Weeds can rejuvenate lakes

Poornima Nataraj, Bangalore, October 18, DHNS:

Water weeds or the aquatic plants, often treated as a problem for development of lakes actually help in rejuvenation of water bodies by absorbing sewage and heavy metals that affet most of the lakes in Bangalore.

According to Dr U V Singh, head of the Lake Development Authority, growing water weeds in lakes should be encouraged as it helped rejuvenation process scientifically.

"The water weeds cover the lake surface reducing foul smell, manufacture biomass, purify the water body and absorbs all heavy metals including sulphur, phosphate, nitrate etc.  Besides, they also invite a variety of birds in the lake area, balancing the ecology," he told Deccan Herald.

Growing water weeds especially Hyacinth which has more absorbing capacity for sometime, harvesting it and replanting it again will rejuvenate the water in the Ulsoor Lake which is often targeted for pollution and non-maintenance, Singh said. 

But, the growth of the weeds needs to be monitored well as they grow at a very rapid pace, and once they are harvested, they have to be disposed scientifically to ensure that they have no adverse effect on the environment. The harvested weeds can be dumped into a compost pit for being converted into manures, he added.

R M N Sahai, Director General, Environmental Management and Policy Research Institute (EPMRI) said there has been a study on the contamination of the lakes on a few lakes in the City where the growth of water weeds were also studied. 

"Growing weeds especially in Bangalore City lakes will definitely help since most of the lakes have been contaminated due to sewerage and chemical waste.  However, the growth of the weed also needs managed well as it should not cover the entire lake area," he said.

See the article online here.