Professor Ir Dr Abdul Wahab is an authority on nanofiltration (NF) membrane processes. His interest has been on the understanding of NF membrane processes; development of predictive modelling; utilization in process design and optimization; fabrication and characterization of membranes; diversified applications in desalination and wastewater treatment; and integrated application of membranes within a production process. One of his major contributions in this area is the development of the Donnan-Steric-Pore model (DSPM) for predicting the performance of NF membrane, which has been accepted within the international research community as one of the main model for describing the NF system.

Professor Ir Dr Abdul Wahab is not only very active in his technical fields but also actively involved with professional activities. He is a past member of the Engineering Accreditation Council (EAC) for Board of Engineers Malaysia (BEM). He has participated in R&D projects in Malaysia as well as in collaboration with partners in United Kingdom, United States, Belgium, and Jordan. He is often engaged as a consultant for various companies in the areas of environmental impact and risk and hazard assessment. He has led more than 20 consultancy projects for companies such as Petronas Gas Berhad, BASF Petrochemicals, Petronas Penapisan Terengganu, and Megasteel. His collaborative R&D works with industries have been implemented with companies such as Halagel, Sime Darby, KLK Oleochemical and Altus Technology.

He has published more than 200 papers in refereed journal and conference proceedings within this area of research (H index = 19, no of citation = 1450). He has also won many awards and among them is the 3rd Prince Sultan International Water Award in 2008 worth 250,000 Saudi Riyals.