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Contamination of drinking water by bacterial pollutants is a major environmental problem. In the current study, the possibility of using zinc oxide-mediated sonocatalysis, as a potential advanced oxidation process for the removal of a major pollutant, i.e.Escherichia coli, is investigated. Critical parameters for optimum efficiency are identified. The organism deactivation is fully irreversible in the case of ZnO-mediated sonocatalysis. Scanning electron microscopy images show that morphological changes and cell-wall disruption of organisms are more in sonocatalysis compared to sonication alone. The deactivation is practically unaffected by initial pH in the range 5–9. Reactive oxygen species includingin situ-formed free radicals play significant role in the deactivation. Sonoluminescence-induced photocatalysis is a major contributor in the disinfection process. A probable mechanism involving physical effects and semiconductor activation by ultrasound followed by the events leading to the deactivation of the bacteria is proposed. [ABSTRACT FROM PUBLISHER]

Seedlings from six crosses between susceptible × resistant and two between susceptible parents were screened against P3 isolate of Phytophthora drechsleri f. sp. cajani in the glasshouses. Disease reaction was scored on a rating scale of 1–5. Resistance was found to be controlled by one dominant gene and some minor genes and is affected by ontogeny. The resistance gene appeared to be different from the one reported earlier (Pd1) and is designated here as Pd3. [ABSTRACT FROM AUTHOR]