Kandasamy Thangavadivel (PhD Student)
University of South Australia

Project Title
Development and application of high frequency ultrasound for persistent organic remediation

Biography
Kandasamy is a chemical engineer with over 12 years of experience in water & waste water treatment plant design, installation, commissioning and operation. As a process engineer, he was responsible for copper plating, gold plating and gold recovery process of one of the world leading PCB company. He also worked for a sulfuric acid and alum production plant and completed his MSc in environmental technology. Kandasamy enjoys reading psychology books and exploring nature.

Start Date
August 2006

Project Details
A chemical which is very stable to the chemical and biological system is known as persistent. There are a lot of persistent organic contaminated sites in Australia, mainly located in New South Wales. Cattle–dip sites have highly polluted with DDT, which is a one of the persistent organic pollutants. Plants grown in this area too will have DDT contamination. When animals eat these contaminated plants, the animal will then also ingest DDT. Since humans are at the top of the food chain, DDT can accumulate in humans and be transmitted to the next generation, and is suspected of causing cancer and affecting the nervous system.

The polluted sites are mainly located in rural areas, and require a very low-cost but effective solution to remediate them. Among the existing technologies, the thermal process is the most effective method - but is also very expensive. Secure landfill does not eliminate the pollutant, and so it will be a long-term burden to society.

Ultrasound is an emerging technology, and uses the pressure wave to transmit the energy. It has a very high potential to remediate the contaminated soil in a cost-effective way. This study will focus on the application of high frequency ultrasound to remediate the persistent organic contaminated soil. The commercial software will be used to optimise the reactor design.

PhD Thesis Abstract - Summary
The necessity of cost-effective, environmentally-friendly technology has become increasingly important to remediate persistent organic pollutants (POPs) in the environment. The emerging greener ultrasound technology has the potential to serve the remediation industry. In this study, the use of low power, high frequency (HF) ultrasound (1.6 MHz, 145 W/L) has been shown to effectively remediate the non-polar, volatile POP known as DDT in water and sand slurries.