Overview

Advanced oxidation processes (AOPs) have been widely utilised for industrial wastewater treatment; however, their high cost has generally limited their application to high-strength wastewaters. Furthermore, biological treatment options for high-strength wastewater remain limited due to the toxic nature of these streams. In recent work, Professor Kun-Lin Yang and his research team demonstrated an integrated chemical-biological treatment approach that combines oxidative oligomerisation with a simultaneous nitrification-denitrification (SND) process to treat high-strength aniline wastewater, achieving near-complete removal efficiency. The process has also proven to be both highly efficient and cost-effective.

In the first stage, aniline is partially oxidised using hydrogen peroxide (H₂O₂) in the presence of a green catalyst, iron tetra amido macrocyclic ligand (Fe-TAML). This reaction produces insoluble aniline oligomers along with soluble inorganic nitrogen species, including ammonium (NH₄⁺) and nitrate (NO₃⁻). Microscopic analysis revealed that the insoluble aniline oligomers consist of colloidal particles with an average size of 890 nm, forming a sticky precipitate layer that can be readily separated by decantation.

The remaining nitrogen species are subsequently treated biologically using Thauera sp. strain SND5. Prior to inoculation, the solution contained 28.5 mg/L NH₄⁺ and 40.2 mg/L NO₃⁻. Following 48 hours of incubation, these concentrations were reduced to 1.6 mg/L and 3.4 mg/L, respectively. After further optimisation, the research team successfully applied the process to real high-strength industrial wastewater, demonstrating its effectiveness under practical operating conditions.

This environmentally friendly integrated chemical-biological treatment process offers a promising and sustainable solution for the treatment of high-strength industrial wastewater.

Speaker

Dr Yang Kun-Lin, Associate Professor and Deputy Head of the Department, National University of Singapore 

Dr Yang Kun-Lin is currently an Associate Professor and Deputy Head of the Department of Chemical Engineering and Biomolecular Engineering at the National University of Singapore (NUS). His research areas include liquid crystal elastomers, microfluidic systems, and chemical and biological sensors. As a pioneer in the field of liquid crystal microfluidic sensors, he has leveraged this platform to develop a series of real-time, naked-eye sensors capable of detecting poisonous gases, proteins, nucleic acids, and antibody antigens.

In addition to his contribution to sensors, Dr Yang is also an expert in green technology, wastewater treatment and biofuels. His green catalysts and oxidation processes have been widely used in industrial applications, including oil bleaching, wastewater treatment, sludge digestion, and production of sustainable aviation biofuels. Over the past five years, he has actively translated his research findings into start-up companies, including GreenAct, GreenCOP and GreenDr. Notably, GreenCOP has received several awards, including Shell Startup Engine (2022), 1st runner-up in Pier 71 Smart Port Challenge (2022), University Startup World Cup Global Challenge Award (2023), and Grand Finalist in the Liveability Challenge by Temasek Foundation (2024).

Dr Yang has more than 160 papers and 10 patents under his name. He has also been invited to serve as a consultant for many companies, assisting them in addressing sustainability and wastewater challenges.

He obtained his Doctor of Philosophy from Georgia Institute of Technology, and a Bachelor of Science in Engineering from National Taiwan Univ. He is a Chartered Engineer and is the chair of Water SIG, Singapore. 

Time

21:00 - 22:00 SGT