Characteristics of biosolids in dimethyl ether dewatering method

Area of Science:

• Environmental Engineering
• Chemical Engineering
• Waste Management

Background:

• Biosolids management presents challenges in water removal.
• Conventional dewatering methods can be energy-intensive.
• Dimethyl ether (DME) is explored as a novel extractant for biosolid dewatering.

Purpose of the Study:

• To evaluate the applicability of the dimethyl ether (DME) dewatering method for biosolid cakes.
• To determine the optimal conditions for achieving a high dewatering ratio using DME.
• To compare the energy efficiency of DME dewatering with conventional thermal drying.

Main Methods:

• Utilized a DME flow-type experimental apparatus to test biosolid cakes.
• Varied the liquefied DME to biosolid ratio and liquefied DME linear velocity.
• Analyzed changes in dewatered biosolid carbon content and separated liquid TOC.
• Estimated the energy input required for water removal via DME and conventional drying.

Main Results:

• High dewatering ratios were achieved by increasing the DME/biosolid ratio and lowering DME linear velocity.
• Increased DME/biosolid ratio led to a slight decrease in dewatered biosolid carbon content.
• Significant increase in TOC concentration was observed in the separated liquid.
• DME dewatering requires approximately one-third of the energy input compared to conventional thermal drying.

Conclusions:

• DME dewatering is a highly effective method for removing water from biosolid cakes.
• The process offers substantial energy savings over traditional thermal drying techniques.
• Further research into optimizing DME dewatering for biosolid treatment is warranted.