Professor of Civil Engineering

Facilities

Research within the Blatchley group is conducted in the Environmental Engineering Laboratories within the School of Civil Engineering at Purdue University. These labs include an extensive array of analytical capabilities for characterization and quantification of organic and inorganic constituents in water and air. Analytical instrumentation within these labs include: several mass spectrometers (MS), with gas chromatographic (GC), liquid chromatographic (LC), and membrane interfaces; UV and fluorescence spectroscopic capabilities; metals analysis by inductively-coupled plasma atomic emission spectrometry (ICP-AES), atomic absorption spectrometry (AA), and ion chromatography (IC). The lab is also equipped with many conventional GC and LC instruments, with a variety of detector capabilities.

Excimer Lamp Reactor

FWater treatment research to inactivate microorganisms. View movie of reactor

 

In addition, the Environmental Engineering Laboratories are equipped to conduct a broad range of microbiological assays, including conventional aerobic incubation and respiration, as well as capabilities to conduct experiments with anaerobic cultures. Several biological safety cabinets are also available for experiments involving pure microbial cultures, or microorganisms that express pathogenicity toward humans.

Research specific to the Blatchley group employs a number of scientific and analytical instruments that have been designed and built to facilitate experiments with germicidal UV radiation and halogen-based disinfectants.

Facilities for Excimer Lamp Reactor

This water treatment research inactivates microorganisims as the water flows through UV rays.

 

 

Facilities for Photochemical Experiments

Much of the experimentation with ultraviolet (UV) radiation within the Blatchley group employs flat-plate collimated beam systems. These devices, which were developed by Professor Blatchley in the mid-1990s, provide an extremely uniform, collimated beam of radiation from essentially any conventional source of electromagnetic radiation, but are particularly well-suited for applications involving UV or visible radiation.

Flat-plate collimated beam system
 

Flat-plate collimated beam system used for delivery of a beam of collimated electromagnetic radiation for use in photochemical experiments. This particular system is based on two conventional low-pressure Hg lamps, with a (nearly) monochromatic output at a characteristic wavelength of 254 nm.

Their internal geometry guarantees beam uniformity, which aids subsequent interpretation of experimental data. Flat-plate collimators are available within the Blatchley lab to provide essentially monochromatic radiation at characteristic wavelengths of 222 nm, 254 nm, and 282 nm; these devices are based on a KrCl excimer lamp, a low-pressure Hg lamp, and a XeBr excimer lamp as radiation sources, respectively. An image of one such device is provided below. These devices are available as custom orders directly from Professor Blatchley for laboratories that have an interest in conducting photochemical experiments.

A polychromatic collimated beam system has also been constructed for use in photochemical experiments. This device is built around a medium-pressure Hg lamp. Experiments can be conducted using the polychromatic output from this system; however, interpretation of these experiments is complicated by the polychromatic output of the system. This system was designed for use with narrow band-pass optical filters to simplify the output spectrum of the system, as well as the interpretation of data from experiments involving it.

Radiation delivery can be quantified using any of several calibrated radiometers, as well as a fiber-optic spectrometer system. Analytical instrumentation for characterization of organic and inorganic constituents in aqueous solution (see description above) allows application of chemical actinometry as a primary standard in photochemical experiments. In conjunction with researchers in the group of Professor Donald E. Bergstrom (), the Blatchley group recently reported on the development of a new actinometer system based on the chemical (E)-5-[2-(methoxycarbonyl)ethenyl]cytidine (Shen et al., [2005], Environmental Science & Technology, 39, 10, 3826-3832).

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