Identification of industrial sewage sludge based on heavy metal profiles: a case study of printing and dyeing industry.

Xufeng Zhang,Limin Jin,Ningzheng Zhu,Shuyu Chen,Xiang-Zhou Meng,Fangting Ai

doi:10.1007/s11356-021-16569-5

Abstract

The illegal disposal of industrial sewage sludge has caused serious environmental pollution. To develop identification technology of industrial sewage sludge based on the characteristic fingerprints is a promising method that is helpful to clarify the responsibility of illegal enterprises. In this study, heavy metal profiles of sewage sludge from industries (including printing and dyeing industry and other industries) and municipal sewage treatment plant located in eastern China were determined, and their performance of classification was evaluated by principal component analysis (PCA) and linear discrimination analysis (LDA). Results showed that heavy metal composition can be an effective tool for distinguishing sewage sludge between printing and dyeing industry and other industries, with an accuracy rate of 82.9%. Meanwhile, heavy metal speciation may be a promising method for identification of printing and dyeing sludge from municipal sewage sludge, the accuracy rate of which reached 100%. Moreover, antimony (Sb) and zinc (Zn) are two indicators, which can be used to identify sewage sludge between printing and dyeing sub-industries, and the accuracy rate was 90%. We concluded that heavy metal profiles may be a precise and promising tool for identification of printing and dyeing sludge. This study developed a potential method for tracing the source of industrial sewage sludge and establishing the identification database of industrial sewage sludge and provided technical support for the government to supervise the illegal dumping and disposal of industrial sewage sludge.

Highlights

With the development of urbanization and industrialization, water consumption and wastewater production are increasing annually in China
Heavy metal composition and speciation of sewage sludge from industries and municipal sewage treatment plant located in eastern China were determined and their performance of classification was evaluated by principal component analysis (PCA) and linear discrimination analysis (LDA)
Results showed that heavy metal composition and speciation can be an effective tool for distinguishing sewage sludge between printing and dyeing industry and other industries, with an accuracy rate of 82.9% and 100%, respectively

Summary

Introduction

With the development of urbanization and industrialization, water consumption and wastewater production are increasing annually in China. According to statistics (GOMEP, 2016), a total of 3809 wastewater treatment plants (WWTPs) have been established in China in 2016, which has doubled in the past decade (Xu et al, 2019; Zhou et al, 2019). The sewage treatment capacity (i.e., the wastewater treatment rate) of WWTPs has rapidly increased from 25.6 billion m3/a (70.2%) to 46.5 billion m3/a (94.5%) (MOHURD, 2017; Zhou et al, 2019). China’s sewage sludge production (80% moisture content) increased from 30 million tonnes in 2012 to 34 million tonnes in 2015, and it is expected to exceed 60 million tonnes in 2020, with an annual growth rate of 15% (Chen et al, 2019; Feng et al, 2015). The accumulation of sewage sludge will pose growing environmental problems and secondary pollution if treated improperly (Shao et al, 2015)

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Conclusion