20.500.12556/DKUM-95550 Investigation of the influencing parameters of the ▫$H_2O_2-assisted$▫ photochemical treatment of waste liquid from the hydrothermal carbonization process in a microreactor flow system Due to its complex composition and toxicity, the waste liquid from hydrothermal carbonization (HTC) poses a serious environmental challenge that must be addressed before disposal. In this study, the photochemical treatment of HTC liquid in a microreactor flow system was investigated. The effects of wavelength, the presence of atmospheric oxygen, oxidizing agent (H2O2) and catalyst (FeSO4), residence time and pH on the efficiency of the photo-treatment were investigated. In addition, the influence of the addition of deep eutectic solvent (DES) on photo-treatment was studied. The results showed that the photochemical treatment was more efficient at 365 nm than at 420 nm, and that the acidic conditions gave better results than the basic ones. UV365 treatment in the presence of H2O2 (at a dosage of 1 vol%) resulted in removal efficiencies of 31.6% for COD, 17.6% for TOC, 16.9% for NH4-N and 17.2% for PO4-P. The addition of FeSO4 caused coagulation/flocculation effects, but improved phosphorus removal. The addition of DES resulted in slight discolouration of the liquid and proved unsuccessful in COD removal. The GC-MS analysis and 3D-EEM spectra showed significant changes in the fate of organics and in the fluorescence intensity of aromatic proteins and humic acid-like substances. Photochemical treatment in a microreactor flow system in the presence of H2O2 under the selected operating conditions reduced the content of organics and nutrients in the HTC liquid, but the process liquids still showed toxic effects on the organisms V. fischeri and Daphnia magna. hydrothermal treatment waste process liquid photochemical treatment hydrogen peroxide microreactor flow system hidrotermalna obdelava odpadna procesna tekočina fotokemična obdelava vodikov peroksid pretočni sistem mikroreaktorja true false true MDPI Angleški jezik Slovenski jezik https://www.mdpi.com/journal/processes © 2025 by the authors Članek v reviji 2025-09-25 09:06:25 2025-09-25 09:06:25 2026-01-06 03:18:35 0000-00-00 00:00:00 2025 0 0 26 str. št. 9, št. članka 2934 let. 13 2025 0000-00-00 Zaloznikova Objavljeno NiDoloceno 2025-08-01 2025-09-09 2025-09-14 66 250184195 10.3390/pr13092934 2227-9717 processes-13-02934.pdf processes-13-02934.pdf 1 6CC8364C8240258EA504F7146DAD3018 51a69e0e01c9b5748b2f60d0a4492fb11a40e311afd48b7796abef5aecaac03b 56523081-ea3e-11f0-8f12-00155d580e02 https://dk.um.si/Dokument.php?lang=slv&id=201778 https://www.mdpi.com/2227-9717/13/9/2934 0 5cb3c468-ea3e-11f0-8f12-00155d580e02 https://dk.um.si/Dokument.php?lang=slv&id=201779 Fakulteta za kemijo in kemijsko tehnologijo 0 0 0