Have we engineered adsorbents for obsolescence? A critical mandate for regeneration in the age of perpetual pollution

Biochar is widely promoted as a sustainable solution for pharmaceutical water treatment, yet its environmental value depends entirely on a capability that is frequently assumed but rarely proven: long-term regenerability. This study challenges the prevailing single-use paradigm by quantifying the durability and methodological rigor of contemporary biochar research. Through a systematic review of 258 studies (2021–2025), we identified a final cohort of 57 experimental papers (N=147 datasets). The review exposes a critical blind spot: 60% of high-quality studies completely omit experimental regeneration data. For the 34 studies that did report cycling metrics, we performed a random-effects meta-analysis to establish the field’s first quantitative benchmark for durability. The results reveal a pooled mean performance loss of 29.8% (95% CI: 21.1%–38.4%) over an average of just five cycles. Subgroup analysis identified the regeneration mechanism as the primary driver of heterogeneity ( I 2 =99.3%); notably, thermal regeneration proved superior (6.7% loss) to the widely used solvent washing methods (36.2% loss). Methodological assessment further reveals that 85% of studies fail to account for the secondary waste generated during regeneration. To bridge this gap between academic claims and engineering reality, we propose the “Minimum Information for Adsorbent Regeneration” (MIAR) guidelines, mandating the reporting of secondary waste, energy inputs, and statistical durability in future research. • Biochar research claims sustainability but often ignores reusability. • 60% of contemporary studies completely omit regeneration experiments. • First meta-analysis sets durability benchmark at 29.8% performance loss. • Thermal regeneration vastly outperforms common solvent washing methods. • Findings reveal an “illusion of sustainability” in the adsorbent field.