Title   The Roles of Soil Microorganisms on Phytoremediation of Contaminated Sites

Speaker   Dr. Li Wai Chin, SES, HKIEd

Abstract   Heavy metals and polycyclic aromatic hydrocarbons are two of the most abundant and potentially harmful pollutants found in most contaminated soils. Phytoremediation present a viable environmental and economical option to eliminate the contaminants. However, practical drawbacks, such as the bioavailability of heavy metals for plants, can reduce the applicability and efficiency of phytoextraction. Recent studies showed that many soil microorganisms are tolerant to contaminants and play significant roles in recycling of plant nutrients, maintenance of soil structure and detoxification of noxious chemicals. Soil microbes have also been shown to facilitate several mechanisms that change metal bioavailability in soil which provides a new strategy for investigating biogeochemical cycling of contaminants in the environment.

About the speaker: Dr. Li received his B.Sc. in Applied Biology (Major in Environmental Science) and Ph.D. from Hong Kong Baptist University. After graduation, he was a lecturer and course coordinator of Environmental Conservation Studies at College of International Education, Hong Kong Baptist University during 2007-2012. Dr Li has been invited as speaker for the Regional Training Course on Novel Technology for Marine Environmental Management organized by a GEF/UNDP Regional programme. His current research mainly focuses on the interrelationship among microorganism, plant and toxic metal in soil.

Title   Fluvial sediment quality and provenance in the East River, China

Speaker   Dr. Fok Lincoln, SES, HKIEd

Abstract   Fluvial sediments, as a product of erosion, are associated with a wide range of environmental issues. In particular, sediment quality and its origin represent one of the focuses of contemporary water management. A field survey was carried out in 2007 to 2008 to evaluate the sediment quality and provenance of the East River basin in South China. The study basin is a humid sub-tropical macro scale catchment which supplies ~70% of potable water to Hong Kong. A geochemical baseline, along with its spatial distribution, was developed for the study basin. The geochemistry was generally consistent with upper crustal abundance of China and with world average suspended matter concentrations, although some analytes, such as arsenic and sulphur, were elevated and were found to associate with anthropogenic activities. Sediment source apportionment was carried out by utilizing the fingerprinting procedure on three geologic groups. Results indicate that provenance of sediments in the East River was more or less uniform among the different geologies, but the accuracy of the apportionment has been compromised by the relatively high within-group variance of the source categories. Moreover, source apportionment was only viable by utilizing the <63-m fraction, and grain size correction factor shall not be employed on samples with a high granulometric variance. REE represents a robust signature to indicate provenance from igneous lithology, in particular, granites.

About the speaker: Dr. Fok is a physical geographer who obtained his MPhil and PhD in the University of Hong Kong.  After graduation, he joined the Department of Science and Environmental Studies at the Hong Kong Institute of Education.  His research interest focuses upon hydrology with a particular emphasis on the impacts of water and sediment quality and their implications on the environment.  In addition to his main field of research on applied hydrology, Lincoln has also published journal articles on climate change and natural hazards.