Treatment of Algal-Laden Water: Pilot-Plant Experiences

In recent years an increase in the eutrophication of reservoirs has added to the problems of lowland surface-water treatment. A pilot plant was installed to test the effectiveness of various treatment regimes for a river source which was subject to occasional algal blooms, and a eutrophic reservoir source which was heavily contaminated with cyanobacteria ( Oscillatoria sp. ). The treatment processes adopted were dissolved-air flotation for chemical coagulation, sand and anthracite filtration, comparative disinfection stages using ozone and chlorine followed by granular activated carbon filtration.
The dissolved-air flotation plant was not particularly effective for the removal of algae, but the sand/anthracite filtration process was capable of removing 50% of the algae. The ozone disinfection stage was adequate for disinfection and also reduced algal numbers. Overall the chlorine/granular activated carbon method did not perform as effectively as the ozone/granular activated carbon process; the iatter process was +99% effective for algai control, with river and reservoir sources.     

Nonplanar dust acoustic solitary and rogue waves in an ion beam plasma with superthermal electrons and ions

The propagation characteristics of dust acoustic solitary and rogue waves are investigated in an unmagnetized ion beam plasma with electrons and ions following kappa-type distribution in nonplanar geometry. The reductive perturbation method(RPM) is employed to derive the cylindrical/spherical Korteweg–de Vries(KdV) equation, which is further transformed into standard KdV equation by neglecting the geometrical effects. Using new stretching coordinates,nonlinear Schr?dinger equation(NLSE) has been derived from the standard KdV equation to study the different order rational solutions of dust acoustic rogue waves(DARWs). The impact of various physical parameters on the characteristics of dust acoustic solitary waves(DASWs) is elaborated specifically in nonplanar geometry. Further, the effects of ion beam and superthermality of electrons/ions on the characteristics of DARWs are studied. The results obtained in the present investigation may be useful in comprehending a variety of phenomena in Earth's magnetosphere polar cap region where the presence of positive ion beam has been detected and also in other regions of space/astrophysical environments where dust along with superthermal electrons and ions exists.     

The effects of Asparagus racemosus (shatavari) extract on oxidative stability of ghee,in relation to added natural and synthetic antioxidants

The potential of Asparagus racemosus (shatavari) extract was evaluated in comparison with natural (rosemary, green tea) and synthetic (butylated hydroxyanisole, tert‐butyl hydroquinone) antioxidants, in ghee using accelerated oxidation tests. Its aqueous and ethanolic extracts significantly retarded deterioration of ghee relative to the control (without addition of synthetic or natural herb extract), as observed in peroxide value (8.3, 13.2 and 25.8 mmolO₂/g fat respectively), conjugated diene% (1.30, 1.44 and 1.78, respectively), radical‐scavenging potential (40.0, 25 and 5.5% inhibition, respectively) and oxidative stability index (16.8, 13.5 and 10.3 h respectively) after 21 days. However, these were less effective than the natural and synthetic antioxidants. The ethanolic extract of shatavari, having polyphenol content of 24.99 ± 0.74 mg gallic acid equivalent/g, exhibited some antioxidative and radical‐scavenging activities.