Microplastics as emerging contaminants in textile dyeing sludge: Their impacts on co-combustion/pyrolysis products, residual metals, and temperature dependency of emissions

Ziyi Ding; Weijie Li; Zhibin Chen; Li Wang; Shenzheng Huang; Fatih Evrendilek; Chunxiao Yang; Haiming Cai; Sheng Zhong; Zuoyi Yang; Jingyong Liu

doi:10.1016/j.jhazmat.2024.133465

Microplastics as emerging contaminants in textile dyeing sludge: Their impacts on co-combustion/pyrolysis products, residual metals, and temperature dependency of emissions

J Hazard Mater. 2024 Mar 15:466:133465. doi: 10.1016/j.jhazmat.2024.133465. Epub 2024 Jan 9.

Authors

Ziyi Ding¹, Weijie Li², Zhibin Chen¹, Li Wang³, Shenzheng Huang¹, Fatih Evrendilek⁴, Chunxiao Yang⁵, Haiming Cai¹, Sheng Zhong¹, Zuoyi Yang¹, Jingyong Liu⁶

Affiliations

¹ Guangdong Key Laboratory of Environmental Catalysis and Health Risk Control, School of Environmental Science and Engineering, Institute of Environmental Health and Pollution Control, Guangdong University of Technology, Guangzhou 510006, China.
² The Key Laboratory of Water and Air Pollution Control of Guangdong Province, State Environmental Protection Key Laboratory of Water Environmental Simulation and Pollution Control, South China Institute of Environmental Sciences, Ministry of Ecology and Environment, Guangzhou 510535, China. Electronic address: liweijie@scies.org.
³ China Construction Fourth Engineering Division Corp, Ltd, Guangzhou, 510665, China.
⁴ Department of Electrical & Computer Engineering, College of Engineering, Boston University, Boston, MA 02215, United States.
⁵ School of Analysis and Test Center, Guangdong University of Technology, Guangzhou, 510006, China.
⁶ Guangdong Key Laboratory of Environmental Catalysis and Health Risk Control, School of Environmental Science and Engineering, Institute of Environmental Health and Pollution Control, Guangdong University of Technology, Guangzhou 510006, China. Electronic address: Liujy@gdut.edu.cn.

PMID: 38246059
DOI: 10.1016/j.jhazmat.2024.133465

Abstract

As emerging contaminants in textile dyeing sludge (TDS), the presence and types of microplastics (MPs) inevitably influence the combustion and pyrolysis of TDS. Their effects on the co-combustion/pyrolysis emissions and residual metals of TDS remain poorly understood. This study aimed to quantify the impacts of polyethylene (PE) and polypropylene (PP) on the transports and transformations of gaseous emissions and residual metals generated during the TDS combustion and pyrolysis in the air, oxy-fuel, and nitrogen atmospheres. Thermal degradation of the MPs in TDS occurred between 242-600 °C. MPs decomposed and interacted with the organic components of TDS to the extent that they increased the release of VOCs, dominated by oxygenated VOCs and hydrocarbons under the incineration and pyrolysis conditions, respectively. The presence of PE exerted a limited impact on the concentration and chemical form of metals, while PP reduced the residual amount of most metals due to the decomposition of mineral additives. Also, PP (with CaCO₃ filler) reduced the acid-extractable content of cadmium, copper, and manganese in the bottom slag or coke but increased that of chromium. This study provides actionable insights into optimizing gas emissions, energy recovery, and ash reuse, thus reinforcing the pollution control strategies for both the MPs and TDS.

Keywords: Heavy metals; Microplastics; Textile dyeing sludge; Thermochemical conversion; Volatile pollutants.