The adsorption of Congo red onto titanium dioxide (TiO₂) material has been investigated at batch conditions. The effects of contact time (0–60 min), initial pH (3–11), agitation speed (100–500 rpm), temperature (298–343 K), adsorbent dosage (0.5–2 g/L), and Congo red concentration (5–15 mg/L) on the Congo red adsorption by TiO₂ have been studied. The kinetic parameters, rate constants, and equilibrium adsorption capacities were calculated and discussed for each kinetic model. The adsorption of Congo red onto TiO₂ is well described by the pseudo-second order equation. The adsorption isotherm follows the Langmuir model, providing a better fit of the equilibrium data. The batch adsorption experiments were carried out to optimize the physical parameters on the Congo red removal efficiency. It has been found that 152 mg/g at 25 °C is removed. The thermodynamic parameters indicate the spontaneous and endothermic nature of the adsorption process with activation energy (Ea) of −64.193 kJ/mol. The positive value of the entropy (ΔS°) clearly shows that the randomness is decreased at the solid–solution interface during the Congo red adsorption onto TiO₂, indicating that some structural exchange may occur among the active sites of the adsorbent and the ions.

在间歇条件下研究了刚果红在二氧化钛（TiO ₂）材料上的吸附。接触时间（0-60分钟），初始pH（3-11），搅拌速度（100-500 rpm），温度（298-343 K），吸附剂量（0.5-2 g / L）和刚果的影响研究了TiO ₂对刚果红的红色吸附浓度（5-15 mg / L）。为每个动力学模型计算并讨论了动力学参数，速率常数和平衡吸附容量。刚果红在TiO ₂上的吸附用伪二阶方程很好地描述了。吸附等温线遵循Langmuir模型，可以更好地拟合平衡数据。进行分批吸附实验以优化物理参数对刚果红的去除效率。已经发现在25℃下除去了152mg / g。热力学参数表明吸附过程的自发和吸热性质，活化能（Ea）为-64.193 kJ / mol。熵的正值（ΔS°）清楚地表明，在刚果红吸附到TiO ₂上的过程中，固溶界面处的随机性降低了，这表明吸附剂和离子的活性位之间可能发生某些结构交换。