Characterization and performance evaluation of an innovative mesoporous activated carbon used for drinking water purification in comparison with commercial carbons

The preparation, characterization, and performance evaluation of an innovative mesoporous activated carbon (C-XHIT) were conducted in this study. Comparative evaluation with commercial carbons (C-PS and C-ZJ15) and long-term performance evaluation of C-XHIT were conducted in small-scale system-A (S-A) and pilot-scale system-B (S-B-1 and S-B-2 in series), respectively, for treating water from Songhua River. The cumulative uptake of micropollutants varied with KBV (water volume fed to columns divided by the mass of carbons, m³ H₂O/kg carbon) was employed in the performance evaluation. The results identified that mesoporous and microporous volumes were simultaneously well-developed in C-XHIT. Higher mesoporosity (63.94 %) and average pore width (37.91 Å) of C-XHIT ensured a higher adsorption capacity for humic acid compared to C-PS and C-ZJ15. When the KBV of S-A reached 12.58 m³ H₂O/kg carbon, cumulative uptake of organic pollutants achieved by C-XHIT increased by 32.82 and 156.29 % for DOC (QC) and 22.53 and 112.48 % for UV₂₅₄ (QUV) compared to C-PS and C-ZJ15, respectively; in contrast, the adsorption capacity of NH₄ ⁺-N did not improve significantly. C-XHIT achieved high average removal efficiencies for DOC (77.43 ± 16.54 %) and UV₂₅₄ (83.18 ± 13.88 %) in S-B over 253 days of operation (KBV = 62 m³ H₂O/kg carbon). Adsorption dominated the removal of DOC and UV₂₅₄ in the initial phases of KBV (0–15 m³ H₂O/kg carbon), and simultaneous biodegradation and adsorption were identified as the mechanisms for organic pollutant uptake at KBV above 25 m³ H₂O/kg carbon. The average rates contributed by S-B-1 and S-B-2 for QC and QUV were approximately 0.75 and 0.25, respectively. Good linear and exponential correlations were observed between S-A and S-B in terms of QC and QUV obtained by C-XHIT, respectively, for the same KBV ranges, indicating a rapid and cost-saving evaluation method. The linear correlation between mesoporosity and QC (QUV) was also identified by the evolution of the property indices of C-XHIT.