海水中过氧化氢的研究进展

Abstract

海水中过氧化氢(H2O2)能与多种痕量金属发生氧化还原反应并改变其存在状态,从而间接影响海洋生态系统。综述了过去30多年的研究结果并提出进一步研究方向。H2O2在100~200M以浅的上层海洋中普遍存在,浓度介于0~102nMOl/l之间。H2O2在表层含量最高,随深度增加而减小;近岸海区H2O2浓度通常高于寡营养大洋;并且海水中H2O2出现典型的周日波动(白天浓度增加,于午后达到最大值后逐渐降低,至黎明达到最低值)。海水中H2O2的来源包括光化学生产、大气沉降和生物生产,一般以光化学生产为主。去除过程包括生物分解、光化学分解和化学分解,以生物分解为主。目前对H2O2在受河流影响的近岸陆架海区中的生物地球化学、光化学生产的影响因素以及H2O2的去除机制尚缺乏全面认识,在这些方面还需更多研究。

Hydrogen peroxide can oxidize or reduce a number of biological important trance metals in seawater.Therefore,it can indirectly affect the marine ecosystem by causing the changes in the speciation of these metals.The results of researches about hydrogen peroxide in seawater in the last more than thirty years were reviewed and the direction of study in the further was proposed in this paper.Hydrogen peroxide can be found rather ubiquitously in the upper water at concentration of 0 ~ 102nmol /L.In water column the maximum of the concentrations of hydrogen peroxide presents in surface water and the concentrations decrease with the increase of depth.In general,the concentrations in costal seawater are higher than these in the oligotrophic ocean.Diel variation of hydrogen peroxide occurs in seawater: the concentrations increase since sunup until the mixmum of afternoon and decrease until the minimum at drawn.The sources of hydrogen peroxide in marine environment include photochemical production,atmospheric deposition and biological production,and the photochemical production is primary among them.The sinks of hydrogen peroxide in the ocean consist of biological and chemical and photochemical decomposition and the main one is biological decomposition.The biogeochemistry of hydrogen peroxide in the continental shelf influenced by river water and factors affecting photochemical production and detail of decomposition should be studied in the future.