Jiaxiao Wang , Lei Luo , Aichu Yan , Zhizhi Pan , Xiaojun Zuo , Zhengang Liu
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引用次数: 0
Abstract
Hydrothermal treatment (HT) is a suitable disposal strategy for pollutant removal and nutrient recovery from food waste digestate (FWD). However, the fate of heavy metals (HMs) and polycyclic aromatic hydrocarbons (PAHs) during HT remains poorly understood. Here, the distribution, transformation, and ecological risks of HMs and PAHs in FWD during HT were systematically investigated. The results revealed that HT immobilized most HMs in hydrochar, exhibiting enrichment factors of 79 %-116 %. The bioavailability of HMs in hydrochar was decreased significantly at 200–220 °C. Specifically, the bioavailability of As, Cd, Cu, Ni, and Pb in hydrochar was decreased by 11.9 %, 57.1 %, 100 %, 72.2 %, and 84.0 % compared with that in raw FWD, respectively. Meanwhile, HT resulted in a 40.4 % reduction of total PAH contents at 140 °C compared to FWD. The polymerization of organic matter increased the aromaticity of derived hydrochar while converting low-ring PAHs into high-ring PAHs at 160–180 °C. The maximum reduction of total PAH contents (42.7 %) occurred at 180 °C. Higher temperatures (200–220 °C) favored lignin decomposition to produce PAH precursors, which simultaneously polymerized into new PAHs. These findings provide a comprehensive understanding of HMs and PAHs transformation mechanisms during HT, offering valuable guidance for optimizing FWD management processes and ensuring the safe utilization of hydrothermal products.
期刊介绍:
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