原位覆盖控制沉积物磷释放效果的验证评估  

Validation and Evaluation of In-situ Capping for Controlling Phosphorus Release in Sediment

作　　者：王增龙 吴志皓[2,3] 王书航[2,3] 姜霞[2,3] 李艳华 田雨桐 包牧仁 王前勇 庞博 敖文 WANG Zenlong;WU Zhihao;WANG Shuhang;JIANG Xia;LI Yanhua;TIAN Yutong;BAO Muren;WANG Qianyong;PANG Bo;AO Wen(Hulunbuir Academy of Inland Lakes in Northern Cold and Arid Areas,Hulunbuir 021008,China;National Engineering Laboratory for Lake Pollution Control and Ecological Restoration,Institute of Lake Ecological Environment,Chinese Research Academy of Environmental Sciences(CRAES),Beijing 100012,China;State Environmental Protection Key Lab for Lake Pollution Control,Institute of Lake Ecological Environment,Chinese Research Academy of Environmental Sciences(CRAES),Beijing 100012,China)

机构地区：[1]呼伦贝尔市北方寒冷干旱地区内陆湖泊研究院,内蒙古呼伦贝尔021008 [2]中国环境科学研究院湖泊生态环境研究所,湖泊水污染治理与生态修复技术国家工程实验室,北京100012 [3]中国环境科学研究院湖泊生态环境研究所,国家环境保护湖泊污染控制重点实验室,北京100012

出　　处：《环境科学与技术》2024年第4期140-151,共12页Environmental Science & Technology

基　　金：呼伦湖保护区科学技术研究能力加强关键技术研究项目委托课题1期(2022-地方科研-0071);国家重点研发计划项目(2022YFC3204000,2022YFC3204004)。

摘　　要：文章通过覆盖材料(方解石、湖沙或方解石+湖沙)对底泥磷释放的阻控实验以及利用梯度扩散薄膜(DGT)的底泥原位测试,验证评估覆盖剂对呼伦湖沉积物磷的生态修复效果。结果发现:(1)方解石、方解石+湖沙或湖沙能有效降低表层沉积物的DGT-P浓度(CDGT(PO_(4)^(3-)-P)),沉积物/水界面扩散通量和上覆水溶解反应性磷;方解石、方解石+湖沙覆盖的表层沉积物的CDGT(PO_(4)^(3-)-P)峰值或平均值明显低于对照样;方解石、方解石+湖沙的上覆水DRP的去除率分别超过78%和81%;方解石+湖沙可以将沉积物/水界面无机磷扩散通量降低至负值;(2)方解石和方解石+湖沙能明显地降低表层沉积物总磷(TP)、活性磷(NH_(4)Cl-P和BD-P)含量及其占TP的百分比,沉积物反应性磷再补给系数r减少而惰性成份(NaOH_(85)-P和Ca-P)及其占TP的百分比增加;(3)方解石+湖沙覆盖的表层沉积物TP变化范围:-45~-30 mg/kg;磷提取相(NH_(4)Cl-P、BD-P、Ca-P和NaOH_(85)-P)含量变化值,磷提取相变化量占对照沉积物对应提取成份的百分比分别为-17~-10 mg/kg (-38.46%~-29.31%);-23~-16 mg/kg (-46.15%~-32.86%);10~15 mg/kg (2.41%~3.63%)和8~14 mg/kg(3.20%~3.99%);r降低范围:0.02~0.19。综上,方解石的吸附或阻隔作用能降低沉积物总磷和活性磷,降低沉积物磷再补给能力;NH_(4)Cl-P和BD-P被转化为情性成份(NaOH_(85)-P和Ca-P),磷迁移性降低。覆盖剂对沉积物磷内源负荷控制效果为方解石+湖沙>方解石>湖沙。方解石+湖沙的磷阻控机制是方解石对磷的吸附,磷和方解石的共沉淀以及湖沙的物理阻隔;方解石+湖沙的多层覆盖是一种应用价值较高的沉积物原位修复技术。By way of the experiment regarding the obstruct/control of P release in bottom sediments by use of calcite,lake sand and calcite+lake-sand,and the in-situ sediment test by diffusive gradients in thin films(DGT),the ecological resto-ration of P-containing sediments in Lake Hulun using the covering materials was validated and evaluated.Consequently,the results obtained presented that calcite,lake-sand and calcite+lake-sand could effectively depleted DGT concentrations of P(CDGT(PO_(4)^(3-)-P)in top sediments,diffusive fluxes at sediment/water interface and dissolved reactive P in overlying water;CDGT(PO_(4)^(3-)-P)peak value in top sediment covered by calcite and calcite+lake-sand were distinctly lower than that of the con-trol sediment sample,and removal efficiencies of DRP(dissolved reactive phosphorus)in overlying water exceeded 78%and 81%,respectively;the diffusive fluxes of inorganic P in sediment/water interface would be reduced to negative value as calcite+lake-sand was used.Calcite and calcite+lake-sand could remarkably reduced the contents of TP(total P)and reactive P(NH_(4)Cl-P and BD-P),and the percentage of reactive P/TP and the re-supply constant of reactive P in surface sediment(r)were declined,while the(NaOH_(85)-P or Ca-P)was increased,as well as the percentage of inert P fraction in TP;and for the top sediments that were covered by calcite+lake sand,the variation range of TP was between-45 and-30 mg/kg;the variation amounts of NH_(4)Cl-P,BD-P,Ca-P or NaOH_(85)-P,and the percentage of the variation of P fraction of covered sediments in the corresponded fraction in the control sediment were in the ranges of-17 to-10 mg/kg(-38.46%to-29.31%),-23 to-16 mg/kg(-46.15%~-32.86%),10 to15 mg/kg(2.41%to 3.63%)or 8~14 mg/kg(3.20%to 3.99%),respectively and the reduction range of r was between 0.02 and 0.19.In summary,the effects of adsorption and obstruction of covering ma-terials could reduce TP and reactive P contents and thus depleted the re-supply ability of sediment P.NH_(4)Cl-P and BD-P turned into inert f

关 键 词：原位覆盖 方解石 梯度扩散薄膜 沉积物/水界面 内源负荷 

分 类 号：X52[环境科学与工程—环境工程]