Results from a field trial commissioned for the Australian Department of Defence at the Army Aviation Centre Oakey evaluated the effectiveness of the Surface-Active Foam Fractionation (SAFF) process at removing per-and polyfluoroalkyl substances (PFAS) in groundwater. The study showed that the SAFF process is effective in removing ≥99.5% of the aggregate of perfluorooctane sulfonate (PFOS), perfluorohexane sulfonate (PFHxS), and perfluorooctanoic acid (PFOA) in PFAScontaminated groundwater, and consistently achieved the criteria for these PFAS species prescribed in the Australian PFAS National Environmental Management Plan (HEPA, 2020) water quality specification, and exceeded such by a factor of 3.3 over the 12-month study period. The field trial also demonstrated the sustainability attributes of SAFF since it requires no chemical reagents nor adsorbent media, other than air introduced to the foam fractionation vessels. However, when an anionic exchange (AIX) resin "polisher" was installed downstream of SAFF, all trace detectable PFAS species were removed. In addition, by reducing the PFAS loading, the SAFF process extends the AIX resin lifespan. The field trial demonstrated that the removal (i.e., separation and concentration) extent of PFAS species due to SAFF is closely correlated with the adsorption coefficient of the molecules at the gas-liquid interface. When the reported adsorption coefficient is greater than approximately 1.0 × 10 −6 m, practically all of the PFAS species, including PFOS, PFHxS, and PFOA, were removed by SAFF. Longer-chain PFAS species that benefit from higher adsorption coefficients are easier to remove than shorter-chain species that exhibit lower adsorption coefficient values. It is noted that the presence of dissolved electrolytes arising from the site groundwater being classified as hard is believed to enhance the adsorption coefficients, and so SAFF is likely to become still more effective in brackish, saline, and reverse osmosis reject waters. | INTRODUCTIONThe contamination of groundwaters by per-and polyfluoroalkyl substances (PFAS) has been suggested as a significant global environmental health crisis (Pelch et al., 2019). The epidemiological review of Rappazzo et al. (2017) has reported that PFAS may be associated with various adverse health outcomes in humans including thyroid diseases, testicular and kidney cancers and, in children, delayed onset of puberty. PFAS molecules exhibit environmental persistence due to the strength of their characteristic C-F bonds. There are many general sources of PFAS contamination in groundwater and surface waters arising from the historical use of Class B aqueous film-forming foams (AFFFs) used for firefighting and training purposes, particularly at global defense sites and larger
The molecular regulation of stilbene phytoalexin biosynthesis in developing Vitis vinifera L. grape berries was investigated using a UV induction system. Berries were collected at 1, 5, 10 and 16 weeks post-flowering from the cultivars Shiraz, Semillon, Cabernet Sauvignon and Chardonnay and the skins analysed for resveratrol production following irradiation with UV-C light. The rate and maximal level of resveratrol accumulation increased markedly in berries sampled from 1–5 weeks post-flowering and then dramatically declined in maturing berries sampled from 10–16 weeks post-flowering in all cultivars. In berries sampled at 1 and 5 weeks post-flowering, maximal levels of resveratrol accumulation were recorded at incubation periods of 24 and 48 h respectively whereas maximal resveratrol levels were not recorded in week 16 berry skins until 72 h after UV-treatment. Gene expression analysis indicated that stilbene synthase (STS) mRNA accumulated within 4–8 h of UV treatment in berries sampled at 1 and 5 weeks post-flowering, but did not increase in week 16 berries until 24–48 h following UV-irradiation. Furthermore, the overall level of STS gene expression declined in berries sampled 10–16 weeks post-flowering. The results demonstrate that inducible stilbene accumulation in ripening grape berries is highly regulated at the level of STS gene transcription. This decline in inducible STS gene expression may be a major factor contributing to the increased susceptibility of ripening grape berries to Botrytis cinerea infection.
In 1998 a circle of timber posts within the intertidal zone on the north Norfolk coast was brought to the attention of the Norfolk County Council Archaeological Service. A subsequent programme of archaeological recording and dating revealed that the structure was constructed in the spring or early summer of 2049 BC, during the Early Bronze Age. Because of the perceived threat of damage and erosion from the sea a rescue excavation was undertaken during the summer months of 1999. The structure was entirely excavated, involving the removal of the timbers and a programme of stratigraphic recording and environmental analysis. A survey was also undertaken within the environs of the site which has identified further timber structures dating from the Bronze Age. Detailed examination of the timber from the circle has produced a wealth of unexpected information which has added greatly to our understanding of Early Bronze Age woodworking, organisation of labour and the layout and construction of timber ritual monuments.
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