Electrochemical monitoring of phenol biosorption by using factory solid organic waste as a biosorbent

Increasing industrial production with the developing population in the world and in our country has brought serious environmental problems. One of the most important environmental problems is phenol among the causes of water pollution. Phenolic compounds are accepted as primary pollutants in wastewater due to their high toxicity, high oxygen demand, suspended solids, oil and odor. Conventional treatment methods may be insufficient for the removal of phenolic compounds and organics resistant to biodegradation. As seen in the Water Pollution Control Regulation, the receiving environment discharge standard values are very low and must be removed before discharge. The biosorbent was obtained from the solid organic waste of lemon pulp, which is the output of the liquor production process in a factory producing alcohol in Bilecik. Biosorption experiments were carried out in liquid media containing a certain amount of phenol with a temperature and speed controlled stirrer. In our electrochemical studies, a triple electrode system was used. This system consists of a working electrode, a reference electrode and an auxiliary (opposite) electrode. The working electrode is a pencil graphite electrode (PGE). The reference electrode is the Ag/AgCl reference electrode (BAS, Model RE-5B, W. Lafayette, USA). The auxiliary electrode is a platinum wire. All electrochemical measurements we performed were carried out with the cyclic voltammetry (CV) technique in the potential range of 0.5 V- 1.2 V and with a scanning speed of 50 mV/s. Microscopic analyzes were carried out with scanning electron microscopy (SEM) technique to examine the changes in the biosorbent after biosorption. In this study, biosorption could be performed more effectively as the contact time increased, however, the % removal reached the highest level (88.36%) after 6 hours, and no increase in biosorption efficiency was observed as the time extended. The biosorption time of 6 hours was determined as optimum for this study. It was determined that the porous structure of the biosorbent was coated after biosorption and phenol removal could be achieved successfully. Thus, it has been shown that the electrochemical and microscopic results are compatible with each other and that the biosorption can be successfully performed with the developed biosorbent. Keywords: Phenol, Treatment, Wastewater, Electrode, Biosorption