A novel mesoporous zeolite-activated carbon composite as an effective adsorbent for removal of ammonia-nitrogen and methylene blue from aqueous solution

Abstract

A mesoporous zeolite-activated carbon composite (Z-AC) was prepared by hydrothermal synthesis method for both ammonia-nitrogen (NH₃-N) and methylene blue (MB) removal from aqueous solution. For Z-AC with the reparation temperature of 90 °C and kaolin/AC = 4, the adsorption capacity of MB (754.75 mg/g, 298 K) was 83% of that for pure AC, and the adsorption capacity of NH₃-N were 9.00 mg/g, which was higher than that for AC and Z (the kaolin after hydrothermal treatment). The Z-AC exhibited obvious mesoporous structure, the S_BET of the Z-AC (378 cm²/g) was 31% of that for AC (1215 cm²/g). The introduction of a small amount of AC into Z increased the S_BET of Z, thus, the adsorption capacity of MB was improved dramatically. On the other hand, the dispersion of Z was enhanced by adding AC, which promoted the contact between Z and NH₃-N, and then led to improvement of the NH₃-N adsorption.

Keywords: Adsorption; Ammonia-nitrogen; Mesoporous; Methylene blue; Zeolite-activated carbon composite.