 vs. 1.2). Total PCBs showed no differences (5.4 vs. 6.6), but detailed analysis of congener composition indicated a higher presence in Spanish samples of the most persistent chlorinated PCBs. No sample presented levels of concern for any single organochlorine compound. It is interesting to note that consumption of butter in Spain is low so, although levels of organochlorines are higher than those found in other countries, consumers are less exposed through this foodstuff than in other European countries. These results also confirm the fact that environmental pollution by organochlorines is more important in Spain than in the rest of Europe.     

Extraction of arsenate and arsenite species from soils and sediments

The primary objective of this study was to develop a simple method that can be used to extract the more readily mobilizable and bioavailable arsenic species from soil and sediment while at the same time minimizing the transformation between (AsIII) and (AsV), the two most commonly found arsenic species in the environment. Several extraction strategies were evaluated using phosphate as extractant in combination with either ethylenediaminetetraacetic acid (EDTA), hydroxylamine hydrochloride (NH2OH.HCl), or sodium diethyldithiocarbamate trihydrate (NaDDC). The addition of EDTA in the phosphate solution did not prevent AsIII from oxidation. While promising results were shown when 1% NH2OH.HCl was added, conversion of AsIII began to occur with extended extraction time (> 12 h). Good results were achieved using 10 mM phosphate and 0.5% NaDDC where AsIII oxidation was clearly minimized. The combined phosphate and NaDDC solution was applied to several soil and sediment samples. AsIII spiked was quantitatively recovered in all soil types tested.     

Isolation and identification of beta-nitrostyrene from smoked chicken

Extraction and identification of beta-nitrostyrene from smoked chicken is described. Commercially obtained smoked chicken was homogenised and extracted with chloroform-methanol (2:1). The extracts were fractioned by silicic acid column chromatography. The purified extract using thin-layer chromatography was identified by a colour reaction (this qualitative method for some nitrated compounds is developed this time), high pressure liquid chromatography and gas chromatography/mass spectrometry. The concentration of beta-nitrostyrene in the smoked chicken was 94 ppb. The average recovery of added beta-nitrostyrene was 107%. However, the toxicity of this material was not tested in the present paper.     

Comparison of residue levels of persistent organochlorine compounds in butter from Spain and from other European countries

Commercially available butter from Spain (n = 36) and from other European countries (n = 20) has been analyzed by high resolution gas chromatography with an electron capture detector for organochlorine contaminants. The results showed that both groups of samples have a similar pattern of these pollutants, but in all cases where significant differences in concentrations were found, Spanish samples presented higher values. This was especially notable for lindane (median values 11.6 vs. 3.0 ng/g wet weight), hexachlorobenzene (6.4 vs. 0.5) and beta-hexachlorocyclohexane (3.1 vs. 1.2). Total PCBs showed no differences (5.4 vs. 6.6), but detailed analysis of congener composition indicated a higher presence in Spanish samples of the most persistent chlorinated PCBs. No sample presented levels of concern for any single organochlorine compound. It is interesting to note that consumption of butter in Spain is low so, although levels of organochlorines are higher than those found in other countries, consumers are less exposed through this foodstuff than in other European countries. These results also confirm the fact that environmental pollution by organochlorines is more important in Spain than in the rest of Europe.     

培养方式对废水脱氮与沼气脱硫污泥驯化影响

实验研究了底物、接种污泥和微生物生长方式对猪场废水脱氮和沼气脱硫耦联污泥驯化及活性恢复的影响,以解决快速富集培养废水脱氮与沼气脱硫微生物的问题。研究发现,就脱氮脱硫均达到60%的时间而言,接种厌氧污泥反应器为9 d,比接种好氧污泥反应器(18 d)和不接种污泥加填料反应器(21 d)更短。以含氮含硫废水为底物驯化时,接种厌氧污泥更有利于脱氮脱硫污泥的驯化;而同为接种好氧污泥时,以含氮含硫废水为底物的驯化方式更有利于脱氮脱硫污泥的驯化。污泥活性恢复实验中,以含氮废水+沼气(H2S)为底物培养驯化的污泥,硫转化活性恢复所用的时间为15 d,比含氮含硫废水为底物驯化污泥的活性恢复时间更长。     

Novel carbon nano-onions from paraffinum liquidum for rapid and efficient removal of industrial dye from wastewater

Environmental Science and Pollution Research - Carbon nano-onions (CNOs) are fascinating zero-dimensional carbon materials owning distinct multi-shell architecture. Their physicochemical properties...     

Amendment of arsenic and chromium polluted soil from wood preservation by iron residues from water treatment

An iron-rich water treatment residue (WTR) consisting mainly of ferrihydrite was used for immobilization of arsenic and chromium in a soil contaminated by wood preservatives. A leaching batch experiment was conducted using two soils, a highly contaminated soil (1033 mg kg⁻¹ As and 371 mg kg⁻¹ Cr) and slightly contaminated soil (225 mg kg⁻¹ As and 27 mg kg⁻¹ Cr). Compared to an untreated reference soil, amendment with 5% WTR reduced leaching in the highly contaminated soil by 91% for Cr and 98% for As. No aging effect was observed after 103 d. In a small field experiment, soil was mixed with 2.5% WTR in situ. Pore water was extracted during 3 years from the amended soil and a control site. Pore water arsenic concentrations in the amended soil were more than two orders of magnitude lower than in the control for the upper samplers. An increased release of arsenic was observed during winter in both fields, mostly in the deepest samplers. This is likely due to the formation of a pseudo-gley because of precipitation surplus. Stabilization of arsenic and chromium contaminated soil using WTR is a promising method but the transformation of ferrihydrite in soil proves a concern in case of waterlogged soils. Still the amendment minimized the leaching of arsenic, even in cases of seasonal releases.     

Radionuclides in deer and elk from Los Alamos national laboratory and the doses to humans from the ingestion of muscle and bone

Abstract

This paper summarizes radionuclide concentrations (³H, ⁹⁰Sr, ¹³⁷Cs, ²³⁸Pu, ^239,240Pu, ²⁴¹Am, and ^totU) in muscle and bone tissue of mule deer (Odocoileus hemionus) and Rocky Mountain elk (Cervus elaphus) collected from Los Alamos National Laboratory (LANL), Los Alamos, New Mexico, lands from 1991 through 1998. Also, the committed effective dose equivalent (CEDE) and the risk of excess cancer fatalities (RECF) to people who ingest muscle and bone from deer and elk collected from LANL lands were estimated. Most radionuclide concentrations in muscle and bone from individual deer (n = 11) and elk (n = 22) collected from LANL lands were either at less than detectable quantities (where the analytical result was smaller than two counting uncertainties) and/or within upper (95%) level background (BG) concentrations. As a group, most radionuclides in muscle and bone of deer and elk from LANL lands were not significantly higher (p<0.10) than in similar tissues from deer (n = 3) and elk (n = 7) collected from BG locations. Also, elk that had been radio collared and tracked for two years and spent an average time of 50% on LANL lands were not significantly different in most radionuclides from road kill elk that have been collected as part of the environmental surveillance program. Overall, the upper (95%) level net CEDEs (the CEDE plus two sigma for each radioisotope minus background) at the most conservative ingestion rate (50 lbs of muscle and 13 lbs of bone) were as follows: deer muscle = 0.22 mrem y^‐1 (2.2 μSv y^‐1), deer bone = 3.8 mrem y^‐1 (38 μSv y^‐1), elk muscle = 0.12 mrem y^‐1 (1.2 μSv y^‐1), and elk bone = 1.7 mrem y^‐1 (17 μSv y^‐1). All CEDEs were far below the International Commission on Radiological Protection guideline of 100 mrem y^‐1 (1000 μSv y^‐1), and the highest muscle plus bone net CEDE corresponded to a RECF of 2E‐06, which is far below the Environmental Protection Agency upper level guideline of 1E‐04.     

Comparison of Emission of Dioxins and Furans from Gasohol- and Ethanol-Powered Vehicles

ABSTRACT

The exhaust emissions of 17 polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs) were investigated in two spark-ignition light-duty vehicles, one gasohol-fueled and a flexible-fuel one fueled with hydrated ethanol. Gasohol is a mixture of gasoline and 22% ethanol. The influence of fuel type and quality, lubricant oil type, and use of fuel additives on the formation of these compounds was tested using standardized U.S. Federal Test Procedure (FTP)-75 cycle tests. The sampling of the PCDD/Fs followed the recommendations of a modified U.S. Environmental Protection Agency (EPA) Method 23 (http://www.epa.gov/ttn/emc/promgate/m-23.pdf) and the analysis basically followed the U.S. EPA Method 8290 (http://www.epa.gov/osw/hazard/testmethods/sw846/pdfs/8290a.pdf). Results showed that emission factors of PCDD/Fs for the gasohol vehicle varied from undetected to 0.068 pg international toxic equivalency (I-TEQ) km^?1 (average of 0.0294 pg I-TEQ km^?1), whereas in the ethanol vehicle they varied from 0.004 to 0.157 pg (I-TEQ) km^?1 (average of 0.031 pg I-TEQ km^?1). In the gasohol-powered vehicle, the use of fuel additive diminished the emission of Octachlorodibenzo-p-dioxin (OCDD) significantly, whereas in the ethanol vehicle no significant associations were observed between the investigated variables and the emissions.

IMPLICATIONS The objective of this work was to analyze differences in emissions from a traditional fossil fuel (gasoline) and an alternative renewable fuel (ethanol from sugarcane), and the influence of fuel additives and lubricant oils on the formation of chlorinated dioxins and furans in spark-ignition light-duty gasohol and ethanol vehicles. Renewable fuels are very important in terms of climate change but the risk to the population's health must not increase. Thus the results of this work could help in the development of environmental impact studies as well as orienting policy-makers in formulating strategies for air pollution control.     

Comparison of emission of dioxins and furans from gasohol- and ethanol-powered vehicles

The exhaust emissions of 17 polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs) were investigated in two spark-ignition light-duty vehicles, one gasohol-fueled and a flexible-fuel one fueled with hydrated ethanol. Gasohol is a mixture of gasoline and 22% ethanol. The influence of fuel type and quality, lubricant oil type, and use of fuel additives on the formation of these compounds was tested using standardized U.S. Federal Test Procedure (FTP)-75 cycle tests. The sampling of the PCDD/Fs followed the recommendations of a modified U.S. Environmental Protection Agency (EPA) Method 23 (www.epa.gov/ttn/ emc/promgate/m-23.pdf) and the analysis basically followed the U.S. EPA Method 8290 (http://www.epa.gov/osw/ hazard/testmethods/sw846/pdfs/8290a.pdf). Results showed that emission factors of PCDD/Fs for the.gasohol vehicle varied from undetected to 0.068 pg international toxic equivalency (I-TEQ) km(-1) (average of 0.0294 pg I-TEQ km(-1)), whereas in the ethanol vehicle they varied from 0.004 to 0.157 pg (I-TEQ) km(-1) (average of 0.031 pg I-TEQ km(-1)). In the gasohol-powered vehicle, the use of fuel additive diminished the emission of Octachlorodibenzo-p-dioxin (OCDD) significantly, whereas in the ethanol vehicle no significant associations were observed between the investigated variables and the emissions.