Synthesis of the functional graphene in adsorptive removal of phenol from liquid streams

Industrial technology produces some different aromatic molecules which can be caused pollutant water due to negative impacts for ecosystems and humans’ toxicity. Phenol is generated in large amount annually, with a significantly increasing trend. Phenolic products as industrial raw materials are very important in the production of certain artificial resins. Phenol can be produced from many industries such as petrochemicals, petroleum refineries, coke-oven, steel foundry, insecticides and herbicides. Due to the toxicity of the phenol even at low concentrations, the phenolic derivate is one of the most common organic water pollutants. The researchers evaluated the role of aromatic structure and –OH substitution in the polar aromatics carbon-based system. The adsorption of phenolic compounds by graphene was improved with increasing number of aromatic rings. In the other hand the –COOH substitution was enhanced the adsorptive removal of phenol from liquid streams. In this paper we synthesized the graphene as the base of the adsorbent then functionalized with –COOH. The solutions of the phenol as effluent model and graphene-COOH as adsorbents were chosen to evaluate the phenol adsorption mechanisms. Therefore, the Langmuir and Freundlich models are used to consider adsorption isotherms models. To complete our research, the effects of initial phenol concentration, contact time and adsorbent loaded are explored to adsorb phenol from aqueous stream by graphene-COOH. Scanning electron microscopy (SEM) images were taken from synthesized graphene, the surface area, pore volume and pore size distribution were measured by nitrogen adsorption at 77 K using an ASAP-2010 porosimeter from the micromeritics corporation GA. Fourier-transform infrared spectroscopy (FT-IR) was used to analyze the changes in the surface chemical bonding and structure in the frequency range of 4000–400 cm-1.

Keywords:

Graphene , Adsorption , Chemical bonding , Langmuir