Removal of microfiber and surfactants from household laundry washing effluents by powdered activated carbon: kinetics and isotherm studies

Abstract

Domestic laundry wastewater discharge contributes significantly to the presence of microfiber and surfactant pollutants in aquatic ecosystems, which have detrimental and toxic effects on humans and the environment. Investigating the efficacy of powdered activated carbon (PAC) in removing micro-/nanofibers with or without surfactant from household laundry effluent is the purpose of the current research. To simulate real-world scenarios, PAC adsorption kinetics and isotherms in laundry effluents under controlled conditions were studied. These studies showed that the kinetics obeyed a pseudo-second-order process and the isotherms varied between Langmuir and Freundlich models depending on the water types. In the results of experiments using distilled water and tap water, it was observed that the adsorption capacity was higher in tap water. When the adsorption of 0.1 μm filtered synthetic garments, detergent, and tap water was compared with the adsorption of the raw sample, it was observed that the adsorption capacity of the 0.1 μm filtered version was higher. Even though this study is preliminary, the results indicate that PAC has the capacity to serve as a viable approach for mitigating micro-/nanoplastic and surfactant contamination from laundry wastewater, thereby offering valuable guidance for advancing eco-friendly laundry techniques. HIGHLIGHTS The adsorption capacity of PAC is higher for nanofibers than microfibers.; Surfactants and microfibers can be removed with low dosages of PAC.; With PAC adsorption, more than 60% of TOC and ANS removal was obtained in the first 30 min.; The ions in the tap water play a role in increasing the adsorption capacity.;

Keywords

• adsorption
• detergent
• household wastewater
• laundry
• microfiber
• nanofiber