Progress 01/01/10 to 12/31/10
Outputs
OUTPUTS: The results of this study were presented at a regional conference by the collaborators. One journal article is published and another is being drafted. One set of experiments, sorption of phenanthrene on soils, is now a standard laboratory session in an undergraduate course (environmental analytical chemistry) offered by the environmental science program of Rutgers. The results of this study were also used the Chinese collaborators in water quality modeling of agricultural activity related nonpoint source pollutants in South China. PARTICIPANTS: PI: Dr. Weilin Huang; Collaborators (2): Dr. Chen Yang, School of Environmental Science and Engineering, South China University of Technology, University Town, Guangzhou, China; Dr. Baohua Xiao, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang, China TARGET AUDIENCES: Undergraduate students and graduate students at Rutgers University; Research scientists and water quality experts in New Jersey and South China PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
One of the goals of this study was to investigate the effects of both concentration levels and loading sequence or contamination history of each pollutant on the equilibrium sorption of mixed organic pollutants on soils. We measured binary sorption equilibria for a soil using ten concentration levels for both phenanthrene and naphthalene. Both solutes were either simultaneously loaded or sequentially loaded (i.e., the second sorbate was loaded after the sorption of the first sorbate had attained equilibrium) on soil. The results showed different competitive sorption equilibria between phenanthrene and naphthalene. In the presence of phenanthrene and regardless of loading sequence, naphthalene exhibited consistently lower sorption capacities and the ideal adsorbed solution theory (IAST) slightly underestimates the naphthalene sorption equilibria. Conversely, the sorption equilibria of phenanthrene in the presence of naphthalene depended upon the loading sequence of the two sorbates on the soil. Little competition from naphthalene on the sorption equilibria of phenanthrene was observed when phenanthrene was loaded either simultaneously with or sequentially after naphthalene, but appreciable competition from naphthalene was observed when the soil had been pre-contaminated with phenanthrene. IAST slightly underestimates the phenanthrene sorption equilibria observed in the latter system, but it cannot estimate the phenanthrene sorption equilibria in the former two systems. We proposed that adsorption on internal surfaces of ink-bottle shaped pores within relatively flexible sorbent matrix may have caused the competitive sorption phenomena observed in this study. It appears that the different abilities of phenanthrene and naphthalene to modify, and to be sorbed by, the micropores of the soil result in significant differences of their competitive sorption equilibria shown in this study. The creation of tenant pores by naphthalene for accommodating phenanthrene violates the basis of IAST, causing the failure of IAST prediction on phenanthrene sorption in these two experimental systems. The study suggests that contamination history may have strong influence on the binding and hence transport of organic pollutant mixtures in soils.
Publications
- Xiao, B.; Huang, W. (2011) The Equilibria of Bisolute Sorption on Soil. Chemosphere. (in press)
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Progress 06/01/04 to 05/31/10
Outputs
OUTPUTS: The results of this study were presented in 2011 at a regional conference by the collaborators. One journal article is published in Chemosphere in 2011 and another is being drafted and will be published in 2012. One set of experiments, sorption of phenanthrene on soils, is now a standard laboratory session in an undergraduate course (environmental analytical chemistry) offered by the environmental science program of Rutgers. The results of this study were also used by the Chinese collaborators in water quality modeling of agricultural activity related nonpoint source pollutants in South China. PARTICIPANTS: PI: Dr. Weilin Huang; Collaborators (2): Dr. Chen Yang, School of Environmental Science and Engineering, South China University of Technology, University Town, Guangzhou, China; Dr. Baohua Xiao, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang, China TARGET AUDIENCES: Undergraduate students and graduate students at Rutgers University; Research scientists and water quality experts in New Jersey and South China PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
In 2011, we studied the competitive sorption between tylison (an antibiotic compound with positive charge at neutral pH conditions) and phenanthrene. The purpose of the study was to quantify the effect of coexisting emerging antibiotic chemical (tylison) and traditional organic pollutant (nonionizable less polar petroleum related chemical) on the sorptive distribution of antibiotics between soils and water. Two clay minerals, kaolinite and montmorillonite, were used in this study. The results indicated that the equilibrium sorption of tylison (antibiotics) was variously affected by coexisting phenanthrene (petroleum chemical). At low background electrolyte concentrations (at the level close to freshwater), the presence of phenanthrene enhanced the sorption of tylison while opposite phenomenon was observed at high background electrolyte concentrations (at the levels close to estuary and marine water). The equilibrium data are still under reduction. We plan to seek appropriate scientific interpretation via ion exchange and hydrophobic interaction mechanisms and hope to propose certain model for predicting the complex sorption phenomena found in aquatic systems contaminated with mixed organic pollutants. A manuscript is expected to be drafted in 2012, and the data will be presented in regional or international conferences. The finding of this study is very important for predicting the environmental behavior of emerging pollutants in the presence of petroleum related organic pollutants.
Publications
- No publications reported this period
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Progress 01/01/09 to 12/31/09
Outputs
OUTPUTS: We characterized dissolved organic matter and kerogen materials with different physical and chemical methods. We used differnt fractions of organic matter isolated from a soil and model kerogen and black carbon materials as the sorbents for studying equilibrium sorption of different PAHs. The results were presented orally in an international conference. four manuscripts were drafted based on the data, among which three were published in 2009. PARTICIPANTS: Dr. Hualin Chen, Associate Professor, School of Environmental and Biological Sciences, Wenzhou University, Wenzhou, Zhejiang, China. Dr. Chen Yang, Associate Professor, College of Environmental Science and Engineering, South China University of Technology, Guangzhou, China. Dr. Baohua Xiao, Professor. Institute of Geochemistry, Chinese Academy of Sciences, Guiyang, China TARGET AUDIENCES: Not relevant to this project. PROJECT MODIFICATIONS: Not relevant to this project.
Impacts
The objectives of this study were to elucidate the chemical and structural properties of organic matter in both soil solution and soil particles. Dissolved organic matter (DOM) derived from aerobic decay of rice straw was used as model DOM. The obtained DOMs at different decay times were fractionated into four fractions: hydrophilic matter (HIM), acid insoluble matter (AIM), hydrophobic acid (HOA), and hydrophobic neutral (HON) fraction. The structural and chemical properties of the bulk DOMs and their fractions were quantified and characterized (see Chen et al., 2009). Their impact on sorption of pyrene on soil were examined using a batch reactor systems (manuscript was accepted for publication in Environmental Toxicology and Chemistry). The results indicated that among the four DOM fractions, HOA, HON and AIM significantly lowered the pyrene sorption coefficients but HIM had little or no effect on the pyrene sorption by the soil. It appears that less polar AIM and HON had stronger binding affinities for pyrene in water, hence reducing the sorption coefficient for the soil, but more polar and less aromatic HIM had much weaker binding affinity for pyrene in water, causing little or no effect on the pyrene sorption by the soil. The study showed that rice straw derived DOM may enhance desorption and transport of organic pollutants in soil-water systems and that the currently-adopted straw disposal in farm fields should be reevaluated on a risk-benefit basis. In two separate tests, we systematically characterized model kerogen materials and quantified sorption of phenanthrene and pyrene on the kerogens having different properties and diagenetic histories. The results are presented in two papers recently published in Environmental Toxicology and Chemistry.
Publications
- Yang, C.; Yu, Z.; Xiao, B.; Huang, W.; Fu, J.; Dang, Z. (2009) Impact of kerogen heterogeneity on sorption of organic pollutants. 2. Sorption equilibria. Environmental Toxicology and Chemistry, 28(8): 1592-1598.
- Yang, C.; Huang, W.; Fu, J.; Dang, Z. (2009) Impact of kerogen heterogeneity on sorption of organic pollutants. 1. Sorbent characterization. Environmental Toxicology and Chemistry, 28(8): 1585-1591.
- Chen H.; Zhou J.; Huang W.; Yu W.; Wan Z. (2009) Biodegradability of dissolved organic matter derived from rice straw. Soil Science, 174: 143-150.
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Progress 01/01/08 to 12/31/08
Outputs
OUTPUTS: Over the past 12 months, we have collected experimental data indicating that strong effects of loading sequence of coexisting sorbates on the sorption equilibrium of each sorbate on soils. In this recent study, phenanthrene and naphthalene were used as the probe solutes. Competitive sorption was examined by loading these two chemicals on soils in three different sequences; i.e., phenanthrene was introduced to the soil after naphthalene had reached sorption equilibrium in the system, or vise versa, or both sorbates were introduced simultaneously to the system. The results showed that the three sorption isotherms obtained for the three bisolute systems are different. This strong impact of pollution history on sorption equilibrium of organic pollutants may result from slowed diffusion and entrapment of the preceding sorbate within soil organic matrix that causes less favored interaction of the succeeding sorbate with the soil. We are currently drafting the manuscript for publication. PARTICIPANTS: Dr. Baohua Xiao, a postdoc of our research group, has worked on this project for 3 months. Ms. Il Kim, and Mr. Yingjun Ma, two PhD graduate students, have worked on this project for three months each. TARGET AUDIENCES: Nothing significant to report during this reporting period. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
The current finding has significant impact on prediction of organic pollutants in historically contaminated aquatic systems. Our research group is currently working with Philadelphia Water Department on fate of current contaminants in Philadelphia watersheds. It is known that the sediments in the streams and rivers of the city of Philadelphia have been variously contaminated. When pollutants such as PCBs and PAHs are newly introduced to the surface water, the interactions of these incoming pollutants with sediments may be less favored due to preoccupation of old pollutants on active sites within pore structures of sediments. This can result in greater bioavailability and mobility of the incoming pollutants, a phenomenon that cannot be predicted with current theories.
Publications
- No publications reported this period
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Progress 01/01/07 to 12/31/07
Outputs
OUTPUTS: continuously collecting data in the laboratory; presenting results at national and international conferences; presenting seminars in universities. Miss Samriti Sharma sucessfully defended her thesis in the summer of 2007 and received her PhD degree in Environmental Sciences from Rutgers University.
PARTICIPANTS: PhD Graduate students: Samriti Sharma, Il Kim.
PROJECT MODIFICATIONS: None
Impacts
Our results have drawn attention from Phildalphia Water Department who has provided us a four-year grant to study the fate and transport of mixed organic pollutants in urban watersheds.
Publications
- Kim, I.; Yu, Z.; Xiao, B.; Huang, W. (2007) Sorption of male hormones on soils and sediments. Environmental Toxicology and Chemistry. 26(2): 264-270.
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Progress 01/01/06 to 12/31/06
Outputs
Over the past 12 months we have focused on studies of different types of soil organic matter in the sorption of atrazine and other organic pollutants by soils. We found that the purified particulate organic matter isolated from soils has much greater sorption capacities for organic pollutants, but the same particulate organic matter may exhibit much lower sorption capacities when it is associated with soil aggregates. We are currently conducting experiments to characterize the aggregation structure and its effect on sorption of pesticide mixtures by soil particulate organic matter.
Impacts
The study indicated that contaminant mixtures may compete with each other for interaction with soils. This competitive behavior may affect the fate and transport of individual organic pollutants in the environment.
Publications
- Liang, C.; Dang, Z.; Xiao, B.; Huang, W.; Liu, L. (2006) Equilibrium sorption of phenanthrene by soil humic acids. Chemosphere 63(11): 1961-1968.
- Yu, Z.; Huang, W.; Song, J.; Qian, Y.; Peng, P. (2006) Sorption of organic pollutants by pristine marine sediments: The role of kerogen and black carbon. Chemosphere. 65(11): 2493-2501.
- Pignatello, J.J.; Lu, Y.; LeBoeuf, E.J.; Huang, W.; Song, J.; Xing, B. (2006) Nonlinear and competitive equilibrium sorption of apolar organic compounds in black carbon-free natural organic substances. Journal of Environmental Quality. 35(3): 1049-1059.
- Yu, Z; Sharma, S.; Huang, W. (2006) Differential roles of humic acid and particulate organic matter in the equilibrium sorption of atrazine by soils. Environmental Toxicology and Chemistry. 25(8): 1975-1983.
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Progress 01/01/05 to 12/31/05
Outputs
Over the past 12 months, we have examined competitive sorption of organic pollutant mixtures on soils. Two sets of contaminants used in this study were phenanthrene/naphthalene and 17alpha-estradiol/phenanthrene or naphthalene. One paper was publilshed in Environmental Science and Technology and the other manuscript is being drafted. Steroid hormones such as 17alpha-ethinyl estradiol (EE2) have been frequently detected at various levels in surface waters downstream of many municipal wastewater treatment facilities. Their fate, transport, and environmental risk are currently not well characterized. This study examined the competitive sorption between EE2 and two aromatic hydrocarbon compounds, phenanthrene and naphthalene, by three sediments. The sorption isotherms of phenanthrene and naphthalene were measured at room temperature using a batch technique with initial aqueous concentrations (Co) of EE2 at 0, 100, 500, and 2000 ug/L. Competitive sorption varied between
EE2 and phenanthrene or naphthalene on the sediments. The linearity of the naphthalene sorption isotherm was found to increase as a function of the cosorbate EE2 concentration from 0 to 2000 ug/L. The single-point naphthalene KD value at equilibrium aqueous-phase naphthalene concentration (Ce) of 25 ug/L was reduced by 19-26% and 27-48% at Co (EE2) 100 and 500 ug/L, respectively. The sorption of phenanthrene at its low Ce range was similarly affected by EE2, but to a much less extent, possibly because phenanthrene is more hydrophobic than EE2. At high phenanthrene Ce, no measurable change was observed even at Co (EE2) 2000 ug/L. While the effect of naphthalene on EE2 sorption was insignificant, the competitive effect on the sorption of EE2 by phenanthrene was very significant at low EE2 concentrations. The measured single-point EE2 KD values decreased as much as 35% as the phenanthrene Ce increases from below 10 ug/L to slightly above 100 ug/L. This study suggests that the fate and
transport of emerging pollutants such as EE2 could be affected in the presence of more hydrophobic pollutants in aquatic systems.
Impacts
The study indicated that contaminant mixtures may compete with each other for interaction with soils. This competitive behavior may affect the fate and transport of individual organic pollutants in the environment.
Publications
- Yu, Z.; Huang, W. (2005) Competitive sorption between 17alpha-ethinyl estradiol and naphthalene / phenanthrene by sediments. Environ. Sci. Technol. 39: 4878-4885.
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Progress 01/01/04 to 12/31/04
Outputs
We have started the project since last summer (July 2004). We are currently measuring sorption of pesticide mixtures on soils collected from Michigan and Florida. We will have our first set of data by the summer of 2005 and will report the results next year.
Impacts
The results of this study will elucidate the mechanisms for environmental fate of mixed organic pesticides in soils.
Publications
- No publications reported this period
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