RESEARCH ARTICLE Arsenic adsorbent derived from the ferromanganese slag Nishant Jain 1 & Abhijit Maiti 1 Received: 1 July 2020 /Accepted: 6 September 2020 # Springer-Verlag GmbH Germany, part of Springer Nature 2020 Abstract Arsenic-contaminated groundwater has a severe negative impact on the health of living beings. Groundwater majorly contains arsenite (As(III)) as well as arsenate (As(V)). Among these two, the arsenite species are more carcinogenic, mobile, and lethal. Hence, it is more difficult to remove by conventional water treatment methods. Ferromanganese slag, waste generated from steel industries, has been utilized in this study for the development of arsenic adsorbent. A chemical treatment method is applied to the ferromanganese slag to prepare efficient arsenic adsorbent, and it is easy to scale up. An adsorbent with the capacity for simultaneous oxidation of As(III) and adsorption of total arsenic species can be efficient for arsenic decontamination. X-ray photoelectron spectroscopy and X-ray absorption near edge spectra techniques prove the As(III) oxidation capability of the developed material is about 70 ± 5% based on initial As(III) concentration. The adsorbent not only oxidizes the As(III) species but also adsorbs both the arsenic species. The Langmuir isotherm model estimates the maximum adsorption capacities at the equilibrium concentration of 10 μg/L are 1.010 ± 0.004 mg/g and 1.614 ± 0.006 mg/g for As(III) and As(V), respectively. The rate of adsorption of As(III) was higher compared to the As(V), which was confirmed by the pseudo-second-order kinetic model. Therefore, the treated water quality meets the World Health Organization and Indian drinking water standards. Keywords Arsenite oxidation . Adsorption . Value-added product . Metallurgical waste Introduction The scarcity of safe drinking water is a common problem for many countries. Less than 1% of the total water on earth is freshwater available for the drinking purpose, either directly or after treatment using available techniques (Schouwenaars et al. 2017). Contaminants in natural water-resources vary by regions and countries, but some are common and more toxic (Gimeno et al. 2016). There is a vast list of contaminants present in groundwater throughout the World, among which the arsenic poses the acute toxicity at its long exposure (Maiti et al. 2010a; Fischel et al. 2015b). Among the various arsenic species in water, inorganic forms of arsenic species are more carcinogenic (Maiti et al. 2012; Penke et al. 2017). Natural groundwater sources are majorly contaminated by the arsenite (As(III)) as well as arsenate (As(V)) (Maiti et al. 2012). Since arsenite shows easy mobility through natural water bodies because it holds a neutral charge, hence, it is almost ten times more toxic than arsenate anion (Minocha and Bhatnagar 2007), whereas the arsenate present in the anionic form in natural water pH and charge varies from 1 to 3 (Maiti et al. 2010b; Fischel et al. 2015a; Miralles-Cuevas et al. 2017). The maximum permissible limit of 10 μg/L for arsenic in drinking water is defined by the World Health Organization (Nigam et al. 2013; Simeonidis et al. 2016). Therefore, As(III) decon- tamination is more complicated than As(V), so further re- search and development in this field are urgently warranted (Bangari et al. 2019). Various technologies have developed for the removal of both the arsenic species such as oxidation (Bhandari et al. 2011; Kumar et al. 2014), advanced oxidation techniques (Yuan et al. 2016), adsorption (Minocha and Bhatnagar 2007; Maiti et al. 2012; Chaudhary et al. 2019), electro-coagulation (Nguyen et al. 2016; Dhadge et al. 2018), coagulation-flocculation (Su et al. 2018), biological treatment (Shakya and Ghosh 2018a, b), nanotechnology (Dey et al. 2014), and phytoremediation (Wang et al. 2017). Among all available techniques, adsorption is found to be the most suit- able technique for the remediation of arsenic from Responsible Editor: Ioannis A. Katsoyiannis * Abhijit Maiti abhijit.maiti@pe.iitr.ac.in 1 Department of Polymer and Process Engineering, Indian Institute of Technology Roorkee, Saharanpur Campus, Saharanpur, Uttar Pradesh 247001, India Environmental Science and Pollution Research https://doi.org/10.1007/s11356-020-10745-9