A review on the high-value utilization of plant waste from arsenic-contaminated-soil phytoremediation

Phytoremediation generates massive biomass contaminated with heavy metals like arsenic (As), cadmium (Cd), and lead (Pb), posing disposal challenges and environmental risks. This review synthesizes cutting-edge strategies for recycling phytoremediation waste into value-added products, focusing on As hyperaccumulator Pteris vittata as a model. We catalog three valorization pathways, including materialization into composites and adsorbents, energy recovery via biofuels, and high-value extraction of polyphenols and other bioactives. Based on the characteristics of P. vittata biomass, currently available techniques, the involved costs and benefits, we propose an integrated cascade utilization framework sequentially extracting polyphenols, producing bioethanol, and pyrolyzing residues into biochar/fertilizer, achieving > 98 % As containment while generating revenue streams. Economic analysis confirms the viability, as processing costs ($823/t) are offset by product value ($1024–8461/t), while avoided disposal costs ($9685/ha) further enhance net benefits. Despite progress, scaling requires resolving the high costs dominated by ethanol consumption, lignin recalcitrance in bioethanol production, and regulatory gaps for hazardous-to-resource reclassification. Future efforts should prioritize pilot-scale integration of cascaded processes, deep-As removal technologies, and lifecycle assessments to position phytoremediation as a sustainable engine driving resource recovery. • Pros and cons of current recycling methods are analyzed. • Cascade utilization framework is proposed, transforming phytoremediation waste into resources. • Achieves > 98 % As containment while generating $8461/ton revenue. • Offsets 100 % remediation costs through circular resource recovery.