We have constructed a low cost, portable, battery-powered quadrupole mass spectrometer for use in the analysis of gaseous, liquid or solid field samples. The system may be configured for continuous sampling of ambient gas samples, or for the analysis of small solid, liquid or gas samples in sealed glass vials. The system is capable of measuring partial pressures down to the 10-10 Torr range, and may be operated on battery power for several hours in a field deployment. In this paper, we present information on the design and testing of the instrument, as well as data taken on chlorinated hydrocarbons and other contaminants in water.

Magnetotactic bacteria are a unique species of bacteria, commonly recognized by the presence of magnetic particles within them. These intracellular, nanosized magnetic particles enable the bacteria to migrate and be manipulated by magnetic force. To date, magnetotactic bacteria have been widely researched and implemented in various biotechnology based applications. In this study, as an extension to its applications, the magnetotactic bacterium, Magnetospirillum magneticum AMB-1, was applied in the microbial recovery of gold from plating waste. M. magneticum AMB-1 successfully precipitated approximately 42% and 100% of gold from growth medium containing 10 μM gold and from a mixture of plating waste/growth medium containing 0.4 μM gold, respectively. These observations and results strongly suggests that an important advancement in biorecovery of rare metals and bioremediation of toxic metals was achieved in which the application of whole cell bacteria, and direct precipitation of metals from plating waste using magnetotactic bacteria was performed for the first time.

New materials, methods, and membranes are being developed for applications in water purification. One of the model systems that can be used for fundamental studies in nanoscale transport phenomena for new membrane technologies are nanocapillary array membranes (NCAMs). Toward developing more efficient membranes for water desalination, parameters such as the concentration polarization region which are influenced by the unstirred layers, surface properties (e.g., surface charge and surface energy) of the nanocapillaries, and the electric double layer (EDL) which mediates transport across NCAMs must be better understood. In this paper, a series of parametric experiments that were conducted to better understand the relative importance of unstirred layers with respect to the transport across nanocapillaries are described. Bulk salt concentration and potential drop across the NCAMs, were varied in a systematic manner to determine the influence EDL thickness and electromigration on transport regimes for ionic permeation across NCAMs. Based on previously developed methodologies, the experiments reported here were conducted in a permeation cell with an NCAM separating two reservoirs containing potassium phosphate buffer with a concentration range from 200 μM-10 mM. Methylene blue (MB) is used as an organic marker and the transport is quantified by tracking MB concentration in each reservoir with UV/VIS spectroscopy.

Molecular recognition capabilities are evoked at artificial materials by the NANOCYTES®-technology of the Fraunhofer IGB, Stuttgart, Germany. The biomimetic nanoparticles described here possess such molecularly recognizing properties. For this purpose they carry molecularly defined binding sites at their surface. In this particular case molecularly imprinted nanospheres (nanoMIPs) were developed for the specific adsorption of micropollutants from hospital waste water. Active pharmaceutical substances and their metabolites which were not decomposed by waste water plants were chosen as model compounds. One of this model compounds is Pentoxifylline. The nanoMIPs are prepared by a miniemulsion polymerization technique, where the monomer, the template, the cross-linker, and the initiator do react in the droplet cavities of the miniemulsion. The reaction to obtain nanoMIP particles is complex, but nevertheless it runs in a single reaction chamber and in a single step chemical process. For synthesis of the polymer system p(methacrylicacid-co-ethylenglycoldimethacrylate), p(meth-acrylicacid-co-methylmethacrylate-co-ethylenglycoldimethacrylate) and p(4-vinylpyridin-co-ethylenglycoldimethacrylate) are used. The technique of miniemulsion polymerization results in particles with a typical size distribution of 50 nm to 500 nm. Additionally, an introduced magnetic core will allow the final separation of the nanoMIPs and more important of the recognized pollutants from (waste) water. We demonstrate that magnetite can be incorporated into the polymer system, and that the template Pentoxifylline does not affect the polymerization process.

A sol-gel derived organosilica material that energetically swells when exposed to organic molecules was tested as a means to extract dissolved organic species from water. Swellable organically modified silica (SOMS) was demonstrated to be effective at removing butanol, methyl t-butyl ether (MTBE), tetrachloroethylene, trichloroethylene, ethanol, and toluene from lab grade water, salt water, and natural waters. Partition coefficients for the absorption of organic species from water by SOMS ranged from 2.8�105 – 1.0�102, and vary depending on polarity of the contaminant, concentration, and the total mass of contaminant absorbed. Absorption of organic species to SOMS appears to be enhanced by matrix expansion of nanometer sized pores leading to non-selective capture of organics beyond what could be attributed to physisorption.