SEDIMENT OXYGEN DEMAND AND RELEVANT FACTORS IN WETLAND OF MANGROVE FOREST IN HAINAN ISLAND
海南红树林湿地沉积物耗氧及其相关因素

SOD (Sediment oxygen demand) was measured by a new SOD determination device (self-owned intellectual property rights) in Hainan island mangrove forest during August, 2009, and the relevant factors were studied simultaneity. The result showed that the process of SOD of mangrove wetland consists of two stages, which are instantaneous oxygen demand stage and decrescent oxygen demand stage. The SOD ranged from 120mg/(m2·h) to 160mg/(m2·h) and instantaneous oxygen demand value accounted for 23.3% to 45.5% of the total SOD. The correlation between SOD and environmental factors were also analyzed. There are distinct positive correlation between SOD and sulfide content in sediment and COD, NH4+ concentration in overlay water, while the correlation between SOD and organic matter in sediment is unconspicuous. Organic matters are released to water from mangrove sediment, which will consume oxygen and cause water pollution, so it is valuable to reconsider to employ mangrove wetland to treat urban waste water.