Witharana, A., Ratnayake, N., Manatunge, J., Nanayakkara, C.M. 2017. Biodegradation of Grease Trap Waste by Lipolytic Fungi under Local Ambient Conditions. 5^th International Symposium on Advanced Civil and Environmental Engineering Practices for Sustainable Development. 16 March, Faculty of Engineering, University of Ruhuna.

Witharana, A., Ratnayake, N., Manatunge, J., Nanayakkara, C.M. 2016. A sustainable solution to problems encountered in the management of fat, oil and grease from food service industry wastewater. The Young Researchers’ South Asian Symposium on Sustainable Development Goals (SDGs). 6–8 October, TERI University, New Delhi, India.

Witharana, A., Ratnayake, N., Nanayakkara, C., Manatunge, J. 2015. Fat, oil and grease removal by a consortium of lipase-producing microorganisms. 20^th International Forestry and Environment Symposium, 16–17 October, Club Hotel Dolphin, Negombo, Sri Lanka.

Jayaweera, M., Manatunge, J., Witharana, A. 2012. Evolution of Green Jobs Towards Green Economy in Sri Lanka. 17^th International Forestry and Environment Symposium, 16–17 November, Pegasus Reef Hotel, Wattala, Sri Lanka.

Jayaweera, M., Witharana, A. 2011. Long-term performance of a constructed wetland planted with Typhaangustifolia. The Symposium of Civil Engineering Research for Industry, Department of Civil Engineering, University of Moratuwa

Witharana, A., Jayaweera, M., Manatunge, J. 2010. Zinc Adsorption by Low-cost Sorbent Materials: Clay Tile, Brick, Sawdust and Rice Husk, International Conference on Sustainable Built Environments. Special Session: Natural Systems to Control Water Resources Pollution and Water Hazards, Earl’s Regency Hotel, Kandy, Sri Lanka. Vol. 4, pp 21–28.

Witharana, A., Jayaweera, M., Manatunge, J.2010. Investigation of Zinc Removal Capacities of Different Sorbent Materials to be used in Constructed Wetlands, 15^th International Symposium on Forestry and Environmental Science, Department of Forestry and Environment Science, University of Sri Jayewardenepura, Nugegoda, Sri Lanka, pp, 18–24, ISBN: 978-955-9054-88-7.

Witharanage, A.U.W., Meulepas Lens, P.N.L. 2010. Anaerobic bioleaching of metals from organic wastes. 12^th World Congress on Anaerobic Bioleaching, International Water Association, Guadalajara, Jalisco-Mexico.

Jayaweera, M., Randeniya, K.P.S., Witharana, A., Manatunge,J. 2008. Enhancement of heavy metal removal from wastewaters in subsurface flow constructed wetlands comprising crushed clay tile media. International Collaborative Symposium on Development of Sustainable Infrastructure in Asia. 21 March, University of Moratuwa, Sri Lanka.

Witharana, A., Bandara, N.J.G.J., Piyasiri, S. 2005. Investigation of heavy metals in edible fish species in the section of Bellanwila-Attidiya canal, Sri Lanka Association of Advancement of Science (SLAAS), Section D, pp 43, ISSN 1391–0248.