Expertise:
Dr. Pignatello has expertise in physical organic chemistry; soil chemistry; environmental chemistry and engineering; fate of organic compounds in the environment; and water and soil treatment processes.

Education:
B.A., Chemistry, University of Minnesota, Minneapolis
Ph.D., Chemistry, University of California, Berkeley

Present research:
In general terms, the group’s research interests include interactions of organic compounds with soils and sediments, remediation of contaminated water and soil, and sunlight-driven reactions in the environment. Its research covers both fundamental and applied aspects of these areas, and deals with a diversity of compounds within the categories of legacy pollutants, emerging pollutants such as endocrine disrupting compounds and pharmaceuticals, and nanomaterials. The group uses a variety of physical and chemical techniques, such as gas and liquid chromatography, solid and liquid state NMR spectroscopy, high resolution gas adsorption, diffuse-reflectance FTIR and UV/visible spectroscopies, XRD, HRTEM, SEM, AFM, thermomechanical and thermogravimetric analyses, radioisotope techniques, and computational molecular modeling.

Many of the projects are collaborative with individuals at CAES, Federal research laboratories, American and foreign universities, and private industry. In addition to my position at CAES, I also hold the position of Professor Adjunct of Chemical and Environmental Engineering at Yale University http://seas.yale.edu/departments/chemical-and-environmental-engineering.

Below is a brief description of current projects in the group.

• Adsorption of contaminants to pyrogenic carbons. Pyrogenic carbons include natural chars, biochars, activated carbons, and related models such as graphite, graphene, and carbon nanotubes. The group is investigating novel interactions of organic compounds on their surfaces, including, i) formation of exceptionally strong hydrogen bonds with ionizable contaminants (e.g., carboxylic acids, phenols, sulfonamides); ii) p-p electron donor-acceptor interactions with compounds containing electron-poor aromatic rings; and iii) impacts on adsorption of physical-chemical changes in carbons induced by air oxidation during pyrolysis and after aging in the environment.

• Potential roles for biochar in environmental management. Biochar is the carbonaceous byproduct of anoxic pyrolysis of biomass waste that has potential beneficial applications as a soil amendment in agriculture and environmental remediation, partially as a consequence of its strong adsorptive properties. We are tailoring biochars with superior ability to capture nutrient ions in animal wastes into less leachable forms. We are studying the use of biochar to remediate marine and land spills of crude oil, relying on its efficient absorption of crude and its ability to stimulate microbial activity. And we are investigating the interaction of nitrous oxide with biochar following reports that biochare inhibits emissions of the potent greenhouse and ozone-depleting gas, nitrous oxide, in soil.

• Advanced oxidation processes for treating contaminated water. We are conducting fundamental chemical studies on advanced oxidation processes for ‘deep’ oxidation of organic pollutants that use hydrogen peroxide, peracetic acid, peroxymonosulfate, and peroxydisulfate as the bulk oxidant.  We are designing carbonaceous or inorganic nano-scale catalysts and photocatalyst for peroxides activation. Our emphasis is on the kinetics and mechanisms of these reactions, with special concern for the effects of water chemistry, since many treatable waters contain high levels of dissolved substances.
  
  
• Involvement of Low-Barrier Hydrogen Bonds in Natural Environmental Processes. Hydrogen bonds between weak acid groups with similar pK_a values can be much stronger and shorter than ordinary hydrogen bonds. We are examining whether such bonds play a role in bonding between soil organic matter molecules or strands, between SOM and pyrogenic carbons, and between SOM and natural and anthropogenic inorganic weak acids.

Recent publications available from the author, Joseph.Pignatello@ct.gov, (see http://www.ISIHighlyCited.com for a full list)

• Charge-assisted hydrogen bonding as a cohesive force in soil organic matter: water solubility enhancement by addition of simple carboxylic acids, Ni, Jinzhi and Pignatello, J.J., Environ. Sci.: Processes and Impacts, 2018; DOI: 10.1039/c8em00255j.
• Oxidation of Organic Contaminants by Unactivated Peroxymonosulfate, Yi Yang, Gourab Banerjee, Gary W. Brudvig, Jae-Hong Kim, Joseph J. Pignatello*, Environ. Sci. Technol., 52 (10), 5911–5919 (2018); DOI: 10.1021/acs.est.8b00735.
• Thermal Air Oxidation Changes Surface and Adsorptive Properties of Black Carbon (Char/biochar), Feng Xiao*, Alemayehu H. Bedane, Julia Xiaojun Zhao, Michael D. Mann, Joseph J. Pignatello, Science of The Total Environment, 618, 276-283 (2018).