Mass Loadings of Triclosan and Triclocarbon from Four Wastewater Treatment Plants to Three Rivers and Landfill in Savannah, Georgia, USA

Abstract

Triclosan (TCS) and triclocarbon (TCC) are bactericides used in various consumer and personal-care products. Recent studies have revealed considerable levels of these bactericides in wastewater, aquatic wildlife, and human samples. Consequently, in this study we measured TCS and TCC in influent and effluent, sludge, and pond water/sediment samples from four wastewater treatment plants (WWTPs) and three major rivers in Savannah, Georgia (USA). Among these treatment plants, the Wilshire plant showed elevated concentrations of TCS (influent, 86,161; effluent, 5370 ng/L), whereas TCC was greater in the Georgetown plant (influent, 36,221) and the Wilshire plant effluent (3045 ng/L). Clearance of TCS and TCC were 95 and 92%, respectively, in the President Street plant, 94 and 85%, respectively, in the Wilshire plant, 99 and 80%, respectively, in the Travis Field plant, and 99 and 99%, respectively, in the Georgetown plant. Based on the mass flow estimate, 138 g/day of TCS and 214 g/day TCC are released into the Savannah River from the President Street, Travis Field, and Wilshire plants and 1.60 g/day TCS and 1.64 g/day TCC are released to the Ogeechee River from the Georgetown plant. Based on the sludge data, the loading estimate can be calculated that 32 and 0.004 g/day TCS and 53 and 0.01 g/day TCC (nonincinerated and incinerated, respectively) are deposited in landfill from the President Street plant alone, whereas 4.6, 26, and 6.8 g/day TCS and 3.8, 23, and 5.9 g/day TCC (wet sludge) were produced and dumped in landfill from the rest of the WWTPs. Incineration of wet sludge can eliminate 99.99% of TCS and TCC. Concentrations of TCS and TCC in water and sediment were greater in the Vernon River, followed by the Savannah River and the Ogeechee River.