Morán-Valencia Marien, Huerta-Aguilar Carlos Alberto, Mora Abrahan, Mahlknecht Jurgen, Saber Ayman N, Cervantes-Avilés Pabel
Escuela de Ingeniería y Ciencias, Tecnológico de Monterrey, Campus Puebla, Vía Atlixcáyotl 5718, Reserva Territorial Atlixcáyotl, Puebla, 72453, Puebla, México.
Escuela de Ingeniería y Ciencias, Tecnológico de Monterrey, Campus Monterrey, Eugenio Garza Sada 2501, Monterrey, 64149, Nuevo León, México.
Heliyon. 2023 Jun 23;9(6):e17586. doi: 10.1016/j.heliyon.2023.e17586. eCollection 2023 Jun.
PFAS have demonstrated to affect some aerobic microorganisms applied for wastewater treatment. This study evaluated the nutrient removal of three types of hydrogels containing a consortium of microalgae-bacteria (HB), activated carbon (HC), or both (HBC) in presence of perfluorodecanoic acid (PFDA). The nutrients evaluated were ammonium nitrogen (NH-N), nitrate nitrogen (NO-N), phosphate (PO), and chemical oxygen demand (COD). Fluorine (F) concentration and the integrity of HB exposed to PFDA were also determined at the end of experiments to understand the potential sorption and effects of PFDA on hydrogel. The results indicated that the presence of PFDA did affect the nitrification process, 13% and 36% to HB and HBC, respectively. Mass balance confirmed negative impact of PFDA on nitrogen consumption in HB (-31.37%). However, NH-N was removed by all types of hydrogels in a range of 61-79%, while PO was mainly removed by hydrogels containing activated carbon (AC), 37.5% and 29.2% for HC and HBC, respectively. The removal of both NH and PO, was mainly attributed to sorption processes in hydrogels, which was enhanced by the presence of AC. PFDA was also adsorbed in hydrogels, decreasing its concentration between 18% and 28% from wastewater, and up to 39% using HC. Regarding COD concentration, this increased overtime but was not related to hydrogel structure, since Transmission Electron Microscopy imaging revealed that their structure was preserved in presence of PFDA. COD increasement could be attributed to soluble algal products as well as to PVA leaching from hydrogels. In general, the presence of AC in hydrogels can contribute to mitigate the toxic effect of PFDA over microorganisms involved in biological nutrient removal, and hydrogels can be a technique to partially remove this contaminant from aqueous matrices.
全氟和多氟烷基物质（PFAS）已被证明会影响一些用于废水处理的好氧微生物。本研究评估了在全氟癸酸（PFDA）存在的情况下，三种含有微藻-细菌联合体（HB）、活性炭（HC）或两者都有（HBC）的水凝胶对营养物质的去除情况。评估的营养物质包括铵态氮（NH-N）、硝态氮（NO-N）、磷酸盐（PO）和化学需氧量（COD）。在实验结束时还测定了氟（F）浓度以及暴露于PFDA的HB的完整性，以了解PFDA对水凝胶的潜在吸附作用和影响。结果表明，PFDA的存在确实影响了硝化过程，对HB和HBC的影响分别为13%和36%。质量平衡证实了PFDA对HB中氮消耗的负面影响（-31.37%）。然而，所有类型的水凝胶对NH-N的去除率在61%-79%之间，而PO主要被含有活性炭（AC）的水凝胶去除，HC和HBC对PO的去除率分别为37.5%和29.2%。NH和PO的去除主要归因于水凝胶中的吸附过程，AC的存在增强了这种吸附。PFDA也被吸附在水凝胶中，使废水中其浓度降低了18%-28%，使用HC时降低了39%。关于COD浓度，其随时间增加，但与水凝胶结构无关，因为透射电子显微镜成像显示在PFDA存在的情况下其结构得以保留。COD的增加可能归因于可溶性藻类产物以及水凝胶中聚乙烯醇的浸出。总体而言，水凝胶中AC的存在有助于减轻PFDA对参与生物营养物质去除的微生物的毒性作用，并且水凝胶可以作为一种从水性基质中部分去除这种污染物的技术。
