Journal Article

Inorganic Carbon of Sediments in the Yangtze River Estuary and Jiaozhou Bay

Song, Jinming, Li, Xuegang, Yuan, Huamao

2006

Overview

JGOFS results showed that the ocean is a major sink for the increasing atmospheric carbon dioxide resulting from human activity. However, the role of the coastal seas in the global carbon cycling is poorly understood. In the present work, the inorganic carbon (IC) in the Yangtze River Estuary and Jiaozhou Bay are studied as examples of offshore sediments. Sequential extraction was used to divide inorganic carbon in the sediments into five forms, NaCl form, NH₃·H₂O form, NaOH form, NH₂OH·HCl form and HCl form. Studied of their content and influencing factors were also showed that NaCl form < NH₃·H₂O form < NaOH form < NH₂OH·HCl form < HCl form, and that their influencing factors of pH, Eh, Es, water content, organic carbon, organic nitrogen, inorganic nitrogen, organic phosphorus and inorganic phosphorus on inorganic carbon can be divided into two groups, and that every factor has different influence on different form or on the same form in different environment. Different IC form may transform into each other in the early diagenetic process of sediment, but NaCl form, NH₃·H₂O form, NaOH form and NH₂OH·HCl form may convert to HCl form ultimately. So every IC form has different contribution to carbon cycling. This study showed that the contribution of various form of IC to the carbon cycle is in the order of NaOH form > NH₂OH·HCl form > NH₃·H₂O form > NaCl form > HCl form, and that the contribution of HCl form contributes little to carbon cycling, HCl form may be one of end-result of atmospheric CO₂. So Yangtze River estuary sediment may absorb at least about 40.96×10¹¹ g atmospheric CO₂ every year, which indicated that offshore sediment play an important role in absorbing atmospheric CO₂.

• Publisher: Springer,Springer Nature B.V
• Subject: Ammonia / Atmospherics / Biogeochemical cycle / Brackish / Carbon cycle / Carbon dioxide / Cluster analysis / Coastal waters / Diagenesis / Dissolution / Earth sciences / Earth, ocean, space / Estuaries / Estuarine dynamics / Exact sciences and technology / Geochemistry / Hydrogen chloride / Inorganic carbon / Marine and continental quaternary / Moisture content / Nitrogen / Offshore / Organic carbon / Organic nitrogen / Organic phosphorus / Phosphorus / Rivers / Seas / Sediment / Sediments / Sodium chloride / Sodium hydroxide / Soil and rock geochemistry / Surficial geology / Water content