Monitoring of Para-Hydroxy Benzoic Acid Esters (Antimicrobial and Preservative) in Tehran Wastewater Treatment Plants and Performance Evaluation of Various Wastewater Treatment Method in the Removal of These Compounds

Background and Purpose: Parabens are a group of Para-hydroxy Benzoic acid alkyl esters which extensively used as preservative in personal care products. Parabens have been recently found in wastewater, rivers, soil and dust. Therefore, the purpose of this study aimed to Monitor the occurrence of parabens from selected wastewater treatment plants (Shahrak Ghods and south of Tehran) and evaluate the performance of different treatment methods for removing these compounds. Methods: In this study, the samples from influent and effluent were collected from Shahrak Ghods and South of Tehran wastewater treatment plant as Seasonal and Three samples per season. Concentration of Para-hydroxy Benzoic acid esters was determined by HPLC, CECIL, 4100 at 242 nm. Result: After sampling in the different seasons from the west and south treatment plants, two selective paraben concentrations (Methyl paraben and Ethyl paraben) were measured. The results showed that average concentration of Methyl paraben (MeP) and Ethyl paraben) EtP( respectively were 740.7 and 277.7 ng/L in the Influent and 179.3 and 45.8 ng/L in the effluent of Shahrak Ghods treatment plant. Also, the average concentration of MeP and EtP respectively were 835.3 and 295.3 ng/L in Influent and 132.8 and 29.7 ng/L in the effluent of South of Tehran treatment plant. In the next step, Risk assessment of effluent treatment plants discharging to environment with comparing the studies was done. According to the paraben concentration in the effluent of both treatment plants, discharge of effluent treatment plants whit selective contaminants, have little biological effects on ecosystems. Conclusions: The removal efficiency of Shahrak Ghods treatment plant in removing parabens, was lower than the South of Tehran. But the effluent quality of both treatment plant was less than the Effluent discharge standard. So both of treatment plant have appropriate performance to removal contaminants.