REVIEW Application of nanoadsorbents for removal of lead from water M. Bhatia 1 • R. Satish Babu 1 • S. H. Sonawane 2 • P. R. Gogate 4 • A. Girdhar 3 • E. R. Reddy 1 • M. Pola 1 Received: 1 December 2015 / Revised: 8 July 2016 / Accepted: 16 November 2016 Ó Islamic Azad University (IAU) 2016 Abstract Enormous increase in the application of various heavy metals including lead for commercial and non- commercial purposes has also led to their enhanced occurrence in the effluents from industries and domestic discharge creating substantial environmental concerns. The existing techniques for removal of these contaminants such as reverse osmosis and ion exchange suffer a few disad- vantages and hence, thrust to develop efficient techniques for the removal have been ever increasing. Adsorption based on the use of nanoadsorbents is promising being cost effective and based on the ease of operation. The present work furnishes a detailed overview on nanoadsorbents for removal of lead from water. The various nanoadsorbents covered in the analysis include alumina, anatase, carbon nanotubes, chitosan, copper, iron and zinc oxide, mag- netite, nanoclay and zirconium nanoparticles. The review also gives an insight into the synthesis and characterization of nanoadsorbents followed by guidelines on optimum operating parameters to be used in the removal process for maximizing the extent of removal. The typical optimum conditions established based on the critical analysis of literature are pH B 6, contact time C60 min and optimum adsorbent dose dependent on the nanomaterials. Compar- ison of different nanoparticles revealed that titanium oxide and hematite nanoparticles are the best, giving 100% removal efficiency for lead ions. The sequestration was mainly dependent on adsorbent dose that has to be kept optimum to yield adequate surface area and number of adsorption sites. Overall, nanoadsorbents have been established to yield efficient removal of lead from water. Keywords Adsorption Á Inorganic pollutants Á Lead Á Nanoparticles Á Water pollution Introduction Water pollution has always been a concern for the growing population as the quantum of usable water is slowly reducing with the increasing contamination and depleting natural resources. The inorganic, organic and biological pollutants from point and non-point sources have posed a significant threat for contamination of drinking and groundwater (Ali 2014). Inorganic pollutants like arsenic, lead, cadmium, chromium, copper, cobalt, selenium, nitrates and fluoride ions are the major cause for water pollution, and among the commonly observed contaminants, lead stands second on the list of most hazardous metals (Ali and Aboul- Enein 2006; Ensie and Samad 2014; Ghaemi et al. 2015; Gupta and Ali 2012; Kumari et al. 2015a; Ling et al. 2015; Mahmoud et al. 2014; Salam 2013; Wang et al. 2014; Zhang et al. 2014) with significant health risks for the living beings. Presence of lead in even trace amounts is a major concern (Ozlem Kocabas-Ataklı and Yurum 2013) and the permis- sible lead limit in drinking water is 0.05 mg L -1 , whereas in the case of surface water and discharge in public sewers, Editorial responsibility: Sivakumar Durairaj. & R. Satish Babu satishbabu@nitw.ac.in 1 Department of Biotechnology, National Institute of Technology, Warangal, Telangana State 506004, India 2 Department of Chemical Engineering, National Institute of Technology, Warangal, Telangana State 506004, India 3 Department of Biotechnology, Indian Institute of Technology, Hyderabad, Telangana State 502285, India 4 Department of Chemical Engineering, Institute of Chemical Technology, Mumbai, Maharashtra State 400019, India 123 Int. J. Environ. Sci. Technol. DOI 10.1007/s13762-016-1198-6