Qian Gao

Year Admitted
2017

Year Graduated
2022

Research Areas
The application of magnetic material and nanotechnology for water quality improvement.

Faculty Advisor
Arturo Keller

Committee
Patricia Holden, Helene Gardner

Dissertation Title & Abstract

Novel disinfection system with recyclable magnetic nanoparticles and metal ions: Evaluation with bacteria, algae, and virus

Water pollution with pathogenic microorganisms is one of the serious threats to human health, particularly in developing countries. Although traditional disinfection technologies are effective to control microorganism contamination in water and have been widely applied in wastewater treatment plants, the disadvantages, such as disinfection byproducts or high energy consumption, are major concerns when considering sustainable use. Thus, this dissertation proposed a novel disinfection system with an optimization of the traditional methods, by using metal ions as disinfectants and aided by magnetic nanoparticles to achieve sustainable treatment. Various microorganisms, including bacteria, toxic cyanobacteria, and waterborne viruses were used for case studies to evaluate the efficacy of this novel method, and the reusability of disinfectants and magnetic nanoparticles were explored for long term application. Chapter 1 demonstrated the feasibility of this novel disinfection method with a case study on E. coli. Chapter 2 optimized the disinfection method for cyanobacteria contamination and achieved the simultaneous removal of both residual metal ions and the cyanotoxins, making the system suitable for a complicated environment. Chapter 3 shortened the time needed for operating the system by using the magnetic nanoparticles with adsorbed metal ions as the disinfectants, and evaluated the disinfection effectiveness on waterborne viruses.

Education
MS Environmental Science, Peking University