Microwave assisted green synthesis of Fe 2 O 3 /biochar for ultrasonic removal of nonsteroidal anti-inflammatory pharmaceuticals.

Iron oxide/biochar (Fe 2 O 3 /biochar) was prepared by green synthesis via a microwave to evaluate ultrasound-assisted adsorption capacity of Nonsteroidal Anti-inflammatory Drugs (NSAIDs) (salicylic acid, naproxen, and ketoprofen) from the water. Several techniques of characterization, including, Fourier transform infrared spectrometry, scanning electron microscopy, EDS analysis, N 2 adsorption-desorption, X-ray diffraction, and Raman spectrometry were applied. The adsorption of NSAIDs onto Fe 2 O 3 /biochar was performed using an ultrasonic bath. The effects of batch adsorption under various experimental parameters such as contact time (0-120 min), initial concentration (10-500 mg L -1 ) and pH (2-12) were tested. The obtained Fe 2 O 3 /biochar specific surface area, mesopore volume/micropore volume, and pores size were equal to 786 m 2 g -1 , 0.409 cm 3 g -1 , and 1.534 cm 3 g -1 , respectively. The pseudo-second-order model could describe better all NSAID adsorptions onto Fe 2 O 3 /biochar. The Langmuir model agreed well with the NSAID adsorptions and the maximum adsorption capacities reached 683 mg g -1 , 533 mg g -1 and 444 mg g -1 for salicylic acid, naproxen, and ketoprofen, respectively. Fe 2 O 3 /biochar can be used as an excellent adsorbent for the treatment of NSAIDs in water.