Centre for the Research and Technology of Agro-Environmental and Biological Sciences (CITAB)/Inov4Agro (Institute for Innovation, Capacity Building, and Sustainability of Agri-Food Production), University of Trás-os-Montes and Alto Douro (UTAD), 5000-801 Vila Real, Portugal.
Centro de Química de Vila Real (CQVR), Departamento de Química, Universidade de Trás-os-Montes e Alto Douro (UTAD), Quinta de Prados, 5000-801 Vila Real, Portugal.
Int J Environ Res Public Health. 2022 Mar 31;19(7):4134. doi: 10.3390/ijerph19074134.
Re-using and adding value to by-products is one of the current focuses of the agri-food industry, following the Sustainable Development Goals of United Nations. In this work, the by-products of four plants, namely chestnut burr, acorn peel, olive leaf, and grape stem were used as coagulants to treat elderberry wastewater (EW), a problematic liquid effluent. EW pre-treatment using these natural coagulants showed promising results after pH and coagulant dosage optimization. However, the decrease in total organic carbon () was not significant, due to the addition of the plant-based natural coagulants which contain carbon content. After this pre-treatment, the photo-Fenton advanced oxidation process was selected, after preliminary assays, to improve the global performance of the EW treatment. Photo-Fenton was also optimized for the parameters of pH, HO, Fe, and irradiance power, and the best conditions were applied to the EW treatment. Under the best operational conditions defined in the parametric study, the combined results of coagulation-flocculation-decantation (CFD) and photo-Fenton for chestnut burr, acorn peel, olive leaf, and grape stem were, respectively, 90.2, 89.5, 91.5, and 88.7% for removal; 88.7, 82.0, 90.2 and 93.1%, respectively, for turbidity removal; and finally, 40.6, 42.2, 45.3, and 39.1%, respectively, for TSS removal. As a final remark, it is possible to suggest that plant-based coagulants, combined with photo-Fenton, can be a promising strategy for EW treatment that simultaneously enables valorization by adding value back to food by-products.
再利用和增加副产品的价值是农业食品行业目前的重点之一，这符合联合国的可持续发展目标。在这项工作中，利用栗蓬、橡实皮、橄榄叶和葡萄梗这四种植物的副产物作为凝结剂来处理接骨木果废水（EW）这种有问题的液体废水。经过 pH 值和凝结剂剂量优化后，这些天然凝结剂在 EW 预处理中表现出了有前景的结果。然而，由于添加了含有碳含量的植物基天然凝结剂，总有机碳（TOC）的减少并不显著。在此预处理之后，选择了光芬顿高级氧化工艺，经过初步试验，以提高 EW 处理的整体性能。光芬顿还针对 pH、HO、Fe 和辐照度功率等参数进行了优化，并将最佳条件应用于 EW 处理。在参数研究中定义的最佳操作条件下，栗蓬、橡实皮、橄榄叶和葡萄梗的凝结-絮凝-沉淀（CFD）和光芬顿联合处理的结果分别为 90.2%、89.5%、91.5%和 88.7%的 去除率；88.7%、82.0%、90.2%和 93.1%的浊度去除率；最后，TOC、TSS 的去除率分别为 40.6%、42.2%、45.3%和 39.1%。最后，可以建议将植物基凝结剂与光芬顿结合使用，作为 EW 处理的一种有前途的策略，同时通过将附加值返还给食品副产品来实现增值。
