Abstract:
Sewage sludge (SS) has been connected to a variety of global environmental problems.
Assessing the risk of various disposal techniques can be quite useful in recommending appropriate
management. The preparation of sewage sludge biochar (SSB) and its impacts on soil characteristics,
plant health, nutrient leaching, and greenhouse gas emissions (GHGs) are critically reviewed in
this study. Comparing the features of SSB obtained at various pyrolysis temperatures revealed
changes in its elemental content. Lower hydrogen/carbon ratios in SSB generated at higher pyrolysis
temperatures point to the existence of more aromatic carbon molecules. Additionally, the preparation
of SSB has an increased ash content, a lower yield, and a higher surface area as a result of the rise in
pyrolysis temperature. The worldwide potential of SS output and CO2
-equivalent emissions in 2050
were predicted as factors of global population and common disposal management in order to create
a futuristic strategy and cope with the quantity of abundant global SS. According to estimations,
the worldwide SS output and associated CO2
-eq emissions were around 115 million tons dry solid
(Mt DS) and 14,139 teragrams (Tg), respectively, in 2020. This quantity will rise to about 138 Mt DS
sewage sludge and 16985 Tg CO2
-eq emissions in 2050, a 20% increase. In this regard, developing
and populous countries may support economic growth by utilizing low-cost methods for producing
biochar and employing it in local agriculture. To completely comprehend the benefits and drawbacks
of SSB as a soil supplement, further study on long-term field applications of SSB is required.
