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.
Among the many extraction technologies for recovering metal resources from tailings, bioleaching technology is gradually showing its momentum. In our research, the enhanced effect of biochar on the bioleaching of stone coal tailings by Thiobacillus ferrooxidans (T. ferrooxidans) has been explored. In the static bioleaching experiment for 10 days, the leaching rate of vanadium (V) and copper (Cu) increased by 26.8% and 21.0% respectively after adding 5 g/L biochar. The dynamic bioleaching experiment further verified that under the promotion of biochar, the 44 day cumulative leaching rate of V and Cu increased by 15.3% and 14.5%, respectively. The promoting effect of biochar on T. ferrooxidans was mainly reflected in two aspects. The unique porous structure of biochar created a microenvironment for free microorganisms for inhabitation, while storing abundant nutrients. Biochar can also act as an excellent electronic medium to promote electron transfer, improving the oxidation ability of T. ferrooxidans on Fe 2+ . Furthermore, the presence of biochar may effectively inhibit the formation of jarosite precipitation on tailings in bioleaching, thereby improving the dissolution of tailings and the release of metal elements. This study demonstrates that biochar-enhanced bioleaching may be an efficient and environmentally friendly method for recovering metal resources from tailings.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.