A study of the water quality of diyawanna oya conducted during the south-west monsoon period
| dc.contributor.author | Joseph, J. S. | |
| dc.date.accessioned | 2024-11-01T03:47:02Z | |
| dc.date.available | 2024-11-01T03:47:02Z | |
| dc.date.issued | 2009 | |
| dc.description.abstract | Diyawanna Oya located in the Greater Colombo area comprises a network of large opendrainage canals, smaller tributary canals and low lying marshes functioning as natural water retention areas. However, pollution of this waterway has been a serious concern due to various anthropogenic activities, though no published literature is still available to document the pollution status. Therefore, this report provides an insight in to the current water quality status of this waterway assessed during the south-west monsoonal period (May-September, 2009). pH was found to be within the Central Environmental Authority (CEA) enacted Inland Water Quality Standards (6-8.5). TSS content was relatively high (though there are ‘no standards enacted in Sri Lanka) with the highly urbanized areas showing higher levels due to urban runoff, disposal of wastewaters and solid wastes. BOD and COD levels exceeded the CEA limits for ambient water quality. Also the COD/BOD; ratios were higher than the COD/BODs; ratio of 1:2-1:4 for domestic wastewaters indicating industrial wastewater disposal is a possible major point source of non- biodegradable organics, though heavy rains possibly caused a considerable dilution of the waters. Additionally, the study showed that oil and grease contamination is significant (especially at the highly urbanized areas) with levels exceeding the maximum permissible levels for Class If Waters and Class Il Waters and most of the time period ammonical nitrogen levels exceeded CEA enacted limits of 0.94 mg/L and 0.91 mg/L under pH < 7.5 for Class If Waters (fish and aquatic life survival) and Class III Waters (minimum quality), respectively with the pristine areas showing consistently higher levels due to the availability of more N rich detritus. However, there was no evidence of contamination by Pb, Cd and As. Nevertheless, further studies are required to evaluate the heavy metal levels in sediments and biota and also to conduct water quality analysis during the drier periods. | |
| dc.identifier.uri | https://ir.lib.pdn.ac.lk/handle/20.500.14444/3007 | |
| dc.language.iso | en_US | |
| dc.publisher | The University of Peradeniya | |
| dc.subject | Environment Sciences | |
| dc.subject | Water Quality | |
| dc.subject | Diyawanna Oya | |
| dc.subject | South-West Monsoon | |
| dc.title | A study of the water quality of diyawanna oya conducted during the south-west monsoon period | |
| dc.type | Thesis |