Dacewicz Ewa, Grzybowska-Pietras Joanna
Faculty of Environmental Engineering and Land Surveying, University of Agriculture in Kraków, Al. Mickiewicza 24/28, 30-059 Kraków, Poland.
Faculty of Materials, Civil and Environmental Engineering, Institute of Civil Engineering, The University of Bielsko-Biala, ul. Willowa 2, 43-309 Bielsko-Biała, Poland.
Materials (Basel). 2021 Feb 16;14(4):933. doi: 10.3390/ma14040933.
The aim of the study was to assess the possibility of using polyurethane foams (PUF) as a filling of a foam-sand filter to directly treat domestic sewage with increased content of ammonium nitrogen and low organic carbon to nitrogen ratio (C/N). The study compared performance of two types of flexible foams: new, cylinder-shaped material (Novel Foams, NF) and waste, scrap foams (Waste Foams, WF). The foams serving as a filling of two segments of a foam-sand filter were assessed for their hydrophobic and physical properties and were tested for their cell structure, i.e., cell diameter, cell size distribution, porosity, and specific surface area. The study accounted also for selected application-related properties, such as hydrophobicity, water absorption, apparent density, dimensional stability, amount of adsorbed biomass, and the possibility of regeneration. Cell morphology was compared in reference foams, foams after 14 months of the filter operation, and regenerated foams. The experimental outcomes indicated WF as an innovative type of biomass carrier for treating domestic sewage with low C/N ratio. SEM images showed that immobilization of microorganisms in NF and WF matrices involved the formation of multi-cellular structures attached to the inner surface of the polyurethane and attachment of single bacterial cells to the foam surface. The amount of adsorbed biomass confirmed that the foam-sand filter made up of two upper layers of waste foams (with diameters and pore content of 0.50-1.53 mm and 53.0-63.5% respectively) provided highly favorable conditions for the development of active microorganisms.
本研究的目的是评估使用聚氨酯泡沫（PUF）作为泡沫 - 砂滤池填料直接处理铵氮含量增加且有机碳氮比（C/N）较低的生活污水的可能性。该研究比较了两种类型柔性泡沫的性能：新型圆柱形材料（新型泡沫，NF）和废弃泡沫碎片（废弃泡沫，WF）。对用作泡沫 - 砂滤池两段填料的泡沫的疏水和物理性质进行了评估，并测试了其孔结构，即孔径、孔尺寸分布、孔隙率和比表面积。该研究还考虑了选定的与应用相关的性质，如疏水性、吸水性、表观密度、尺寸稳定性、吸附生物量以及再生可能性。比较了参比泡沫、滤池运行14个月后的泡沫以及再生泡沫的细胞形态。实验结果表明，废弃泡沫是一种用于处理低C/N比生活污水的新型生物质载体。扫描电子显微镜图像显示，微生物在新型泡沫和废弃泡沫基质中的固定涉及到在聚氨酯内表面形成多细胞结构以及单个细菌细胞附着在泡沫表面。吸附生物量的数量证实，由两层上层废弃泡沫（直径和孔隙率分别为0.50 - 1.53毫米和53.0 - 63.5%）组成的泡沫 - 砂滤池为活性微生物的生长提供了非常有利的条件。
