Vol.:(0123456789) 1 3 International Journal of Energy and Water Resources https://doi.org/10.1007/s42108-019-00024-w ORIGINAL ARTICLE Application of sugarcane leaves as biomass in the removal of cadmium(II), lead(II) and zinc(II) ions from polluted water O. A. Adigun 1,2  · V. O. Oninla 3  · N. A. Adesola Babarinde 4 Received: 20 February 2019 / Accepted: 7 May 2019 © Islamic Azad University (IAU) 2019 Abstract Here, we present the removal of cadmium(II), lead(II) and zinc(II) ions, by sugarcane (Saccharum spontaneum) leaves. Bio- mass characterisation was performed with Fourier transform infrared spectroscopy, scanning electron microscopy, energy dispersive X-ray and X-ray difractometry. The efects of parameters such as solution pH, initial metal ion concentration and contact time were investigated. To understand the adsorption process, data were ftted into models such as the pseudo-frst order, pseudo-second order, Weber–Morris, Langmuir, Freundlich and Dubinin–Radushkevich (D–R). The surface of the adsorbent was oval and irregular in shape, with scattered adsorptive sites. Carbon and oxygen were the main element present in the adsorbent, claiming about 59% and 38% of the total elemental compositions, respectively. Optimum pH for lead and zinc ions was 5, while 6 was chosen for cadmium ions. Adsorption increased with time and eventually plateaued after 5 h for lead and 4 h for cadmium and zinc ions. Metal uptake increased with increase in initial metal ion concentration up to 250 mg/L. Adsorption data ftted best to the Langmuir isotherm, with maximum sorption capacity, q max , obtained as 142.86, 156.25 and 166.67 mg/g for the removal of cadmium, lead and zinc, respectively. The pseudo-second-order model provided the best ft for the kinetic data (R 2 of > 0.95), indicating that the sorption process was controlled by chemisorption mecha- nism. Information from Freundlich and D–R models signifed that the uptake of the three metal ions was by physisorption and that ion-exchange mechanism was also involved in zinc adsorption. Keywords Adsorption process · Isotherm · Kinetic mechanism · Metal uptake · Physisorption Introduction The discharge of untreated industrial efuents and sewage from metabolic wastes into water bodies, especially in the developing countries, has been on the increase for some years. Due to the debilitating efects of this environmen- tal pollution on the ecosystem (Gnanasekaran et al. 2015), global environmentalists have since been looking for ways of combating the menace. One of the main reasons for the upsurge is the steady increase in the urbanisation and industrialisation trend around the world, which results in large pollutants being released into the environment (Denny 1997; Muñoz et al. 2018). Other reasons include high cost of advanced technological methods for the treatment of wastewater and insufcient information on the danger the pollutants pose to aquatic and human lives (Denny 1997; Krishnani et al. 2008). Heavy metal ions are regarded as environmental toxins and elevated concentrations of these toxic metal ions have been detected in some rural areas of the world (Denny 1997). Cadmium(II), lead(II) and zinc(II) are few of the toxic metal ions that pollute natural potable water sources. These hazardous metal ions and other pollutants are released into the environment via indiscriminate dis- charge of toxic chemicals through effluents from a wide * O. A. Adigun oaadigun@mun.ca * V. O. Oninla vinzoninla@daad-alumni.de 1 Department of Chemistry, University of Ibadan, Ibadan, Nigeria 2 School of Science and the Environment/Boreal Ecosystem Research Facility, Memorial University of Newfoundland, Grenfell Campus, 20 University Drive, Corner Brook, NL A2H 5G4, Canada 3 Department of Chemistry, Obafemi Awolowo University, Ile-Ife, Nigeria 4 Department of Chemical Sciences, Olabisi Onabanjo University, Ago-Iwoye, Nigeria