Lecturer in Environmental Engineering
MSc Environmental Engineering (UPM)
BEng Mineral Resources Engineering (USM)
Research Interest: Waste Utilization Technology
Reutilization of wastes is important to protect the quality of our environment. At the same time, it provides solutions for problems in various sectors including environmental pollution control, agricultural applications, feedstock for livestock, and energy sources. My research interest is in waste utilization technologies, with main focuses on the utilization of agrowastes and sewage sludge.
My current research activities are mainly on the development of sorbent from agricultural waste via chemical modification and filter design for the removal of oil, colour and other contaminants in oily wastewater.
Another area of interest is the design and application of microwave pyrolysis technique for conversion of agrowastes for instance sago, palm oil and wood wastes into clean and environmentally acceptable fuel material. Investigation on the chemical compounds in the microwave-induced fuel is also of my interest.
My research work also involves the preparation of various types of adsorbents for removing contaminants and heavy metal from wastewater. Used are the raw and chemically treated agrowastes, and again the application of microwave technology for rapid and efficient carbonization of these wastes prior chemical modification during adsorbent preparation is studied. The possible utilization of used adsorbents as chemical feedstock is also studied.
In addition, studies on the use of agrowastes for agricultural applications are also conducted, in particular, the composting of agrowastes and their effects on plant growth. Other researches are on the determination of pollutants including heavy metals in wastewater and aquatic organism.
Wahi, R., Ngaini, Z., Chuah, L.A., Nourouzi, M.M. &Choong, T.S.Y. (2014). Esterification of M. sagu bark as an adsorbent for removal of emulsified oil. Journal of Environmental Chemical Engineering 2 (2014): 324-331.
Wahi, R., Chuah, L.A. Choong, T.S.Y., Ngaini, Z., & Nourouzi, M.M. (2013). Oil removal from aqueous state by natural fibrous sorbent: An overview. Separation and Purification Technology, 113: 51-63.
Aziz, S.M.A., Wahi, R., Ngaini, Z., & Hamdan, S. (2013). Bio-oils from microwave pyrolysis of agricultural wastes. Fuel Processing Technology, 106: 744-750.
Wahi, R., & Senghie, H. (2011). The use of microwave derived activated carbon for removal of heavy metal in aqueous solution. Journal of Science and Technology, 3(1): 97-108.
Wahi, R., Kanakaraju, D., & Yusof, N.A. (2010). Preliminary study on zinc removal from aqueous solution by sago wastes. Global Journal of Environmental Research, 4(2): 127-134.
Wahi, R., Ngaini, Z., & Jok, V. U. (2009). Removal of mercury, lead and copper from aqueous solution by activated carbon from empty fruit bunch. World Applied Sciences Journal , 5 (Special Issue for Environment), 84-91.
Kanakaraju, D., Daud, R., Wahi, R. (2009). Preliminary study on accumulation and depuration of copper, zinc and lead in tilapia (Oreochromis mossambicus) under laboratory conditions. Journal of Sustainability Science and Management, 4(2), 44-52.
Wahi, R., Idris, A., Mohd Salleh, M.A., & Khalid, K. (2006). Low-temperature microwave pyrolysis of sewage sludge for conversion as fuel material. International Journal of Engineering and Technology, 3(1), 132-138.
Abdul Aziz, S. M., Wahi, R., Hamdan, S., & Ngaini, Z. (2009). Thermochemical properties of palm oil, sago and wood wastes and microwave pyrolysis study. In Z. Ngaini, D. Kanakaraju, & K. Mustafa (Eds.), Chemistry Fundamentals and Applications (pp. 30-37). Kuching: Perpustakaan Negara Malaysia. ISBN 978-967-5418-02-0