Occurrence, spatial and seasonal variations of emerging contaminants in the aquatic environment of Sharjah, United Arab Emirates

Abstract

The occurrence, seasonal variations and spatial distribution of emerging contaminants (ECs) in wastewater effluents from wastewater treatment plant (WWTP) and UAE's receiving coastal aquatic environment (seawater and sediments) were evaluated in the present study. A total of 21, 23, and 22 contaminants in the effluents, seawater, and sediments, respectively, at concentrations ranging from low ng L^-1 up to 1782 ng L^-1 in effluents, from low ng/l up to 236.10 ng L^-1 in seawater, and from low ng g^-1 up to 60.15 ng g^-1 in sediments were recorded. The study revealed that imidacloprid, thiabendazole, and acetaminophen were the most ubiquitous compounds in effluents, seawater, and sediments, respectively, since they were found in all samples collected with a detection frequency of 100%. The study also revealed that the higher concentrations of most contaminants were recorded in autumn. However, thiabendazole in effluents and seawater, acetamiprid in effluents, and sulphapyridine in seawater and sediments showed a higher load in winter. This study highlights the need for proper monitoring and management of ECs in wastewater effluents, seawater, and sediments, especially during the autumn and winter seasons, to minimize their impact on the marine ecosystem and public health.

Keywords: Effluents; Emerging contaminants (ECs); Occurrence; Seasonal variation; Seawater; Sediments.