沉积物可交换态磷量与颗粒物浓度的关系探讨  

Discussions on the relationship betweenexchangeable phosphorus in sediments and the concentration of particulate matter

作　　者：欧志超 高增文 程晨 OU Zhichao;GAO Zenwen;CHENG chen(College of Environmental Science and Engineering,Qingdao University,Qingdao 266071,China;Nanjing Institute of Geography&Limnology Chinese Academy of Sciences,Nanjing 210008,China;University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]青岛大学环境科学与工程学院,山东青岛266071 [2]中国科学院南京地理与湖泊研究所,江苏南京210008 [3]中国科学院大学,北京100049

出　　处：《海洋湖沼通报》2022年第2期35-40,共6页Transactions of Oceanology and Limnology

基　　金：中海油能源发展专项(ZX2020ZCGCF6839)。

摘　　要：天然沉积物上的可交换态磷量对水体磷浓度具有重要的调控作用,它是水体富营养化预测与调控时关注的重点之一。截距法是计算沉积物可交换态磷量的常用方法,通过该方法计算的可交换态磷量常与固体浓度(C_(s))正相关,这与提取法和固体浓度效应理论的结果相反。故本文通过理论分析与实验探讨截距法出现正相关关系的潜在原因。结果表明,截距法计算的结果可以表示在实验条件下沉积物与水体间可交换的磷量(Q_(0)),而不能表示沉积物全部含有的可交换磷量(NAP)。对于同一组实验数据,吸附等温图横坐标的选择影响Q_(0)与C_(s)的相关关系:以初始磷浓度(C_(0))为横坐标对应的Q_(0)-C_(s)是负相关关系,以平衡磷浓度(C_(e))为横坐标对应的Q_(0)-C_(s)是正相关关系。此外,若以C_(e)为横坐标,计算得到的Q_(0)的物理含义不明确。因此,为尽可能避免C_(s)与Q_(0)正相关关系的出现以及使Q_(0)的含义合理化,建议在使用截距法时宜以C_(0)为横坐标。Exchangeable phosphorus in natural sediments plays an important role in regulating phosphorus concentration in water columns,and it is one of the focuses considered in the prediction and regulation of water eutrophication.The intercept method is usually used to calculate the concentration of exchangeable phosphorus in sediment which is positively correlated with the solid concentration(C_(s)).However,this result is contrary to that obtained by the extraction method.This study discusses the potential causes of the contradiction through theoretical and experimental analyses.The results show that the phosphorus from the intercept method is not the total amount of native absorbed phosphorus(NAP),but the amount of phosphorus(Q_(0))involved in the exchange process under actual experimental conditions.For the same set of experimental data,the selection of the abscissa for the adsorption isotherm affects the correlation between Q_(0) and C_(s):negative when C_(0) is used,but positive when C_(e) is used.In addition,if C_(e) is taken as the abscissa,the physical meaning of the calculated Q_(0) is unclear.Therefore,in order to avoid the positive correlation between C_(s) and Q_(0),we suggest that the initial phosphorus concentration(C_(0))should be used as the abscissa when obtaining Q_(0) by the intercept method.

关 键 词：截距法 沉积物 可交换态磷 固体浓度效应 

分 类 号：X55[环境科学与工程—环境工程]