MULTIMEDIA MONITORING OF POLYCYCLIC AROMATIC HYDROCARBONS (PAHs) IN A LARGE INDUSTRIAL CITY: PHASE DISTRIBUTION AND EMISSION SOURCE IDENTIFICATION

Department of Urban and Environmental Engineering (Environmental Science and Engineering)Ulsan is one of the largest industrial cities of South Korea and has several main industrial areas, including petrochemical, non-ferrous, shipbuilding, and automobile complexes. These industrial activities contribute to the need for monitoring of pollutants, especially the polycyclic aromatic hydrocarbons (PAHs), in Ulsan since the petrochemical and non-ferrous industrial activities are believed to be one of the important emission sources of PAHs. This dissertation aims to investigate PAHs (i.e., concentrations, profiles, phase distribution, and exchange) in the multimedia environment of Ulsan, including the air, soils, overland runoff, and surface water. Moreover, types (e.g., coal combustion and biomass burning) and areas (i.e., local and regional areas) of the PAH emission sources were also identified. The diagnostic ratios, principal component analysis (PCA), and positive matrix factorization (PMF) were used to identify the emission source types. The emission source areas of PAHs were identified using hybrid receptor models and conditional bivariate probability function. Moreover, the fugacity approach and Whitman???s two-film model were applied to investigate the multimedia exchange of PAHs between the air-water and air-soil. Regarding the atmospheric PAHs, winter and spring had the highest and lowest PAH concentrations, respectively. Fractions of the gaseous or 3- and 4-ring PAHs were high in summer, and those of the particulate or 5- and 6-ring PAHs increased in winter. For the seasonal emission sources of PAHs, pyrogenic (e.g., coal combustion) source was dominant in winter. Other types of the pyrogenic (e.g., industrial fuel combustion) and petrogenic sources were the main PAH sources in summer and fall. In spring, two types of the pyrogenic sources, diesel and coal combustion, were identified as the main PAH sources in this season. Regarding the areas of emission sources, the particulate PAHs in Ulsan could be more affected by distant sources in the spring and winter, such as long-range transport from northeastern China (e.g., Beijing, Tianjin, and Hebei), northern China (e.g., Jilin and Liaoning), and North Korea. In contrast, the gaseous PAHs were affected by local emissions (i.e., industrial and vehicle emissions) mostly throughout the year. Particularly, in summer and fall, the local emission sources could more affect the gaseous and particulate PAHs compared to the outside sources (i.e., trans-boundary transport from China). However, the opposite trend was observed in spring and winter, that is, PAHs originated from northeastern China, northern China, and North Korea could contribute to those in Ulsan. The PAHs in other environmental media (i.e., overland runoff, surface water, and soils) of Ulsan were also studied to understand the interaction of PAHs in the air to those in the other media. For PAHs in the runoff and surface water, the runoff PAHs reached their highest concentrations in April (middle spring), which could be strongly affected by meteorological conditions before the sampling events (i.e., the long dry period and the lower rainfall amount). Moreover, the contributions of the dissolved PAHs were mostly higher than those of particulate ones, especially in July (summer) when the higher water temperature could lead to the desorption of PAHs from the particulate to the dissolved phase. Regarding the source identification, PAHs in the runoff and surface water could share similar emission sources, which were mixed sources from both petrogenic and pyrolysis sources. Additionally, the PAHs in the runoff of July could be also originated from coal/coke/heavy oil combustion as a result of industrial emissions and local advection. Regarding the multimedia exchange, the surface water could be a source for most of the atmospheric PAHs in Ulsan. However, the contribution of the water to the atmospheric PAHs (i.e., volatilization from the water to the air) could be not important. The soil could be a source or a sink of the atmospheric PAHs, mostly depending on the molecular weights of the compounds (i.e., a source for 3-ring PAHs and a sink for 4-ring species). Additionally, the PAHs in Ulsan mostly distributed in the soil, followed by the air, and the surface water. The highest distributions of PAHs in the soil could be because of their strong affinity to the soil organic matter, leading to their accumulation in the soil. The PAHs secondly distributed in the air, however, the atmospheric PAHs in Ulsan should be concerned due to the effect of trans-boundary transport and local advection from the industrial complexes. Overall, this dissertation can contribute to the understanding of PAHs in the multimedia environment, including the air, overland runoff, surface water, and soils, and can support the decision-making related to the environmental issues in Ulsan. Based on this dissertation, further studies should more focus on other PAH compounds, such as oxygenated and halogenated PAHs, in the air and soil of Ulsan. Moreover, trans-boundary transport of PAHs and other organic compounds should be further studied to more understand the effect of long-range transport on air pollution in Ulsan.clos

Evaluation of Ammonia, Greenhouse Gas Emissions and Characterization of Different Particulate Matter During Sugarcane Production in Southern Louisiana

Application of N fertilizers and special land management practices during agricultural production could have significant implication in influencing the air quality. In this study, field experiments were established at different research sites in Louisiana to evaluate the emission of ammonia (NH3), greenhouse gases (GHG), and fine particulates from sugarcane cultivation and harvesting. Specifically, this study was planned to (i) evaluate the effect of different N sources (urea and urea ammonium nitrate) and residue management schemes (residue burned, RB; and residue retained, RR) on NH3 and GHG emissions, (ii) characterize the chemical and morphological characteristics of fine particles generated during sugarcane harvesting operations (regular harvesting, RH; ground burn, GB; standing burn, SB; and combine harvesting, CH), and (iii) evaluate the micrometeorological study of NH3 flux above sugarcane crop canopy. Ammonia (NH3) and greenhouse gas samples were collected through active and passive chamber methods, respectively, following N application in the field. Then those NH3 and GHG samples were analyzed using ion chromatography (IC) and gas chromatography, respectively. Organic/elemental carbon, water soluble species, elemental species, and morphological features were determined using thermal carbon analyzer, ion chromatography, inductively-coupled plasma-optical emission spectroscopy, and scanning electron microscopy, respectively. Volatile organic carbon and polycyclic aromatic hydrocarbons were analyzed using gas chromatography-mass spectroscopy. Bi-directional NH3 emission was obtained from two installed denuders (at 10 ft and 18 ft) equipped with meteorological tower in the sugarcane field and the captured NH3 was analyzed in IC. Field experiments showed that urea treatment produced almost 2.8 times and 1.6 times higher NH3 and N2O, respectively, as compared to UAN plots. However, N had little effect on CH4 and N2O emissions. Overall, majority of total NH3 and N2O emission was observed within 3-4 weeks after N application in the field. On the other hand, residue retained treatment resulted significantly higher NH3, N2O, and CH4 emissions as compared to RB treatments over the years. Ammonia and N2O emissions were highly correlated with water filled pore space (%), but higher correlation was found in 2012 due to higher rainfall received within 3 weeks of N application. Particulates released during different sugarcane harvesting operations showed that carbonaceous compounds contributed about 30-70% of the total particle mass. Ammonia was the major cation found in the burning particulates (GB and SB) and showed high correlation with SO42- ions. Overall, organic carbon, major ionic species, elemental species were significantly higher in GB particles than SB particles. Low molecular weight polycyclic aromatic hydrocarbons were mainly released during sugarcane residue burning operations. Molar ratio of standing burn smoke samples was found lower than ground burn samples over four years. Ammonia emission above sugarcane crop canopy was highly dependable on different meteorological parameters such as temperature, rainfall, and wind speed. Major NH3 emission peaks were found during heavy rainfall days combined with favorable temperature. Higher rainfall increased anaerobic soil conditions and thus released more NH3 from soil surface. Daytime NH3 emission was significantly higher than nighttime emission because of higher temperature during day which helps in NH3 volatilization both from soil and crop surface. Higher wind speed created turbulence in atmospheric boundary layer and thus helped more NH3 emissions. Overall, these results are useful in managing sugarcane production while minimizing NH3, GHG and particle matter emissions

Occurrence and Removal of Polychlorinated Biphenyls (PCBs) in Urban Stormwater

Polychlorinated biphenyls (PCBs) are a group of chlorinated organic compounds. They are persistent in the environment and can threaten the health of humans and wildlife. Urban stormwater runoff is considered as an important source of PCBs to aquatic environments. The objective of this study is to provide information on the occurrence and removal of PCBs in stormwater; specifically, the occurrence, concentrations, and biological transformations of stormwater PCBs were studied together with their removal. Concentrations of 209 PCB congeners were determined in surface stormwater sediments collected from various roadway sites and bioretention media. The total PCB concentrations ranged from 8.3 to 57.4 ng/g dry weight (dw), with a mean value of 29.2 ng/g dw. Land use had an impact on the concentration of PCBs, where higher stormwater sediment PCB concentrations were found in dense urban areas (average: 39.8 ± 10.5 ng/g) compared to highways passing through greenspace (average: 18.0 ± 0.4 ng/g). PCB sorption tended to increase with the concentration of total organic carbon (TOC) and smaller particle size (< 75 µm) of stormwater particulate matter. In bioretention core samples, PCB concentrations decreased with bioretention media depth (from 30.0 ± 2.0 ng/g at the surface to 21.2 ± 4.8 ng/g at 40 cm depth), and with distance from the stormwater entrance (from 38.4 ± 2.3 ng/g at the entrance to 33.2 ± 2.9 ng/g at 3 m distance). A non-Aroclor congener, PCB 11, was detected in all samples, likely originating from yellow road paint. Putative organohalide respiring bacteria within Chloroflexi and aerobic PCB degrading bacteria containing the functional genes encoding for biphenyl dioxygenase (bphA) and ring cleavage (bphC) were detected in some of the stormwater sediments and bioretention media. The presence of such bacteria and a higher level of ortho-chlorinated biphenyls indicated the potential of PCB biotransformation in these samples. The performance of an on-campus bioretention indicated that bioretention is effective in removing PCBs from stormwater, with 64–92% reduction of dissolved PCB concentrations. Overall, urban stormwater is an important environmental source of PCBs. Bioretention has the potential to remove PCBs from stormwater via adsorption and biotransformation

Ecotoxicology of biochar-bound PAHs in runoff from amended soils

Mestrado em Estudos Ambientais (JEMS)While the appeal of biochar application to soils continues growing, so does the concern about the possibility for surface and groundwater contamination, due to biochar-bound contaminants, such as polycyclic aromatic hydrocarbons (PAHs). Up to now, insufficient information exists on to what extent that PAH fraction can become bioavailable in the soil solution over time and which are the associated potential ecotoxicological implications, as a result of processes such as runoff. This pilot study aimed to evaluate the ecotoxicological effects of biochar-bound PAHs in runoff from soils amended with biochar, having been identified as a gap in current knowledge. Combining soil wetting-drying cycles with PAH water-extraction, a good first approach was obtained for evaluating their potential occurrence in soil solution, while taking into consideration natural soil processes and soil-biochar interactions. LUFA 2.2 soil alone and containing biochar (at usual field rates, 4% ww-1) was subjected to 0, 6 or 12 (sampling times ST-0, ST-1 or ST-2 respectively) consecutive wetting-drying cycles, after which the corresponding test elutriates were extracted. Alongside PAH quantification, a battery of standard aquatic bioassays were used with representative test organisms (Vibrio fischeri, Pseudokirchneriella subcapitata and Daphnia magna), for a robust ecotoxicological evaluation of the biochar-soil (BS) aqueous extracts, while LUFA soil elutriates were used as control (SS). Compared to the control (SS) and to elutriates of biochar alone (B), BS extracts showed the highest total PAH contents, suggesting that a relevant PAHs fraction in biochar-amended soil may be easily water-extractable, perhaps due to interactions between biochar and soil components. Yet, the number of soil wet-dry cycles on aqueous total PAH concentrations was often not significant, suggesting that natural soil wetting-drying events might have little influence on increased PAH bioavailability in pore water, on the short term. BS extracts induced toxicity in all tested species, although its extent was species-specific and varied with the number of wet-dry cycles. For example, the highest sensitivity was observed in the acute assay with D. magna exposed to BS extract for ST-0, while P. subcapitata and V. fischeri were most sensitive when exposed to BS, ST-1. Nevertheless, sub-lethal effects were also observed for P. subcapitata and V. fischeri, when exposed to the control (SS) extracts. Although the levels of individual PAHs in all samples (BS, SS and B) were below the acutely toxic concentrations reported in the literature, it cannot be excluded the combined effects of the multiple PAHs in the test elutriates when explaining these results. Furthermore, although individual PAH concentrations were below that to produce acute effects, chronic effects can occur, and therefore, long-term exposure to these elutriates and using additional non-target species, various biochars and soil properties are necessary for a full evaluation of the bioavailability and ecotoxicity of biochar-bound PAH contaminants in runoff from treated soils

Priority pollutants in urban stormwater: Part 2 - Case of combined sewers

Postprint de l'article : Priority pollutants in urban stormwater in urban stormwater - Case of combined sewers. J. Gasperi, S. Zgheib, M. Cladière, V. Rocher, R. Moilleron, G. Chebbo. Water research, special issue on urban stormwater 2011International audienceThis study has evaluated the quality of combined sewer overflows (CSO) in an urban watershed, such as Paris, by providing accurate data on the occurrence of priority pollutants (PPs) and additional substances, as well as on the significance of their concentrations in comparison with wastewater and stormwater. Of the 88 substances monitored, 49 PPs were detected, with most of these also being frequently encountered in wastewater and stormwater, thus confirming their ubiquity in urban settings. For the majority of organic substances, concentrations range between 0.01 and 1 µg.l-1, while metals tend to display concentrations above 10 µg.l-1. Despite this ubiquity, CSO, wastewater and stormwater feature a number of differences in both their concentration ranges and pollutant patterns. For most hydrophobic organic pollutants and some particulate-bound metals, CSOs exhibit higher concentrations than those found in stormwater and wastewater, due to the contribution of in-sewer deposit erosion. For pesticides and Zn, CSOs have shown concentrations close to those of stormwater, suggesting runoff as the major contributor, while wastewater appears to be the main source of volatile organic compounds. Surprisingly, similar concentration ranges have been found for DEHP and tributyltin compounds in CSOs, wastewater and stormwater. The last section of this article identifies substances for which CSO discharges might constitute a major risk of exceeding Environmental Quality Standards in receiving waters and moreover indicates a significant risk for PAHs, tributyltin compounds and chloroalkanes. The data generated during this survey can subsequently be used to identify PPs of potential significance that merit further investigation

Particulate pollution and stone deterioration

The soiling and damage of building surfaces may be enhanced by particulate air pollution, reducing the aesthetic value and lifetimes of historic buildings and monuments. This thesis focuses on the deposition of atmospheric particulate material to building surfaces and identifies potential sources of this material. It also identifies environmental factors influencing two deterioration effects: surface soiling and black crust growth. Two soiling models have been compared to assess their effectiveness in predicting the soiling rates of two materials - stone and wood - in five cities in Europe. An exponential decay model was found to describe the reduction of reflectance well at two of these sites, while a square root relationship is not as effective. Different measures of weekly particulate concentration were not statistically related to soiling rate, whereas S02, rainfall, and temperature were statistically related to reflectance loss over time. Wind speed and solar insolation were also indicated to influence soiling rates. Concentrations of total suspended particulate (TSP), particulate elemental carbon (PEC), total organic carbon (TOC) and thirty-nine particulate-associated hydrocarbons were measured in airborne particles at two sites in London, for one year. These hydrocarbons were also measured in black crusts from St Paul's Cathedral to relate atmospheric and deposited material, and to identify potential sources of the deposited particulate matter. Detailed scanning electron microscope-energy dispersive X-ray (SEM-EDX) analysis of black crust \ similarly indicated potential sources of these deposition layers. Analysis revealed the complex structure of these crusts, comprising gypsum "growth stems ", calcite and large numbers of particles mainly originating from oil combustion. Hydrocarbon analysis supported the fact that oil combustion - probably at Bank power station - was the dominant source of this deposited layer. Other particle morphologies were commonly found, such as those typical of coal combustion and diesel engine exhaust. Metals analyses also indicated other possible sources such as vehicles

Freshwater umbrella - the effects of nitrogen deposition & climate change on freshwaters in the UK

In upland areas of the UK located away from direct human disturbance through agriculture, industrial activities and urban pollution, atmospheric pollution poses one of the major threats to the chemical and biological quality of lakes and streams. One of the most important groups of pollutants is nitrogen (N) compounds, including oxidised forms of N called NOx, generated mainly by fossil fuel combustion especially in motor vehicles, and reduced forms of N (ammonia gas or dissolved ammonium compounds) generated mainly from agricultural activities and livestock. These nitrogen compounds may dissolve in rain or soilwater to form acids, or may be taken up as nutrients by plants and soil microbes in upland catchments, and then subsequently released in acid form associated with nitrate leaching at a later date. It is well established that nitrate leaching contributes to acidification of upland waters, with damage to aquatic ecosystems including plants, invertebrates and fish. However it has recently been suggested that nitrate leaching may also be associated with nutrient enrichment of upland waters that contain biological communities adapted to very low nutrient levels

Occurrence and distribution of PAHs in rainwater and urban runoff

Master'sMASTER OF ENGINEERIN

Sediment Deposition Characteristics in Shallow Saturation Excess Overland Flow with Application to Bioswales and Construction of a Novel Bioswale Design for Improved Contaminant Removal from Stormwater

Over the last two decades, urban stormwater management has grown to include green infrastructure, such as bioswales. These systems were primarily designed to mitigate hydraulic peaking during rainstorms but were also found to remove particulate and dissolved contaminants. However, little is known about the fate of these particulate contaminants after depositing in bioswales. To better understand how the bed slope angle affects the deposition characteristics at a field scale, a two-foot-long flume was filled with soil from the OSU-Benton County Green Stormwater Infrastructure Research (OGSIR) facility. A fluorescent, paramagnetic sediment tracer was used to mimic silt sized particles carried by stormwater flows. A custom photographic hood with a specialized lens was used to image the flume surface after subsequent pulses of tracer slurry. The resulting images were analyzed to calculate the sediment trapping efficiency using the mean fluorescence intensity as a proxy for tracer mass. The sediment trapping efficiency estimates the amount of tracer that will be captured on the soil surface, thus removing particulate contaminants from the water. Samples of the flume effluent were collected for total suspended solids analysis to provide an approximate mass balance of deposited tracer with each slurry pulse. The bed slopes angles investigated were two, three, and four degrees. The experimental sediment trapping efficiencies were found to decrease with increasing bed slope angle, which indicates soils at greater bed slopes will be less capable of retaining particulate-associated contaminants. These results were also compared with two mathematical models from the literature. While previous studies have shown that bioswales are also able to remove dissolved contaminants, there is great interest in improving the removal efficiencies, especially for heavy metals. One approach is to add commercial sorbents, which can have higher trapping affinities for a variety of contaminants. To investigate the impact of adding sorbents, a new bioswale design was created to mimic a treatment train with a traditional bioswale followed by two sets of sorbents: biochar and RemBind®. This new design utilizes the pre-existing OGSIR infrastructure, and its performance will serve as a comparison to the other traditional bioswales at the facility. The design, construction, and future sampling efforts are discussed to showcase the potential treatment performance improvement using this new treatment train system