RESEARCH ARTICLE Surfactant-modified titania for cadmium removal and textile effluent treatment together being environmentally safe for seed germination and growth of Vigna radiata Paromita Das 1,2 & Nupur Bahadur 2,3 & Vibha Dhawan 1,3 Received: 20 May 2019 /Accepted: 20 December 2019 # Springer-Verlag GmbH Germany, part of Springer Nature 2019 Abstract The present work describes synthesis, detailed characterization, and application of bare and surfactant-modified titania nanomaterials (NMs) for various wastewater treatment applications as individual cases like cadmium (Cd) removal, methylene blue (MB) dye degradation, and treatment of real textile and dyeing industry effluent. These NMs are used as adsorbents and photocatalysts in an indegenously developed end-to-end treatment process and a photocatalytic reactor for treatment of textile wastewater. The used NMs are suitably filtered and recovered for reuse; however, still this work focusses on the extent of potential risk and environmental safety of these engineered NMs towards seed germination and plant growth, in the event they escape wastewater treatment plants and reach out to natural water bodies and soil systems, accumulate over a period of time, and comes in contact with plant species. For synthesis, sol-gel method was utilized; cetyltrimethylammonium bromide (CTAB) and sodium dodecyl sulfate (SDS) were used as cationic and anionic surfactants, respectively, to act as particle growth templates and improve surface morphology. Detailed characterization involved XRD (X-ray diffraction), FTIR (Fourier-transform Infrared Spectroscopy), SEM (Scanning Electron Microscopy), TEM (Transmission Electron Microscopy), EDX (Energy Dispersive X-ray analysis), and BET (Brunauer-Emmett-Teller) surface area analysis. Improved morphology and surface properties, from irregular shape in Bare TiO 2 to spherical shape in surfactant-modified titania, led to en- hanced Cd removal and MB dye degradation efficiency. Bare TiO 2 was used for complete treatment of textile wastewater, which took 5 h in achieving water quality, which is safe for discharge and reuse as per norms of Central Pollution Control Board (CPCB), Govt. of India. Phytotoxicity studies of these NMs at a wide concentration range (0–1000 mg L -1) were undertaken towards Vigna radiata, and 500 mg L -1 concentration was found to be optimally safe for seed germination and plant growth. Keywords Surfactant modification . Titania . Cadmium removal . Textile wastewater . Seed germination and plant growth . Vigna radiata Introduction Titanium dioxide has numerous applications in various fields of Science and Technology, and it is the method of synthesis which affects its properties and applications and ultimately the performance. Among several methods of synthesis, sol-gel is most preferred, due to its simplicity and ease; however, it leads to irregular shape and agglomeration of particles (Ganguli 1999). To prevent these, many approaches have been devised, among which modification with surfactants has shown prom- ising results in terms of improved morphology and controlled particle size (Imae et al. 1991; Cassiers et al. 2004; Chai et al. Responsible editor: Gangrong Shi * Nupur Bahadur nupur.bahadur@teri.res.in 1 Department of Biotechnology, TERI School of Advanced Studies, Plot No. 10 Institutional Area, Vasant Kunj, New Delhi 110070, India 2 TERI-Deakin Nano Biotechnology Centre, TERI Gram, The Energy and Resources Institute, Gual Pahari, Gurgaon Faridabad Road, Gurgaon, Haryana 122 001, India 3 The Energy and Resources Institute, Darbari Seth Block, India Habitat Center, Lodhi Road, New Delhi 110003, India https://doi.org/10.1007/s11356-019-07480-1 Environmental Science and Pollution Research (2020) 27:7795–7811 /Published online: 30 December 2019