Abstract
In this research, we investigated the hydrophobicity and dynamic adsorption-desorption behaviors of volatile organic compounds (VOCs) by applying different optimized coating dosage (25, 50, and 75%) on designed novel ZSM-5/MCM-41 and ZSM-5/Silicalite-1 hierarchical composites. The relatively large specific surface area and pore volume of adsorbents ZSM-5/MCM-41 and ZSM-5/Silicalite-1 composites with excellent stability were affirmed by ex-situ XRD, FTIR, BET, SEM, and water contact angle analyses. Regarding, toluene adsorption-desorption investigation, ZSM-5/MCM-41 composite lead a longer stable toluene breakthrough time no matter under dry or 50% humid conditions. However, under different loading dosage condition, the breakthrough time of 75% coating ratio was the longest, which was 1.6 times as long as that of pure ZSM-5 under wet adsorption. Meanwhile, the complete elimination of toluene for ZSM-5/MCM-41-75% was done by largest desorption peak area and the lowest desorption temperature of 101.9°C, while, the largest contact angle of ZSM-5/MCM-41-75% was 17.0° higher than pure ZSM-5 zeolite. Therefore, we believe that the present hydrophobic sorbent will provide new insight with great research potential for removing low concentration of VOCs at industrial scale.
Highlights
With industrialization, volatile organic compounds (VOCs), as the significant precursors of photochemical smog and secondary organic aerosol (SOA), have raised stringent environmental threat for many industrial processes
The result illustrates that the part of ZSM-5 particulates were disintegrated into Si-Al nanoclusters forming the hexagonal mesopore structure owing to the presence of Cetyltrimethyl ammonium bromide (CTAB) templates (Tanaka et al, 2008)
There was no presence of impurity phases in X-ray diffraction (XRD) curves, indicating the successful synthesis of ZSM-5/siliceous zeolite composites
Summary
Volatile organic compounds (VOCs), as the significant precursors of photochemical smog and secondary organic aerosol (SOA), have raised stringent environmental threat for many industrial processes. Constrain was found in each technology during practical and industrial application Such as, operating expense for VOCs extirpation by oxidation technology is extravagant due to high reaction temperature and longer retention time. As for biological treatment, the removal efficiency of VOCs is low, and the persistence time is relatively long. Condensation and absorption technologies would escalate the operating cost due to the secondary treatment of scrubbing liquids and adsorbents. Compared to these techniques, adsorption is more applicable for removing low concentration of VOCs due to its advantages (i.e., high efficiency, easy operation and low system operating costs) (Kim and Ahn, 2012; Tefera et al, 2014)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
