title: Role of microgel formation in scavenging of chromophoric dissolved organic matter and heavy metals in a river-sea system.
abstract: We use riverine and marine dissolved organic carbon (DOC) polymers to examine their aggregation behavior, and to evaluate the roles of microgel formation in scavenging of chromophoric dissolved organic matter (CDOM) and heavy metals in a river-sea system. Our results indicate that riverine and marine microgels did not exhibit very much difference in size and self-assembly curve; however, the assembly effectiveness ([microgel]/DOC) of marine samples was much higher than riverine. Instead of concentration of DOC, other factors such as types and sources of DOC polymers may control the microgel abundance in aquatic environments. After filtering water samples (microgels removed), the CDOM and selected metals (Cu, Ni, Mn) in the filtrate were quantified. CDOM and metals were concurrently removed to an extent via DOC polymer re-aggregation, which also suggested that the microgels had sequestering capability in CDOM and metals. This finding provides an alternative route for CDOM and heavy metals removal from the water column. As such the process of re-aggregation into microgels should then be considered besides traditional phase partitioning in the assessment of the ecological risk and fate of hazardous materials.
authors.affiliation: Department of Marine Environment and Engineering, National Sun Yat-sen University, Kaohsiung, Taiwan.
authors.forename: Ruei-Feng
authors.initials: RF
authors.lastname: Shiu
authors.affiliation: Department of Marine Environment and Engineering, National Sun Yat-sen University, Kaohsiung, Taiwan; Department of Public Health, College of Health Science, Kaohsiung Medical University, Kaohsiung, Taiwan; Asia-Pacific Ocean Research Center, National Sun Yat-sen University, Kaohsiung, Taiwan; Research Center for Environmental Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan. Electronic address: linnohc@fac.nsysu.edu.tw.
authors.forename: Chon-Lin
authors.initials: CL
authors.lastname: Lee
keywords: Aggregation; Chromophoric dissolved organic matter; Heavy metals; Microgel; Scavenging