Identification and significance of sulphonamides (p-TSA, o-TSA, BSA) in an urban water cycle (Berlin, Germany)

Because of the nature of the water cycle in Berlin, a number of persistent wastewater residues are present in the surface water and may potentially reach the groundwater via bank filtration and artificial recharge. The occurrence and behaviour of the wastewater residues para-toluenesulphonamide (p-TSA), ortho-toluenesulphonamide (o-TSA) and benzenesulphonamide (BSA) through wastewater treatment, surface water, bank filtration and drinking water treatment was studied. In addition, groundwater below a former sewage farm was investigated. All three compounds are ubiquitous in the aquatic environment of Berlin. p-TSA concentrations are much higher than those of o-TSA and BSA. p-TSA was found in high concentrations in the wastewater influent (2 to 15 μg/L), in the wastewater effluent (<0.15 to 2.34 μg/L) and in sewage farm groundwater (<0.05 to 20 μg/L) and in lower concentrations in the surface water (<0.05 to 1.15 μg/L), bank filtrate (<0.05 to 0.30 μg/L) and drinking water (<0.05 to 0.54 μg/L). p-TSA is considerably depleted during waste- and drinking water treatment (∼90% reduction each). The concentration ranges for o-TSA and BSA in wastewater influents were 0.11 to 8 μg/L and <0.05 to 0.64 μg/L, respectively, while the values for wastewater effluents were 0.14 to 4 μg/L for o-TSA and 0.25 to 0.49 μg/L for BSA. Wastewater treatment and drinking water treatment do not reduce the concentrations of o-TSA and BSA. The behaviour of o-TSA during wastewater treatment varies largely between different wastewater treatment plants where concentrations increase, remain constant or decrease. BSA forms during treatment. The concentrations measured in surface water, sewage farm groundwater, bank filtrate and drinking water were <0.05 to 1.74 μg/L for o-TSA and <0.05 to 0.53 μg/L for BSA.