The degradation kinetics of Direct Blue 15 (DB15), a diazo dye, were studied over a suspended and immobilized TiO₂ catalyst. For all experiments, the kinetics experiments were performed in a swirl flow photoreactor under the influence of UV light. The effect of different parameters: dye concentration, catalyst loading, and light intensity, on the DB15 kinetics was investigated. The kinetic rates were assessed using apparent $\left({\mathrm{k}}_{\mathrm{a}}\right)$ approach, a single value of reaction rate $\left({\mathrm{k}}_{\mathrm{r}}\right)$ and adsorption constant$\left(\mathrm{K}\right)$, and approach of ${\mathrm{k}}_{\mathrm{r}}$ as of variable. The DB15 mineralization was discussed as well. Using a dip-coating device, the P25 catalyst was deposited on a Pyrex glass. The thin film surface characterization was examined. The coated catalyst was evaluated by checking the effect of two variables: initial dye concentration and light intensity on the DB15 kinetics. In terms of the ${\mathrm{k}}_{\mathrm{a}}$ approach, the results demonstrated that DB15 degradation is described by the pseudo first-order kinetics model. The Langmuir-Hinshelwood (L-H) model was fitted well with the experimental data for the number of process variables. L-H constant ${\mathrm{k}}_{\mathrm{r}}$ was determined as a function of three parameters: initial dye concentration, catalyst loading, and light intensity. The ${\mathrm{k}}_{\mathrm{a}}$ values were evaluated and compared with experimental results. In terms of three variables, ${\mathrm{k}}_{\mathrm{a}}$ can be expressed as ${\mathrm{k}}_{\mathrm{a}}=\frac{0.15 \left[\mathrm{C}{]}_{\mathrm{o}}^{-0.69} \right[\mathrm{W}{]}^{0.73}{ \mathrm{I}}^{0.91} }{1+0.17 [{\mathrm{C}]}_{\mathrm{o}} }$while the empirical model results in the following expression, ${\mathrm{k}}_{\mathrm{a}}=0.77 {\left[\mathrm{C}\right]}_{\mathrm{o}}^{-1.65} {\left[\mathrm{W}\right]}^{0.73}{ \mathrm{I}}_{\mathrm{o}}^{0.89}$. It was observed that 83.64% mineralization was achieved after a period of 16 hrs. In terms of immobilized catalyst, the DB15 degradation kinetics was described by a pseudo first-order model for different dye concentrations. Meanwhile, a power-law model described the impact of light intensity on dye kinetics. In addition, the coated catalyst was successfully reusable with high efficiency for up to four cycles.

Open‐cell phenol (P) formaldehyde (F) foams are used for various applications such as hydroponic seed germination, flower arrangements, and sound insulation. This study investigated the influence of various parameters such as F/P molar ratios, blowing agents, surfactants, wetting agents, polymeric and inorganic additives, and oxidizing agents on the hydrophilicity of PF foams. Experimental results indicate that an F/P ratio of 1.8 was ideal for producing phenolic foams with good foam structure, uniform pore distribution, and favorable mechanical properties. A mixture of pentane and hexane at a mass ratio of 1:3 (wt/wt) used as a blowing agent resulted in a foam with the lowest density. With the optimal foaming catalyst (p‐toluene sulfonic acid) at a loading of 28 wt%, the foam exhibited a low density and excellent mechanical properties. A phenolic foam with a low density (39.27 kg/m³), high water absorption capacity (1210 wt%) and high open cell content (78.94%), was achieved by combining 6 wt% Tween‐80 as the surfactant and 3 wt% sodium dodecyl sulfate as the wetting agent. Additionally, 6.5 wt% loading of H₂O₂ led to a slight decrease in the foam density (38.46 kg/m³), but with a remarkable improvement in the wetting characteristics (water absorption capacity—2404 wt% and nearly 100% open cell content of the produced foam.