Untapped Sepia Shell–Based Composite for the Sorption of Cationic and Anionic Dyes A. M. Elgarahy & K. Z. Elwakeel & G. A. Elshoubaky & S. H. Mohammad Received: 9 March 2019 /Accepted: 29 July 2019 # Springer Nature Switzerland AG 2019 Abstract The current research reports an efficient methodology of new sorbent (SSBC) synthesis based on neglected sepia shells for the sequestration of cation- ic dye (Methylene blue, MB) and an anionic dye (Re- active black 5, RB5) from aqueous solutions. The as- synthesized SSBC was produced by reaction of sepia shell powder with urea in the presence of formaldehyde. In the first part of the work, the sorbent was scrutinized by using scanning electron microscopy, energy- dispersive X-ray analysis, Fourier transform infrared spectrometry, and titration (for determining pH PZC ). In the second step, the influence of several parameters including pH effect, sorbent dosage, temperature, and ionic strength on the two dyes’ sorption effectiveness was examined. The sorption isotherms and uptake ki- netics were analyzed at the optimum pH. Outlined re- sults showed that the dynamic experimental obtained data followed the Langmuir isotherm profile, while the kinetic profile fitted well to the pseudo-second-order rate equation. Maximum sorption capacities reach up to 0.794 mmol g −1 (254.05 mg g −1 ) for MB and 0.271 mmol g −1 (269.18 mg g −1 ) for RB5, at pH 10.5 and 2.3, respectively. By comparing the sorption prop- erties at different temperatures, the endothermic nature of the sorption process was revealed. Sorption process- ing under microwave irradiation (microwave-enforced sorption, MES) enhanced mass transfer, and a contact time as low as 1 min is sufficient under optimized conditions (exposure time and power) reaching equilib- rium, while 2–3 h was necessary for a “simple” sorption. Dye desorption was successfully tested using 0.5 M solutions of NaOH and HCl for the removal of RB5 and MB, respectively. The as-prepared sorbent can be reused for a minimum of 4 cycles of sorption/desorp- tion. Finally, the sorbent was successfully tested on spiked tap water and real industrial wastewater. Keywords Sepia shell functionalization . Sorption . Microwave-enforced sorption . Sorbent reusability . Industrial wastewater 1 Introduction Alongside the rapid industrialization, urbanization, and human civilization, increasingly large volumes of Water Air Soil Pollut (2019) 230:217 https://doi.org/10.1007/s11270-019-4247-1 Electronic supplementary material The online version of this article (https://doi.org/10.1007/s11270-019-4247-1) contains supplementary material, which is available to authorized users. A. M. Elgarahy : S. H. Mohammad Zoology Department, Faculty of Science, Port Said University, Port Said, Egypt K. Z. Elwakeel (*) Environmental Science Department, Faculty of Science, Port Said University, Port Said, Egypt e-mail: Khalid_elwakeel@yahoo.com e-mail: Khalid_elwakeel@sci.psu.edu.eg K. Z. Elwakeel Chemistry Department, Faculty of Science, University of Jeddah, Jeddah, Saudi Arabia G. A. Elshoubaky Botany Department, Faculty of Science, Suez Canal University, Ismailia, Egypt