Characterization and Bioavailability of Metallic Trace Elements in Different Organic Waste

Abstract

It is important to address metabolic and heavy metal issues in organic waste through sustainable development, circular economy principles and effective solid waste management, particularly focusing on composting as a crucial approach recognized in Morocco's Green Generation Plan to reduce waste sent to landfills and mitigate greenhouse effects and gas emissions to fight against environmental pollution. This study aims to elevate the significance of organic waste in agriculture by employing composting technics, thereby mitigating its heavy metal content and safeguarding soil and farmland against various forms of contamination. This approach aligns seamlessly with the principles of sustainable development and the circular economy, advocating for responsible waste management and the augmentation of natural resource value. The findings of the study indicated a decrease in heavy metal levels across all composts, with a minimum values at the end of the composting in Gr compost recorded in all heavy metals analyzed (Pb : 0,1125 mg kg-1 ; Cd : 0,08 mg kg-1 ; Cr : 2,22 mg kg-1 ; Zn : 10,88 mg kg-1 ; Mn : 28,85 mg kg-1 ; Cu : 8,30 mg kg-1 ; Fe : 545,18 mg kg-1 and Ni : 1 mg kg-1). The findings from the assessment of heavy metal levels in the examined compost samples demonstrate their adherence to regulatory standards. Consequently, these composts can be confidently employed as organic soil enhancers, contributing to the enrichment of agricultural soils and fostering plant growth, all while avoiding the potential hazard of undue metal contamination. This study comes to confirm and consolidate previous works findings regarding the valorization of organic solid waste through composting and to minimize their major environmental risks by reducing trace metal elements through this biological process.