Zirconium based metal organic frameworks (Zr-MOFs) have become popular in engineering studies due to their high mechanical stability, thermostability and chemical stability. In our work, by using a theoretical kinetic adsorption isotherm, we can exert MOFs to an acid dye adsorption process, experimentally exploring the adsorption of MOFs, their external behavior and internal mechanism. The results indicate their spontaneous and endothermic nature, and the maximum adsorption capacity of this material for acid orange 7 (AO7) could be up to 358 mg·g−1 at 318 K, estimated by the Langmuir isotherm model. This is ascribed to the presence of an open active metal site that significantly intensified the adsorption, by majorly increasing the interaction strength with the adsorbates. Additionally, the enhanced π delocalization and suitable pore size of UiO-66 gave rise to the highest host–guest interaction, which further improves both the adsorption capacity and separation selectivity at low concentrations. Furthermore, the stability of UiO-66 was actually verified for the first time, through comparing the structure of the samples before and after adsorption mainly by Powder X-ray diffraction and thermal gravimetric analysis.

A raw bio-oil (RBO) from pyrolysis of rice husk was upgraded by catalytic esterification with methanol over an acidic resin. Both RBO and the upgraded bio-oil (UBO) were analyzed with a Fourier transform infrared spectrometer, pH meter, and an elemental analyzer. They were extracted sequentially with n-hexane, CCl 4 , CS 2 , benzene, and CH 2 Cl 2 . All of the extracts were analyzed with gas chromatography/mass spectrometer. The results showed that the carboxylic acids (CA) in the RBO were converted to their corresponding methyl esters (MEs), leading to a significant increase in pH value from 2.8 (RBO) to 5.3 (UBO). The total extract yield of UBO is much higher than that of RBO. In total, 20 CAs and 19 MEs were identified. The CAs include two alkenoic acids, a cycloalkanecarboxylic acid, a hydroxyalkanoic acid, a hydroxyalkenoic acid, an oxyalkanoic acid, a methoxyoxyalkanoic acid, an alkanedioic acid, an oxyalkanedioic acid, an aminoalkanoic acid, two furoic acids, three substituted benzoic acids, and five substituted phenylalkanoic acids.

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