RESEARCH ARTICLE Phytoremediation potential of Azolla filiculoides for sodium dodecyl benzene sulfonate (SDBS) surfactant considering some physiological responses, effects of operational parameters and biodegradation of surfactant Zahra Masoudian 1 & Seyed Yahya Salehi-Lisar 1 & Akbar Norastehnia 2 Received: 18 June 2019 /Accepted: 2 March 2020 # Springer-Verlag GmbH Germany, part of Springer Nature 2020 Abstract In this study, phytoremediation potential of the Azolla filiculoides Lam. was examined for sodium dodecyl benzene sulfonate (SDBS) anionic surfactant. Furthermore, the effect of surfactant treatment on some physiological characteristics of Azolla was studied. The surfactant bioremoval efficiency was studied under variable conditions including treatment time, initial surfactant concentration, Azolla fresh weight, temperature, and pH. Results showed that surfactant removal efficiency of A. filiculoides was significantly enhanced with increasing of temperature, initial surfactant concentration, and amount of Azolla. SDBS led to a reduction in growth rate and total chlorophyll content, but effect index of Azolla increased by higher concentrations of surfactant. In contrast, antioxidant enzymes activities including polyphenol oxidase, ascorbate peroxidase, catalase, and peroxidase, as well as nonenzymatic antioxidants such as total carotenoids and anthocyanin contents significantly increased probably due to the ability of plant to overcome oxidative stress induced by SDBS. An increase in antioxidant activity based on 2, 2-diphenyl-1-picrylhydrazil (DPPH) confirmed this fact. An increase in the amount of hydrogen peroxide and reduction in membrane stability index indicated the induction of oxidative stress. As a result of SDBS biodegradation, 6 homologs of sulfophenyl carboxylates (SPCs) including C 2 to C 7 -SPC and benzenesulfonate ring were identified by liquid chromatography–mass spectroscopy (LC-MS) analysis. Keywords Azolla filiculoides . Oxidative stress . Phytoremediation . SDBS . Biodegradation Introduction Surfactants are one of the main ingredients in commercial and household detergents; they are also used in many industrial and research fields (Planas et al. 2002). More than 15 billion tons of surfactants are produced annually, and it is expected that their production will increase by 4 % by 2020 (Li et al. 2018b). Because of the widespread use of surfactants with low rates of decomposition in anaerobic conditions, the surfactants can be used as indicator molecules to assess pollution caused by human activities (Li et al. 2018b). Surfactants are amphi- pathic compounds, and their hydrophobic and hydrophilic portions can easily interact with the polar and nonpolar parts of biological macromolecules such as protein (Nielsen et al. 2000), peptides, and membrane phospholipids (Heerklotz 2008). The production of surfactants has critical environmen- tal impacts and increases the risks associated with global warming and enhances greenhouse gases level (Rebello et al. 2014). Based on the charge of the hydrophilic group, surfactants are classified as anionic, cationic, nonionic, and ampholytic compounds (Rebello et al. 2014). Anionic surfac- tants are historically older and more common (Liwarska- Bizukojc et al. 2005). Linear alkylbenzene sulfonate (LAS) is a group of anionic surfactants and include a mixture of homologs, with chain lengths of between 10 and 13 carbon atoms. Each of these homologs consists of a varying number of positional isomers. Sodium dodecyl benzene sulfonate (SDBS) is a linear alkyl benzene sulfonate with an alkyl chain Responsible editor: Elena Maestri * Seyed Yahya Salehi-Lisar y_salehi@tabrizu.ac.ir 1 Department of Plant Sciences, Faculty of Natural Sciences, University of Tabriz, Tabriz, East Azerbaijan 5166616471, Iran 2 Department of Biology, Faculty of Sciences, University of Guilan, Rasht, Iran Environmental Science and Pollution Research https://doi.org/10.1007/s11356-020-08286-2