Miranda Suymara Toledo, de Matos Antonio Teixeira, Baptestini Gheila Corrêa Ferres, Borges Alisson Carraro
Universidade Federal de Viçosa, Viçosa, Minas Gerais, Brazil E-mail:
Water Sci Technol. 2016 Oct;74(7):1594-1601. doi: 10.2166/wst.2016.369.
In horizontal subsurface flow constructed wetlands (HSSF-CWs), the main operational problem is clogging of the porous medium. In this study, the unclogging of HSSF-CWs was evaluated, at rest, by adding a nitrogen-based nutrient solution to the influent. For this, six HSSF-CWs were used, consisting of two uncultivated (CW-C), two cultivated with Tifton 85-grass (Cynodon spp.) (CW-T) and two cultivated with alligator weed (Alternanthera philoxeroides) (CW-A), which were fully clogged after being used for the treatment of swine wastewater. The results indicated that passage of the nutrient solution for 55 days through the bed of the HSSF-CWs resulted in reductions of 11 and 33%, respectively, in the total volatile solids (TVS) concentration of fine clogging material in the CW-T and CW-A. With regard to the TVS content of the coarse clogging material, the reduction was even greater, being 33% for CW-T and 62% for CW-A. Measurements of K made along the beds (thirds 1, 2 and 3) before and after passage of the nutrient solution in the CWs indicated respective increases of 7, 13 and 0.1% in CW-C; 21, 11 and 7% in CW-T; and 52%, 6% and -6% (decrease) in CW-A. Runoff of the nutrient solution decreased gradually over time, presenting at the beginning of the experiment 26, 35 and 150 cm, and at the end (after 55 days of application) 0, 0 and 50 cm in the flow direction of the CW-C and CW-T and CW-A, respectively.
在水平潜流人工湿地（HSSF-CWs）中，主要的运行问题是多孔介质堵塞。在本研究中，通过向进水添加基于氮的营养液，对静止状态下的HSSF-CWs的解堵情况进行了评估。为此，使用了六个HSSF-CWs，其中两个未种植植物（CW-C），两个种植了蒂夫顿85草（狗牙根属）（CW-T），两个种植了空心莲子草（Alternanthera philoxeroides）（CW-A），这些湿地在用于处理猪废水后已完全堵塞。结果表明，营养液在HSSF-CWs的床层中通过55天，导致CW-T和CW-A中细堵塞物质的总挥发性固体（TVS）浓度分别降低了11%和33%。对于粗堵塞物质的TVS含量，降低幅度更大，CW-T为33%，CW-A为62%。在湿地中营养液通过前后，沿床层（第1、2和3段）对钾的测量表明，CW-C中钾含量分别增加了7%、13%和0.1%；CW-T中分别增加了21%、11%和7%；CW-A中分别增加了52%、6%和-6%（减少）。营养液的径流随时间逐渐减少，在实验开始时，CW-C、CW-T和CW-A的径流分别为26厘米、35厘米和150厘米，在实验结束时（施用55天后），分别为0厘米、0厘米和50厘米。
