http://dspace.bits-pilani.ac.in:8080/jspui/handle/123456789/1867 Sat, 25 Apr 2026 01:49:10 GMT 2026-04-25T01:49:10Z http://dspace.bits-pilani.ac.in:8080/jspui/handle/123456789/21125 Sourcing faecal pollution from onsite wastewater treatment systems in surface waters using antibiotic resistance analysis Goonetilleke, Ashantha To identify the sources of faecal contamination in investigated surface waters and to determine the significance of onsite wastewater treatment systems (OWTS) as a major contributor to faecal contamination. Thu, 01 Sep 2005 00:00:00 GMT http://dspace.bits-pilani.ac.in:8080/jspui/handle/123456789/21125 2005-09-01T00:00:00Z http://dspace.bits-pilani.ac.in:8080/jspui/handle/123456789/21124 Characteristics of pollutants built-up on residential road surfaces Goonetilleke, Ashantha Pollution build-up in relation to urban stormwater quality is one of the most important pollutant processes that need in-depth investigation. Build-up varies with range of climatic, land-use and regional parameters and illustrates a highly dynamic nature. This paper presents the outcomes of an in-depth investigation into pollutant build-up on typical residential urban road surfaces. The outcomes of the investigation revealed highly site specific rates of build-up that primarily varied with road surface conditions, traffic volume and surrounding land-use. The rate of build-up was initially in the range of 1 to 2g/m2/day and decreased when the antecedent dry days increased. The total build-up varied from site to site but did not exceed 6g/m2. This amount was significantly less compared to numerous previous research studies. It was further noted that particulate pollutant composition varied dynamically when the antecedent dry days increased. It is hypothesised that this is due to the re-distribution of finer particles by the wind and traffic. Analysis of quality parameters revealed that a higher fraction of pollutants is associated with the finer particle size ranges. Furthermore, a relatively high amount of dissolved organic carbon was detected in build-up samples during the study. Dissolved organic carbon enhances the solubility of other pollutants such as heavy metals and hydrocarbons thus increasing their bio-availability. Sun, 01 Jan 2006 00:00:00 GMT http://dspace.bits-pilani.ac.in:8080/jspui/handle/123456789/21124 2006-01-01T00:00:00Z http://dspace.bits-pilani.ac.in:8080/jspui/handle/123456789/21123 Understanding the interrelationships between stormwater quality and rainfall and runoff factors in residential catchments Goonetilleke, Ashantha This paper discusses the outcomes of a research project which involved in-depth investigation of stormwater quality by analysing rainfall-runoff and water quality data from four urban residential catchments. The outcomes of the investigations confirmed that the pollutant export characteristics from these catchments are strongly correlates with the rainfall intensity rather than other rainfall-runoff parameter. Further, the overall pollutant export from the catchment is mostly dependent on lesser number of high intensity storm events. These findings suggested that the rainfall intensity would be the most suitable rainfall-runoff parameter for pollutant export equations in stormwater quality models. Sun, 01 Jan 2006 00:00:00 GMT http://dspace.bits-pilani.ac.in:8080/jspui/handle/123456789/21123 2006-01-01T00:00:00Z http://dspace.bits-pilani.ac.in:8080/jspui/handle/123456789/21122 Assessment via discriminant analysis of soil suitability for effluent renovation using undisturbed soil columns Goonetilleke, Ashantha The use of onsite wastewater treatment systems for the treatment and dispersal of effluent is common in urban fringe areas which are not serviced by centralised wastewater collection systems. However, due to inappropriate siting and soil characteristics, the inherent failure of these systems, in particular subsurface soil treatment systems, are numerous. In order to ensure that these systems are capable of providing adequate treatment and dispersal of effluent in the long term, it is essential that the soils' ability to both renovate as well as dispose of discharged effluent is adequately assessed. This paper discusses the outcomes of a research study undertaken through the use of undisturbed soil columns to assess the ability of different soil types to treat and dispose of primary treated effluent. Discriminant analysis (DA) was utilised for classification of the various soil types based on their respective physical and chemical characteristics and to identify relative changes in each soil type after an extended period of application of effluent. Ferrosol and Dermosol soils were found to provide the most satisfactory conditions for effluent renovation. Kurosol, Sodosl and Chromosol soils even though were found to provide suitable means for removing effluent pollutants, reductions in the soils' permeability over time indicated that these soils may not be appropriate for long term effluent treatment. Finally, Podosol soils were found to have minimal ability to provide adequate treatment of effluent. Wed, 01 Mar 2006 00:00:00 GMT http://dspace.bits-pilani.ac.in:8080/jspui/handle/123456789/21122 2006-03-01T00:00:00Z