Organic pollution affects city lakes

Organic pollution affects city lakes

The Hindu

Students from Mount Carmel College call for sustainable utilisation of water resources

BANGALORE: Identifying indiscriminate discharge of various kinds of pollutants as the prime reason for the sharp fall in the quality of the city's lake ecosystem, a group of B.Sc Environmental Sciences students from Mount Carmel College have called for sustainable utilisation of water resources combined with programmes for lake conservation.

In a study titled "Comparative study of the plankton diversity and physio-chemical characteristic of Bangalore lakes," the student team concluded: "Lakes are our drinking water security deposits, they deserve the best care and attention. Only a well-informed and dedicated population can protect lakes from further deterioration."

As part of the study, water samples were collected from Ulsoor, Vengaiah, Sankey and Cubbon lakes during January 2006. The samples were taken from 10 cm to 20 cm below the surface of the water during morning hours.

While on-site analysis of the lake water included dissolved oxygen, laboratory analyses included acidity, alkalinity, pH, conductivity, total solids, chlorides, nitrates and phosphates following standard methods and plankton study.

It was found that the pH level of the lake water (a measure of the acidity) ranged between 6.1 to 6.89, which was almost neutral or slightly acidic. Domestic waste discharge into the lakes was seen as a possibility for this pH range. Aqueous solutions with pH values lower than 7 are considered acidic, while pH values higher than 7 are considered basic.

Among the five lakes analysed, the "conductivity" of Vengaiah Lake was found to be the highest, followed by Cubbon Lake. This was due to a high proportion of ion content in the lake water, the study said.

The permissible limit of chlorides is 250 mg/litre. Vengaiah Lake showed the highest chloride content, followed by Hebbal and Cubbon lakes. Sankey Tank showed the least, which was within the permissible limits. The permissible limit of total solids was 500 mg/litre. The content of total solids was once again found to be the highest in Vengaiah Lake. The study team attributed this to organic pollutants and sewage inlet. This lake also had phosphate content beyond the permissible limit of 0.1 mg/litre.

The team comprised Helen Kennedy, Pallavi S., Shwetha D., Ranjitha B.N., Suhasini Balachandran and Jinu John. Organic pollution affects city lakes

Staff Reporter

Students from Mount Carmel College call for sustainable utilisation of water resources

BANGALORE: Identifying indiscriminate discharge of various kinds of pollutants as the prime reason for the sharp fall in the quality of the city's lake ecosystem, a group of B.Sc Environmental Sciences students from Mount Carmel College have called for sustainable utilisation of water resources combined with programmes for lake conservation.

In a study titled "Comparative study of the plankton diversity and physio-chemical characteristic of Bangalore lakes," the student team concluded: "Lakes are our drinking water security deposits, they deserve the best care and attention. Only a well-informed and dedicated population can protect lakes from further deterioration."

As part of the study, water samples were collected from Ulsoor, Vengaiah, Sankey and Cubbon lakes during January 2006. The samples were taken from 10 cm to 20 cm below the surface of the water during morning hours.

While on-site analysis of the lake water included dissolved oxygen, laboratory analyses included acidity, alkalinity, pH, conductivity, total solids, chlorides, nitrates and phosphates following standard methods and plankton study.

It was found that the pH level of the lake water (a measure of the acidity) ranged between 6.1 to 6.89, which was almost neutral or slightly acidic. Domestic waste discharge into the lakes was seen as a possibility for this pH range. Aqueous solutions with pH values lower than 7 are considered acidic, while pH values higher than 7 are considered basic.

Among the five lakes analysed, the "conductivity" of Vengaiah Lake was found to be the highest, followed by Cubbon Lake. This was due to a high proportion of ion content in the lake water, the study said.

The permissible limit of chlorides is 250 mg/litre. Vengaiah Lake showed the highest chloride content, followed by Hebbal and Cubbon lakes. Sankey Tank showed the least, which was within the permissible limits. The permissible limit of total solids was 500 mg/litre. The content of total solids was once again found to be the highest in Vengaiah Lake. The study team attributed this to organic pollutants and sewage inlet. This lake also had phosphate content beyond the permissible limit of 0.1 mg/litre.

The team comprised Helen Kennedy, Pallavi S., Shwetha D., Ranjitha B.N., Suhasini Balachandran and Jinu John.