Evaluation of Phthalate Concentration in Landfill Leachate in the West of Guilan Province, Iran

Abstract

Landfill leachate contains pollutants, including phthalates, which pose significant risks to the environment and human health. This study aimed to investigate the phthalates concentration in landfill leachate from three cities in western Guilan: Astara, Talesh, and  Anzali. Samples were collected from three designated stations during both the rainy and dry seasons. Physicochemical parameters such as pH, electrical conductivity (EC), organic matter content, and phthalate concentrations were measured using the standard extraction method EPA Method 8061A, with gas chromatography-mass spectrometry (GC-MS). The results revealed that the average total phthalate concentration in landfill leachate across the three cities was 455.46 ppb, with significant seasonal variation between the rainy and dry seasons (P < 0.05). Astara exhibited the highest phthalate concentration, measuring 239.50 ppb. Throughout both seasons, bis (2ethylhexyl) phthalate (BEHP) accounted for the most significant proportion, comprising 73.2% of total phthalates, followed by dioctyl phthalate (DOP) at 13%, dimethyl phthalate (DMP) at 6.4%, and isobutyl phthalate (IBP) at 5.5%. Diethyl phthalate (DEP), dibutyl phthalate (DBP), and benzyl butyl phthalate (BBP) were less prevalent, representing 1.1%, 0.5%, and 0.2%, respectively. Health risk assessments indicated that the contamination factor (CFi) was highest at the Talesh station (80.30), followed by Anzali (45.52) and Astara (10.69). Similarly, the Pollution Load Index (PLI) was greatest at Talesh (32.32), followed by Astara (20.24) and Anzali (11.32). These findings underscore the critical need for continuous monitoring and effective management of landfill leachate, as well as further investigation into the health and environmental impacts of phthalate contamination.