Evaluation of surfactant removal efficiency in different municipal WWTPs in Romania

The population increase and the continuous development of anthropogenic activities have generated toxic chemical compounds with harmful potential for the environment. In addition, the recent SARS COVID-19 crisis of 2020 spiked in Romania the sales of the cleaning and household products up to 461% compared to last year, same period of time), meaning an increase of inorganic and organic chemical compounds, including the surfactants, in sewage systems. The oldest and the most common type of surfactant used in cleaning detergents and personal care products is the anionic surfactant. Usually, used surfactants are disposed to sewage treatment plants, where the biodegradation processes and adsorption on sludge particles remove these chemicals from wastewaters. The extent of removal depends on the chemical structure of the surfactant molecule and on the operating conditions of the wastewater treatment plants (WWTP’s). The accumulation of surfactants can cause malfunction of WWTP’s by affecting several treatment processes such as the oxygen diffusion, foaming, biodegradation of organic compounds. and denitrification of ammonium nitrogen as well as a negative influence on the structure of flocks in the activated sludge. This paper presents results focused on operational efficiency of municipal WWTP’s in terms of anionic surfactants removal.