Effect of hydrothermal pretreatment on the degrease performance and liquid substances transformation of kitchen waste

Ting Xie; Zhaohan Zhang; Muchen Sun; Miao Lv; Dongyi Li; Jun Nan; Yujie Feng

doi:10.1016/j.envres.2021.112537

Effect of hydrothermal pretreatment on the degrease performance and liquid substances transformation of kitchen waste

Environ Res. 2022 Apr 1:205:112537. doi: 10.1016/j.envres.2021.112537. Epub 2021 Dec 11.

Authors

Ting Xie¹, Zhaohan Zhang², Muchen Sun¹, Miao Lv¹, Dongyi Li¹, Jun Nan¹, Yujie Feng³

Affiliations

¹ State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, No 73 Huanghe Road, Nangang District, Harbin, 150090, China.
² State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, No 73 Huanghe Road, Nangang District, Harbin, 150090, China; Heilongjiang Provincial Key Laboratory of Polar Environment and Ecosystem, Harbin Institute of Technology, China. Electronic address: hitzzh@hit.edu.cn.
³ State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, No 73 Huanghe Road, Nangang District, Harbin, 150090, China. Electronic address: yujief@hit.edu.cn.

PMID: 34906588
DOI: 10.1016/j.envres.2021.112537

Abstract

Hydrothermal treatment (HT) is a pragmatic approach for pretreatment of kitchen waste (KW). This work investigated the effect of hydrothermal pretreatment (HTP) on the deoiling, desalting and liquid substances transformation of KW. The orthogonal test method was used to study the effects of three factors at five levels, including solid to liquid ratio (A_1-5), heating time (B_1-5) and hydrothermal temperature (C_1-5). The results indicated that the floatable oil content was improved significantly after HTP. The highest floatable oil content was 84.54 mL/kg at the hydrothermal condition of 1/1.5, 20 min and 100 °C, which was 2.42 times higher than the control. The maximum desalination ratio (92.66%) was at A₅B₁C₅ (1/2.5, 5 min, 100 °C), which was 4.48 times higher than control group (No.0) (20.67%). The VFAs concentration was the highest (11441.05 mg/kg) at 1/2.5, 5 min and 100 °C, which increased by 711.03% compared to the No.0 (1410.78 mg/kg). In addition, the maximum TOC value was obtained at 53530.84 mg/kg. After HTP, the acetic acid and butyric acid concentrations of the liquid phase increased, while the ethanol concentration decreased. The contents of T,NH₄⁺-N and organic nitrogen in the liquid phase of the HTP system increased, while NO₃^--N remained at a low level (4.96-20.48 mg/kg). The range and variance analysis showed that the temperature had the greatest effect on the deoiling and the liquid substances transformation of KW among these three factors, followed by solid to liquid ratio and heating time. Based on the orthogonal experiment, the optimal parameters for KW deoiling were A₃ (1/1.5), B₄ (25 min) and C₅ (100 °C). This work provided a reference for the KW deoiling and hence improve the efficient utilization of KW.

Keywords: Deoiling; Hydrothermal pretreatment; Kitchen waste; Orthogonal experimental design; Substances transformation.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Temperature*