Sewage sludge derived biochar for environmental improvement: Advances, challenges, and solutions

With the rapid growth yield of global sewage sludge, rational and effective treatment and disposal methods are becoming increasingly needed. Biochar preparation is an attractive option for sewage sludge treatment, the excellent physical and chemical properties of sludge derived biochar make it an attractive option for environ-mental improvement. Here, the current application state of sludge derived biochar was comprehensively reviewed, and the advances in the mechanism and capacity of sludge biochar in water contaminant removal, soil remediation, and carbon emission reduction were described, with particular attention to the key challenges involved, e.g., possible environmental risks and low efficiency. Several new strategies for overcoming sludge biochar application barriers to realize highly efficient environmental improvement were highlighted, including biochar modification, co-pyrolysis, feedstock selection and pretreatment. The insights offered in this review will facilitate further development of sewage sludge derived biochar, towards addressing the obstacles in its appli-cation in environmental improvement and global environmental crisis.

Automated summary

With the rapid growth yield of global sewage sludge, rational and effective treatment and disposal methods are needed. Biochar preparation is an attractive option for sewage sludge treatment, and its excellent properties make it suitable for environmental improvement. This review comprehensively discusses the current application state of sludge derived biochar, its capacity in contaminant removal, soil remediation, and carbon emission reduction, and highlights strategies for overcoming application barriers.