Preparation, Properties, and Application of Biochar for Improving Sewage Sludge Dewatering Performance: A Review

Abstract

Biochar is a widely available carbon-based material that has been used for soil remediation and sewage treatment. However, in recent years, biochar has received more attention as a conditioning agent to improve the dewatering performance of sewage sludge. The sludge from the secondary sedimentation tank of wastewater treatment plants has high microbial activity and poor dewatering performance, which poses a challenge to sludge dehydration. Biochar and modified biochar can be injected into sludge as a skeleton to effectively reduce sludge compressibility, increase permeability, and release bound water, thus improving the dewatering performance of sludge. In this review, the preparation and characteristics of biochar are described, the current methods of sludge dewatering and the properties of sludge are introduced, and the research on the application of biochar in sludge conditioning is summarized. In addition, the existing problems and future development directions of biochar in sludge conditioning are discussed.

Possibilities of Managing Waste Iron Sorbent FFH after CO2 Capture as an Element of a Circular Economy

“…In general, the effectiveness of FFHCO2 does not confirm its suitability as a coagulant. Nor does it state that FFH acts as a skeleton builder, similar to the addition of biochar, which effectively reduces sludge compressibility, increases permeability and releases bound water from the sludge structure [43]. The addition of the coagulant PIX 113 (ferrous sulphate) caused a decrease in the pH of the supernatant after sludge filtration.…”