浙江近岸海域表层沉积物中氮的存在形态及其含量的分布特征

Nitrogen forms and their concentration distribution in surface sediments of Zhejiang offshore

运用分相浸取法分析了浙江近岸海域60个站位的表层沉积物(0～2 cm)中各形态氮的含量和分布.研究结果表明,表层沉积物中总氮(TN)含量为214.66～861.44 mg/kg,均值为580.52mg/kg,位于浅水区的长江口、杭州湾和浙江沿岸的TN含量低于东部远岸海域;可转化态氮(TTN)含量只占总氮的3.06%～37.24%,有机态和硫化物结合态氮(OSF-N)是沉积物中可转化态氮的主要赋存形态,非转化态氮(NTN)是浙江近岸海域表层沉积物中的优势形态.各站位沉积物中氮在不同提取相中的含量差异较大,与沉积物的陆源输入、沉积物重金属含量、粒径分布及沉积海域的水动力条件等因素有关.

Different forms of nitrogen in surface sediments of Zhejiang offshore were studied with sequential extraction method.The result show that total nitrogen concentration in offshore surface sediments of Zhejiang ranged from 214.66 to 861.44 mg/kg with an average 580.52 mg/kg,and the concentration of TN was found higher in the eastern offshore of Zhejiang than Changjiang Estuary,Hangzhou Bay and Zhejiang coastal area.Transferable nitrogen,accounting for least part of total nitrogen,varied from 3.06% to 37.24%.Organic matter-sulfide form（OSF） is the dominant form of transferable nitrogen while non-transferable form is the dominant form in the surface sediments.Distribution of nitrogen forms is controlled by environmental factors,such as terrigenous inputs,grain size,heavy metal contents in surface sediments and hydro-dynamics.