Enhancing soil quality with coal fly ash amendment: a waste recycling approach for climate change mitigation in Indonesia - a review

Coal fly ash (CFA), a byproduct of coal combustion (CCP) from electric/thermal power plants, was classified as hazardous and toxic waste under Government Regulation Number 104/2014 in Indonesia. However, a significant shift in this regulatory viewpoint developed with the introduction of Government Regulation Number 22/2021. This regulation fundamentally altered the treatment and classification of CFA. Managing CFA as a waste has been both extensive and costly. In various countries where CFA is classified as non-hazardous and non-toxic waste, its utilization spans various sectors. Agriculture is a notable sector benefiting from CFA, as it is applied to soil amendment. As a soil amendment, CFA enhances nutrient availability and soil fertility, promotes plant development, and positively alters soil physical properties. In addition, CFA application to soil improves soil carbon storage, contributing to climate change mitigation and adaptation. This paper aims to review Indonesia's state of CFA utilization before the enactment of Government Regulation Number 22/2021, in order to present insights into the potential for expanded CFA utilization in soil amendment following the new regulation (Government Regulation Number 22/2021).