Breaking new ground on waste water treatment

Oil contaminated wastewater is a massive problem that leaves a huge impact on the environment. Global studies have shown that industrial, domestic and municipal sources discharge more oil into water than major oil spills do. When oil contaminated water is released to natural water bodies it damages ecosystems. 

Oil pollution causes serious harm to aquatic plants and animals. It suffocates fish, coats the feathers of birds and mammals and blocks light from reaching underwater photosynthetic plants. Some ecosystems like coral reefs, mangroves and marshes are extremely sensitive to oil pollution. Oil pollution also contaminates water for drinking and other purposes like fishing. People whose livelihoods depend on their local water bodies end up facing extensive problems.

Considering the environmental and social impact, industrial sites and service stations are now legally obligated to treat wastewater. However, cleaning oil contaminated water is beset with problems because such methods of water treatment are expensive.

Scientists at the Energy and Advanced Material Chemistry Project at the NIFS, working on renewable energy and water/air purification methods, have developed a filter to separate waste water from oil. Prof J M S Bandara and Mr. S A D A V Sumithraarachchi are currently working on this sub project. 

The filtering device contains two filters. An underwater superoleophobic-superhydrophilic membrane, which only filters water and repels oil and a superhydrophobic-superoleophilic membrane, which only filters oil and repels water. Mica, which is freely available in Sri Lanka and stainless steel have been used to produce these filter membranes. Another reason for this project’s significance, is its contribution in adding value to our local minerals.

The basic principle of the 'Lotus Effect' (The Lotus Effect refers to self-cleaning properties that are a result of ultra hydrophobicity as exhibited by the leaves of the lotus flower) is used in developing this process. The outcome of this project will break ground on waste water treatment which increases the affordability.

Scientists are working to optimize and increase efficiency of the filter. Currently, research is being conducted to increase the filter speed to have a faster flow rate. Introducing this filter at motor vehicle service stations is a first step in employing this filter in all industries faced with the problem of treating oil contaminated waste water.