Purification of phenol solution using modified montmorillonite

There is growing interest in the modification of clays to organic materials, i.e. organoclays, in which metal cations on the surface of minerals are removed by exchange with organic cations. Organic cations can also enter into ion exchange reactions with cations that are exchanged between layers. The clay surface can be modified to become strongly organophilic. Phenolic hydrocarbons, including p-nitrophenol and p-chlorophenol, are widely used in pharmaceutical, petrochemical and other chemical manufacturing processes. Due to the potential harm of phenolic compounds to human health and the environment, wastes containing phenolic compounds must be treated before being discharged into receiving water bodies. Secondary biological treatment processes are commonly used to treat domestic and industrial wastes, but cannot successfully remove high concentrations of phenolic wastes. Therefore, new treatment technologies are constantly being researched and developed. Such technologies include biodegradation, chemical oxidation and adsorption. Although many different adsorbents have been used to remove phenol, nitrophenol, and p-chlorophenol from wastes, organoclays have been widely used to remove phenolic compounds. The adsorption of phenol on all clays is well described by pseudo-second-order reaction kinetics. In the second-order reaction kinetics, the experimental and calculated values ​​are very close to each other. The negative values ​​of the Gibbs free energy indicate that the adsorption of phenol on all clays is natural. The changes in enthalpy show positive values, and therefore the adsorption mechanism is determined to be endothermik.