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Three birds with one stone: Sewage sludge deep-drying in 1 hour using secondary aluminum ash to fabricate bricks.

Xianghai KongYanping ZhuHe XuJinghong YeShuang WangHeliang XuRongjun ZhangHongxia TangDongfang WangDongqing Cai
Published in: Water research (2024)
Due to the high moisture, strong hydrophilicity, and hard compressibility of sewage sludge (SS), it is difficult to realize the high-efficiency drying. Herein, a novel SS drying technology was developed to quickly and deeply reduce the moisture of SS from 75.6% to 38.5% in 1 h. During the process, secondary aluminum ash (SAA), a solid waste, was added to SS and acted as skeletons to form plenty of channels. Subsequently, NaOH was added and reacted with SAA to produce a lot of heat, resulting in a rapid temperature rise of the system from 20 to 105°C in 60 s. The heat could effectively remove water from these channels, which could be proved by the T 1 -T 2 maps of in-site Low-Field 1 H nuclear magnetic resonance. In addition, the extracellular polymeric substances were decomposed by SAA/NaOH successfully, and thus the SS became hydrophobic, favoring the drying. Finally, the dried SS could be used to fabricate unburned bricks. Thus, this work provides a promising method to realize the rapid SS deep drying and high-efficiency utilization of SAA and dried SS.
Keyphrases
  • sewage sludge
  • high efficiency
  • municipal solid waste
  • heavy metals
  • magnetic resonance
  • anaerobic digestion
  • magnetic resonance imaging
  • heat stress
  • ionic liquid
  • editorial comment
  • aqueous solution