Selection of priority emerging pollutants in gray water

Abstract

The objective of this work was to select priority emerging pollutants in gray water, aiming at the safe reuse of gray water. The methodology used was based on three selection criteria: pollutants identified most frequently in personal care and household cleaning products, potential risks to the environment, and pollutants found in gray water and the environment in higher concentrations. As a result, 33 products were analyzed and 54 emerging pollutants were identified among the components described on the labels, among which fragrances, preservatives and surfactants stand out. It is concluded that there is a relationship of socioeconomic strata on consumption habits, thus making some essential products and other expendable products (such as sunscreen and repellent). Likewise, the user's social class is directly related to the chosen personal care product brand. However, this behavior cannot be noticed for household cleaning products, as the choice of brand used is similar between social classes and they are not chosen based on prices. Moisturizing cream for skin, sunscreen and shampoo are the products that have, on average, the highest number of emerging pollutants. It was also observed that 62.5% of the pollutants have higher concentrations in gray water compared to black water. The predominant pollutants, defined as priority pollutants, were: linalool, benzyl salicylate, eugenol, geraniol, methylparaben, citric acid, phenoxyethanol, citronelool, propylene glycol, limonene, coumarin, hexyl cinnamal, glycerin, propylparaben and ethylparaben. Through the concentrations of PEs in receiving water bodies, it can be observed that they are released at low, but detectable and potentially harmful levels.