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为研究植物生态净化技术集成至循环流水水产养殖系统的可行性,构建了4个(4重复)3.0m×0.5m×0.05m(长×宽×高)的植物滤器处理淡水白鲳(Colossoma brachypomum)高密度养殖废水。每个植物滤器生长0.8m2NFT(营养液膜技术)培多年生黑麦草(Lolium perenneL.)。废水每周更换一次,每次25.4L,连续运行40d。7d循环灌溉处理后,NO3--N、TN、TP、COD的去除率分别达96.1%、86.2%、90.5%、88.7%,pH从6.4升高至8.4,而水体积只消耗29.7%。除UIA由于pH升高而超标外,所有水质指标均符合渔业水质标准。牧草日增长仅2.3mm,显著低于用商品营养液培育的牧草生长速度(日增长13.2mm)。鲜草TAN和NO3--N含量分别为107.9和42.5μg.g-1,试验结束时收获鲜草582.9g.m-2,烘干后得到干草102.5g.m-2,干湿比0.176。结果表明,植物滤器能解决生物滤器引起的N、P、COD累积以及pH下降等问题,是一种环境友好的水处理方法。为使牧草良好生长,建议定期将牧草返回培育系统用商品营养液培养一段时间。
In order to study the feasibility of integrating plant ecological purification into a recirculating aquaculture system, four (4 replicates) plant filters of 3.0 m × 0.5 m × 0.05 m (L × W × H) were constructed to treat Colossoma brachypomum High-density farming wastewater. Each plant filter was grown 0.8 m2 NFT (Nutrient Liquid Membrane Technology) perennial ryegrass (Lolium perenne L.). Wastewater is changed once a week, 25.4L each time, running continuously 40d. After 7d irrigation, the removal rates of NO3 - N, TN, TP and COD reached 96.1%, 86.2%, 90.5% and 88.7% respectively. The pH value increased from 6.4 to 8.4, while the volume of water consumed only 29.7%. All water quality indicators are in line with the fishery water quality standards except UIA which exceeds the standard due to the increase of pH. The growth of pasture was only 2.3mm, significantly lower than the growth rate of forage grown with commercial nutrient solution (daily increase of 13.2mm). The contents of TAN and NO3 - N in fresh grass were 107.9 and 42.5μg.g-1, respectively, and 582.9g.m-2 of fresh grass was harvested at the end of the experiment. After drying, 102.5g.m-2 of hay was obtained, and the dry-wet ratio was 0.176. The results showed that the plant filter could solve the problems of N, P, COD accumulation and pH drop caused by the biofilter. It is an environmentally friendly water treatment method. For good growth of pasture, it is advisable to periodically return the forage to the cultivation system for commercial use for a period of time.