Ammini Joseph

Microbial enhanced separation of oil from a petroleum refinery sludge

Petroleum refineries around the world have adopted different technological options to manage the solid wastes generated during the refining process and stocking of crude oil. These include physical, chemical and biological treatment methods. In this investigation bacterial mediated oil separation is effected. Two strains of Bacillus were isolated from petroleum-contaminated soils, and inoculated into slurry of sludge, and sludge-sand combinations. The bacteria could effect the separation of oil so as to form a floating scum within 48h with an efficiency of 97% at < or =5% level of sludge in the sludge-sand mixture. The activity was traced to the production of biosurfactants by bacteria.

Effect of industrial discharges on the ecology of phytoplankton production in the River Periyar (India).

Abstract The ecology of phytoplankton production in the River Periyar, which receives continuous effluent discharge from a dozen industrial units, has been studied. Spatial variation of phytoplankton composition, chlorophyll pigments and physico-chemical features of water were observed for a period of 1 year. A multiple regression relationship was set up to determine the ecological factors that control phytoplankton production. The industrial zone of the river was observed to have a high standing stock of phytoplankton during the premonsoon (summer), the causative factors of which are discussed.

Ecology And Seasonal Variation Of Microalgal Community In An Oil Refinery Effluent Holding Pond: Monitoring And Assessment

The microalgal community as primary producers has to play a significant role in the biotic and abitoic interactions of anyaquatic ecosystem. Whenever a community is exposed to a pollutant, responses can occur because individuals acclimate topollutant caused changes and selection can occur favouring resistant genotypes within a population and selection among species can result in changes in community structure. The microalgal community of industrial effluent treatment systems arecontinuously exposed to pollutants and there is little data available on the structure and seasonal variation of microalgalcommunity of industrial effluent holding ponds, especially of acomplex effluent like that of refinery. The aim of the presentstudy was to investigate the annual variation in the ecology,biomass, productivity and community structure of the algalcommunity of a refinery effluent holding pond. The results ofthe study showed the pond to be a eutrophic system with a resistant microalgal community with distinct seasonal variation in species composition.

Algae in the Assessment of Industrial Wastewater Holding Ponds

The ecology and photosynthetic behaviour of the microalgalcommunity in an oil refinery wastewater holding pond was studiedwith a view to assess the role of algae in industrial effluenttreatment ponds. The biological and physico-chemical parameterswere measured for one year from February 1994 to February 1995.The assessment of algal population based on chlorophyll andprimary productivity revealed that the pond is a eutrophic systemsupporting continuous algal bloom. There was no significantcorrelation between the algal biomass and the nutrient parameterstested. A comparison of the algal gross primary production andthe community respiration for the period was done to assess thedegree of waste stabilisation, and it was found that the pondwater is of eutrophic potential. Bioassays of the effluent usingpure cultures of algae, Chlorella pyrenoidosa, Oocystispusilla and Oscillatoria quadripunctulata again confirmedthat the effluent is stimulatory to algal growth. Thus thestudy of algal community in the field surveys and the algalbioassays of the effluent, established that algae can be used asan effective tool to assess the degree of stabilisation of industrial effluents.

Delineation of Groundwater Potential Zones in River Basins Using Geospatial Tools—an Example from Southern Western Ghats, Kerala, India

The remote sensing and geospatial tools have wide applications in water resource assessment studies. Satellite images are increasingly being used in groundwater exploration because of their utility in identifying various geomorphic features. The present study has been carried out in two important river basins—the Ithikkara and the Kallada river basins, of Southern Western Ghats, Kerala, India. The groundwater potential zones are delineated from 14 thematic layers such as drainage density, geomorphology, slope, lithology, soil, land use/land cover, lineament density, topographic wetness index, rainfall distribution, roughness, curvature, dissection index, depth to water level and topographic position index using multi-criteria evaluation method. Integration of the factors has been performed in GIS platform using weighted overlay analysis. Different classes of thematic maps have been assigned weights based on influence on groundwater hydrology (through discussions with the experts in the field), and finally, factor ranks are assigned. The final map indicates the potentiality values of groundwater occurrence in the study area, which was classified into three categories—high, moderate and low. A total of 37.2% of the study area fall in low groundwater potential zone, 42.3% in moderate potential zone and 20.5% of the area in high potential zone. The groundwater potential zones delineated using the method are validated with data of springs and dug wells from field investigations, and it was found that the overlay method using GIS and remote sensing gives 95% accuracy.

Floral Radiometry: A Biophysical Basis to Characterize Landscapes.

This paper presents early results on studies of floral spectral reflectance of angiosperms and introduces floral radiometry as an emergent dimension of ecological research in India. Floral spectral reflectance of 121 angiosperm species was measured using hand-held spectroradiometer. The authors describe spectral reflectance of seven representative species within 350-800 nanometer region of the electromagnetic spectrum. Characteristic absorption and reflection of flowers, in ultraviolet and visible regions of the spectrum is reported. Near infrared reflectance was consistently high for all species studied. Flower color is unique to a species and importance of understanding flower color from pollinator’s perspective is highlighted.