Behaviour and fate of nine recycled water trace organics during managed aquifer recharge in an aerobic aquifer

The fate of nine trace organic compounds was evaluated during a 12 month large-scale laboratory column experiment. The columns were packed with aquifer sediment and evaluated under natural aerobic and artificial anaerobic geochemical conditions, to assess the potential for natural attenuation of these compounds during aquifer passage associated with managed aquifer recharge (MAR). The nine trace organic compounds were bisphenol A (BPA), 17β-estradiol (E2), 17α-ethynylestradiol (EE2), N-nitrosodimethylamine (NDMA), N-nitrosomorpholine (NMOR), carbamazepine, oxazepam, iohexol and iodipamide. In the loworganic carbon content Spearwood sediment, all trace organicswere non-retardedwith retardation coefficients between 1.0 and 1.2, indicating that these compounds would travel at near groundwater velocities within the aquifer. The natural aerobic geochemical conditions provided a suitable environment for the rapid degradation for BPA, E2, iohexol (half life b1 day). Lag-times for the start of degradation of these compounds ranged from b15 to 30 days. While iodipamide was persistent under aerobic conditions, artificial reductive geochemical conditions promoted via the addition of ethanol, resulted in rapid degradation (half life b1 days). Pharmaceuticals (carbamazepine and oxazepam) and disinfection by-products (NDMA and NMOR) did not degrade under either aerobic or anaerobic aquifer geochemical conditions (half life N50 days). Field-based validation experiments with carbamazepine and oxazepam also showed no degradation. If persistent trace organics are present in recycled waters at concentrations in excess of their intended use, natural attenuation during aquifer passage alonemay not result in extracted watermeeting regulatory requirements. Additional pre treatment of the recycled water would therefore be required

Fire, drought and phosphite: A stressful story?

Large areas of indigenous forests, Banksia woodlands and heathlands in Australia are devastated by Phytophthora dieback disease caused by P. cinnamomi. Phosphite has been shown to be effective in controlling this pathogen on a wide range of plant species across different families. It acts both directly and indirectly on the pathogen. In order to maximise the efficacy of phosphite the physiological status of the plant at the time of phosphite application affects control needs to be understood. In Mediterranean environments, plants experience stresses due to extremes in water availability and the incidence of wild fire is high for example. Currently, nothing is known about the relative uptake of phosphite by shoots pre- and post-stress event or how stress may alter the redistribution and persistence of phosphite within woody plants. Therefore, from a management perspective when considering all of these stresses native plant communities are subjected to, it is critical to know when to apply phosphite to ensure optimal disease control. Fire and drought stresses on the efficacy of phosphite to control disease are examined independently. Management implications from the completed study are discussed

Does abiotic stress on a plant influence phosphite protection to Phytophthora cinnamomi?

Large areas of indigenous forests, Banksia woodlands and heathlands in Australia are devastated by Phytophthora dieback disease caused by Phytophthora cinnamomi (Weste 1994). In southwestern Australia, some 50 percent of the 5710 plants endemic to the region are susceptible (Shearer and others 2004a). Phosphite has been shown to be effective in controlling this pathogen’s impact on a wide range of plant species across different families (Hardy and others 2001). Recently, disease extension was reduced after phosphite treatment even after fire (Shearer and others 2004b). However, very little is known about the influence of a plant’s physiological status at the time of phosphite application on the subsequent efficacy of phosphite treatment to control Phytophthora dieback disease. The key seasonal stresses in an Australian ecosystem of fire and flooding are explored

Research into natural and induced resistance in Australian native vegetation of Phytophthora cinnamomi and innovative methods to contain and/or eradicate within localised incursions in areas of high biodiversity in Australia. Does the physiological status of the plant at the time of spraying affect the efficacy of phosphite?

Phosphite is of major importance in controlling root disease caused by Phytophthora cinnamomi. It acts both directly and indirectly on the pathogen. In order to maximise the efficacy of phosphite we need to understand how the physiological status of the plant at the time of phosphite application affects control. The physiological status of plants is not constant but varies over time depending on developmental gene expression (e.g. leaf phenology, flowering/fruiting and senescence) and interactions with the environment (e.g. temperature, moisture, light, fire, nutrients and other biota). In Mediterranean environments in particular, plants experience stresses due to extremes in water availability and the incidence of wild fire is high. Furthermore, individuals and species of plants are not in synchrony due to differences in recruitment, ontogeny, longevity and rest periods. Therefore, from a management perspective when considering all of these stresses native plant communities are subjected to, it is critical to know when to apply phosphite to ensure optimal disease control. We examined each of the key environmental stresses (water excess, water deficit, fire and flowering) independently, on the efficacy of phosphite to control disease

Deutsch-jüdische Bibliografie – Digital, vernetzt und erforschbar?

Improved methods have been devised for the isolation of (+)-conocurvone (1) from the roots of Conospermum brachyphyllum Lindl. and for its synthesis. The isolation of (R)-(+)-9-hydroxy-3-(4′-hydroxy-4′-methylpentan-1′-yl)-3,8-dimethyl-3H-naphtho[2,1-b]pyran-7,10-dione [(+)-brachyphyllone] (2), a minor constituent of this species, its structural elucidation and partial synthesis are also described. 8-C-Methylteretifolione-B (9) and 8-C-methyl-9-O-methylteretifolione-B (10), as well as the previously isolated (+)-teretifolione-B (8), also occur in this plant