analysis and monitoring of the herbicide 2,4-d in agricultural drainage systems and karun river using hplc method

The karun river, located in khuzestan province in southwestern iran, is the country’s most important waterway, playing a crucial role in drinking water supply, aquaculture, industry, and agriculture. the discharge of agricultural drainage into the river has led to contamination with various pollutants, including herbicides. one of the most commonly used herbicides in the region is 2,4-dichlorophenoxyacetic acid (2,4-d), which can significantly impact river water quality. this study aims to determine the concentration of 2,4-d in agricultural drainage and the karun river. in this study, the amount of 2,4-d herbicide was sampled and analyzed according to the standard method in summer and winter at five agricultural drainage stations and 17 karun river stations. hplc high-performance liquid chromatography (knauer) was used to measure 2,4-d. a c18 column (250 × 4.6 mm, 5 µm) was used as the stationary phase, and a 2500 ultraviolet (uv) detector made in germany was employed for detection was used to measure 2,4-d. the results revealed that 2,4-d levels exceeded permissible limits at several stations. the highest concentration in agricultural drainage was recorded at 105.26 µg/l in summer (station 18), while the maximum concentration in river water was 66.27 µg/l (station 2). additionally, 2,4-d levels decreased along the river due to processes such as adsorption to suspended solids, photodegradation (uv), and microbial biodegradation. this study provides valuable insights into the distribution of 2,4-d in the karun river and highlights the need for effective agricultural pollution management.