盐碱地区沉积物磷释放特性及影响因素

为研究沉积物磷释放对盐碱地区景观水体富营养化的影响,以天津滨海新区泰达河道为对象,应用沉积物中磷形态的标准测试方法（SMT）,分析了沉积物中磷的形态;研究了沉积物中磷的解吸动力学,并探讨了水力扰动、pH和盐度对沉积物中磷解吸的影响。结果表明,无机磷（IP）为沉积物中磷的主要形态,总量为0.637 mg/g,IP中又以钙磷（Ca-P）为主,约占IP的80%,而铁/铝磷（Fe/Al-P）仅占20%。0-4 h为磷的快速解吸阶段,4-24 h为慢速解吸阶段,并逐渐达到平衡。泰达河道沉积物对磷具有一定的吸持能力,不易解吸。增强水力扰动的强度会促进磷的解吸,但影响不大;在碱性条件下,增加pH对磷的解吸没有显著影响;增加水体盐度,能促进磷的解吸。

Desorption characteristic of phosphorus from a canal sediment in saline areas and influencing factors

In order to elucidate the effect of phosphorus release in sediment on eutrophication of landscape river in coastal saline areas,phosphorus forms in the sediment of TEDA Canal in Tianjin Binhai Area were investigated using the standard measurement and test（SMT）procedure for phosphorus forms in sediment.The desorption kinetics of phosphorus in the sediment and its influencing factors were also discussed,which included disturbance,pH and salinity.The results indicated that the sediment were dominated by inorganic phosphorus（IP） and Ca-P was the major part of IP,which accounted for 80% of IP.Rapid desorption of phosphorus occurred in 0 - 4 h,then phosphorus was desorbed slowly in 4 - 24 h and gradually reached equilibrium.It was not easy for phosphorus to desorb because of the phosphorus sorption ability of the sediment.Increasing the intensity of hydraulic disturbance can promote the desorption of phosphorus,but the impact was not great.Under alkaline conditions,increasing the pH of solution has no significant influence on desorption of phosphorus.High salinity can facilitate phosphorus to desorb from sediment.