High efficiency removal of ibuprofen in water using activated carbon derived from Radix Angelica Dahurica residue

Abstract

The exploitation and utilization of Traditional Chinese medicine have annually produced 30 million tons of waste residues including Radix Angelica Dahurica residue (RAR), which raised environmental concerns. Meantime, the non‐steroidal anti‐inflammatory drug of ibuprofen (IBP) is an emerging contaminant in the aquatic environment, annually producing up to 9000 tons in China. After extracting the active substance, RAR is prepared as activated carbon (AC) for the purification of IBP wastewater. Two kinds AC modified without (RAR‐AC) and with phosphoric acid (M‐RAR‐AC) were characterized by FT‐IR, TG, BET and SEM. The phosphoric acid activation contributed to the high BET surface area (564.9914 m2 g−1) and large total pore volume (0.4894 cm3 g−1). M‐RAR‐AC showed 7.7 folds (15 min) and 2.7 folds (30 min) higher extent of IBP removal compared to commercial activated carbon (C‐AC). The enhancement of IBP removal with M‐RAR‐AC was investigated further by varying initial pollutant concentration, absorbent dosage, temperature, pH and rotating speed. Especially, temperature nearly has no effect on IBP removal by M‐RAR‐AC. Isotherm and kinetic studies suggested IBP was adsorbed on the heterogeneous surface in multilayer form and chemisorption played the dominant role in IBP removal. IBP removal of 93.3 ± 0.1% and 64.2 ± 2.8% was achieved for first and fifth cycle, respectively. The IBP removal on M‐RAR‐AC may be accomplished by a variety of interactions such as electrostatic attraction, pore‐filling, hydrogen bonding, and π‐π interaction. These findings provide new insights into the utilization of RAR for preparing AC and highlight the potential applications for treating industrial wastewater.

Activated Carbons as Effective Adsorbents of Non-Steroidal Anti-Inflammatory Drugs

“…The equilibrium and adsorption kinetics studies were carried out at 25 • C. Moreover, sorption rate data were recorded for approximately 26 h and included several experimental points. Zhang et al [40] studied the adsorption of ibuprofen on activated carbon (Radix Angelica Dahuricaresidue) over a wide temperature range at 20, 30, 40, 50, and 60 • C. Jedynak and colleagues [41] studied the adsorption of paracetamol, ibuprofen, and naproxen on ordered mesoporous carbons at 25 • C. Lach and Szymonik studied the adsorption of naproxen sodium [42] and diclofenac sodium [43] on commercially available activated carbons ROW 08 Supra, F-300, and WG-12. Isotherms at 20, 30, and 40 • C and kinetic curves (including several experimental points) at 20 • C were obtained.…”