Preparation, characterization of fish scales biochar and their applications in the removal of anionic indigo carmine dye from aqueous solutions

Abstract

The preparation and applications of Tilapia (Oreochromis niloticus) fish scale biochars (FSB) as an adsorbent in the removal of indigo carmine dye (ICD) from aqueous solutions is described. The biochars were prepared through pyrolysis over a temperature range of 200 °C–800 °C and characterized for surface charge, functional groups, thermal stability, particle size and morphology, elemental composition, crystallinity, and surface area by using pHpzc, Fourier transform infrared (FTIR) spectroscopy, thermo-gravimetric analysis (TGA), transmission electron microscopy/scanning electron microscopy (TEM/SEM), energy dispersive X-ray (EDX) spectroscopy, powder X-ray diffraction (PXRD) and Brunauer-Emmett-Teller (BET) techniques, respectively. Batch experiments were carried out to determine the variation of adsorption process with initial dye concentration, contact time, initial solution pH, adsorbent load, temperature and adsorbent pyrolysis temperature on the removal of the dye. The percentage removal increased with increase in initial dye concentration and adsorbent dosage. A pH of 2 was the most appropriate for the adsorption experiments. The equilibrium data fitted pseudo-first-order kinetics and Freundlich models, while the thermodynamic parameters confirmed that the adsorption process was endothermic.

Removal of lead from aqueous solutions using three biosorbents of aquatic origin with the emphasis on the affective factors

“…This implies that initially, the biosorbent contains a higher number of binding sites for the binding of Pb. In the studies that the range of contact time was wider compared to that of current research, after a lapse of some time, depending on the biosorbent and the solution environment, the number of unoccupied sites decreased and gradually became saturated 5 , 39 , 79 .…”

Removal of Lead From Aqueous Solutions Using Three Biosorbents of Aquatic Origin: Evaluating the Relative Roles of Factors Affecting the Biosorption Process

“…This implies that initially, the biosorbent contains a higher number of binding sites for the binding of Pb. In the studies that the range of contact time was wider compared to that of current research, after a lapse of some time, depending on the biosorbent and the solution environment, the number of unoccupied sites decreased and gradually became saturated (Ayodele and Adekola 2016; Shahzad et al 2017;Achieng et al 2019).…”

Studies on the efficiency of fish scale adsorbents for treatment of fish processing effluent

“…Further investigation of the elemental analysis results was given in Table 5 which reveals that carbon was present in higher levels than other elements, possibly indicating the dominance of carbon‐containing functional groups 43 in adsorbents used in this study. The content (%) of other elements such as sodium, magnesium, and calcium showed a slight increase in biochar compared to dried fish scale adsorbent, whereas the composition of N and P showed unpredictable trends 10 . The EDS spectra of the adsorbents used in this study are shown in Figure 6.…”