Permeable reactive barrier (PRB) containing zero valent iron (ZVI), plaster and additives to make a porous composite structure, was tested remove an organic nitro compound as model pollutant. An aqueous solution of 4-nitroaniline (PNA) passed through column chemical degradation quantified by UV-Vis spectroscopy. PNA reduced p-phenylenediamine the rate reduction strongly related ZVI amount, poll...

Halting the spread of organic contaminants in subsurface aquifers is a critical environmental problem. We describe a novel "permeable reactive barrier" that results when organophile-solubilizing properties are conferred on siliceous materials by treating them with a cationic polymer and oppositely charged mixed surfactant micelles. Controlled pore glass, quartz sand, and sea sand were treated w...

The permeable reactive barrier (PRB) technology is an in-situ approach for remediating groundwater contamination that combines subsurface fluid flow management with a passive chemical treatment zone. Removal of contaminants from a groundwater plume is achieved by altering chemical conditions in the plume as it moves through the reactive barrier. Because the reactive barrier approach is a passiv...

Assessment of vascularity and blood-tissue barrier was performed by sequential scintigraphy in 43 patients with brain tumours. The blood-tumour barrier was evaluated by use of 99mTc-pertechnetate, and vascularity using 99mTc-labelled red blood cells. Three groups of tumours were found: tumours with low vascularity and permeable barrier, tumours with high vascularity and permeable barrier, and t...

The site BAF-5 is located on the summit of Resolution Island, Nunavut, just southeast of Baffin Island at 61 degrees 35'N and 60 degrees 40'W. The site was part of a North American military defense system established in the 1950s that became heavily contaminated with PCBs during and subsequent, its operational years. Remediation through excavation of the PCB contaminated soil at Resolution Isla...

This study investigates the performance of granular dead anaerobic sludge (GDAS) bio-sorbent as permeable reactive barrier in removing phenol from a simulated contaminated shallow groundwater. Batch tests have been performed to characterize equilibrium sorption properties GDAS and sandy soil phenol-containing aqueous solutions. The results proved that best values operating parameters, which ach...