Microtox testing of pentachlorophenol in soil extracts and quantification by capillary electrochromatography (CEC)--a rapid screening approach for contaminated land

An approach to rapid soil testing which involved the use of simple solvent extraction methods was developed. The analytes of interest were priority pollutants of low water solubility which could not be readily removed from the soil using water. Direct toxicity testing of the soil samples by Microtox showed a high background toxicity which prevented realistic toxicity data from being obtained for the contaminants present. A range of different extraction solutions was used in an attempt to extract the contaminants while eliminating the matrix effects of the soil. It was necessary that the solvents selected for extraction of the soil samples were not of significant toxicity, as this could potentially mask the toxic effects of any compounds extracted from the soil. The extraction efficiencies of solvent systems were evaluated using pentachlorophenol (PCP) as a model compound of known toxicity in the Microtox assay. A rapid and cost-effective method was developed in order to determine the amount of PCP recovered from the soil by the extraction solvents employed. This method consisted of a solid phase extraction (SPE) step followed by quantification using capillary electrochromatography (CEC). Recoveries were greater when a higher proportion of organic solvent (methanol) was used in the extraction process, and lowest when water was used. An extraction based on water could provide information on the potential for leaching of contaminants from the soil into nearby water bodies in an environmental setting. An organic solvent extraction method could indicate how much toxicity soil-dependent organisms might be exposed to through ingestion. Extraction based on 50% (v/v) methanol in water was considered to be the most suitable overall extraction solution for soil screening, given that this permitted extraction of the water-insoluble compound PCP at a level which was clearly toxic in the Microtox assay while also retaining the capability to extract water-soluble contaminants.     

Gas chromatographic methods for monitoring of wastewater chlorophenol degradation in anaerobic reactors

Wastewater samples from an anaerobic reactor were extracted with hexane and derivatized with diazomethane (method 1) and with acetic anidride (method 2). Gas chromatography with electron-capture detection (ECD) was employed for separating the parent compound and intermediates trichlorophenols (TCP) and dichlorophenols (DCP) which originated from the penta chlorophenol (PCP) degradation process. The relations between concentrations of PCP, TCP and DCP areas were linear in the range of concentrations of 0.2 to 8 mg/L and 0.025 mg/L to 5 mg/L for methods 1 and 2, respectively. The repeatability of the extraction methods was satisfactory, with variation coefficients lower than 11%. For method 1, at the fortification level of 0.2 mg/L, recovery of PCP, TCP, and DCP was 112%, 74% and 45%, respectively. For method 2, the corresponding recovery values at the fortification level of 0.1 mg/L were 91%, 93% and 103%, respectively. Storage of the frozen samples did not alter their PCP determination properties. The chromatographic methods adapted for chlorophenol determination in wastewater were suitable with relatively simple manipulation techniques. The obtained results were reproducible and allowed identification of intermediates formed during the PCP degradation process.     

Gas chromatographic methods for monitoring of wastewater chlorophenol degradation in anaerobic reactors

Wastewater samples from an anaerobic reactor were extracted with hexane and derivatized with diazomethane (method 1) and with acetic anidride (method 2). Gas chromatography with electron-capture detection (ECD) was employed for separating the parent compound and intermediates trichlorophenols (TCP) and dichlorophenols (DCP) which originated from the penta chlorophenol (PCP) degradation process. The relations between concentrations of PCP, TCP and DCP areas were linear in the range of concentrations of 0.2 to 8 mg/L and 0.025 mg/L to 5 mg/L for methods 1 and 2, respectively. The repeatability of the extraction methods was satisfactory, with variation coefficients lower than 11%. For method 1, at the fortification level of 0.2 mg/L, recovery of PCP, TCP, and DCP was 112%, 74% and 45%, respectively. For method 2, the corresponding recovery values at the fortification level of 0.1 mg/L were 91%, 93% and 103%, respectively. Storage of the frozen samples did not alter their PCP determination properties. The chromatographic methods adapted for chlorophenol determination in wastewater were suitable with relatively simple manipulation techniques. The obtained results were reproducible and allowed identification of intermediates formed during the PCP degradation process.     

Treated wood in livestock facilities: relationships among residues of pentachlorophenol, dioxins, and furans in wood and beef.

Wood and other environmental samples were collected from sites that produced beef with higher than average residues of dibenzo-p-dioxin (PCDD) and dibenzofuran (PCDF). Analyses of these samples for PCDD/Fs and pentachlorophenol (PCP) indicated that the high beef residues were associated with PCP-treated wood in the animal facilities. Concentrations of PCDD/Fs in wood as toxic equivalents ranged from 10 to 320,000 pg/g. These concentrations were closely related to the concentrations of PCP, indicating that analysis for PCP provides an economical method to identify wood with high concentrations of PCDD/Fs. Further evidence for the PCP-treated wood as the source of the beef residues is provided by the similarity of the congener profiles in beef from the sites and those profiles predicted from the profiles in wood.     

Elemental analysis of ash residue from combustion of CCA treated wood waste before and after electrodialytic extraction

Element distribution in a combined fly ash and bottom ash from combustion of copper chromate arsenate (CCA) treated wood waste was investigated by scanning electron microscopy (SEM/EDX) before and after electrodialytic extraction. The untreated ash contained various particles, including pieces of incompletely combusted wood rich in Cr and Ca, and irregular particles rich in Si, Al and K. Cr was also found incorporated in silica-based matrix particles. As was associated with Ca in porous (char) particles, indicating that Ca-arsenates had been formed during combustion. Cu was associated with Cr in the incompletely combusted wood pieces and was also found in almost pure form in a surface layer of some matrix particles - indicating surface condensation of volatile Cu species. In treated ash, Ca and As were no longer found together, indicating that Ca-arsenates had been dissolved due to the electrodialytic treatment. Instead particles rich in Ca and S were now found, indicating precipitation of Ca-sulphates due to addition of sulphuric acid in connection with the electrodialytic treatment. Cu and Cr were still found associated with incompletely combusted wood particles and incorporated in matrix particles. Chemical analyses of untreated and treated ash confirmed that most As, but only smaller amounts of Cu and Cr was removed due to the electrodialytic extraction. Overall metal contents in the original ash residue were: 1.4 g As, 2.76 g Cu and 2.48 g Cr, after electrodialytic extraction these amounts were reduced by 86% for As, 15% for Cu and 33% for Cr.     

A comparative study on the recovery of polycyclic aromatic hydrocarbons from fly ash and lignite coal

The recovery of polycyclic aromatic hydrocarbons (PAHs) from lignite coal burnt in Greek power stations and the fly ash produced is examined comparatively using Soxhlet, ultrasonic and accelerated solvent extraction procedures with various organic solvents. Soxhlet using toluene/methanol mixture and accelerated solvent extraction/toluene were found to be the most efficient methods for fly ash PAHs, yielding average recoveries of about 80%. The accelerated solvent extraction/toluene procedure was superior for lignite PAHs, yielding 96% average recovery, whereas ultrasonic and Soxhlet extraction yielded relatively lower recoveries (75% and 67%, respectively).     

An ultrasonic assisted extraction method to release heavy metals from untreated sewage sludge samples

A rapid ultrasound accelerated sequential extraction procedure has been used to develop sequential extraction proposed by BCR protocol (the community Bureau of Reference now the European Union "Measurement and Testing Programme"). The effects of the ultrasonic treatment on the extraction of Cu, Cd, Cr, Pb, Ni and Zn from untreated sewage sludge collected from industrial site of Hyderabad city (Pakistan) were compared with those obtained from conventional sequentional extraction procedure of modified BCR protocol. In BCR method, each extraction steps takes 10h, where as with the use of compromise sonication conditions in ultrasonic bath, steps 1-3 of the sequential extraction (excluding the hydrogen peroxide digestion in step 3, which was not performed with sonication) could be completed in 30, 30 and 30 min, respectively. Extractable Cd, Cr, Pb and Ni contents were obtained by both comparable methodologies were measured by electrothermal atomic absorption spectrometry (ETAAS), while for Cu and Zn Flame atomic absorption spectrometry (FAAS) was used. The validations of both methods were compared by the analysis of certified reference material of soil amended with sewage sludge (BCR 483). According to statistical evaluation of the results, the proposed accelerated extraction method is valid alternative to conventional shaking with much shorter extraction time with p value <0.05. The overall metal recoveries in steps 1-3 (excluding residual step) were 95-100% of those obtained with the conventional BCR protocol, except for Cu extracted (91.6%) as related to indicative values of Cu in BCR 483 obtained in 1-3 steps. The results of the partitioning study of untreated industrial waste water sewage sludge, indicate that more easily mobilized forms (acid exchangeable) were predominant for Cd and Zn, in contrast, the largest amount of Pb and Cr was associated with the iron/manganese oxide and organic matter/sulphide fractions.     

Detection and occurrence of pentachlorophenol residues in chicken liver and fat

A method for the detection of pentachlorophenol (PCP) residues in chicken liver and fat is presented. A detection limit of 0.002 mg/kg was achieved. Recoveries from liver and fat were in the range 82-88% and 95-97%, respectively. Low level residues of PCP were found in all 1072 liver and 723 fat samples. These levels were less than 0.010 mg/kg in 92.7% of the fat and 75.6% of the livers. Only 0.75% of the liver samples had PCP levels greater than 0.1 mg/kg. None of the more toxic impurities of PCP were detected in the chicken tissues.     

Detection and occurrence of pentachlorophenol residues in chicken liver and fat

Abstract

A method for the detection of pentachlorophenol (PCP) residues in chicken liver and fat is presented. A detection limit of 0.002 mg/kg was achieved. Recoveries from liver and fat were in the range 82–88% and 95–97%, respectively.

Low level residues of PCP were found in all 1072 liver and 723 fat samples. These levels were <0.010 mg/kg in 92.7% of the fat and 75.6% of the livers. Only 0.75% of the liver samples had PCP levels>0.1 mg/kg. None of the more toxic impurities of PCP were detected in the chicken tissues.     

Biodegradation of low aqueous concentration pentachlorophenol (PCP) contaminated groundwater

Bioremedial treatment to remove low level organic contamination to regulatory standards has met with limited success. In this study source water from a contaminated surficial aquifer at a former wood treatment facility was used to evaluate the potential for indigenous microorganisms to degrade low level (< 1.0 mg) pentachlorophenol (PCP) to a regulatory drinking water standard of 0.001 mg/L. PCP degradation was evaluated in series of batch reactors in a two phase study to (a) determine the rate and extent of PCP removal and (b) evaluate the impact of nutrient amendment (N and P) on removal rate. All reactors with the exception of the abiotic control demonstrated PCP removal to a level < 0.002 mg/L within a maximum period of 32 d with and without nutrient amendment. A regression analysis of reactive phosphate (ortho-P) concentration versus removal rate produced an R2 of 0.94 (p = 0.006) indicating a significant correlation between the level of available phosphate and PCP degradation rate. Selective bacterial enumeration (for PCP degrading bacteria) revealed PCP-degrading bacteria increased in abundance prior to and in conjunction with the degradation phase to a density of between 10(3) to 10(4) CFU/ml. Isolates were also analyzed for total fatty acids using Fatty Acid Methyl Ester (FAME) methodology and the results indicated that PCP degrading bacteria were present in the aquifer and consisted of predominately fluorescent, oxidase positive Pseudomonas species. Overall, data indicate that autochthonous microbes are capable of removing low level PCP (< 1.0 mg/L) to approach if not reach the regulatory standard of 0.001 mg/L with the addition of oxygen, with or without nutrient amendment. Results of this research can be applied to full-scale implementation of in-situ or ex-situ bioremediation of groundwater at former wood treatment facilities.     

Recovery of high purity sulfuric acid from the waste acid in toluene nitration process by rectification

Waste sulfuric acid is a byproduct generated from numerous industrial chemical processes. It is essential to remove the impurities and recover the sulfuric acid from the waste acid. In this study the rectification method was introduced to recover high purity sulfuric acid from the waste acid generated in toluene nitration process by using rectification column. The waste acid quality before and after rectification were evaluated using UV–Vis spectroscopy, GC/MS, HPLC and other physical and chemical analysis. It was shown that five nitro aromatic compounds in the waste acid were substantially removed and high purity sulfuric acid was also recovered in the rectification process at the same time. The COD was removed by 94% and the chrominance was reduced from 1000° to 1°. The recovered sulfuric acid with the concentration reaching 98.2 wt% had a comparable quality with commercial sulfuric acid and could be recycled back into the toluene nitration process, which could avoid waste of resources and reduce the environmental impact and pollution.     

Characterization of polycyclic aromatic hydrocarbons (PAHs) on lime spray dryer (LSD) ash using different extraction methods

In this study, traditional Soxhlet, automatic Soxhlet and ultrasonic extraction techniques were employed to determine the speciation and concentration of polycyclic aromatic hydrocarbons (PAHs) on lime spray dryer (LSD) ash samples collected from the baghouse of a spreader stoker boiler. To test the efficiencies of different extraction methods, LSD ash samples were doped with a mixture of 16 US EPA specified PAHs to measure the matrix spike recoveries. The results showed that the spike recoveries of PAHs were different using these three extraction methods with dichloromethane (DCM) as the solvent. Traditional Soxhlet extraction achieved slightly higher recoveries than automatic Soxhlet and ultrasonic extraction. Different solvents including toluene, DCM:acetone (1:1 V/V) and hexane:acetone (1:1 V/V) were further examined to optimize the recovery using ultrasonic extraction. Toluene achieved the highest spike recoveries of PAHs at a spike level of 10 microg kg(-1). When the spike level was increased to 50 microg kg(-1), the spike recoveries of PAHs also correspondingly increased. Although the type and concentration of PAHs detected on LSD ash samples by different extraction methods varied, the concentration of each detected PAH was consistently low, at microg kg(-1) levels.     

Chemical and physical characterization of emissions from birch wood combustion in a wood stove

The purpose of this study was to characterize the emissions of a large number of chemical compounds emitted from birch wood combustion in a wood stove. Birch wood is widely used as fuel in Swedish household appliances. The fuel load was held constant during six experiments.Particles <2.5 μm in diameter were collected and the size distribution of the particles was measured. The results were compared to the size distribution in road traffic emissions. It could be seen that the number distribution differed between the sources. In traffic exhaust, the number of particles maximized at 20 nm, while the number distribution from wood burning ranged from 20 to 300 nm. The ratio K/Ca on particles was found to be significantly different in wood burning compared to road dust, range 30–330 for the former and 0.8±0.15 for the latter. The source profile of common elements emitted from wood burning differed from that found on particles at a street-level site or in long-distance transported particles.The ratio toluene/benzene in this study was found to be in the range 0.2–0.7, which is much lower than the ratio 3.6±0.5 in traffic exhaust emissions.Formaldehyde and acetone were the most abundant compounds among the volatile ketones and aldehydes. The emission factor varied between 180–710 mg/kg wood for formaldehyde and 5–1300 mg/kg wood for acetone. Of the organic acids analyzed (3,4,5)-trimethoxy benzoic acid was the most abundant compound. Of the PAHs reported, fluorene, phenanthrene, anthracene, fluoranthene and pyrene contribute to more than 70% of the mass of PAH. Of the elements analyzed, K and Si were the most abundant elements, having emission factors of 27 and 9 mg/kg wood, respectively.Although fluoranthene has a toxic equivalence factor of 5% of benzo(a)pyrene (B(a)P), it can be seen that the toxic potency of fluoranthene in wood burning emissions is of the same size as B(a)P. This indicates that the relative carcinogenic potency contribution of fluoranthene in wood smoke would be about 40% of B(a)P.     

Wood-Specific Polycyclic Aromatic Hydrocarbon (PAH) Patterns in Soot Using Gas Chromatography-Atmospheric Pressure Laser Ionization-Mass Spectrometry (GC-APLI-MS)

If organic matter is burnt, the combustion of wood produces the highest amounts of polycyclic aromatic hydrocarbons (PAHs) compared with other fossil energy sources such as oil, coal, or gas. Emissions from wood combustion are increasingly of special interest due to the rising use of wood as a renewable energy source in residential heating in Europe. To the authors' knowledge, reproducible wood-specific PAH patterns in soot were identified for the first time by use of a sampling interval of only 5 min in this study. The short sampling interval was enabled by the very sensitive analytical method of gas chromatography–atmospheric pressure laser ionization–mass spectrometry (GC-APLI-MS) applied. The analysis of 40 PAH of soot from wood logs of spruce, pine, larch (softwood) and beech, birch, oak (hardwood), and wood pellets, as well as wood briquettes, showed 13.46–250.62 mg/kg for ∑40 PAH and 10.75–177.94 mg/kg for the U.S. Environmental Protection Agency PAH standard (without acenaphthylene and anthracene). Highest concentrations occurred in the samples from birch with bark, beech, and wood briquettes. Indeno[1,2,3-cd]pyrene, naphthalene, and alkylated naphthalenes were also detected. Significant concentrations of the very toxic dibenzopyrenes (up to 11.30 mg/kg) are reported. Softwood soot contained highest amounts of 2–4-ring PAH, followed by hardwood which is in accordance with the presence of highest amounts of abietic acid in softwood, a known precursor of retene and phenanthrene. PAH in soot from five spruce samples from different locations show a mean ∑40 PAH concentration of 13.46 mg/kg (n = 5, minimum 8.03, maximum 23.32 mg/kg, SD = 5.65) and exhibited a typical pattern that differed from all other wood soot samples. The distributions of alkylated naphthalenes of the spruce samples show a bell-shape distribution in contrast to the alkylated phenanthrenes/anthracenes of all samples (except the wood pellets), showing a slope distribution. The data indicate that wood-specific PAH patterns exist and under the applied conditions, spruce logs produced the least toxic soot.     

Method development for determination of fluroxypyr in soil

Four methods were developed for the analysis of fluroxypyr in soil samples from oil palm plantations. The first method involved the extraction of the herbicide with 0.05 M NaOH in methanol followed by purification using acid base partition. The concentrated material was subjected to derivatization and then cleaning process using a florisil column and finally analyzed by gas chromatography (GC) equipped with electron capture detector (ECD). By this method, the recovery of fluroxypyr from the spiked soil ranged from 70 to 104% with the minimum detection limit at 5 microg/kg. The second method involved solid liquid extraction of fluroxypyr using a horizontal shaker followed by quantification using high performance liquid chromatography (HPLC) equipped with UV detector. The recovery of fluroxypyr using this method, ranged from 80 to 120% when the soil was spiked with fluroxypyr at 0.1-0.2 microg/g soil. In the third method, the recovery of fluroxypyr was determined by solid liquid extraction using an ultrasonic bath. The recovery of fluroxypyr at spiking levels of 4-50 microg/L ranged from 88 to 98% with relative standard deviations of 3.0-5.8% with a minimum detection limit of 4 microg/kg. In the fourth method, fluroxypyr was extracted using the solid liquid extraction method followed by the cleaning up step with OASIS HLB (polyvinyl dibenzene). The recovery of fluroxypyr was between 91 and 95% with relative standard deviations of 4.2-6.2%, respectively. The limit of detection in method 4 was further improved to 1 pg/kg. When the weight of soil used was increased 4 fold, the recovery of fluroxypyr at spiking level of 1-50 microg/kg ranged from 82-107% with relative standard deviations of 0.5-4.7%.     

Measurement of ammonia emissions using various techniques in a comparative tunnel study

A field-based intercomparison study for ammonia measurements was conducted using seven analytical methods. It included sulphuric acid impinger, citric acid denuder, differential optical absorption spectroscopy (DOAS), Fourier transform infrared spectroscopy (FTIR), photoacoustic spectroscopy (PAS), and continuous aqueous extraction followed by measurement of conductivity (Airrmonia). Measurements were done at the entrance and the exit of the Gubrist highway tunnel near Zurich, Switzerland. For DOAS, FTIR, PAS and Airrmonia, 24 hour means were calculated based on a time resolution of 10 minutes. At the tunnel exit, all 24 hour averages were within 13%, and the continuous data of the time-resolved methods agreed well. At the tunnel entrance, a slightly reduced method comparison included four methods, and daily mean values agreed within 23%. Ammonia emission factors, based on 4 weeks of continuous measurements with the Airrmonia, were 31 ± 4 mg km^-1 for light-duty vehicles and 14 ± 7 mg km^-1 for heavy-duty vehicles.     

硫酸锰废渣浸出毒性及淋溶特性研究

长沙市兴镇13家硫酸锰厂的生产废渣使当地的生态环境造受到了严重破坏。本文在废渣浸出毒性实验、渣柱淋滤实验以及废渣的全分析基础上,全面地研究了废渣的组成、浸出毒性大小以及在当地酸沉降条件下的淋滤特征,为其安全处置提供了理论基础。研究证明,废渣中重金属种类多、含量高,尤其是锰,高达138800mg/kg。渣的浸出毒性虽未达到国家规定的危险废物鉴别标准,但远超过了《污水综合排放标准》,其衰减可用负指数方程来描述。在酸雨淋溶下,渣中的锰离子会在短时期内大量释放后,维持在一相对较低水平长期释放,对环境威胁巨大。     

Arsenic speciation in plants growing in arsenic-contaminated sites

Concentrations of total arsenic and of arsenic species were determined by ICPMS and HPLC-ICPMS in terrestrial plant samples. The arsenic concentration in plant samples from the contaminated sites ranged from 1.14 to 98.5 mg kg(-1) (dry mass). However, a very high value, exceeding largely this range was found in a moss sample growing in the contaminated area (1750 mg kg(-1)). Plants growing in a non-contaminated area with similar geological characteristics contained 0.06-0.58 mg As kg(-1). Plant samples from different species were selected and extracted with water, water/methanol (9+1, v/v), and water/methanol (1+1, v/v). Water/methanol (9+1, v/v) was selected as extractant for the speciation analysis for all the plant samples. The extraction efficiencies ranged from 3.0% to 41.4%, with good agreement between samples from the same plant species. Arsenite and/or arsenate were found in all the plant samples. Additionally, methylarsonate (MA), dimethylarsinate (DMA), trimethylarsine oxide (TMAO) and tetramethylarsonium ion (TETRA) were also identified in several plants, and in some cases MA and DMA were the main species found. TMAO, which is usually found as a trace constituent in organisms, was also a significant arsenical in one of the studied samples, where it constituted 24% of the extracted arsenic. In the present study, the patterns of arsenic species varied with the plant species and much higher proportion of organoarsenicals was found in plants from the more contaminated sites.     

Fractionation of heavy metals in liquefied chromated copper arsenate 9-treated wood sludge using a modified BCR-sequential extraction procedure

Chromated copper arsenate (CCA)-treated wood was liquefied with polyethylene glycol/glycerin and sulfuric acid. After liquefaction, most CCA metals (98% As, 92% Cr, and 83% Cu) were removed from liquefied CCA-treated wood by precipitation with calcium hydroxide. The original CCA-treated wood and liquefied CCA-treated wood sludge were fractionated by a modified Community Bureau of Reference (BCR) sequential extraction procedure. The purpose of the BCR-sequential extraction used in this study was to examine the availability of CCA metals in treated wood for reuse. Both As and Cr had a slightly higher concentration in the sludge sample than in original CCA-treated wood. The sequential extraction showed that As and Cr were principally existed in an oxidizable fraction (As, 67%; Cr, 88%) in original CCA-treated wood. Only 1% of both As and Cr were extracted by hot nitric acid with the last extraction step. The distribution of As and Cr changed markedly in liquefied CCA-treated wood sludge.The amount of As in the exchangeable/acid extractable fraction increased from 16% to 85% while the amount of Cr increased from 3% to 54%. Only about 3% of As was present in the oxidizable fraction. However, there was still about 34% of Cr in the same fraction. Based on these results from sequential extraction procedures, it can be concluded that the accessibilities of CCA metals increase markedly by the liquefaction–precipitation process.     

Lead removal from foundry waste by solvent extraction

Solvent extraction is used to reduce lead concentrations from millpond wastewater solids, a type of foundry process waste. Toluene and toluene mixed with di-(2-ethyl-hexyl) phosphoric acid (HDEHP) have been tried as leaching solvents. Toluene is ineffective as a solvent in extracting lead, but the toluene-HDEHP mixture effectively removes lead from solid foundry waste. The effects of the HDEHP concentration, the contact time, and the amount of solvent used on lead extraction have been investigated. The mass transfer process is rapid: contact time of 1/2 hour has been found to be sufficient to accomplish the leaching process. The concentration of HDEHP significantly impacts lead removal. The optimum concentration of HDEHP is determined to range from 0.05 to 0.1 mol/l. The Toxicity Characteristic Leaching Procedure (TCLP) test of the treated samples gives leachable lead in much lower quantities than those found in the untreated samples. Thus the solvent extraction process appears to be an effective method to significantly reduce the lead content of millpond wastewater solids.