Dr. Kow Kien-Woh, Assistant Professor, Faculty of Built Environment & Technology, UCSI University, Kuala Lumpur

Biography: Our research is mainly emphasized on the utilization of biomass in synthesizing aerogel and its corresponding composites. Continuing from my PhD research work, our research team in UCSI University is now focussing on applications for aerogel composite in industrial processes. This includes heavy metals adsorption with nano-magnetite aerogel composite, high temperature thermal insulation material, fire retardant material and moisture adsorbent. Realizing the highly porous and thermally stable structure of aerogel, our team is now attempt to embed aerogel with/to other materials such as nano-magnetite particles, activated carbon and textile to improve its functional properties. At current stage, applications of these composites are centered on the aspects of adsorption (heavy metal and dye removal in wastewater, toxic and greenhouse gases removal) and thermal insulation (heat resistant and flame retardant textile). Apart from the applications, our team is also looking into aspects to further improve the conversion process from biomass to aerogel composite. Those aspects including process integration to reduce energy utility, reduction of processing time, lower emission and sustainable development. In order to accomplished that, our team had developed close collaboration with other research teams to improve processing and mechanical properties of aerogel composites.

Speech Title: Conversion of rice husks to activated carbon-gel composite for applications in the adsorption of Cu (II) ions and congo red dye
Abstract: Rice husk is agriculture waste that contains high silica and carbon content. Many researchers had attempted to convert this biomass to value added product such as pozzolanic additives, activated carbon and silica aerogel. Activated carbon is well known of its high surface area for adsorption. Nonetheless, the adsorption capacity of activated carbon can be severely hindered by the reduction of surface area due to agglomeration. It is aimed to synthesize both activated carbon and silica gel from rice husks in this work. The activated carbon was then dispersed in the precursor of silica gelation. Upon gelation, the activated carbon is trapped inside the silica gel for form a composite. As the silica gel matrix is highly porous, trapping activated carbon in the gel can prevent agglomeration and providing porous path for the adsorption to take place. In such, the surface area of activated carbon can be fully utilized for adsorption and hence reducing dosage of activated carbon required. Adsorption tests was then carried out to study the effect of loading of activated carbon (1-20 wt%) in gel. Two absorbents were used in the adsorption study of composite, i.e., Cu2+ ion and congo red dye solution. Concentration of Cu2+ as high as 63.5 g/L (i.e., 1M) was used in the adsorption study. Whereas, the concentration of congo red used was 150 ppm. The adsorption data was fitted in pseudo-second order model to determine the equilibrium adsorption capacity. The results showed that adsorption capacity as high as 493.5 mg/g and 85.5 g/g of activated carbon was obtained for adsorption of congo red and Cu2+ solution respectively. Whereas, the corresponding maximum percentage of removal are 53.9% and 16%. The high adsorption capacity of composite indicates that adsorption can be enhanced by embedding activated carbon into porous gel matrix.
Keywords: Activated carbon; silica gel; rice husks; adsorption, congo red