流速对沟渠磷消纳的影响  

Effects of flow rate on phosphorus absorption in ditches

作　　者：佟德利 李梦琦 王海翔 陈浩 夏永秋[2] 王慎强[2] 汪玉 TONG Deli;LI Mengqi;WANG Haixiang;CHEN Hao;XIA Yongqiu;WANG Shenqiang;WANG Yu(College of Life Science,Shenyang Normal University,Shenyang 110034,China;State Key Laboratory of Soil and Sustainable Agriculture,Institute of Soil Science,Chinese Academy of Sciences,Nanjing 210008,China)

机构地区：[1]沈阳师范大学生命科学学院,沈阳110034 [2]中国科学院南京土壤研究所,土壤与农业可持续发展国家重点实验室,南京210008

出　　处：《农业环境科学学报》2025年第1期117-125,共9页Journal of Agro-Environment Science

基　　金：国家重点研发计划项目(2021YFD1700802);国家自然科学基金项目(42277026);长江生态环境保护修复联合研究二期项目(2022-LHYJ-02-0502-05)。

摘　　要：为探究农业排放中沟渠磷消纳的过程,采用沟渠模拟系统,在不同流速(0、1、3、6、10 cm·s^(-1))下探究水体中磷的消纳过程和影响因素,实验设置4个不同处理,分别为S-0.2处理(无植物,初始磷浓度为0.2 mg·L^(-1))、S-0.5处理(无植物,初始磷浓度为0.5 mg·L^(-1))、S+I.-0.2处理(种植水生鸢尾,初始磷浓度为0.2 mg·L^(-1))以及S+I.-0.5处理(种植水生鸢尾,初始磷浓度为0.5 mg·L^(-1))。结果表明:S-0.2、S-0.5、S+I.-0.2和S+I.-0.5处理的全磷(TP)消纳速率均随流速的增加而减小,水体TP消纳速率分别从流速为0时的24.1、63.5、37.5μmol·m^(-2)·h^(-1)和72.9μmol·m^(-2)·h^(-1),降至流速为10 cm·s^(-1)时的5.01、3.92、5.06μmol·m^(-2)·h^(-1)和12.1μmol·m^(-2)·h^(-1)。流速扰动作用影响水-沉积物界面,增加了水体颗粒态磷(PP)的浓度。流速为0时水体PP分别为0.005、0.006、0.005 mg·L^(-1)和0.009 mg·L^(-1),而流速为10 cm·s^(-1)时水体中PP浓度增加至0.04、0.08、0.03 mg·L^(-1)和0.06 mg·L^(-1)。此外,初始磷浓度相同时,种植水生鸢尾可提高水体平均TP消纳速率17%~34%,且也会吸收更多的可溶性无机磷。研究表明,低流速有利于磷的沉降和吸附,流速的增加会促进底泥扰动,导致PP释放;此外,种植植物有助于沟渠中磷的消纳。To explore the process of phosphorus absorption in ditches in agricultural emissions,a ditch simulation system was used to investigate the phosphorus depletion process and influencing factors in water bodies at different flow rates(0,1,3,6 cm·s^(-1),and 10 cm·s^(-1)).Thus,four different treatments were evaluated:S-0.2(no plant,initial P concentration of 0.2 mg·L^(-1)),S-0.5(no plant,initial P concentration of 0.5 mg·L^(-1)),S+I.-0.2(Iris tectorum,initial P concentration of 0.2 mg·L^(-1)),and S+I.-0.5(Iris tectorum,initial P concentration of 0.5 mg·L^(-1)).The results showed that the total phosphorus(TP)dissipation rates of all four treatments decreased as the flow velocity increased.The water TP dissipation rates decreased from 24.1,63.5,37.5μmol·m^(-2)·h^(-1),and 72.9μmol·m^(-2)·h^(-1)at a flow velocity of 0 to 5.01,3.92,5.06μmol·m^(-2)·h^(-1),and 12.1μmol·m^(-2)·h^(-1),respectively(flow velocity of 10 cm·s^(-1)).High flow velocities disturbed the water-sediment and increased the concentration of particulate P(PP)in the water column,which decreased to 0.005,0.006,0.005 mg·L^(-1),and 0.009 mg·L^(-1)in the water column at 24 h of quiescence.By contrast,PP increased to 0.04,0.08,0.03 mg·L^(-1),and 0.06 mg·L^(-1)in the water column at flow velocities of 10 cm·s^(-1).In addition,at the same initial P concentrations,the planting aquatic iris was found to increase the average TP elimination rate of the water body by 17%-34% and absorb more soluble inorganic P.These results indicate that low flow rates favored P deposition and adsorption,while increased flow rates promoted substrate disturbance,leading to the release of more PP and lowering the rate of TP elimination from the water body.In addition,planting was also found to contribute to P depletion in ditches.

关 键 词：面源污染 磷 沿程消纳 模拟沟渠 流速 

分 类 号：X52[环境科学与工程—环境工程]