Arabian Journal for Science and Engineering https://doi.org/10.1007/s13369-020-04504-8 RESEARCH ARTICLE-CHEMISTRY Synthesis of Trifluoroacetylacetone Resin Through Schiff’s Base Reaction for Treatment of Cadmium-Contaminated Water Abdul Majid Channa 1,3 · Saima Qayoom Memon 2 · Muhammad Yar Khuhawar 1 · Sıtkı Baytak 3 Received: 13 October 2019 / Accepted: 30 March 2020 © King Fahd University of Petroleum & Minerals 2020 Abstract The present study reports two-step synthesis of a new resin, i.e. trifluoroacetylacetone (TFAA)-XAD (X) resin via Schiff’s base reaction. Synthesized resin was used to treat cadmium-contaminated water. Before application to the real water system, a method for the removal of Cd(II) ions was optimized using design of experiment. A face-centred composite design (CCD) predicted 97.0% removal at pH 10; other optimum parameters were concentration of Cd(II) ion 10 mg l −1 , sorbent amount 82.0 mg, shaking speed 200 rpm and shaking time 63 min. Predicted removal was found to be in good agreement with experimental removal. Equilibrium data were good fit to Langmuir, Freundlich and D–R isotherms with a correlation coefficient (R 2 ) of 0.98, 0.97 and 0.98, respectively. Monolayer sorption capacity of X-TFAA resin for Cd(II) ions calculated was 403 mg g −1 . The sorption energy (E) calculated was 9.2 kJ mol −1 , revealed chemisorption of Cd(II) ions onto the X-TFAA resin. The developed method was applied successfully for the removal of Cd(II) ions in environmental water samples. Keywords Adsorption · Amberlite XAD resin · Chelating resin · Isotherm · Cadmium 1 Introduction Environmental pollution caused by metallic toxins such as lead, mercury, cadmium and arsenic is issue of great concern because of their accumulation in food chain and low decom- position rates [1]. Cadmium may be found in wastewater discharges from the electroplating industry, the manufacture of nickel–cadmium batteries, fertilizers, pesticides, pigments and dyes and textile operations [2, 3]. According to the rec- ommendation of World Health Organization, the permissible limit for cadmium in drinking water is less than 5 μgl −1 [4]. Hence, the abatement of cadmium from wastewater is the top priority of researchers. Conventional methods for the removal of heavy metals from drinking water include reduc- tion, precipitation, ion exchange, filtration, electrochemical treatment, membrane technology and evaporation removal, B Abdul Majid Channa channa_abdulmajid@yahoo.com 1 Institute of Advance Research Studies in Chemical Sciences, University of Sindh, Jamshoro, Pakistan 2 M. A. Kazi Institute of Chemistry, University of Sindh, Jamshoro, Pakistan 3 Department of Chemical Engineering, Faculty of Engineering, Suleyman Demirel University, 32260 Isparta, Turkey all of which may be ineffective or extremely expensive, when the metals are dissolved in large volumes of solution at rel- atively low concentrations [5]. Among the abovementioned techniques, adsorption has been emerging as a significant technique for the removal of pollutants from aqueous sys- tems. Many attempts have been made for the removal of metal ions from contaminated wastewater using adsorption tech- nique, activated carbon [6], oxide minerals [7], polymer materials [8], resins [9] and biosorbents [10, 11]. A large number of articles are reported on use of Amberlite XAD series resin mainly because of large surface area and greater pore size [12]. The main drawback of commercial Amberlite resins is that they do not possess selectivity among the metal ions, which may cause the interferences of coexisting species with the analyte ion and results in decreasing efficiency [13]. Physical or chemical modification of Amberlite with specific chelating groups has been proposed by many researchers to overcome the selectivity problem [14–18]. Many chelating agents have been used to modify Amberlite XAD surface, for example 1,6-bis(2-carboxy aldehyde phenoxy)butane has been covalently bonded with polystyrene–divinylbenzene, through a –C=N– group, resulting resin was used in a mini column for the separation and preconcentration of Cu(II) and Cd(II) prior to their determination by FAAS [19], octa- 123