Xavier Swamikannu | University of California, Los Angeles (original) (raw)

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Papers by Xavier Swamikannu

Water Science and Technology, Dec 1, 2010

Canadian Journal of Fisheries and Aquatic Sciences, Oct 1, 1989

Periphyton diversity was highest at low to intermediate levels of grazing by the freshwater snail... more Periphyton diversity was highest at low to intermediate levels of grazing by the freshwater snail Physella and suppressed at high grazer densities, in partial support of the intermediate disturbance hypothesis. For the first time, the response curve of algal biomass versus a range of snail densities was used to establish low, intermediate, and high levels of community disturbance. Physella densities corresponding to these levels were added to net enclosures in a small eutrophic pond, to examine differences in attached algal cell densities and diversity after 20 d. Algal standing crop was enhanced in low and depressed in intermediate and higher grazer treatments. Five categories of attached algal response to grazing were identified: (1) filamentous algae suppressed at high grazing pressure; (2) rosette or filamentous taxa suppressed at moderate to high levels of grazing; (3) algae resistant to grazing via sediment-associated recruitment; (4) low profile algae with highest densities at moderate grazing, and; (5) prostrately attached taxa enhanced at moderate and high grazing levels, in contrast to marine macroalgal communities, the primary mechanism mediating community response to different levels of grazing was the morphology of algal attachment.

IWA Publishing eBooks, May 15, 2022

IWA Publishing eBooks, May 15, 2022

Water Science & Technology, 2010

This study assesses the performance of stormwater best management practices (BMPs) in industrial ... more This study assesses the performance of stormwater best management practices (BMPs) in industrial sectors and their effluent quality to facilitate the development of technology-based numerical effluent criteria. Generally, retention ponds outperform other BMP types for reducing total suspended solids, and media filter and wetland basins outperform other BMPs for metal removal. Detention basins were not effective in reducing stormwater pollution although they can retain the stormwater before entering surface waters. However, many BMPs show high variability of influent and effluent concentrations and no significant difference between them, which makes it difficult to determine the effectiveness of the BMP. In some cases, low influent concentrations govern the distribution of effluent concentrations and effluent concentrations are often greater than inflow concentrations. The analysis results can be used to assist in the developing a watershed based multisector industrial stormwater gen...

Water Science and Technology, 2003

Urban drainage systems historically were developed on principles of hydraulic capacity for the tr... more Urban drainage systems historically were developed on principles of hydraulic capacity for the transport of storm water to reduce the risk of flooding. However, with urbanization the percent of impervious surfaces increases dramatically resulting in increased flood volumes, peak discharge rates, velocities and duration, and a significant increase in pollutant loads. Storm water and urban runoff are the leading causes of the impairment of receiving waters and their beneficial uses in Australia and the United States today. Strict environmental and technology controls on wastewater treatment facilities and industry for more than three decades have ensured that these sources are less significant today as the cause of impairment of receiving waters. This paper compares the approach undertaken by the Environmental Protection Authority Victoria for the Melbourne metropolitan area with the approach implemented by the California Environmental Protection Agency for the Los Angeles area to con...

This document represents a remarkable first step towards regional cooperation in stomwater scienc... more This document represents a remarkable first step towards regional cooperation in stomwater science and mamgement for southern California. The culmination of this research agenda was, for the most part, a voluntary activity initiated by both stormwater management agencies and regulatom in a spirit of mutual collabration. The authors wish to thank the workshop panelists who gave h ly of their time and talents. The wonderful mix of local and national experts across a wide variety of disciplines and backgrounds provided a unique opportunity for us. Workshop Panelists:

OF THE DISSERTATION Auto Recycler an Dismantler Facilities : Environmental Analysis of the In ust... more OF THE DISSERTATION Auto Recycler an Dismantler Facilities : Environmental Analysis of the In ustry with a Focus on Storm Water Pollution

E3S Web of Conferences

Diffuse pollution is a major source of contaminants to surface waters in urban areas. Land use ac... more Diffuse pollution is a major source of contaminants to surface waters in urban areas. Land use activities and the degree of imperviousness have a strong influence on the pollutant loadings and the pattern and distribution of the pollutograph. Uncontrolled discharges of contaminated urban storm water runoff contribute to impairments of water quality in receiving waters. In this study, grab samples of storm water runoff were collected from a small high-density residential catchment area in Bucharest. The pollutant concentrations were analysed for several water quality physical and chemical parameters including pH, conductivity, oil and grease, nutrients, pathogen indicator bacteria and some heavy metals. The storm events were monitored through grab sampling. The sample results for this representative residential catchment area in Bucharest were then compared with data reported from other regions of the world. The analysis demonstrates that the characteristics of the urban runoff quali...

Environmental Science & Policy

Water Research, May 1, 2009

Canadian Journal of Fisheries and Aquatic Sciences, 1989

Periphyton diversity was highest at low to intermediate levels of grazing by the freshwater snail... more Periphyton diversity was highest at low to intermediate levels of grazing by the freshwater snail Physella and suppressed at high grazer densities, in partial support of the intermediate disturbance hypothesis. For the first time, the response curve of algal biomass versus a range of snail densities was used to establish low, intermediate, and high levels of community disturbance. Physella densities corresponding to these levels were added to net enclosures in a small eutrophic pond, to examine differences in attached algal cell densities and diversity after 20 d. Algal standing crop was enhanced in low and depressed in intermediate and higher grazer treatments. Five categories of attached algal response to grazing were identified: (1) filamentous algae suppressed at high grazing pressure; (2) rosette or filamentous taxa suppressed at moderate to high levels of grazing; (3) algae resistant to grazing via sediment-associated recruitment; (4) low profile algae with highest densities a...

Water Research, May 1, 2009

Water Science and Technology, Dec 1, 2010

Canadian Journal of Fisheries and Aquatic Sciences, Oct 1, 1989

Periphyton diversity was highest at low to intermediate levels of grazing by the freshwater snail... more Periphyton diversity was highest at low to intermediate levels of grazing by the freshwater snail Physella and suppressed at high grazer densities, in partial support of the intermediate disturbance hypothesis. For the first time, the response curve of algal biomass versus a range of snail densities was used to establish low, intermediate, and high levels of community disturbance. Physella densities corresponding to these levels were added to net enclosures in a small eutrophic pond, to examine differences in attached algal cell densities and diversity after 20 d. Algal standing crop was enhanced in low and depressed in intermediate and higher grazer treatments. Five categories of attached algal response to grazing were identified: (1) filamentous algae suppressed at high grazing pressure; (2) rosette or filamentous taxa suppressed at moderate to high levels of grazing; (3) algae resistant to grazing via sediment-associated recruitment; (4) low profile algae with highest densities at moderate grazing, and; (5) prostrately attached taxa enhanced at moderate and high grazing levels, in contrast to marine macroalgal communities, the primary mechanism mediating community response to different levels of grazing was the morphology of algal attachment.

IWA Publishing eBooks, May 15, 2022

IWA Publishing eBooks, May 15, 2022

Water Science & Technology, 2010

This study assesses the performance of stormwater best management practices (BMPs) in industrial ... more This study assesses the performance of stormwater best management practices (BMPs) in industrial sectors and their effluent quality to facilitate the development of technology-based numerical effluent criteria. Generally, retention ponds outperform other BMP types for reducing total suspended solids, and media filter and wetland basins outperform other BMPs for metal removal. Detention basins were not effective in reducing stormwater pollution although they can retain the stormwater before entering surface waters. However, many BMPs show high variability of influent and effluent concentrations and no significant difference between them, which makes it difficult to determine the effectiveness of the BMP. In some cases, low influent concentrations govern the distribution of effluent concentrations and effluent concentrations are often greater than inflow concentrations. The analysis results can be used to assist in the developing a watershed based multisector industrial stormwater gen...

Water Science and Technology, 2003

Urban drainage systems historically were developed on principles of hydraulic capacity for the tr... more Urban drainage systems historically were developed on principles of hydraulic capacity for the transport of storm water to reduce the risk of flooding. However, with urbanization the percent of impervious surfaces increases dramatically resulting in increased flood volumes, peak discharge rates, velocities and duration, and a significant increase in pollutant loads. Storm water and urban runoff are the leading causes of the impairment of receiving waters and their beneficial uses in Australia and the United States today. Strict environmental and technology controls on wastewater treatment facilities and industry for more than three decades have ensured that these sources are less significant today as the cause of impairment of receiving waters. This paper compares the approach undertaken by the Environmental Protection Authority Victoria for the Melbourne metropolitan area with the approach implemented by the California Environmental Protection Agency for the Los Angeles area to con...

This document represents a remarkable first step towards regional cooperation in stomwater scienc... more This document represents a remarkable first step towards regional cooperation in stomwater science and mamgement for southern California. The culmination of this research agenda was, for the most part, a voluntary activity initiated by both stormwater management agencies and regulatom in a spirit of mutual collabration. The authors wish to thank the workshop panelists who gave h ly of their time and talents. The wonderful mix of local and national experts across a wide variety of disciplines and backgrounds provided a unique opportunity for us. Workshop Panelists:

OF THE DISSERTATION Auto Recycler an Dismantler Facilities : Environmental Analysis of the In ust... more OF THE DISSERTATION Auto Recycler an Dismantler Facilities : Environmental Analysis of the In ustry with a Focus on Storm Water Pollution

E3S Web of Conferences

Diffuse pollution is a major source of contaminants to surface waters in urban areas. Land use ac... more Diffuse pollution is a major source of contaminants to surface waters in urban areas. Land use activities and the degree of imperviousness have a strong influence on the pollutant loadings and the pattern and distribution of the pollutograph. Uncontrolled discharges of contaminated urban storm water runoff contribute to impairments of water quality in receiving waters. In this study, grab samples of storm water runoff were collected from a small high-density residential catchment area in Bucharest. The pollutant concentrations were analysed for several water quality physical and chemical parameters including pH, conductivity, oil and grease, nutrients, pathogen indicator bacteria and some heavy metals. The storm events were monitored through grab sampling. The sample results for this representative residential catchment area in Bucharest were then compared with data reported from other regions of the world. The analysis demonstrates that the characteristics of the urban runoff quali...

Environmental Science & Policy

Water Research, May 1, 2009

Canadian Journal of Fisheries and Aquatic Sciences, 1989

Periphyton diversity was highest at low to intermediate levels of grazing by the freshwater snail... more Periphyton diversity was highest at low to intermediate levels of grazing by the freshwater snail Physella and suppressed at high grazer densities, in partial support of the intermediate disturbance hypothesis. For the first time, the response curve of algal biomass versus a range of snail densities was used to establish low, intermediate, and high levels of community disturbance. Physella densities corresponding to these levels were added to net enclosures in a small eutrophic pond, to examine differences in attached algal cell densities and diversity after 20 d. Algal standing crop was enhanced in low and depressed in intermediate and higher grazer treatments. Five categories of attached algal response to grazing were identified: (1) filamentous algae suppressed at high grazing pressure; (2) rosette or filamentous taxa suppressed at moderate to high levels of grazing; (3) algae resistant to grazing via sediment-associated recruitment; (4) low profile algae with highest densities a...

Water Research, May 1, 2009