García-Ballesteros Sara, Grimalt Jaume, Berto Silvia, Minella Marco, Laurenti Enzo, Vicente Rafael, López-Pérez Maria F, Amat Ana M, Bianco Prevot Alessandra, Arques Antonio
Grupo de Procesos de Oxidación Avanzada, Departamento de Ingeniería Textil y Papelera, and Departamento de Ingeniería Química y Nuclear, Universitat Politècnica de València, Plaza Ferrándiz y Carbonell 1, 03801 Alcoy, Spain.
Dipartimento di Chimica, Università di Torino, Via P. Giuria 7, 10125 Torino, Italy.
ACS Omega. 2018 Oct 11;3(10):13073-13080. doi: 10.1021/acsomega.8b01816. eCollection 2018 Oct 31.
The valorization of olive oil mill solid wastes (OMW) has been addressed by considering it as a possible source of humic-like substances (HLSs), to be used as auxiliary substances for photo-Fenton, employing caffeine as a target pollutant to test the efficiency of this approach. The OMW-HLS isolation encompassed the OMW basic hydrolysis, followed by ultrafiltration and drying. OMW-HLS structural features have been investigated by means of laser light scattering, fluorescence, size exclusion chromatography, and thermogravimetric analysis; moreover, the capability of OMW-HLS to generate reactive species under irradiation has been investigated using spin-trap electronic paramagnetic resonance. The caffeine degradation by means of photo-Fenton process driven at pH = 5 was significantly increased by the addition of 10 mg/L of OMW-HLS. Under the mechanistic point of view, it could be hypothesized that singlet oxygen is not playing a relevant role, whereas other oxidants (mainly OH radicals) can be considered as the key species in promoting caffeine degradation.
通过将橄榄油厂固体废物（OMW）视为腐殖质类物质（HLSs）的可能来源，探讨了其增值利用，将其用作光芬顿反应的辅助物质，并以咖啡因作为目标污染物来测试该方法的效率。OMW-HLS的分离包括OMW的碱性水解，然后进行超滤和干燥。通过激光散射、荧光、尺寸排阻色谱和热重分析对OMW-HLS的结构特征进行了研究；此外，还使用自旋捕获电子顺磁共振研究了OMW-HLS在辐照下产生活性物种的能力。在pH = 5条件下，添加10 mg/L的OMW-HLS可显著提高光芬顿法对咖啡因的降解效果。从机理角度来看，可以推测单线态氧不起相关作用，而其他氧化剂（主要是羟基自由基）可被视为促进咖啡因降解的关键物种。
