Thabo Falayi

Thabo earned his BSc (Hons) first class from National University of Science and Technology, Zimbabwe, MTech  and D.Phil from the University of Johannesburg. He joined NUST in March 2022. His research interests are in solid waste solidification and valorisation together with remedial treatment of industrial wastewater.  He has published at least 40 high impact research articles and peer reviewed conference proceedings. He has over 267 citations from international peers and as of 2022 his google scholar h index is 10 and i10 index is 11.

Qualifications

• D.Phil Civil Engineering Science (UJ, SA)
• M.Tech. Chemical Engineering (UJ,SA)
• B.Sc. Hons Applied Chemistry (NUST, Zimbabwe) 

Research Focus Areas

• Industrial solid waste solidification and valorisation
• Industrial wastewater treatment
• Electrodialytic separation of solid waste

Courses CurrentlyTeaching

Undergraduate

• Process Modelling Simulation and Optimisation
• Biochemical Engineering
• Applied Thermodynamics
• Chemical Engineering Principle
• Chemical Reaction Engineering
• Heat and Mass Transfer
• Introduction to reactor Technology
• Process Fluid Flow
• Process Synthesis and Integration
• Solid Waste Treatment
• Thermodynamics and Separation Processes

Postgraduate

• Advanced Chemical Metallurgy
• Process Modelling Design and Optimisation
• Thermodynamics and Kinetics
• Hydrometallurgical Separation techniques and Processes

Community Development Activities

• Neutralisation of mining lechates

Selected Publications

Peer-reviewed articles

• M Moreroa-Monyelo, T Falayi, F Ntuli, N Magwa (2022). Studies towards the adsorption of sulphate ions from acid mine drainage by modified attapulgite clays. South African Journal of Chemical Engineering, 42, 241–254
• T Falayi, BD Ikotun, (2021). A comparison in metal leachability between phosphoric acid and ascorbic acid stabilised ferrochrome slag. Journal of Solid Waste Technology and Management, 47, 207-215.
• T Falayi, BD Ikotun, (2021). A comparison between ferrochrome slag and gold mine tailings based geopolymers as adsorbents for heavy metals in aqueous solutions: Analyzing reusability and sustainability. Korean Journal of Chemical Engineering, 38,  816–825
• T Lekgoba, F Ntuli, T Falayi, 2021. Application of coal fly ash for treatment of wastewater containing a binary mixture of copper and nickel. Journal of Water Process Engineering, 40, 101822.
• T Falayi, F Ntuli, FN Okonta, 2020. The influence of thermo-mechanical activation on the geopolymerisation of acidic gold mine tailings. Journal of Solid Waste Technology and Management, 46, 509-518.
• T Falayi, 2020. A comparison between fly ash‑ and basic oxygen furnace slag‑modified gold mine tailings geopolymer. International Journal of Energy and Environmental Engineering, 11, 207–217.
• T Falayi, 2019. Removal of sulphates from acid mine drainage using tetradecytrimethylammonium bromide modified desilicated fly ash. Journal of Solid Waste Technology and Management, 45, pp. 450-456
• T Falayi, 2019. Sustainable solidification of ferrochrome slag through geopolymerisation: a look at the effect of curing time, type of activator and liquid solid ratio. Sustainable Environment Research, 29, pp. 1-10.
• T Falayi, F Ntuli, FN Okonta, 2019. Desilication of calcined pulverised fly ash and use of silicate solution to prepare a mesoporous silica adsorbent for heavy metals in acid mine drainage. Int. J. Environmental Technology and Management, 22, pp. 155-176.
• T Falayi 2019, Effect of potassium silicate and aluminate on the stabilisation of gold mine tailings. Proceedings of the Institution of Civil Engineers – Waste and Resource Management, 172, pp. 56-63.
• T Falayi, 2019. Alkaline Recovery of Phosphorous from Sewage Sludge and Stabilisation of Sewage Sludge Residue. Waste Management, 84, pp 166-172.
• FN Okonta, T Falayi, F Ntuli, 2019. Potassium Aluminate Geopolymerisation of Acidic Gold Mine Tailings. In: Khabbaz H., Youn H., Bouassida M. (eds) New Prospects in Geotechnical Engineering Aspects of Civil Infrastructures. GeoChina 2018. Sustainable Civil Infrastructures. Springer, Cham
• T Falayi, F. Ntuli, F.N. Okonta, 2018. Synthesis of a paste backfill geopolymer using pure acidic gold mine tailings. Journal of Solid Waste Technology and Management, 44, pp. 311-320.
• T. Falayi, F. Ntuli, F.N. Okonta, 2017. Desilication of fly ash and development of lightweight construction blocks from alkaline activated desilicated fly ash, International Journal of Environment and Waste Management, 23, pp. 233-253.
• T Falayi, FN Okonta, F Ntuli, 2017. Influence of Open Porosity, Hydration Products and Extent of Hydration on the Strength of Desilicated Lime Fly Ash Composites. Materials Science, 23, pp. 150-155.
• T Falayi, FN Okonta,  F Ntuli, 2017. Kinetic Mechanism of Desilicated Fly Ash Lime Consumption. Materials Science, 24, pp. 192-196.
• T Falayi, FN Okonta, F Ntuli, 2016. The geotechnical and microstructural properties of desilicated fly ash lime stabilised expansive soil. Materials and Structures, 49, pp. 4881–4891.
• T Sithole, F Ntuli, T Falayi, 2015. The removal of Ni & Cu from a mixed metal system using sodium borohydride as a reducing agent.   South African Journal of Chemical Engineering, 20, pp.  16-29
• T Falayi, F Ntuli, 2015. Effect of attapulgite calcination on heavy metal adsorption from acid mine drainage. Korean Journal of Chemical Engineering, 32, pp. 707-716.
• T Falayi, F Ntuli, 2013. Removal of heavy metals and neutralization of acid mine drainage with un-activated attapulgite. Journal of Industrial and Engineering Chemistry, 20, pp. 1285-1292.
• F Ntuli, T Falayi, P Molala, 2014. Adsorption of Cu and Ni from AMD using activated Bentonite.  International Journal of Research in Chemical, Metallurgical and Civil Engineering. (IJRCMCE), 1, pp. 79-83

Book Chapters

• M Moyo, T Falayi, (2022). Generation and Management of Microplastic Waste. Impact of Plastic Waste on the Marine Biota in M. Shahnawaz, M.K. Sangale, Z. Daochen and A. B. Ade (Eds), Springer Nature, Singapore
• T Mashifana, J Sebothoma, T Falayi, F Ntuli, 2019. Recovery of Thorium from phosphogypsum by acid leaching. In P Zhang, J Miller, G Akdogan, E Wingate, N Snyders (Eds) Beneficiation of Phosphates: Sustainability, Critical Materials, Smart Processes. Society for mining metallurgy and exploration, pp. 107-116.

Conference presentations & invited talks

• T Falayi, G Dzinomwa, H Musiyarira (2022). Geopolymer (green) Concrete Technology: State of art, Challenges/Gaps and way forward. 10th Sustainable Development in the Minerals Industry (SDIMI) 2022, Windhoek, Namibia
• T Falayi, G Dzinomwa, H Musiyarira (2022). Namibia - its potential role in the development and application of green hydrogen. 10th Sustainable Development in the Minerals Industry (SDIMI) 2022, Windhoek, Namibia
• T Falayi, T Mashifana & F Ntuli (2019). Silicon and aluminium leaching kinetics from acidic gold mine tailings. IOP Conference Series: Materials and Science Engineering 652 012046.
• T Falayi, T Sithole& FN Okonta (2019). Durability of desilicated fly ash lime composites. IOP Conference Series: Materials and Science Engineering 652 012047.
• T Falayi & F Ntuli (2018). Adsorption of Al, Cr and Zn from a process effluent stream using basic oxygen furnace slag. The 4th International Conference on Water Resource and Environment (WRE 2018).
• T Falayi & F Ntuli (2017). Adsorption of Zinc and Iron from acidic industrial effluent using basic oxygen furnace slag.  The 9th International Conference on Humanoid, Nanotechnology, Information Technology, Communication and Control, Environment and Management (HNICEM 2017), Manila, Philippines.
• T Falayi & F Ntuli (2017). Stabilisation and solidification of steel industry sludge. The 9th International Conference on Humanoid, Nanotechnology, Information Technology, Communication and Control, Environment and Management (HNICEM 2017), Manila, Philippines.
• F Okonta, T Falayi & R Makhado, 2017. The Strength of Lightly Cemented Power Plant Ash. Materials for Sustainable Infrastructure, Proceedings of the 1st GeoMEast International Congress and Exhibition, Egypt 2017 on Sustainable Civil Infrastructures, pp. 240-248.
• F Ntuli, T Falayi & U Thwanane, 2016. Removal of Sulphates From Acid Mine Drainage Using Desilicated Fly Ash Slag. 8th International Conference on Waste Management and the Environment, Valencia, Spain
• T Falayi, F Ntuli & FN Okonta, 2016. Preparation of mesoporous silica (MCM41) and its use as an adsorbent for heavy metals in acid mine drainage. 8th International Conference on Waste Management and the Environment, Valencia, Spain
• T Falayi, V Ngobeni & F Ntuli, 2015. Use of desilicated fly ash as an adsorbent for heavy metals in acid mine drainage. Proceeding of the International conference on solid waste, Hong Kong, pp. 1025-1028.
• T Falayi, F Ntuli & FN Okonta, 2015. Kinetic and thermodynamic parameters of silica leaching from Camden power station fly ash. Advances in Environmental and Agricultural Science, pp. 241-248.
• F Ntuli, T Falayi & C Mabasa, 2015. Adsorption, kinetic and thermodynamic study of Al, Mn and Fe adsorption with natural attapulgite. Advances in Environmental and Agricultural Science, pp. 229-235.
• F Ntuli, T Falayi & M Mabatho, 2013. A kinetic and thermodynamic study of sulphate removal from AMD using fly ash. WIT Transactions on the Built Environment, 145, pp. 259-266
• F Ntuli, T Falayi & L Harmse, 2013. Immobilisation of Co, Fe and Mn from acid mine drainage using activated bentonite. WIT Transactions on the Built Environment, 145, pp. 267-276
• F Ntuli, T Falayi & T Dlamini 2013. Thermally Activated Attapulgite as an Adsorbent for Heavy Metals.  3rd International Conference on Medical Sciences and Chemical Engineering, Bangkok, Thailand (ICMSCE'2013)
• F Ntuli, T Falayi, M Mhlungu, & P Thifhelimbilu 2013. Extraction and precipitation of phosphorous from sewage sludge: A feasibility study. 3rd International Conference on Medical Sciences and Chemical Engineering Bangkok, Thailand (ICMSCE'2013).

Social Media links

• ResearchGate: https://www.researchgate.net/profile/Thabo_Falayi
• Google Scholar: https://scholar.google.com/citations?user=IhPsnTcAAAAJ&hl=en&oi=ao