Limited-Access Bioremediation in a Factory Setting

A factory in New Hampshire had a volatile organic compound (VOC) release detected in a storm-water outfall pipe. Hydrogen Release Compound (HRC) injection was determined to be the best remedial solution. Tight soils, shallow water table, access limitations, and pending property sale complicated remediation. Groundwater was directly below the floor slab. The plume was centered on the storm-water drain which carries runoff from the upgradient parking lot under the building. The VOCs are believed to have entered the subsurface in the central area of the building through spillage; the storm drain system was a preferential pathway. The groundwater contamination was addressed through bioremediation using HRC. Application required many injection points and applications, due to the low permeability of the soil. Due to interference with operations and property sale, repeated openings of the floor for injections using a drill rig were not feasible. Permanent injection points were installed, but would not be accessible for direct injection. Therefore, a trench was cut into the concrete floor slab between each point and the wall. Piping ran from the injection point to the wall, terminating at a standpipe with a quick-connect fitting. Each trench was then fillled with concrete to restore the floor slab. Since starting HRC treatment, VOC levels at the outfall have dropped to below the state regulatory standard. One well had levels of 1800 ug/L and 1200 ug/L of Cis-1,2 Dichloroethene and Vinyl Chloride in April, 2008. By January, 2009, both were below MCLs. Site closure is expected to be completed in a reasonable timeframe. The treatment has not interfered with Site activities or with sale of the Site

Limited-Access Bioremediation in a Factory Setting

A factory in New Hampshire had a volatile organic compound (VOC) release detected in a storm-water outfall pipe. Hydrogen Release Compound (HRC) injection was determined to be the best remedial solution. Tight soils, shallow water table, access limitations, and pending property sale complicated remediation. Groundwater was directly below the floor slab. The plume was centered on the storm-water drain which carries runoff from the upgradient parking lot under the building. The VOCs are believed to have entered the subsurface in the central area of the building through spillage; the storm drain system was a preferential pathway. The groundwater contamination was addressed through bioremediation using HRC. Application required many injection points and applications, due to the low permeability of the soil. Due to interference with operations and property sale, repeated openings of the floor for injections using a drill rig were not feasible. Permanent injection points were installed, but would not be accessible for direct injection. Therefore, a trench was cut into the concrete floor slab between each point and the wall. Piping ran from the injection point to the wall, terminating at a standpipe with a quick-connect fitting. Each trench was then fillled with concrete to restore the floor slab. Since starting HRC treatment, VOC levels at the outfall have dropped to below the state regulatory standard. One well had levels of 1800 ug/L and 1200 ug/L of Cis-1,2 Dichloroethene and Vinyl Chloride in April, 2008. By January, 2009, both were below MCLs. Site closure is expected to be completed in a reasonable timeframe. The treatment has not interfered with Site activities or with sale of the Site

Effects of age of acquisition on brain activation during Chinese character recognition

The age of acquisition of a word (AoA) has a specific effect on brain activation during word identification in English and German. However, the neural locus of AoA effects differs across studies. According to Hernandez and Fiebach [Hernandez, A., & Fiebach, C. (2006). The brain bases of reading late-learned words: Evidence from functional MRI. Visual Cognition, 13(8), 1027¿1043], the effects of AoA on brain activation depend on the predictability of the connections between input (orthography) and output (phonology) in a lexical network. We tested this hypothesis by examining AoA effects in a non-alphabetic script with relatively arbitrary mappings between orthography and phonology¿Chinese. Our results showed that the effects of AoA in Chinese speakers are located in brain regions that are spatially distinctive including the bilateral middle temporal gyrus and the left inferior parietal cortex. An additional finding was that word frequency had an independent effect on brain activation in the right middle occipital gyrus only. We conclude that spatially distinctive effects of AoA on neural activity depend on the predictability of the mappings between orthography and phonology and reflect a division of labour towards greater lexical-semantic retrieval in non-alphabetic scripts