XU Jin,XU Jun,LQiu-ying,et al.Perspectives on Hydrothermal Carbonization Technology for Municipal Sludge Treatment and Disposal[J].China Water & Wastewater,2020,36(16 16):54-59.
Perspectives on Hydrothermal Carbonization Technology for Municipal Sludge Treatment and Disposal
China Water & Wastewater[ISSN:1000-4062/CN:12-1073/TU]
volume:
第36卷
Number:
16 16
Page:
54-59
Column:
Date of publication:
2020-08-17
- Keywords:
- hydrothermal carbonization; municipal sludge treatment and disposal; biomass conversion technology; sludge-based hydrothermal biochar
- Abstract:
- Due to hindered agriculture use and limited space for landfill as well as secondary pollution, the mainstream technology route of municipal sludge treatment and disposal is facing difficulties in China. So it is urgent to analyze its feasible path from scientific approaches. According to requirements of moisture content in sludge disposal process, it is suggested to remove or transform organic matter when sludge moisture exists. Meanwhile, the feasibility analysis is carried out from the point of view of biomass conversion technology. Among them, hydrothermal carbonization (HTC) technology has the advantages of treating object without drying, easy to combine with other waste biomass and technology, sterile product and high recovery rate of phosphorus. Sludge-based hydrothermal biochar has two formation pathways, which are solid-solid and liquid phase nucleation transformations. It has the same calorific value as coal, good dehydration performance, high phosphorus enrichment recovery rate, and could fix heavy metals. Its carbon backbone could be used as a slow-release carrier of nitrogen and phosphorus so as to increase soil fertility. Moreover, the biochar with inorganic fertilizer reduction and application has both functions of agricultural economic value and environmental ecological benefits. Sludge HTC treatment could realize sludge reduction, stabilization, harmlessness and resource recovery. As a result, the process of gravity concentration/mechanical dehydration+HTC was taken as the recommended sludge treatment and disposal scheme, which was suitable for in situ and decentralized processing. In addition, low temperature (150-170 ℃) in HTC was suggested to prevent soluble refractory organics generating from Maillard reaction during high temperature, consequently, the liquid product could be used as an effective carbon source to supplement the low-carbon WWTP.
Last Update:
2020-08-17