Kalliat T. Valsaraj
Charles & Hilda Roddey Distinguished Professor of Chemical Engineering
Ike East Professor of Chemical Engineering
Room 3314R Patrick F. Taylor Hall
Louisiana State University
Baton Rouge, LA 70803
Phone: (225) 578-6522
PhD, Vanderbilt University, 1983
MSc, Indian Institute of Technology, Madras, 1980
BSc, University of Calicut, India, 1978
- Environmental Chemical Engineering
- Atmospheric Chemistry
- Wastewater Treatment
Research in the Valsaraj group involves several areas of environmental, chemical and materials engineering.
Chemistry of aqueous surfaces in the atmospheric context
Aqueous surfaces such as thin water films on aerosols, water droplets (fog, mist, dew, rain) and frozen precipitation (snow, ice) exist in the atmosphere. In most cases they have very high surface area to bulk volume ratio. A number of gas phase atmospheric trace gases (e.g., semi-volatile and volatile hydrophobic organic compounds) adsorb and react with gas phase oxidants (hydroxyl radical, singlet oxygen, ozone, nitrate radical, etc.) at these surfaces. These heterogeneous, multiphase processes are important in tropospheric chemistry. Our group uses a variety of techniques to probe the heterogeneous chemistry of several polycyclic aromatic hydrocarbons (PAH) on aqueous surfaces. These include falling droplet reactor and thin film flow reactors. We also collaborate with the groups of Professor Bin Chen (LSU Chemistry) and Prof Collin Wick (Louisiana Tech) on Molecular Dynamics and Monte Carlo simulations of PAHs at the air-water interfaces.
Fog processing of organic compounds in the near-surface atmosphere
Fog is a near surface cloud with water droplets condensed on sub micron particles. The typical size of fog droplets are 1 to 50 microns and are therefore high surface area. Sunlight induced photochemistry in these systems can help to process most inorganic and organic species via oxidative reactions to form secondary organic aerosol precursors. It is also well known that a large fraction of organic carbon in fog is not spectated. To understand these problems, our group is engaged in both field collection and analysis of fog waters. We use active cloud water collectors. We then use a variety of analysis techniques (GC/MS, HPLC/MS, ICP/MS) to understand the composition of fog waters.
Aerosol transport of oil and dispersant components from a deep sea oil spill
During the Deep Water Horizon Spill a substantial amount of crude oil, as well as chemicals (dispersant) to combat the spill were set free in the Gulf of Mexico. This scenario can repeat in future accidents as well. This research investigates the contribution of the aerosolization of semi-volatile components of crude oil via bursting bubbles on the sea surface. Preliminary experiments from our laboratory have lent credible evidence for this process. Ejection rates of alkanes (C>15) from collected oil mousse samples and model mixtures are being assessed in a small-scale bubble reactor via GC-MS in the absence and the presence of dispersants and pure surfactants. The generated particulate matter are being characterized for its organic and inorganic constituents with SEM, ICP-MS, GC-MS and X-ray microscopy.
Photochemical reactors for waste treatment
Our on-going research in this area involves the use of highly ordered three-dimensional structures such as photonic crystals of titania for photocatalytic applications. These photonic crystals can influence electromagnetic waves in a manner similar to electrons in semiconductors. Fabricating them on optical fibers and using them in a monolith configuration is a vast improvement in current designs of photochemical reactors.
A E Heath, F Ehrenhauser, KT Valsaraj, “Determination of aldehydes and acetone in fog water samples via online concentration and HPLC,” Journal of Atmospheric Chemistry 72: 165-182 (2015). https://dx.doi.org/10.1007/s10874-015-9312-6
A Heath, KT Valsaraj, “Effects of temperature, oxygen level, ionic strength, and pH on the reaction of benzene with hydroxyl radicals at the air-water interface in comparison to the bulk aqueous phase,” Journal of Physical Chemistry, Part A 119(31): 8527-8536 (2015). https://dx.doi.org/10.1021/acs.jpca.5b05152
C C Stevens, LJ Thibodeaux, EB Overton, KT Valsaraj, K Nadakumar, A Rao, ND Walker, “Sea surface oil slick light component vaporization and heavy residue sinking: Binary mixture and experimental proof of concept,” Environmental Engineering Science 32(8): 694-702 (2015). https://dx.doi.org/10.1089/ees.2015.0022
Marcia RM Chaves, KT Valsaraj, RP Gambrell, RD DeLaune, PM Buchler, “Mackinawite modified with L-cysteine as an active material in in-situ sediment capping for mercury containment,” Environmental Research Science & Technology 1(1): 16-29 (2016).
Z Z Zhang, P Avij, TP Liyana-Arachchi, M Perkins, J Field, KT Valsaraj, FR Hung, “A combined experimental and molecular simulation investigation of the individual effects of Corexit surfactants on the aerosolization of oil spill matter,” Journal of Physical Chemistry, Part A 120(30): 6048-58 (2016). https://dx.doi.org/10.1021/acs.jpca.6b04988
C Stevens, LJ Thibodeaux, E Overton, K Valsaraj, N Walker, “Dissolution and heavy residue sinking of subsurface oil droplets: Binary component mixture dissolution theory and model-oil experiments,” Journal of Environmental Engineering 143(10):04017067 (2017). https://dx.doi.org/10.1061/(ASCE)EE.1943-7870.0001242
S Raja, S Chandrasekaran, L Lin, X Xia, P Hopke, KT Valsaraj, “Analysis of beta attenuation monitor filter rolls for particulate matter speciation,” Aerosol and Air Quality Research 17(1): 14-23 (2017). https://dx.doi.org/10.4209/aaqr.2016.03.0122
A A Heath, K T Valsaraj, “An experimental study of the atmospheric oxidation of a biogenic organic compound (methyl jasmonate) in a thin water film as in fog or aerosols,” Open Journal of Air Pollution 6: 44-51 (2017). https://dx.doi.org/10.4236/ojap.2017.62004
Z Zhang, A heath, K T Valsaraj, W L Ebert, T Yao, J Lian, J Wang, “Mechanisms of iodide release from iodoapatite in aqueous solution,” RSC Advances 8: 3951-57 (2018). https://dx.doi.org/doi:10.1039/c7ra11049a
A Mass, KT Valsaraj, FK Alexander, A Cooper, “Building an innovation ecosystem: Proof-of-concept programs to help change culture,” Technology and Innovation, Journal of the National Academy of Inventors (Submitted, 2018).
H Vempati, M Vaitilingom, Z Zhang, TP Liyana-Arachchi, CS Stevens, FR Hung, KT Valsaraj, “Physico-chemical properties of green leaf volatiles for ascertaining atmospheric fate and transport in fog,” Advances in Environmental Research 7(2): 139-159 (2018). https://doi.org/10.12989/aer.2018.7.2.139
J G Lee, L L Larive, K T Valsaraj, B Bharti, “Binding of lignin nanoparticles at the oil-water interface: An eco-friendly alternative to oil spill recovery,” ACS Applied Materials & Interfaces 10: 43282-43289 (2018). https://doi.org/10.1021/acsami.8b17748
Z Zhang, WL Ebert, T Yao, J Lian, KT Valsaraj, J Wang, “Chemical durability of iodoapatite in aqueous solution,” ACS Earth and Space Chemistry (2018).
K T Valsaraj, K E Thompson, D D Reible and L Yan: Environmental Remediation of Dense Organic Contaminants using Polyaphron Treatments, U.S. Patent # 6,602,024 issued August 5, 2003.
L J Thibodeaux, D P Harrison and K T Valsaraj: Cascade Cross flow Tower, U.S. Statutory Invention Registration, H 1206, issued July 6, 1993.