Ann-Margret Hvitt Strömvall

Phthalates and nonylphenols in urban runoff: Occurrence, distribution and area emission factors

The urban water system is believed to be an important sink for the nonpoint-source pollutants nonylphenols and phthalates. The presence of nonylphenols (NPs), nonylphenol ethoxylates (NPEOs), and eight phthalates was analyzed in urban stormwater and sediment from three catchment areas in Sweden. Emission loads for these substances were then calculated for a specific urban catchment area. In addition, substance distribution in road runoff passing through a sedimentation facility was modeled using a modified QWASI-model for chemical fate. High concentrations of DEHP, DIDP and DINP (<or=48, 66 and 200 microg/g dw, respectively) as well as nonylphenol mono- and di-ethoxylate (6.6 and 20 microg/g dw, respectively) were found in the sediment. Aqueous concentrations of the pollutants varied considerably; branched NP was detected in concentrations up to 1.2 microg/L, whereas di(2-ethylhexyl) phthalate (DEHP), diisodecyl phthalate (DIDP), and diisononyl phthalate (DINP) were the most frequently detected phthalates in concentrations up to 5.0, 17 and 85 microg/L, respectively. The fate modeling demonstrated that predicted substance levels in water agreed well with measured levels, whereas the modeled sediment levels were underestimated. Calculation of catchment area emission factors from an urban highway environment revealed that as much as 2.1 kg of total phthalates and 200 g of NP and NPEOs may be emitted per hectare and year. The results indicate that all monitored phthalates, branched NPs and lower NPEOs are present in Swedish urban water systems. The long-chain phthalates DIDP and DINP are believed to occur at higher concentrations than other phthalates because of their higher environmental persistence and their increasing use in Sweden.

Protection of terpenes against oxidative and acid decomposition on adsorbent cartridges

Sampling of monoterpenes from air on Tenax porous polymer may introduce analytical errors owing to oxidation and acid rearrangements on the adsorbent. Particularly terpenes which react rapidly with ozone, e.g. myrcene and limonene, are partially lost when sampling air with high photooxidant levels. On acidified adsoption cartridges, alpha-pinene and beta-pinene may be converted into camphene, limonene, para-cymene and several minor monoterpenes. Pretreatment of the adsorption cartridges with thiosulphate as an antioxidant and hydrogencarbonate as a buffer were found to prevent decomposition and rearrangements. Applications to monoterpenes emitted from the kraft, thermo-mechanical and sulphite pulp industries are presented.

Sorption and degradation of petroleum hydrocarbons, polycyclic aromatic hydrocarbons, alkylphenols, bisphenol A and phthalates in landfill leachate using sand, activated carbon and peat filters

Landfill leachates are repeatedly found contaminated with organic pollutants, such as alkylphenols (APs), phthalates and polycyclic aromatic hydrocarbons (PAHs) at levels exceeding water quality standards. It has been shown that these pollutants may be present in the colloidal and truly dissolved phase in contaminated water, making particle separation an inefficient removal method. The aim of this study was to investigate sorption and degradation of petroleum hydrocarbons (PHCs), selected APs, bisphenol A (BPA), phthalates and PAHs from landfill leachate using sand, granulated activated carbon (GAC) and peat moss filters. A pilot plant was installed at an inactive landfill with mixed industrial and household waste and samples were collected before and after each filter during two years. Leachate pre-treated in oil separator and sedimentation pond failed to meet water quality standards in most samples and little improvement was seen after the sand filter. These techniques are based on particle removal, whereas the analysed pollutants are found, to varying degrees, bound to colloids or dissolved. However, even highly hydrophobic compounds expected to be particle-bound, such as the PHCs and high-molecular weight PAHs, were poorly removed in the sand filter. The APs and BPA were completely removed by the GAC filter, while mass balance calculations indicate that 50-80% of the investigated phenols were removed in the peat filter. Results suggest possible AP degradation in peat filters. No evidence of phthalate degradation in the landfill, pond or the filters was found. The PHCs were completely removed in 50% and 35% of the measured occasions in the GAC and peat filters, respectively. The opposite trend was seen for removal of PAHs in GAC (50%) and peat (63%). Oxygenated PAHs with high toxicity were found in the leachates but not in the pond sediment. These compounds are likely formed in the pond water, which is alarming because sedimentation ponds are commonly used treatment techniques. The oxy-PAHs were effectively removed in the GAC, and especially the peat filter. It was hypothesized that dissolved compounds would adsorb equally well to the peat and GAC filters. This was not completely supported as the GAC filter was in general more efficient than peat.

Exposure of commuters to volatile aromatic hydrocarbons from petrol exhaust.

Twenty-two volatile aromatic hydrocarbons were determined in the air of an automobile during commuting. Sampling was made on Tenax cartridges and laboratory determinations were carried out using thermal desorption combined with temperature-programmed capillary gas chromatography. Selected hydrocarbons representative of petrol exhaust were determined in the automobile and in an electric commuter train during eight parallel commuter trips. In the automobile, the concentrations of benzene were 35-70 micrograms/m3 and those of total aromatic hydrocarbons 200-400 micrograms/m3. The petrol exhaust levels were 5-10 times higher in the automobile than in the compartment of the commuter train.

Conifer monoterpenes emitted to air by logging operations

Concentration levels in air were determined for monoterpenes emitted from forestry operations in south-west Sweden. Field samples were collected on Tenax cartridges and analyzed in the laboratory by techniques based on gas chromatography. Processing of Scots pine as well as Norway spruce with a harvestor gave rise to about 1000 microgram/m3 of total monoterpenes near the machine. The corresponding levels above fresh branch wood were 100-500 microgram/m3. The background level was around 1 microgram/m3. The major monoterpenes were alpha-pinene and 3-carene from Pinus sylvestris and alpha-pinene and beta-pinene from Picea abies. Compounds constituting 1-10 % each of the total monoterpenes were camphene, 3-carene, limonene, beta-phellandrene and myrcene for spruce and camphene, beta-pinene, limonene, beta-phellandrene, myrcene and terpinolene for pine. Representative percent compositions for the two species are given for 13 monoterpenes. Photo-oxidant formation from the monoterpenes is discussed with respect to potential local contributions to strain and damage of the forests. Possible preventive measures are suggested.

ALTERNATIVE MATERIALS FOR ADSORPTION OF HEAVY METALS AND PETROLEUM HYDROCARBONS FROM CONTAMINATED LEACHATES

ABSTRACT In the present work, waste products from forest industries (sawdust, pine bark and fibre sludge ash), as well as some biological materials (peat, shrimp shells and seaweed), have been investigated with respect to their capacities to adsorb metals and hydrocarbons from contaminated waters. Batch and column experiments were carried out with artificial metal ion solutions and contaminated leachates from an industrial landfill. The fibre sludge ash and the Sphagnum peat showed the highest sorption capacities for metals among the materials studied in batch experiments with single‐metal solutions. The uptake of metals by the fibre ash for the metals studied was: Cu and Pb 112 μg g−1, Zn 115 μg g−1 and Cr 97 μg g−1. For peat the uptake was: Pb 109 μg g−1, Cu 105 μg g−1, Zn 100 μg g−1 and Cr 99 μg g−1. These materials were also effective in adsorption of diesel oil, and the n‐alkanes C16 and C12. Peat and ash adsorbed respectively 36.6 and 36.4 mg g−1 of C12, 1.84 and 1.94 mg g−1 of C16 and for both 0.98 mg g−1 of diesel oil. Bark adsorbed diesel oil to 0.83 mg g−1. In the column experiments, the removal of metals from a contaminated landfill leachate by ash and peat was lower than from artificial solutions with only a few metals. The results suggest interference from other components in the leachates, such as competition of ions for the same active sites. It is quite clear that laboratory tests can overestimate the performance of adsorbents and that experiments should be specific for the intended application. For most of the metals studied in columns, peat appeared to be the best adsorbent, with respect to both sorption capacity and service time. The addition of 10 % by weight of fibre ash to the peat gave higher adsorption capacities for Cd, Ni and Pb but lower for the Cu and Zn.

Leaching of organic contaminants from storage of reclaimed asphalt pavement

Abstract Recycling of asphalt has been promoted by rapid increases in both the use and price of petroleum‐based bitumen. Semi‐volatile organic compounds in leachates from reclaimed asphalt pavement, measured in field samples and in laboratory column test, were analysed through a GC/MS screen‐test methodology. Sixteen PAH (polyaromatic hydrocarbons) were also analysed in leachates from the column study. The highest concentrations of semi‐volatile compounds, ‐ 400 μg 1‐1, were measured in field samples from the scarified stockpile. Naphthalene, butylated hydroxytoluene (BHT) and dibutyl phthalate (DBP) were the most dominant of the identified semi‐volatiles. The occurrence of these compounds in urban groundwater, also indicate high emission rates and persistent structures of the compounds, making them potentially hazardous. Car exhausts, rubber tires and the asphalt material itself are all probable emission sources, determined from the organic contaminants released from the stockpiles. The major leaching mechanism indicated was dissolution of organic contaminants from the surface of the asphalt gravels. In the laboratory column test, the release of high‐molecular weight and more toxic PAH was higher in the leachates after two years than at the commencement of storage. The concentrations of semi‐volatiles in leachates, were also several times lower than those from the field stockpile. These results demonstrate the need to follow up laboratory column test with real field measurements.

Particle phase distribution of polycyclic aromatic hydrocarbons in stormwater - Using humic acid and iron nano-sized colloids as test particles

The distribution of polycyclic aromatic hydrocarbons (PAHs) in different particulate fractions in stormwater: Total, Particulate, Filtrated, Colloidal and Dissolved fractions, were examined and compared to synthetic suspensions of humic acid colloids and iron nano-sized particles. The distribution of low-molecular weight PAHs (LMW PAHs), middle-molecular weight PAHs (MMW PAHs) and high-molecular weight PAHs (HMW PAHs) among the fractions was also evaluated. The results from the synthetic suspensions showed that the highest concentrations of the PAHs were found in the Filtrated fractions and, surprisingly, high loads were found in the Dissolved fractions. The PAHs identified in stormwater in the Particulate fractions and Dissolved fractions follow their hydrophobic properties. In most samples >50% of the HMW PAHs were found in the Particulate fractions, while the LMW and MMW PAHs were found to a higher extent in the Filtrated fractions. The highest concentrations of PAHs were present in the stormwater with the highest total suspended solids (TSS); the relative amount of the HMW PAHs was highest in the Particulate fractions (particles>0.7 μm). The highest concentration of PAHs in the Colloidal fraction was found in the sample with occurrence of small nano-sized particles (<10nm). The results show the importance of developing technologies that both can manage particulate matter and effectively remove PAHs present in the Colloidal and Dissolved fractions in stormwater.

Colloid-facilitated metal transport in peat filters.

The effect of colloids on metal retention in peat columns was studied, with the focus on colloids from two sources-organic matter leached from peat, and introduced organic and hydrous ferric oxide (HFO) colloids. A significant fraction of metals was found to be associated with peat-produced organic colloids; however the concentrations of organic colloids leached are low (trace concentrations) and temporal and have a limited effect on the efficiency of peat filters. In contrast, the presence of organic and HFO colloids in the input water causes a significant decrease in the performance of peat filters. Organic colloids were identified as the main vector of cadmium, copper, nickel, and zinc, while lead is transported by both organic and HFO colloids. The colloidal distribution of metals obtained in this study has important implications for the mobility of trace metals in porous media. The occurrence of colloids in the input waters and their characteristics must be considered when designing water treatment facilities.

Photooxidant-forming monoterpenes in air plumes from kraft pulp industries.

Monoterpenes emitted to air from two Swedish kraft (sulphate) pulp-mills were determined by sampling on the Tenax adsorbent followed by laboratory analysis using thermal desorption combined with high-resolution gas chromatography. The composition of the terpenes was found to be similar in the emissions from various parts of the process as well as in the mill plume. The bicyclic terpenes alpha-pinene and 3-carene, originating principally from wood of Scots pine (Pinus sylvestris), predominated among the thirteen assessed hydrocarbon monoterpenes. Terpinolene was the most prominent among the particularly reactive terpenes with a lifetime in ozone-rich air of only a few minutes. The rapid formation of photooxidants by chemical reactions of the terpenes with other components of the mill plume is discussed. It is concluded that a variety of phytotoxic photooxidants are formed which may contribute significantly to forest decline within 50 km of mills located along coasts.