Hydraulic performance of a full-scale peat and ash biofilter in treatment of industrial landfill leachate.

The purpose of this study was to evaluate the hydraulic performance of a full-scale on-site vertical-flow biofilter, consisting of a mixture of peat and carbon-containing ash, and a 500 m(3) equalization pond prior to the filter-system. The treatment plant was constructed to clean up leachate from an industrial mono-landfill that contained shredder residues of end-of-life vehicles and white goods. With the limited storage capacity of the equalization pond, peak loading rates exceeded up to five to six times the designed daily hydraulic load limit of the biofilter system. Such relatively short overloading events did not negatively affect the purification efficiency. To provide the designed annual irrigation rate on the biofilter of 97 m(3) day(- 1) (or 133 mm day(-1)), with large seasonal variations in precipitation, a relatively large pond would be needed. Calculations showed that a storage volume of about 23 000 m(3) would be sufficient for annual leachate volumes up to about 35 000 m(3). A combination of sprinkler and drip irrigation with straw insulation of the latter made it possible to run the plant continuously even when the ambient air temperature was below zero for more than a month at a time. The grain size distribution of the biofilter medium was noticeably changed after 4 years of usage due to the loading of suspended solids from the leachate and decomposition of the peat, causing reduced hydraulic conductivity.

Performance of a full-scale biofilter with peat and ash as a medium for treating industrial landfill leachate: a 3-year study of pollutant removal efficiency.

Shredder residues of end-of-life vehicles and white goods are a complex waste stream, which nowadays most often is disposed of at industrial landfills. This paper describes the most important findings concerning the complex composition of the landfill leachate and its on-site, year-round treatment under cold-climate conditions. A 3-year investigation has confirmed that concentrations of different types of pollutants, most of them at low initial concentrations, can be simultaneously reduced in vertical-flow biofilters consisting of a mixture of peat and carbon-containing ash. For metals such as Mn, Cu, Sn, Cd, Pb, Fe and Ni the average removal was 73, 72, 66, 60, 55, 55 and 37%, respectively. An average reduction of NH(4)-N (45%), N(tot) (25%), total organic carbon (30%), dissolved organic carbon (28%) and suspended solids (38%) was also obtained. A good reduction was achieved for phenols (between 75 and 95%), polychlorinated biphenyls (between 22 and 99%), and gas chromatography-mass spectrometry amenable pollutants, considered at initial concentration above 50 microg L( -1) (between 80 and 100%). The performance of the biofilter system was good in spite of large variations of inlet concentration during the considered period.

Occurrence and removal of pharmaceuticals in a municipal sewage treatment system in the south of Sweden.

The occurrence and removal rate of seven pharmaceuticals (ibuprofen, naproxen, diclofenac, fluoxetine, ofloxacin, norfloxacin, ciprofloxacin), two metabolites (norfluoxetine, clofibric acid), one degradation product (4-isobutylacetophenone) and 3 estrogens (17alpha-ethinylestradiol, 17beta-estradiol, estrone) were studied in the inlet and outlet of a tertiary sewage treatment plant (STP) in Sweden as well as between different treatment steps in the STP which includes a conventional activated sludge step. Pharmaceuticals in raw household and raw hospital sewage streams leading to the STP were as well investigated. Hydraulic retention times (HRT) of each treatment step was considered for sampling and for the calculation of the removal rates. These rates were above 90%, except for diclofenac, clofibric acid, estrone and ofloxacin. However, only diclofenac and naproxen showed significant effluent loads (>145 mg/d/1000 inh). Diclofenac was not eliminated during the treatment and in fact even higher concentrations were found at the effluent than in the inlet of the STP. 17alpha-Ethinylestradiol was not detected in any of the samples. Results indicate that a STP such as the one in Kristianstad, Sweden, with a tertiary treatment is sufficient to remove significantly most of the investigated pharmaceuticals. The chemical treatment improved the removal of several pharmaceuticals especially the antibiotics, which showed step removal rates between 55 and 70%. The expected concentration levels of the pharmaceuticals in the surface water (dilution 1 to 10) close to the outlet of the STP are below the no-observed effect-concentration (NOEC). However, despite that this would imply no important effects in the aquatic environment one cannot rule out negative consequences nearby the STP because most of the NOEC values are derived from acute toxicity data. This may underestimate the real impact of pharmaceuticals in the aquatic ecosystem.

Selective determination of acidic pharmaceuticals in wastewater using molecularly imprinted solid-phase extraction.

The determination of acidic pharmaceuticals, such as non-steroidal anti-inflammatory drugs NSAIDs and clofibric acid (metabolite of clofibrate), at low ngL(-1) levels in wastewater requires highly selective and sensitive analytical procedures. The removal of matrix components during sample preparation results in significant benefits towards reducing the matrix effects during LC-MS analysis. Therefore this work describes a simple method to enrich and clean up NSAIDs and clofibric acid from sewage water using molecularly imprinted solid-phase extraction (MISPE). Final analysis was performed by liquid chromatography-tandem mass spectrometry. The performance of this method has been evaluated in fortified tap and sewage water in terms of recovery, precision, linearity, and method quantification limit. Recovery for all compounds ranged in all matrices between 84 and 116% with intra-day R.S.D. values below 11.5%. Matrix effect evaluation demonstrated that even complex sample matrixes, such as pond or sewage water did not showed significant ion suppression/enhancement compared to tap water. The performance of the method was further emphasized by the study of pond water, which receives treated water from a sewage treatment plant in south Sweden. Raw sewage and treated water were also tested. In those samples, all acidic pharmaceuticals were detected in concentration above method quantification limits ranging from 5.1 to 5153.0ngL(-1).

Analysis of triazines and associated metabolites with electrospray ionization field-asymmetric ion mobility spectrometry/mass spectrometry.

Triazines comprise an important pollutant class owing to continued use in certain countries, and owing to strong environmental persistence that leads to problems even in countries like Sweden where the use of triazines has been prohibited for some years. We investigated mass-selective detection for analysis of triazines. More specifically, we studied the background reduction and sensitivity enhancement that result from the use of a new interface technique, field-asymmetric ion mobility spectrometry (FAIMS), in conjunction with electrospray ionization ion-trap mass spectrometry. This technique allows for ion sorting and discrimination against the considerable "chemical noise", nonspecific cluster and fragment ions, which are typically generated in electrospray ionization. This paper presents results of a pilot study of triazines and some metabolites in ideal solvents. Our long-range goal is automated analysis with mass-selective detection coupled to membrane-based sample cleanup and enrichment for additional enhancement in sensitivity.

Comparison of solid-phase sorbents for the determination of fluoroquinolone antibiotics in wastewater.

Three different SPE sorbents (weak cation exchange, mixed cation exchange, and hydrophobic-lipophilic balance polymers) were compared in terms of recovery, precision, and the effect of matrix components on analyte response for the determination of fluoroquinolones antibiotics. The influence of ethylenediaminetetraacetic acid disodium salt (Na2-EDTA) was as well tested. Two of the sorbents, hydrophilic-lipophilic balance (HLB) and weak cation exchange (WCX), turned out to be suitable for ultratrace analysis. HLB sorbent showed higher capacity for analyte trapping and better precision while weak cation exchange sorbent had a superior performance in terms of selectivity. In complex samples, the higher capacity of HLB was outweighed by the higher selectivity of WCX when considering the LODs of the methods.

Assessment of organochlorine pesticide pollution in Upper Awash Ethiopian state farm soils using selective pressurised liquid extraction.

Upper Awash Agro Industry Enterprises (UAAIE) is one of the major state farms in Ethiopia with known large-scale pesticide use. Although organochlorine pesticides (OCPs) have been applied for about three decades, no studies have been carried out on levels of residue in the region. In this work a fast selective pressurised liquid extraction (SPLE) methodology has successfully been applied for screening of 13 OCPs in 12 soil samples from different fields in UAAIE, which further strengthen this methodology. Quantitative and qualitative analyses were done using a dual column gas chromatography-electron capture detection system (GC-ECD) and a GC equipped with a mass spectrometer (MS), respectively. The main contaminants identified comprised of previously used persistent organic pollutants (POPs) and currently used insecticides. Low concentrations or non-detectable levels of certain OCPs (aldrin, dieldrin, endrin, and heptachlor) indicate a positive phasing out of these persistent organic pollutants (POPs). Similarly HCHs were found in few soils and at low concentrations. Endosulfans and DDTs were detected in substantial amounts in the soils with Sigmaendosulfans up to 56000 and SigmaDDTs up to 230 ng g(-1) dry weight, which is a threat to the surrounding and downstream ecosystems, especially considering that the investigated OCPs constituted 29000 l of the 63000 l of pesticide applied annually on the fields. Additional concerns must be raised concerning synergistic effects of all pesticides added.

Steroid hormone determination in water using an environmentally friendly membrane based extraction technique.

In this study, a method was developed for determination of steroid hormones (17beta-estradiol, estrone, 17alpha-ethynylestradiol) in tap and sewage water samples from Sweden. Sample preparation and analysis were performed by a hollow-fibre microporous membrane liquid-liquid extraction (HF-MMLLE) set-up combined with gas chromatography-mass spectrometry (GC-MS). In this approach, only the organic liquid in the lumen (10microL) of the hollow-fibre membrane was utilised for depleting extraction. Several parameters were studied, including: type of organic solvent, sample pH, salt and humic acid content. The optimised method allowed the determination of the analyte at the low ngL(-1) level in tap and sewage water. A linear plot gave correlation coefficients better than 0.995 and resulted in a method limit of detection of 1.6, 3 and 10ngL(-1) for 17beta-estradiol, estrone, and 17alpha-ethynylestradiol, respectively, in sewage water. Enrichment factors were over 1400 after derivatisation. The repeatabilities at 50 and 600ngL(-1) were better than 10% and 6%, respectively.

Hollow-fibre supported liquid membrane extraction for determination of fluoxetine and norfluoxetine concentration at ultra trace level in sewage samples.

In this study, a method was developed for determining the concentration of the pharmaceutical fluoxetine and its metabolite, norfluoxetine, in sewage water samples. Sample preparation was performed by hollow-fibre supported liquid membrane (HF-SLM) extraction with final analysis using liquid chromatography with UV detection. Several parameters were studied including type of organic solvent, sample and acceptor pH, and salt and humic acid content. The optimised method allowed determination of the analyte at the ng/L level in sewage water. A linear plot gave a correlation coefficient better than 0.991 for both analytes and resulted in limits of detection in sewage water of 11 and 12 ng/L, for fluoxetine and norfluoxetine, respectively. The enrichment factor was over 1700 for both analytes in sewage water. The repeatability and reproducibility were better than 8% and 17%, respectively. The developed methodology was used to study daily variations of fluoxetine and norfluoxetine in municipal sewage streams. Norfluoxetine has been detected for the first time in sewage water and a preliminary analysis gave average concentrations of 150 and 225 ng/L for norfluoxetine and fluoxetine, respectively.

A novel hollow-fibre microporous membrane liquid-liquid extraction for determination of free 4-isobutylacetophenone concentration at ultra trace level in environmental aqueous samples.

In this study, a method was developed for determination of the free concentration of 4-isobutylacetophenone, a toxic degradation product of ibuprofen, in river and sewage water samples from Sweden. Sample preparation and analysis were performed by a hollow-fibre microporous membrane liquid-liquid extraction (HF-MMLLE) set-up and gas chromatography-mass spectrometry (GC-MS), respectively. In this novel approach, only the liquid in the membrane pores is utilised for non-depleting extraction. Several parameters were studied, including: type of organic solvent, sample pH, and salt and humic acid content. The optimised method allowed the determination of the analyte at the ng L(-1) level in river and sewage water. A linear plot gave a correlation coefficient better than 0.992 and resulted in a limit of detection of 7 and 14 ng L(-1) for river and sewage water, respectively. The enrichment factor was over 2000 in the fibre and over 300 after dilution. The repeatability and reproducibility were better than 5% and 10%, respectively. For the first time, 4-isobutylacetophenone was found at free concentrations of 40 ng L(-1) or below in sewage waters, while it could not be quantified in a river downstream from a municipal sewage treatment plant.

Extracting syringe for extraction of phthalate esters in aqueous environmental samples.

The use of the extracting syringe (ESy), a fully automated membrane-based extraction technique, for analysis of phthalate esters in complex aqueous samples has been investigated. The ESy, working as an autosampler that combines the extraction process and injection into the gas chromatograph (GC) in one single step, is placed on top of the GC equipped with a flame ionisation detector. The aqueous samples are loaded in a tray and automatically extracted by employing microporous membrane liquid-liquid extraction principle. After the extraction, the extract is directly injected into the GC's programmable temperature vaporisation injector. Six different phthalate esters were used as model compounds. Four extraction solvents were tested and the addition of sample organic modifier was examined. Toluene was the optimal solvent to use for extraction. Due to the large variation in polarity of phthalate esters, 50% methanol as organic modifier had to be added to the samples so as to extract the most nonpolar phthalate esters; di-2-ethylhexylphthalate and di-n-octylphthalate, whereas the other four relatively polar phthalate esters were extracted from unmodified samples. No significant difference between extraction of river water, leachate water from a landfill and reagent water was noted, except for minor deviations. The extraction time was 20 min for extraction of a 1-mL sample, resulting in a good linearity for all aqueous media investigated, good enrichment factors (54-110 folds) and low LOD values (0.2-10 ng mL(-1)) and relative standard deviation (%R.S.D.; 0.9-3.7%).

Selective pressurized liquid extraction for multi-residue analysis of organochlorine pesticides in soil.

A selective pressurized liquid extraction (SPLE) procedure capable of performing simultaneous extraction and clean-up has been demonstrated for multi-residue analysis of organochlorine pesticides (OCPs) in soil. The final method was performed at 100 degrees C for 3 x 10 min using acetone/n-heptane (1:1, v/v). Florisil was placed inside the extraction cell downstream the sample to remove interfering compounds. Extraction of two soil samples by SPLE gave a recovery which was over 80% for beta-endosulfan, endosulfan sulfate, p,p'-DDT and p,p'-DDE compared to PLE with off-line clean-up. The same trend was observed when applying the SPLE method to a certified reference soil sample (CRM 811-050) containing 13 OCPs, where the SPLE method gave 80-90% recovery vis-à-vis the PLE method with off-line clean-up. Feasibility of the SPLE method was further demonstrated by applying it to five real soil samples collected in Ethiopia.

Emissions from baled municipal solid waste: II. Effects of different treatments and baling techniques on the emission of volatile organic compounds.

This paper focuses on the volatile organic compound emissions from baled municipal solid waste (MSW). The analytical methodology was based on sampling with adsorbent tubes once a month during seven occasions within a time period of 1 year. Automated analyses were carried out on-line work-up with thermal desorption directly connected to a gas chromatograph-mass spectrometer. The effect of different baling techniques, cylindrical and rectangular baling was compared. It was found that cylindrically baled MSW emitted larger concentration of esters than their rectangular counter parts. Conversely, aromatic compounds emissions dominated in rectangularly baled MSW. This indicates that different degradation mechanisms operate in the waste bales. Cylindrical and rectangular bales are generally wrapped with six layers of 250 microm thick low density polyethylene (LDPE). It was observed that by wrapping an extra six layers of LDPE film onto the bales, the emissions from cylindrical bales increased while emissions from the rectangular counterpart decreased. Over time, the volatile organic compound emissions from cylindrical bales decreased two orders of magnitudes from 96.2 +/- 20.8 microg m(-3) in September 2003 to 0.80 +/- 0.07 microg m(-3) in July 2004. The rectangular bales exhibited an almost identical relative emission reduction from 54.4 +/- 4.3 microg m(-3) in September 2003 to 0.46 +/- 0.02 microg m(-3) in July 2004. Future work will concentrate on full-scale storages, taking into account waste type, storage size, temperature development and the different baling techniques among other variables.

Emissions from baled municipal solid waste: I. Methodological approach for investigation of gaseous emissions.

This paper presents a methodological approach for the study of volatile organic compounds (VOCs) in air, emitted during storage of municipal solid waste in bales. Determination of VOCs was based on sampling with adsorbent tubes followed by automated analysis using on-line work-up with a thermal desorption unit directly connected to a gas chromatograph-mass spectrometer. Using calculation algorithms and multidimensional statistical analysis of large amounts of data collected, the information was compressed and visualized. The approach was applied to initial measurements of emissions of VOCs from 24 bales composed of municipal solid waste, each bale stored in a wooden box. These bales were produced using the two types of baling equipment available, resulting in cylindrical or rectangular bales, with different densities. Hundreds of different VOCs emitted from these bales sorted out into groups with different chemical structure. Differences in VOC concentrations in air were found between wastes stored in cylindrical or rectangular bales. For instance, it was found that the concentration of VOCs (relative to the concentration of toluene), in the first experiment after storing, for cylindrical bales with six layers of LDPE was 115 +/- 10 microg m(-3), while for rectangular bales it was only 64 +/- 8 microg m(-3). The procedure used for data interpretation suggested different degradation mechanisms in different types of bales. The use of multiple data interfaces, multidimensional statistics and automated chemical analysis methods are likely to be more and more common for waste companies and waste research in the near future. This is due to the interdisciplinary nature of the subject that relies heavily on various areas of science and information technology.

Development of a combined solid-phase extraction-supercritical fluid extraction procedure for the determination of polychlorinated biphenyls in wastewater.

A combined solid-phase extraction (SPE)-supercritical fluid extraction (SFE) procedure was developed for the analysis of polychlorinated biphenyls (PCBs) in wastewater. The importance of cleaning and drying the filters and SPE-disks prior to eluting PCBs with SFE was studied, leading to improved recoveries for all congeners investigated. The average PCB recovery of the final procedure, at a concentration of 18 ng/L in reagent water, was 101% with relative standard deviations ranging from 1 to 5% for the different congeners. Spiked leachate to a final concentration of 4 ng/L was extracted directly after spiking, or after 24 h of spiking. An average recovery of 112% was obtained in the direct extraction of spiked leachate.

Optimisation of pressurised liquid extraction for the determination of p,p'-DDT and p,p'-DDE in aged contaminated Ethiopian soils.

The effectiveness of extracting p,p'-DDT and p,p'-DDE from aged contaminated soil samples by means of pressurized liquid extraction (PLE) was evaluated. Two soil samples, which were contaminated more than 10 years ago, were used in the investigation. The static extraction time was optimised and then validated against the total sum of target analytes obtained from multiple sequential extractions. The PLE results were also compared with Soxhlet extraction (SOX). PLE for 3x10 min at 100 degrees C was proven to be more exhaustive than SOX in the determination of p,p'-DDE from both soil samples. In the case of p,p'-DDT, PLE was found to be equally as exhaustive as SOX. Additionally, most of the previous PLE investigations used hazardous organic solvents such as n-hexane, toluene and dichloromethane mixed with acetone, whereas in this investigation the less toxic solvent combination n-heptane/acetone has been employed.

Supercritical fluid extraction (SFE) for determination of metalworking fluid aerosols.

A common methodology for analyzing metalworking fluid (MWF) aerosols in workplace air is based on gravimetry before and after organic solvent extraction of the MWFs from a suitable collection filter. Because MWFs have different chemical and physical properties, various mixtures of organic solvents have been used to extract the MWFs from their collection device. An alternative to organic solvents, used in the work presented in this article, is the use of a supercritical fluid. The efficiency of supercritical fluid extraction (SFE) was investigated by weighing conditioned filters before and after extraction of samples spiked with MWFs at different concentrations using the American Society for Testing and Materials method. For three common straight oil MWFs spiked on filters, supercritical carbon dioxide gave recoveries of 92-101% with a low standard deviation (0.2-1.9%). For semisynthetic MWFs, carbon dioxide had to be mixed with methanol to obtain recoveries above 80%. With the optimized method using 7% methanol in carbon dioxide, the 10 investigated MWFs could be extracted in 30 min with a recovery of 90-98%. The amount of MWFs spiked on the filters varied between 0.10-1.65 mg. In Sweden, the limit value for MWFs is 1 mg/m3. Thus, our spike level is in the range of 10-200% of the limit value if sampling for 8 hours with 2 L/min. The use of SFE methodology results in small volume extracts (3 mL) with concentrations at such high levels that analysis of chemical components in the MWF can be carried out without further volume reduction.

Leachability testing of sludge from street gullies.

Sludge from gullies, on two types of streets with different traffic intensity, was investigated using two recommended EU methods for leachability testing of waste: a two-stage batch test and an up-flow percolation test. The main purpose of this investigation was to gain more knowledge about these leaching test methods to be able to make future decisions on the general applicability of the proposed tests. A number of parameters were determined in the sludge as well as in the eluates obtained from the two leaching tests. These include pH, conductivity, dissolved organic carbon and inorganic ions as chloride ions. A number of metals as Cd, Cr, Cu, Hg, Ni and Zn, were determined by inductive coupled plasmamass spectrometry and organic compounds were screened by high performance liquid chromatography-diode array UV detection and gas chromatography-mass spectrometry. It was found that the concentrations of metals and organic compounds in the sludge were several orders of magnitudes higher than the actual eluate concentrations. For all metals the concentrations were well below the proposed limit values for non-hazardous waste included in the Council decision document 2003/33/EC. Generally, concentrations obtained in batch test were equal or higher than from percolation tests. The repeatability of the percolation and the batch test were in average 28 and 17%, respectively.

The performance of a natural treatment system for landfill leachate with special emphasis on the fate of organic pollutants.

A natural treatment system for the treatment of leachate was studied at Moskogen landfill in southern Sweden. This facility consists of three consecutive ponds and a soil-plant (SP)-system. A test area, receiving water from the third pond with the same hydraulic load as the SP-system, was used for estimation of the latter system. Quality parameters including biochemical oxygen demand, total organic carbon, ammonium, nitrate, orthophosphate, and total suspended solids along the treatment line were determined as well as soluble metals (Cu, Cd, Zn, Cr, Ni, and Pb). In addition a thorough investigation along the treatment line has also been performed concerning volatile organic compounds and semi-volatile organic compounds. Non-polar organic compounds were investigated using gas chromatography-mass spectrometry. Quantification was based on the assumption of equal response for the compounds found in comparison with the chosen marker substances. For polar, water-soluble compounds the measurements were restricted to phenolic compounds using high-performance liquid chromatography. Several different types of organic compounds were found in the raw leachate including aromatics, benzene-sulfonamides, biphenyls, naphthalene, organic phosphates, polycyclic aromatic hydrocarbons, polychlorinated biphenyls, phenols and phthalates. The treatment system efficiently reduced organic pollutants, heavy metals, and nitrogen/phosphorous compounds. Most metals and organic compounds in the leachate were already significantly reduced to a low level in the treatment ponds and ammonium-N was efficiently transformed to nitrate-N in the SP-system.

Development of a pressurized liquid extraction and clean-up procedure for the determination of alpha-endosulfan, beta-endosulfan and endosulfan sulfate in aged contaminated Ethiopian soils.

Pressurized liquid extraction (PLE) was investigated for the extraction of two endosulfan isomers and their metabolite from two real contaminated soil samples. PLE for 3x10min at 100 degrees C was proven to be more exhaustive than Soxhlet extraction (SOX) in one soil sample. On the other soil sample investigated the method was found to be equally exhaustive as SOX. The use of hazardous organic solvents such as n-hexane, toluene, and diethyl ether has been avoided in PLE and clean-up. Instead less toxic solvents have been used both at the extraction step (acetone/n-heptane) and clean-up step (ethyl acetate/n-heptane). A column Florisil clean-up procedure that consumes relatively low solvent volumes has been optimized and applied to purify soil extracts. The developed analytical procedure was validated by applying it to a certified reference soil material (CRM811-050). A recovery of 103% total endosulfan residue was obtained versus certified values.