Pollution is one of the major concerns not only in environmental research, but also in our society. Waterways are the most vulnerable areas and it can carry pollutants.

It includes the issues of dispersion of the trace elements in the natural aqueous systems (including pharmaceuticals and hormones); engineered nanostructures (degradation concerns); and inefficiency of the water treatment plants (WTPs) to treat the trace elements.

These concerns were discussed in the lecture entitled “Trace Metal Hosts and Transporters- Zeta Potential and Contaminants” by Dr. Jessica D. Villanueva, Science Research Collaborator and PhD Graduate of University of Bordeaux, Pessac, France, last March 14, 2017 at SESAM Lecture Hall, UP Los Baños.

As a researcher in hydrogeochemistry, Dr. Villanueva characterized the particles as hosts and transporters of contaminants (trace metals). She also sought to know the importance of the zeta potential and particle suspension phase in natural tropical aqueous system (aggregate vs. suspension). Also in her study, she also described the general behavior of the particles and trace metals.

Dr. Villanueva defined zeta potentials as the surface change– the potential difference between the dispersion medium and the stationary layer of fluids attached to a dispersed particle. She added that once the particle is in the water, it will be hydrated and its hydrodynamic size will change. 

“In particle science, 1 nanometer to 1 micrometer are called colloids, which can carry contaminants”, Dr. Villanueva said. She added commercial colloids are engineered for suspension to prevent sedimentation.

“It is really difficult to detect, since smaller particles are easily accessible to microorganisms and these microorganisms can be adsorbed and/or absorbed by organisms channeling to humans”, Dr. Villanueva stressed.

According to particle science, the factors considered in her study of particle science were surface change; nature/type of group; number and distribution dissociation; preferential adsorption; hydrophobic/hydrophilic balance; surface (interfacial) tension; and contact angle.

Dr. Villanueva graduated BS Economics at UP Los Baños and was a former research associate of SESAM in 2009. SESAM students, faculty and research staff attended her presentation.