The Use of Linear Alkylbenzene Sulphonates as a Molecular Marker for Tracing Urban Sewage Pollution in Abbasabad River (Hamadan) in 2019: A Descriptive Study

In the past decades, due to population growth and industrial activities, important water resources around the world have been exposed to domestic, industrial and agricultural wastewater. One of the most important wastewater pollutants is linear alkylbenzene sulphonates (LASs). This study aimed to investigate the concentration and health risk assessment of these compounds in the Abbasabad River in Hamadan.

This descriptive study was conducted in the spring of 2019 from the water sample of Abbasabad River in 17 stations. In this study, the optimized and modified method of methylene blue was used to measure the amount of LAS. After preparing the samples using the methylene blue method, the organic phase of the sample was separated and the LAS absorption was read using a spectrophotometer at a wavelength of 650 nm, and the LAS concentration was calculated using the obtained absorption and calibration curve. LAS health risk assessment was performed by calculating the risk quotient (RQ) index.

The results showed LAS concentration ranged from 0.11 to 2.65 mg/L with a mean of 1.25 mg/L. Based on field observations, the entry of untreated wastewater into the Abbasabad River was the main cause of the high concentration of LAS. The results of the health risk assessment showed no risk in different age groups.

The results show that at this level of LAS concentration in the Abbasabad River of Hamadan, there is no significant concern for human health. However, it is worthwhile to prevent the entry of untreated or inadequately treated wastewater into valuable water resources.