The concentration of certain toxic organic chemicals in waterway sediments can be reduced by 83 percent using electron beams—the same technology already used to decontaminate mail—scientists from the National Institute of Standards and Technology (NIST) and the University of Maryland will report in the Sept. 1 issue of Environmental Science & Technology. In an additional series of laboratory experiments, the team found that ultraviolet light also can substantially reduce the concentration of these chemicals.
The results are significant because sediments, soupy mixtures of water and particles of various sizes, arenotoriously difficult and expensive to decontaminate. Further, electron beams and ultraviolet light effectively detoxified the banned chemicals known collectively as polychlorinated biphenyls, or PCBs, which can get into the food chain and increase the risk of cancer in humans. Waterways such as the Hudson River have bottom sediments heavily contaminated with PCBs. However, whether electron beams and ultraviolet light are practical decontamination techniques will depend on cost-effectiveness comparisons to existing methods, such as chemical treatment and incineration. In addition, issues such as availability of electron beams will need to be resolved. The scientists used a beam at the University of Maryland for the recent studies.
Electron beams and ultraviolet light remove chlorine ions (charged atoms) from PCBs, which reduces toxic-ity and enhances prospects for biodegradation of the remaining material by living organisms. The scientists evaluated the effectiveness of the treatment methods in removing PCBs from a NIST Standard Reference Material containing sediments with carefully measured amounts of contaminants. Research continues on additives and conditions that might enhance the decontamination processes. The research is funded by NIST, the university, and the Maryland Water Resources Center.
Laura Ost, | NIST
Dispersal of Fish Eggs by Water Birds – Just a Myth?
19.02.2018 | Universität Basel
Removing fossil fuel subsidies will not reduce CO2 emissions as much as hoped
08.02.2018 | International Institute for Applied Systems Analysis (IIASA)
A newly developed laser technology has enabled physicists in the Laboratory for Attosecond Physics (jointly run by LMU Munich and the Max Planck Institute of Quantum Optics) to generate attosecond bursts of high-energy photons of unprecedented intensity. This has made it possible to observe the interaction of multiple photons in a single such pulse with electrons in the inner orbital shell of an atom.
In order to observe the ultrafast electron motion in the inner shells of atoms with short light pulses, the pulses must not only be ultrashort, but very...
A group of researchers led by Andrea Cavalleri at the Max Planck Institute for Structure and Dynamics of Matter (MPSD) in Hamburg has demonstrated a new method enabling precise measurements of the interatomic forces that hold crystalline solids together. The paper Probing the Interatomic Potential of Solids by Strong-Field Nonlinear Phononics, published online in Nature, explains how a terahertz-frequency laser pulse can drive very large deformations of the crystal.
By measuring the highly unusual atomic trajectories under extreme electromagnetic transients, the MPSD group could reconstruct how rigid the atomic bonds are...
Quantum computers may one day solve algorithmic problems which even the biggest supercomputers today can’t manage. But how do you test a quantum computer to...
For the first time, a team of researchers at the Max-Planck Institute (MPI) for Polymer Research in Mainz, Germany, has succeeded in making an integrated circuit (IC) from just a monolayer of a semiconducting polymer via a bottom-up, self-assembly approach.
In the self-assembly process, the semiconducting polymer arranges itself into an ordered monolayer in a transistor. The transistors are binary switches used...
Breakthrough provides a new concept of the design of molecular motors, sensors and electricity generators at nanoscale
Researchers from the Institute of Organic Chemistry and Biochemistry of the CAS (IOCB Prague), Institute of Physics of the CAS (IP CAS) and Palacký University...
15.02.2018 | Event News
13.02.2018 | Event News
12.02.2018 | Event News
23.02.2018 | Physics and Astronomy
23.02.2018 | Health and Medicine
23.02.2018 | Physics and Astronomy