title: Determination of Sediment Oxygen Demand in the Ziya River Watershed, China: Based on Laboratory Core Incubation and Microelectrode Measurements.
abstract: A study coupling sedimentcore incubation and microelectrode measurement was performed to explore the sediment oxygen demand (SOD) at 16 stations in the Ziya River Watershed, a severely polluted and anoxic river system in the north of China. Total oxygen flux values in the range 0.19-1.41 g/(m²·d) with an average of 0.62 g/(m²·d) were obtained by core incubations, and diffusive oxygen flux values in the range 0.15-1.38 g/(m²·d) with an average of 0.51 g/(m²·d) were determined by microelectrodes. Total oxygen flux obviously correlated with diffusive oxygen flux (R² = 0.842). The microelectrode method produced smaller results than the incubation method in 15 of 16 sites, and the diffusive oxygen flux was smaller than the total oxygen flux. Although the two sets of SOD values had significant difference accepted by the two methods via the Wilcoxon signed-rank test (p < 0.05), the microelectrode method was shown to produce results that were similar to those from the core incubation method. The microelectrode method, therefore, could be used as an alternative method for traditional core incubation method, or as a method to verify SOD rates measured by other methods. We consider that high potential sediment oxygen demand would occur in the Ziya River Watershed when the dissolved oxygen (DO) recovered in the overlying water.
authors.affiliation: State Key Laboratory on Environmental Aquatic Chemistry, Research Center for Eco-Environmental Science, Chinese Academy of Science, Beijing 100085, China. rongnan420@163.com.|University of Chinese Academy of Science, Beijing 100049, China. rongnan420@163.com.
authors.forename: Nan
authors.initials: N
authors.lastname: Rong
authors.affiliation: State Key Laboratory on Environmental Aquatic Chemistry, Research Center for Eco-Environmental Science, Chinese Academy of Science, Beijing 100085, China. bqshan@rcees.ac.cn.
authors.forename: Baoqing
authors.initials: B
authors.lastname: Shan
authors.affiliation: Changjiang Water Resource Protection Institution, Wuhan 430051, China. cwwhu@163.com.
authors.forename: Chao
authors.initials: C
authors.lastname: Wang
mesh_terms: D057919:Biological Oxygen Demand Analysis; D002681:China; D004784:Environmental Monitoring / Q000379:methods*; D019015:Geologic Sediments / Q000032:analysis*; D008839:Microelectrodes; D010100:Oxygen / Q000032:analysis*; D045483:Rivers / Q000737:chemistry*; D014867:Water; D014874:Water Pollutants, Chemical / Q000032:analysis
chemical_list: D014874:Water Pollutants, Chemical; D014867:Water; D010100:Oxygen
keywords: microelectrode; microprofile; oxygen flux; sediment oxygen demand; the Ziya River Watershed