表面流人工湿地在池塘养殖循环经济模式中的净化效能研究

Purification Effect of Free Water Surface Constructed Wetland on Circular Economy Pattern of Pond Culture

2005年7月30日—12月2日,每月一次对人工湿地的进、出水进行采样,以总磷(TP)、总氮(TN)、正磷酸盐(PO43--P)、硝酸盐氮(NO-3-N)、亚硝酸盐氮(NO-2-N)、氨氮(NH4+-N)、高锰酸盐指数(CODMn)、叶绿素a(Chla)等为主要水质指标,研究了在池塘养殖循环经济模式中表面流人工湿地对混养区养殖废水的净化效能。结果表明,5次测定中,人工湿地对NH4+-N、NO-2-N、NO3--N、PO34--P、TN、TP和CODMn的去除率分别变化在56.25%～91.67%、38.46%～79.59%、43.75%～81.82%、47.50%～78.67%、31.37%～80.00%、39.53%～71.43%和32.07%～50.00%,平均去除率分别为76.91%、53.06%、60.88%、61.33%、54.22%、59.15%和41.69%。出水水质的综合营养状态指数(TLI(∑))分别从50.33、51.11、50.28、56.00和51.08的富营养状态降低到39.86、41.28、42.70、47.76和46.16的中营养状态,而且CODMn在所有测定时间下的出水水质中均达到地表水环境质量标准(GB3838—2002)的Ⅱ类水质标准,出水中的TP在大多时间下达到了地表水环境质量标准(GB3838—2002)的Ⅰ类或Ⅱ类水质标准。说明表面流人工湿地对养殖废水具有很好的净化效果。

The influent and effluent water of free water surface constructed wetland was sampled once every month from July 30th to December 2th, and using total phosphorus（TP）, total nitrogen（TN）, orthophosphate phosphorus（PO4^3- -P）, nitrate nitrogen（NO3^--N）, nitrite nitrogen（NO2^-- N）, ammonium nitrogen （NH4^＋-N）, CODMn, and chlorophyll-a （Chla） as the main water quality indexes, the test researched the purification effects of free water surface constructed wetland on wastewater from co-cultivation area in circular economy pattern of pond culture system. The results showed that the removal rates of NH4^＋-N、NO2^--N、NO3^--N、PO4^3--P,TN,TP and CODMn ranged 56.25%～91.67%, 38.46%～79.59%, 43.75%～81.82%, 47.50%～78.67%, 31.37%～80.00%, 39.53%～71.43% and 32.07%～50.00%, respectively, with the average removal rates being 76.91%, 53.06%, 60.88%, 61.33%, 54.22%, 59.15% and 41.69%, respectively. The comprehensive trophic state indexes at the influent water of constructed wetland were 50.33, 51.11, 50.28, 56.00 and 51.08 on July 30th, August 28th, September 29th, October 28th, December 2th, respectively, while, the indexes at the effluent water were 39.86, 41.28, 42.70, 47.76 and 46.16, respectively, indicating that the comprehensive trophic state indexes had changed from eutrophication state at the influent water to middle trophic state at effluent water of constructed wetland during the experiment. CODMn of effluent water reached the Ⅱclassification of environmental quality standard for surface water （GB3838-2002）, and the total phosphorus achieved Ⅰ or Ⅱ classification of environmental quality standard for surface water （GB3838-2002） at most cases. So, the free water surface constructed wetland had good purification efficiency for aquaculture wastewater.