Abstract
In this study, the prepared bio-adsorbents from Labeo rohita fishbones were used to remove the anionic acid dye Melioderm HF (High Fastness) Brown G (MHFB) from the aqueous solution. Scanning electron microscopy (SEM) and Fourier-transform infrared spectroscopy (FTIR) were used to analyze the morphology and chemical composition of fishbone powder (FBP) before and after MHFB dye adsorption. In a batch experiment, factors such as initial dye concentration (100–250 mg/mL), contact time (5–180 min), pH of the solution (2.0–8.0), and the adsorbent dosage (1.0–3.5 g/L) were analyzed for their impact on the dye adsorption process. The batch experiments were studied to evaluate the influence of different operational variables such as pH, adsorbent dosage, contact time, and initial concentration of dye and were found optimum at 2, 2 g/L, 120 min, and 200 ppm, respectively, for maximum dye removal (98.33%) at ambient temperature (298 K). The isotherm models demonstrated that dye molecules were adsorbed heterogeneously in multilayer following the Freundlich isotherm (R2 = 0.9300). The data were fitted for pseudo-second-order kinetics. Thus, L. rohita fishbone could be used as a bio-adsorbent to remove anionic dye from tannery effluents at a minimal cost.
HIGHLIGHTS
The fishbone powder (FBP) adsorbent was prepared and characterized.
The anionic dye removal efficiency of FBP from tannery effluent was 98.33%.
The pH, dosage, contact time, and initial concentration of dye were optimized.
Freundlich isotherm and pseudo-second-order kinetic model were followed.
INTRODUCTION
The tanning process consists of several distinct chemical and physical steps, including pre-tanning, tanning, post-tanning, and finishing. After the leather has been tanned, it is then subjected to dyeing to impart various colours to the leather surface. During leather manufacturing, major discharge comes from the tanning process as chrome liquor and dyeing process containing different types of dyes, such as anionic, cationic, azo, and metal complex dyes, which reduces the water qualities. These heavy metals from spent liquor and metal complex dye contaminate not only waterbodies but also soil, and pose health risks due to the heavy metal accumulation in animals, plants, or vegetables (Ahmed et al. 2022a). In the leather dyeing process, a wide range of dyes are utilized, and approximately 30–40% of these dyes are wasted, which are discharged as effluent into the aquatic environment. Around 70,000 metric tons of commercial colourants are released into wastewater globally each year, as per estimation (Auta & Hameed 2011; Nassar et al. 2012). Different types of adsorbents are developed to reduce the chrome content in the spent liquor (Ahmed et al. 2022b; Tuj-Zohra et al. 2022) and dye from the discharged effluent. Melioderm HF (High Fastness) Brown G is mainly a homogeneous anionic dyestuff. It is most often used in leather manufacturing since it provides unique colouring and fastness capabilities for all types of leather and is thus widely employed in the leather industry. During the manufacturing of leather, some of these dyes are inevitably wasted, which results in the production of coloured effluent. Since synthetic dyes are poisonous, carcinogenic, and mutagenic, even releasing a trace amount into natural aquatic streams may have an impact on aquatic and human life (Laasri et al. 2007; Duman et al. 2016). Moreover, most dyes are resistant to deterioration by light, biological breakdown, and oxidation (Ramakrishna & Viraraghavan 1997). Therefore, proper treatment is required before releasing them into the surrounding environment. Even better approaches such as the use of non-toxic eco-friendly natural dyes extracted from natural plants, flowers, and bark instead of azo dyes (Mahdi et al. 2021) can reduce the pollution load.
Dye removal from aquatic environments may be accomplished in a variety of ways at present, including through the application of physical and chemical processes, biological processes, electrical and electromagnetic processes, and nuclear treatments. The processes of adsorption, ion exchange, and reverse osmosis are all examples of physicochemical processes. Meanwhile, biological processes include the reduction of microorganisms, along with aerobic and anaerobic treatment, as well as bacterial treatment (Gupta et al. 2009). In recent years, commercial activated carbons have gained greater popularity due to their high efficiency in dye removal from wastewater using adsorption. However, the expensive price of such adsorbent has led researchers to seek cheaper alternatives. Researchers are now pursuing several attempts to produce cost-effective adsorbents as an alternative to using instead of commercially available activated carbons. Flocculation and coagulation (Liang et al. 2014), oxidation (Benjelloun et al. 2016), and adsorption (Aguiar et al. 2016) are just a few of the numerous initiatives in this field. However, the majority of these approaches have serious drawbacks, such as high reagent and power requirements, low selectivity, steep operating costs, and the creation of undesirable by-products (Senturk et al. 2010). However, adsorption is still one of the most useful methods since it is effective, easy to implement, and relatively cheap, and there is a large variety of adsorbents to choose from (Sharma & Bhattacharyya 2005). Adsorbents for removing dyes from aqueous solutions were described in several studies, some of which are included in Table 5. Recently, Crini published a comprehensive literature review on the use of adsorbent for dye removal (Crini 2006). Furthermore, rather than discarding fishbones, which have no economic value and emit an unpleasant odour into the environment, fish wastes and leather wastewater can be managed collaboratively by using fishbone powder (FBP) as a bio-sorbent, eliminating the need for wasteful fishbone disposal. Scales from several fishes have been utilized as adsorbents in recent literature to remove anionic dyes. A recent study on the removal powder dye efficiency on two different reactive dyes, which include reactive red 2 (Begum & Kabir 2013) and reactive orange 16 (Marrakchi et al. 2017a), have been investigated using the bio-adsorbent derived from Labeo rohita fish scales. Scales of Oreochromis niloticus (Nile tilapia), and Leporinus elongatus were also used as bio-adsorbents for the removal of reactive blue 5G (Ribeiro et al. 2015; Neves et al. 2017) and remazol (yellow, blue, and red) (Vieira et al. 2012), respectively. There was also an attempt made to use the fish scale adsorbent to remove the cationic basic dyes, such as methylene blue dyes; nevertheless, the results were not very promising (Marrakchi et al. 2017b). Though multiple types of research have been carried out with fish scales, no research has been carried out using fishbone as an adsorbent, which generates a large amount of waste from the fish processing industries.
The goal of this research was to examine the feasibility of utilizing L. rohita FBP as a novel, uncommon, and commercially cost-effective adsorbent for the removal of Melioderm HF (High Fastness) Brown G (MHFB) dye from tannery wastewater. The organic protein collagen found in FBP is mainly accountable for the protein's capacity to absorb anionic dyes. Hydroxyapatite, an inorganic mineral, also contributes to the adsorption process (Kunkun et al. 2013). When it comes to dyeing wool, leather, and synthetic polyamide textiles like nylon, acid dyes are among the most popular options (Ogawa et al. 2004). As mentioned earlier, fishbone consists of collagen, which contains different cationic derivatives such as amide I, amide II, and amide A (Ogawa et al. 2004), which, as a result of their strong affinity for the anionic component of acid dyes, could have the potential to play a substantial role in the process of dye absorption. The purpose of this study was to evaluate the efficacy of FBP of L. rohita as a bio-adsorbent by treating fishbone with sodium hydroxide (NaOH) and then, after drying, grinding it to make powder for the removal of acid dye.
MATERIALS AND METHOD
Raw materials, dyes, and reagents
At first, fishbone was brought from the local market of Hazaribagh, Dhaka. During the research, MHFB was utilized as a source of reagents, which were considered model pollutants. MHFB (purity of 95.0%, a molecular weight of 342.2 g/mol, λmax 443 nm) was bought from STAHL, which is a Dutch-based leather chemical manufacturing company. This dye was selected because it is most commonly used in leather industries. As a result, there is a significant opportunity for the widespread discharge of these dyes into effluents.
Preparation and characterization of adsorbent
Dye solution preparation
To prepare a stock solution with a concentration of 1,000 mg/L, 1 g of the adsorbate (MHFB dye) was dissolved in 1,000 mL of deionized water. Additionally, deionized water was used appropriately to dilute the stock solution for all subsequent experimental solutions.
Analytical methods
The sample was filtered through Whatman filter paper and the resulting supernatant was analyzed with a single-beam UV-vis spectrophotometer (VARIAN-Cary 50) at the maximum absorption wavelength (λmax = 443 nm); known concentrations of the standard MHFB dye solution were used to generate a calibration curve.
Batch adsorption experiments
To evaluate the impact that the quantity of FBP used has on the total amount of MHFB dye that is absorbed, a series of 250 mL stoppered glass (Erlenmeyer flasks) holding a known volume (25 mL in each flask) of a predetermined initial concentration (200 mg/L) of dye solution was shaken at room temperature with varying dosages of FBP (1, 1.5, 2, 2.5, 3, and 3.5 g/L). The batch experiment was carried out at room temperature in an orbital shaker and agitated at 150 rpm for 180 min. Dye concentrations were determined during a state of equilibrium.
In order to determine the optimal contact time for adsorption, 25 mL dye solution at a fixed concentration (100–250 ppm) was treated with 2 g/L adsorbent throughout several time intervals (5–180 min).
The concentration of the dye in the liquid phase at a specific time is denoted by the symbol Ct (mg/L).
Kinetic models

Isotherm analysis
The equilibrium statistics are important prerequisites for the design of an adsorption system. Under the given circumstances, these statistics reveal the adsorbent's capacity to remove a certain amount of adsorbate. Adsorption equilibrium physiologies have been interpreted using Langmuir and Freundlich isotherms. To derive the isotherm constants, linear regression is often employed for model evaluation, and the least squares technique has been mostly abandoned (Cecen & Aktaş 2011; Liu et al. 2011; Hariani et al. 2013).
Among different isotherm models, the most well-known Langmuir and Freundlich models were chosen for this study because of their clarity and consistency. Adsorption of MHFB dye onto FBP was represented using the standard equilibrium models of Langmuir and Freundlich.
Langmuir isotherm
If 0 > RL > 1, then adsorption is favourable.
If RL > 1, unfavourable adsorption will occur.
If RL = 1, adsorption is linear.
If RL = 0, then adsorption is irreversible.
Freundlich isotherm
The Freundlich constants kF and n were determined from the linear plot of ln qe vs ln Ce.
Adsorption thermodynamics
Studies in thermodynamics were carried out, and the characteristics and fundamental processes of the adsorption reactions were investigated and validated. The Gibbs free energy (ΔG), enthalpy (ΔH), and change in standard entropy (ΔS) are all examples of thermodynamic parameters (Ponnusamy & Gayathri 2009). These parameters are a true measure of how well the dye adsorption procedure will work in real life. In the dye adsorption procedure, the value of the parameter ΔG indicates whether or not the reaction has spontaneously occurred; similarly, dye adsorption reactions may be characterized as either endothermic reaction or exothermic, depending on the value of ΔH, and the value of ΔS during the adsorption of dye to a solid or liquid surface reflects the level of disorder present at the solid–liquid interface.
RESULTS AND DISCUSSION
Adsorbent characterization
Spectral analysis
Absorption peaks of FBP adsorbent before and after dye adsorption
Before adsorption . | After adsorption . | References . | ||||
---|---|---|---|---|---|---|
Main functional groups . | Peaks (cm−1) . | Corresponding vibrations . | Main functional groups . | Peaks (cm−1) . | Corresponding vibrations . | |
Amide I | 1,639 | Stretching vibrations C = O | Amide I | 1,639 | C–O stretching vibration | Payne & Veis (1988) |
Amide II | 1,419 | C–H stretching and N–H bending | Amide II | 1,434 | C–H stretching and N–H bending | Jackson et al. (1995) |
Amide III | 1,253 | NH bending coupled with CN stretching | Amide III | 1,222 | N–H bending coupled with C–N stretching | Payne & Veis (1988) |
1,180 | ||||||
Amide A | 3,421 | N-H stretching | Amide A | 3,302 | N–H stretching | Ji et al. (2020) |
Amide B | 2,927 | CH2 asymmetrical stretching | Amide B | 2,927 | CH2 asymmetrical stretching | Abe & Krimm (1972) |
Acid groups | 2,528 | OH group | Alkane | 2,862 | CH3 stretching vibration | Do et al. (2013), Dobos et al. (2012) |
Before adsorption . | After adsorption . | References . | ||||
---|---|---|---|---|---|---|
Main functional groups . | Peaks (cm−1) . | Corresponding vibrations . | Main functional groups . | Peaks (cm−1) . | Corresponding vibrations . | |
Amide I | 1,639 | Stretching vibrations C = O | Amide I | 1,639 | C–O stretching vibration | Payne & Veis (1988) |
Amide II | 1,419 | C–H stretching and N–H bending | Amide II | 1,434 | C–H stretching and N–H bending | Jackson et al. (1995) |
Amide III | 1,253 | NH bending coupled with CN stretching | Amide III | 1,222 | N–H bending coupled with C–N stretching | Payne & Veis (1988) |
1,180 | ||||||
Amide A | 3,421 | N-H stretching | Amide A | 3,302 | N–H stretching | Ji et al. (2020) |
Amide B | 2,927 | CH2 asymmetrical stretching | Amide B | 2,927 | CH2 asymmetrical stretching | Abe & Krimm (1972) |
Acid groups | 2,528 | OH group | Alkane | 2,862 | CH3 stretching vibration | Do et al. (2013), Dobos et al. (2012) |
The N-H stretching mode of amide A displays a relatively wide and elevated shape reminiscent of a mountain, with the peak positioned approximately at 3302 and 3421 cm−1. The success of dye removal relied on the surface properties of the prepared adsorbent, underscoring their crucial role in the adsorption process. To find out the particular functional groups accountable for anionic dye adsorption, FTIR was used in the range of 4,000–400 cm−1. Fishbone has characteristic amide I, amide II, amide III, OH bond, amide B, and acid group, which were confirmed by FTIR peaks of 1,639, 1,419, 1,253, 3,421, 2,927, and 2,528 cm−1, respectively. Stretching vibrations of carbonyl groups (C = O bond) were primarily responsible for the presence of the amide I band, with typical frequencies in the range of 1,600–1,700 cm−1 (Payne & Veis 1988). It has been revealed that the location of the amide II bands has changed to a lower frequency, 1,419 cm−1, indicating the presence of H-bonding in each collagen molecule.
The O–H stretching mode of alcohols displays a relatively wide and elevated shape reminiscent of a mountain, with the peak positioned approximately at 3,400 cm−1. The hydrogen bonds that existed between different molecules were responsible for the propagation of this signal. The peak found between 2,900 and 3,000 cm−1 indicated the presence of amide B having CH2 asymmetrical vibration. The peak at 1,735 cm−1 suggested that C = O bonds were present (Chandrajith & Marapana 2018). Fishbone-derived collagen exhibits characteristics similar to type I collagen, comprising two α1 chains and one α2 chain (Kimura et al. 1991; Yunoki et al. 2003). Fishbone is comprised of collagen and consists of different types of amides (amide I, amide II, and amide II) having NH2 and NH groups. According to the study of Nawi et al. (2010), these groups are protonated as NH3+. Negatively charged anionic dye molecules are fixed with positively charged amide groups of adsorbents via hydrogen bonding during adsorption.
SEM analysis
SEM images at (a) 500× and (b) 1,000× magnification of FBP after dye adsorption.
Effect of pH on dye adsorption
A synergistic and beneficial effect for adsorption might be provided by the attraction of the negatively charged dye molecules and the repulsion between the positively charged polymeric chains of collagen caused by the protonated amino groups. Both of these factors contributed to the positive charge on the collagen chains. A previous study discovered a pattern that was quite similar to this one when they absorbed RB19 dye onto hollow chitosan nanofibers (Mirmohseni et al. 2012). They were able to demonstrate an increase in adsorption capacity by bringing the initial pH of the solution down from 7.5 to 3.5. An analogous research endeavour involved using fish scales as a bio-adsorbent to effectively eliminate anionic acid dyes (acid red 1, acid blue 45, and acid yellow 127) present in the wastewater produced during textile dyeing operations (Kabir et al. 2019). The investigation of the FTIR peaks revealed that the primary facilitators in the reaction with anionic dyes (sodium salts of sulfonic acid dyes) were polypeptide (amide) groups derived from polymer chain amino acids (amide A, amide I, and amide II).
Effect of adsorbent dosage on dye adsorption
The adsorption studies indicated a continuous rise in the MHFB removal proportion up to 2 g/L of adsorbent dosage. However, after reaching its maximum at 3 g/L, further increases in the dosage had no additional effect on dye removal, maintaining a stable removal percentage. It was found that the maximum adsorption capacity was achieved for a 2 g/L dosage, and the capacity was progressively reduced with an increasing amount of adsorbent. As a result, the experiment showed that 2 g/L was the optimum dosage concentration.
Effect of contact time and initial concentration
Contact time and initial concentration effect on dye adsorption onto FBP adsorbent.
Contact time and initial concentration effect on dye adsorption onto FBP adsorbent.
The plots can be divided into three distinct stages: (1) the immediate adsorption that takes place within the first 15 min, (2) the gradual movement towards equilibrium until reaching the equilibrium point for each concentration, and (3) the equilibrium state. Dye removal from the water sample was shown to be dosage-dependent, with longer contact times resulting in a greater reduction in dye concentration, until a point when the adsorption rate became negligible after 120 min. For that reason, the optimum contact time was 120 min for this adsorption study. The data showed that the adsorption of MHFB dye onto FBP was increased with increasing initial MHFB dye concentration. To ensure that complete equilibrium had been reached, the experiment was run for 180 min, and the experimental results were collected.
These findings were consistent with the notion that dye molecules must first interact with the boundary layer, and then molecules enter the adsorbent surface by diffusing from the boundary layer film. Afterwards, they must enter the adsorbent's porous matrix through diffusion (Senthilkumaar et al. 2005; Faust & Aly 2018). Since there were more dye molecules in higher initial concentrations of MHFB solutions, it took more time for them to reach equilibrium. Maximum adsorption capabilities were also seen in all dosages at greater initial concentrations. Increasing the initial MHFB dye concentration from 100 to 250 mg/L influenced the adsorption capacity, which went from 47.66 to 119.22 mg/g at equilibrium.
Isotherm analysis
Experiments were conducted in batches with MHFB dosages ranging from 100 to 250 mg/L. Factors influencing the adsorption process were kept constant throughout the operation (2.0 g/L FBP dosage, 200 rpm shaker speed, a 25.0 mL solution volume, and a temperature of 298 K).
The calculated values for the Langmuir and Freundlich parameters, as well as the R2 values (which were obtained from the non-linear regression analysis), are presented in Table 2. The findings of this study revealed that the Freundlich isotherm model offered a superior fit for the dye adsorption process compared to the Langmuir model. This observation indicates that the adsorption of dye onto FBP involves heterogeneous multilayer adsorption.
Isotherm parameters for MHFB dye removal by FBP
Isotherms . | Parameters . | Value . |
---|---|---|
Langmuir | kL (L/mg) | 0.0214 |
R2 | 0.6800 | |
RL | 0.1550 | |
Freundlich | kF ((mg/g) (L/mg)(1/n)) | 5.6670 |
n | 0.8379 | |
R2 | 0.9300 |
Isotherms . | Parameters . | Value . |
---|---|---|
Langmuir | kL (L/mg) | 0.0214 |
R2 | 0.6800 | |
RL | 0.1550 | |
Freundlich | kF ((mg/g) (L/mg)(1/n)) | 5.6670 |
n | 0.8379 | |
R2 | 0.9300 |
Adsorption kinetics
The experimental data used to describe the sorption mechanism and identify the rate-limiting phase were represented in the field of sorption kinetics. Similar to isothermal studies, kinematics feasibility can be estimated with a linear plot of reaction models and an estimate of the regression coefficient (R2). The kinetics were evaluated by introducing 2 g/L of adsorbent at pH 2 and conducting the adsorption test for a predetermined period and concentration of dye (100–250 ppm).
Summary of adsorption studies
Kinetics model . | Parameters . | 100 mg L−1 . | 150 mg L−1 . | 200 mg L−1 . | 250 mg L−1 . |
---|---|---|---|---|---|
Pseudo-first-order (PFO) | qea (mg g−1) | 47.14 | 70.56 | 95.35 | 119.22 |
k1 | 0.0916 | 0.049 | 0.0462 | 0.0245 | |
R2 | 0.995 | 0.991 | 0.981 | 0.985 | |
qeb (mg g−1) | 12.175 | 11.4 | 15.59 | 17.10 | |
Pseudo-second-order (PSO) | qea (mg g−1) | 47.14 | 70.56 | 95.35 | 119.22 |
k2 | 0.0175 | 0.01127 | 0.00733 | 0.00477 | |
R2 | 1.000 | 0.999 | 0.999 | 0.999 | |
qeb (mg g−1) | 48.07 | 71.28 | 96.43 | 120.48 |
Kinetics model . | Parameters . | 100 mg L−1 . | 150 mg L−1 . | 200 mg L−1 . | 250 mg L−1 . |
---|---|---|---|---|---|
Pseudo-first-order (PFO) | qea (mg g−1) | 47.14 | 70.56 | 95.35 | 119.22 |
k1 | 0.0916 | 0.049 | 0.0462 | 0.0245 | |
R2 | 0.995 | 0.991 | 0.981 | 0.985 | |
qeb (mg g−1) | 12.175 | 11.4 | 15.59 | 17.10 | |
Pseudo-second-order (PSO) | qea (mg g−1) | 47.14 | 70.56 | 95.35 | 119.22 |
k2 | 0.0175 | 0.01127 | 0.00733 | 0.00477 | |
R2 | 1.000 | 0.999 | 0.999 | 0.999 | |
qeb (mg g−1) | 48.07 | 71.28 | 96.43 | 120.48 |
aExperimental.
bTheoretical.
Pseudo-first-order reaction models for dye adsorption onto fishbone adsorbent.
Pseudo-second-order reaction models for dye adsorption onto fishbone adsorbent.
Adsorption thermodynamic results
The changes in thermodynamic parameters such as Gibbs free energy (ΔG), enthalpy (ΔH), and standard entropy (ΔS) as a result of the dye's presence are the most significant. Adsorption thermodynamics were analyzed using the typical values for entropy (ΔG, ΔH, and ΔS). Table 4 displays the findings.
Study of thermodynamic parameters for dye adsorption onto FBP adsorbent
Temperature (K) . | Ce . | Capacity (qe) . | ΔG (kJ/mole) . | ΔH (kJ/ mole) . | ΔS (kJ/mole K) . |
---|---|---|---|---|---|
298 | 5.67 | 94.33 | −6.956 | − 14.541 | 0.026 |
308 | 8.86 | 91.94 | −5.977 | ||
318 | 9.08 | 90.92 | −6.091 | ||
328 | 9.63 | 90.37 | −6.105 |
Temperature (K) . | Ce . | Capacity (qe) . | ΔG (kJ/mole) . | ΔH (kJ/ mole) . | ΔS (kJ/mole K) . |
---|---|---|---|---|---|
298 | 5.67 | 94.33 | −6.956 | − 14.541 | 0.026 |
308 | 8.86 | 91.94 | −5.977 | ||
318 | 9.08 | 90.92 | −6.091 | ||
328 | 9.63 | 90.37 | −6.105 |
The negative ΔG values suggested that the adsorption of both dyes occurred spontaneously and favourably. At a temperature of 298 K, more negative ΔG values were discovered; this finding provided more evidence that adsorption was preferred at this temperature. The positive ΔS values (0.026 kJ/mole) indicated that some rearrangements on the solid–liquid interface had been placed throughout the adsorption process. Additionally, these values also showed how the adsorption of MHFB dye onto FBP adsorbent led to a lessening of haphazardness at the solid solution interface. The negative values of enthalpy (ΔH = −14.541 kJ/mole < 0) verify the exothermic nature of dye adsorption.
During adsorption, molecules of the adsorbate are attracted to the adsorbent's surface. The heat of adsorption is negative, indicating that energy is continually being released throughout the adsorption process, making it exothermic. Due to the magnitude of ΔH, it was determined that physical interactions were involved in the adsorption of the dye (Von Oepen et al. 1991). In particular, these ΔH values are indicative of the potential participation of both van der Waals and electrostatic interactions in the adsorption of the dye on the FBP (Khani et al. 2011; Hemmateenejad et al. 2015). A reduction in adsorption from 94.33 to 90.37 mg/g was observed for MHFB dye on FBP adsorbent when the temperature was raised from 298 to 328 K. Rising temperatures inhibit dye absorption, which explains the phenomenon. This is supported by the fact that the solubility of the dye decreases with increasing temperature (Dotto et al. 2012), which is a reflection of the increased interaction between the adsorbed dye molecules.
Comparison of fish scale with other sorbents
The maximal adsorption capabilities of a variety of bio-adsorbents, including FBP, were compared and summarized. Based on the findings of the comparison, the fish scale has a greater malachite green (MG) binding capacity than the majority of the other biosorbents that have been described. Fish scales provided several other benefits, including their simple accessibility and favourable cost structure, which pointed to a bright future for their use in the elimination of MG from aqueous solutions. It can be observed from Table 5 that L. rohita FBP showed higher adsorption capacity than the L. rohita fish scales and other bio-adsorbents such as tamarind fruit shell, bentonite, sea shell powder, Luffa cylindrica fibres, yellow passion fruit waste, sunflower seed hull, and pineapple leaf powder.
Efficiency of fishbone powder adsorbent in comparison to other bio-adsorbents
Bio-adsorbent . | Dye investigated . | Max. adsorption capacities (mg/g) . | Reference . |
---|---|---|---|
Labeo rohita scales | MG | 38.46 | Chowdhury et al. (2012) |
Tamarind fruit shell | MG | 1.951 | Saha et al. (2010) |
Bentonite | MG | 7.72 | Tahir & Rauf (2006) |
Oil palm trunk fibre | MG | 149.35 | Hameed & El-Khaiary (2008a) |
Seashell powder | MG | 42.33 | Chowdhury & Saha (2010) |
Neem leaf powder | MG | 66.72 | Das et al. (2020) |
Caulerpa racemosa var. cylindracea | MB | 3.423 | Cengiz & Cavas (2008) |
Luffa cylindrica fibres | MB | 47 | Demir et al. (2008) |
Grass waste | MB | 457.640 | Hameed (2009) |
Broad bean peels | MB | 192.7 | Hameed & El-Khaiary (2008b) |
Castor seed shell | MB | 158.73 | Oladoja et al. (2008) |
Yellow passion fruit waste | MB | 44.70 | Pavan et al. (2008) |
Untreated desert plant | MB | 295 | Bestani et al. (2008) |
Chemically activated desert plant | MB | 130 | |
Pyrolized desert plant | MB | 53 | |
Watermelon (Citrullus lanatus) rinds | MB | 115.61 | Shukla et al. (2023) |
Chitosan-pectin composite | MB | 328.02 | Mohrazi & Ghasemi-Fasaei (2023) |
Cellulose citrate | MB | 96.2 | Olivito et al. (2021) |
Composite beads of sodium alginate/halloysite/hemp hurd | MB | 50 | Viscusi et al. (2022) |
ZnCl2 modified (ZAB) | MO | 101.43 | Maiti et al. (2023) |
Date seed | MV | 59.5 | Ali et al. (2022) |
Pineapple leaf powder | BG 4 | 56.64 | Chowdhury et al. (2011) |
Chitosan-based adsorbent | BB 3 | 166.5 | Crini et al. (2008) |
Soy meal hull | DR 80 | 178.57 | Arami et al. (2006) |
DR 81 | 120.482 | ||
AB 92 | 114.943 | ||
AR 14 | 109.89 | ||
Mg (OH)2/Fe3O4/PEI functionalized enzymatic lignin composite | CR | 74.7 | Zong et al. (2023) |
Wheat flour | RB | 142.26 | Hasan et al. (2021) |
L. rohita fishbone powder | Melioderm HF Brown G | 119.22 | This study |
Bio-adsorbent . | Dye investigated . | Max. adsorption capacities (mg/g) . | Reference . |
---|---|---|---|
Labeo rohita scales | MG | 38.46 | Chowdhury et al. (2012) |
Tamarind fruit shell | MG | 1.951 | Saha et al. (2010) |
Bentonite | MG | 7.72 | Tahir & Rauf (2006) |
Oil palm trunk fibre | MG | 149.35 | Hameed & El-Khaiary (2008a) |
Seashell powder | MG | 42.33 | Chowdhury & Saha (2010) |
Neem leaf powder | MG | 66.72 | Das et al. (2020) |
Caulerpa racemosa var. cylindracea | MB | 3.423 | Cengiz & Cavas (2008) |
Luffa cylindrica fibres | MB | 47 | Demir et al. (2008) |
Grass waste | MB | 457.640 | Hameed (2009) |
Broad bean peels | MB | 192.7 | Hameed & El-Khaiary (2008b) |
Castor seed shell | MB | 158.73 | Oladoja et al. (2008) |
Yellow passion fruit waste | MB | 44.70 | Pavan et al. (2008) |
Untreated desert plant | MB | 295 | Bestani et al. (2008) |
Chemically activated desert plant | MB | 130 | |
Pyrolized desert plant | MB | 53 | |
Watermelon (Citrullus lanatus) rinds | MB | 115.61 | Shukla et al. (2023) |
Chitosan-pectin composite | MB | 328.02 | Mohrazi & Ghasemi-Fasaei (2023) |
Cellulose citrate | MB | 96.2 | Olivito et al. (2021) |
Composite beads of sodium alginate/halloysite/hemp hurd | MB | 50 | Viscusi et al. (2022) |
ZnCl2 modified (ZAB) | MO | 101.43 | Maiti et al. (2023) |
Date seed | MV | 59.5 | Ali et al. (2022) |
Pineapple leaf powder | BG 4 | 56.64 | Chowdhury et al. (2011) |
Chitosan-based adsorbent | BB 3 | 166.5 | Crini et al. (2008) |
Soy meal hull | DR 80 | 178.57 | Arami et al. (2006) |
DR 81 | 120.482 | ||
AB 92 | 114.943 | ||
AR 14 | 109.89 | ||
Mg (OH)2/Fe3O4/PEI functionalized enzymatic lignin composite | CR | 74.7 | Zong et al. (2023) |
Wheat flour | RB | 142.26 | Hasan et al. (2021) |
L. rohita fishbone powder | Melioderm HF Brown G | 119.22 | This study |
Note: MG, malachite green; MB, methylene blue; MO, methyl orange; MV, methyl violet; BG, basic green; BB, basic blue; DR, direct red; AB, acid blue; AR, acid red; CR, Congo red; RB, rhodamine B; PEI, Poly(ethyleneimine).
CONCLUSIONS
The results of this investigation showed that FBP, a by-product of the fish processing industry, had excellent adsorption capacity for anionic dye from aqueous solutions. Since 98.33% removal was achieved at a pH level of 2, it is clear that the adsorption mechanism is very sensitive to pH. Dye is adsorbed rapidly during the first 15 min of contact time and then at a decreasing rate until equilibrium is reached after around 120 min, as shown by the impact of contact time. Langmuir and Freundlich's isotherms were employed to analyze the equilibrium data, and the Freundlich isotherm demonstrated the strongest correlation (R2 was extremely close to the unity), suggesting chemisorption behaviour on a heterogeneous multilayer surface. For a variety of starting MHFB concentrations, the kinetic data are highly consistent with a PSO model (R2 ≥ 0.999). There was an increase in order at the adsorbent–solution interface, which is consistent with the adsorption process being spontaneous, exothermic, and technically viable, as shown by the thermodynamic characteristics. The thermodynamic constants show a very low rate and indicate physisorption. Based on kinematics and thermodynamics, we can conclude the process is physicochemical adsorption. The successful synthesis of the adsorbent was confirmed through the examination of its morphology, structural properties, and elemental compositions using SEM and FTIR techniques. FTIR confirmed the presence of amide groups in the adsorbent. The morphological structure and surface of FBP adsorbent were visible with a rough surface. The SEM image indicated the changed morphology by destroying the surface with no noticeable edges and a nearly smooth surface due to chemical modifications. According to the findings of this research, the FBP derived from L. rohita can be employed effectively as a cost-effective adsorbent for the removal of anionic dyes from an aqueous solution.
DATA AVAILABILITY STATEMENT
All relevant data are included in the paper or its Supplementary Information.
CONFLICT OF INTEREST
The authors declare there is no conflict.