In consequence of spiralling global environmental concerns such as pollution, climate change and depleting energy resources, green technology has emerged as an important research trend and development in the 21st century. My research motivation has always been to help the world to work towards a sustainable future through the use of fundamental science and innovative chemical engineering technologies. The work in my research group is in the domain of applying green cleaning technology and process optimisation to reduce the consumption of energy, water and resources, as well as to minimise or mitigate the negative impacts on the environment from human activities.

Air purification

I have strong interest in the design and development of multi-functional adsorbent structures for use in air purification applications such as those found in industrial and domestic air filters, and respiratory protection equipment for emergency responders. One of the main challenges in traditional air filter devices and respiratory escape mask is the high pressure drop incurred in the granular activated carbon packed bed filter. I am working with adsorbent structures (e.g. hollow fibres, polymeric foams and carbonised monoliths) that are low burden i.e. incur low pressure drop, and capable of physically and chemically adsorb toxic species from air.  More recently, we are also focusing on incorporating heat absorbing capability in respiratory protection masks that are used in fire situations by using shape stable phase change materials.  

Fouling and cleaning

I have strong interest in the research area related to surface layers. I have been working on issues related to fouling and cleaning of surface layers in the food, textile, polymer processing, membranes and biotechnological industries since 2004. Fluid Dynamic Gauging (FDG) is a technique developed in my research group to measure the thickness of solid layers deposited on a substrate in situ and in real time. The technique is based on the steady flow of a fluid through a nozzle located near the layer surface, so that the device does not touch the layer but senses its presence, by virtue of its influence on the flow rate of the fluid. Measurement of the flow rate tells us the thickness and strength (cohesive and adhesive) of the surface layers. With careful mechanical design, FDG has been extended to an automated system that can now measure thickness and attachment strength or deformability of fouling layers in situ and in real time. The advances have come through combining experimental measurements and numerical modelling.

Water and wastewater treatment

Bubbles and droplets, are ubiquitous in everyday life, both in nature and in technology. My research on gas-liquid systems is centred on understanding the hydrodynamics and interfacial interactions of small scaled fluid particles with their continuous phase during the course of their movements in a piece of equipment. The most important feature of the fluid particles that sets them apart from the rigid particles is their mobile surface and their ability to deform during motion. I am using a combination of experimental and computational techniques to understand the dynamics of these bubbles in processes such as wastewater treatment, fermentation and surface cleaning. Recent work includes using microbubbles to remove/recover microplastics from wastewater streams.

Interested in supervising students studying:

• Green cleaning
• Air purification
• Water treatment
• Membranes
• Sensors for fouling and cleaning
• Gas-liquid phase flows
• Non-Newtonian fluids
• Microplastics