title: Carbonaceous particles reduce marine microgel formation.
abstract: An increase in ambient carbonaceous particle (CNP) levels has been found, potentially leading to significant environmental/health hazards. These particles will ultimately enter the oceanic environment and interact with dissolved organic carbon. However, a detailed mechanistic understanding of their behavior, transport, and fate in marine systems is still much needed. This study, using carbon black (CB, 14 nm) nanoparticles as a model, aimed to investigate the impact of CNPs on marine microgel formation, a critical shunt between DOC and particulate organic carbon that potentially represents a ~70-Gt organic carbon flux. We found that CB can enhance the stability of DOC polymers and reduce microgel equilibrium sizes in concentration as low as 1 μgL(-1) CB, possibly due to negative surface charges on CB that decrease cross-linking bridges through Ca(2+) bonds. The reduction of marine microgel formation induced by CB could lead to a decrease in the downward transportation of microbial substrates and nutrients, and therefore, could have a significant impact on the carbon cycle and the marine ecosystem.
authors: Department of Marine Environment and Engineering, National Sun Yat-sen University, 80424 Kaohsiung, Taiwan, ROC.
authors: Ruei-Feng
authors: RF
authors: Shiu
authors: School of Engineering, University of California at Merced, Merced, California, USA.
authors: Wei-Chun
authors: WC
authors: Chin
authors: 1] Department of Marine Environment and Engineering, National Sun Yat-sen University, 80424 Kaohsiung, Taiwan, ROC [2] Kuroshio Research Group, Asia-Pacific Ocean Research Center, National Sun Yat-sen University, 80424 Kaohsiung, Taiwan, ROC.
authors: Chon-Lin
authors: CL
authors: Lee
mesh_terms: D002122:Calcium Chloride / Q000737:chemistry; D057486:Carbon Cycle; D005782:Gels; D053758:Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D052638:Particulate Matter / Q000737:chemistry*; D012623:Seawater / Q000737:chemistry*; D012965:Sodium Chloride / Q000737:chemistry; D053260:Soot / Q000737:chemistry*; D055672:Static Electricity; D014874:Water Pollutants, Chemical / Q000737:chemistry*
chemical_list: D005782:Gels; D052638:Particulate Matter; D053260:Soot; D014874:Water Pollutants, Chemical; D012965:Sodium Chloride; D002122:Calcium Chloride