Solar-powered circulators to improve water quality at Rawal Lake

t('articles.tweet')

* denotes required field.

• Your name *
• Email to *
• Comments *
• CAPTCHA *

Reset

ISLAMABAD — To remove water contaminants from Rawal Lake, the Water and Sanitation Agency (WASA) said on August 20 that it planned to install 17 floating solar-powered high-flow circulators, and ten portable wastewater treatment plants at a cost of US$4.8 million.

Rawal Lake, the main source of drinking water for Rawalpindi, has become highly polluted due to an increase in waste generated by the local population and commercial enterprises. Poultry farms also contaminating the lake, which is now little more than an oxidation pond.

A Capital Development Authority (CDA) spokesperson said that “there is a problem of taste and odour in the treated water. It is also highly contaminated with blue-green algae cyanobacteria and invasive aquatic weeds.”

The major problem is eutrophication, an increase in the concentration of chemical nutrients in an ecosystem which causes abnormal plant growth. The CDA and WASA concluded that aeration on a large scale and the use of water circulators are the best methods of combating these contaminants.

The circulators will prevent and control the growth of harmful blue-green algae blooms, reduce taste and odour problems, allay public health concerns about cyanotoxins and improve the aesthetics, water clarity and biodiversity of the lake.

The CDA spokesperson also indicated “an urgent need to install ten portable treatment plants around Rawal Lake. One Solarbee brand portable treatment plant costs $242,500.”

“The energy provided by each solar unit is almost equal to the yearly electrical energy requirements of 20 homes, and in all will eliminate 150 tonnes of carbon dioxide emissions per year,” said a WASA spokesperson.

WASA has also proposed the construction of portable wastewater treatment plants around Rawal Lake that can be moved from one tributary to another as needed. “Potable water sources for a rapidly growing population are already declining at a fast rate," said Dr. Noor Sheikh, Dean of Electrical Engineering at the University of Engineering and Technology in Lahore. "The water circulators will help improve the quality of water in lakes and other potable water sources. By using the sun's energy instead of grid power, water circulators minimise aeration equipment run-time, significantly reducing energy costs,” he said.