Novel Biosorption Method for Eliminating Methylene Blue Dye from Wastewater Using Sweet Potato Peels.

doi:10.21203/rs.3.rs-5014317/v1

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Novel Biosorption Method for Eliminating Methylene Blue Dye from Wastewater Using Sweet Potato Peels.

https://doi.org/10.21203/rs.3.rs-5014317/v1

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This study investigates the use of sweet potato peels as a biosorbent for the removal of Methylene Blue (MB) dye from aqueous solutions. Batch adsorption experiments were conducted to evaluate the effects of key variables, including adsorbent dosage, contact time, and initial dye concentration, on the removal efficiency of MB. The results demonstrated that the removal efficiency of MB increased with the adsorbent dosage, reaching an optimal value of 70% at a dosage of 1.1 g/100 mL. Additionally, the adsorption process achieved equilibrium at 50 minutes of contact time. However, higher concentrations of MB in the solution led to a decrease in removal efficiency, likely due to the saturation of the adsorbent surface. Further analysis using FTIR spectroscopy revealed the presence of functional groups such as hydroxyl, carboxyl, and phenolic groups on the sweet potato peel surface, which play a crucial role in the adsorption process. The study concluded that sweet potato peels are an effective, eco-friendly adsorbent for MB dye removal, offering a sustainable approach to wastewater treatment. The findings highlight the potential of this agricultural byproduct in addressing water pollution concerns, providing a viable solution aligned with environmental conservation efforts.

Earth and environmental sciences/Environmental sciences/Environmental impact

Earth and environmental sciences/Hydrology

Wastewater Treatment

Agricultural Waste

Eco-friendly Adsorbent

Synthetic Dyes

Sustainable Water Management

The discharge of synthetic dyes into wastewater has emerged as a significant environmental challenge, posing serious threats to aquatic ecosystems and human health. Among these dyes, methylene blue (MB) is particularly notable due to its widespread application in various industries, including textiles, paper, and leather. MB is a cationic dye with a stable structure, making it resistant to degradation in the environment. When released into water bodies, MB can persist for extended periods, leading to the contamination of water resources [1–2]. The presence of MB in industrial wastewater is a growing concern, as it contributes to water pollution, which has far-reaching implications for both the environment and public health [2].

Methylene blue's stability and solubility in water make it challenging to remove through conventional wastewater treatment methods. Traditional approaches, such as flocculation, coagulation, and oxidation, have been widely used to treat industrial effluents containing MB [2]. However, these methods are often associated with significant drawbacks. For instance, they can be expensive, requiring high energy inputs and the use of chemicals, which can generate secondary pollutants. Additionally, these processes may not always achieve complete dye removal, leading to the discharge of residual contaminants into the environment. The limitations of conventional methods underscore the need for alternative, cost-effective, and environmentally sustainable solutions for the efficient removal of MB from wastewater.

In response to the challenges posed by conventional treatment methods, researchers have increasingly focused on the potential of biosorption as an alternative technique for dye removal. Biosorption involves the use of natural materials, often agricultural byproducts, to adsorb and remove contaminants from wastewater [2–3]. This approach is gaining popularity due to its cost-effectiveness, environmental friendliness, and the abundance of suitable biosorbent materials. Agricultural waste products, in particular, are attractive candidates for biosorption due to their availability, low cost, and biodegradable nature. Utilizing these waste materials not only addresses the issue of waste disposal but also contributes to the development of sustainable wastewater treatment technologies [4].

Sweet potato peels, an agricultural byproduct generated in large quantities, have shown promise as a potential biosorbent for methylene blue removal. The peels are rich in cellulose, hemicellulose, and lignin—compounds known for their adsorption properties. These natural polymers possess functional groups, such as hydroxyl, carboxyl, and phenolic groups, which can interact with dye molecules, facilitating their adsorption onto the peel surface [3]. The use of sweet potato peels as a biosorbent offers several advantages, including low cost, renewability, and the potential for large-scale application. Moreover, the repurposing of agricultural waste aligns with the principles of sustainability and circular economy, transforming waste materials into valuable resources for environmental remediation.

The adsorption process using sweet potato peels is influenced by various factors, including the concentration of the dye, contact time, temperature, and the dosage of the biosorbent. Understanding the interaction between these factors is crucial for optimizing the adsorption process and maximizing the removal efficiency of methylene blue. Previous studies have demonstrated that sweet potato peels exhibit a high adsorption capacity for methylene blue, making them a viable option for dye removal in wastewater treatment [3]. This research aims to further explore the adsorption potential of sweet potato peels, examining the influence of key parameters on the removal efficiency of methylene blue.

One of the critical aspects of this study is the investigation of the adsorption mechanism involved in the interaction between methylene blue and sweet potato peels. The adsorption process is believed to involve a combination of electrostatic attraction, hydrogen bonding, and π-π interactions between the dye molecules and the functional groups on the peel surface [4]. Fourier transform infrared (FTIR) spectroscopy is employed to characterize the functional groups present on the peels and to gain insights into the adsorption mechanism [4]. By analyzing the changes in the FTIR spectra before and after adsorption, the study aims to elucidate the nature of the interactions between the dye and the biosorbent.

In addition to the adsorption capacity, the regenerability and reusability of the sweet potato peels as a biosorbent are also evaluated. For the biosorption process to be economically viable and sustainable on a large scale, the biosorbent must be capable of being regenerated and reused in multiple adsorption cycles [4–5]. Various regeneration techniques, including washing with solvents, heating, and microwave-assisted regeneration, are explored to determine their effectiveness in restoring the adsorption capacity of the peels. The study also examines the impact of repeated adsorption-regeneration cycles on the structural integrity and adsorption performance of the sweet potato peels.

The environmental benefits of using sweet potato peels as a biosorbent extend beyond wastewater treatment. By diverting agricultural waste from landfills and repurposing it for dye removal, this approach contributes to waste reduction and promotes the sustainable use of natural resources. Furthermore, the spent sweet potato peels, once saturated with methylene blue, have potential applications in other fields [3]. For instance, the peels could be used as feedstock for biofuel production, composted to enrich soil, or even incorporated into materials for green synthesis processes. The valorization of spent biosorbents aligns with the concept of a circular economy, where waste is minimized, and resources are continuously reused.

This research not only addresses a specific environmental issue but also contributes to the broader discourse on sustainable water management. The increasing global awareness of environmental pollution and the need for sustainable practices have driven the search for innovative solutions to address these challenges. By exploring the use of sweet potato peels as a biosorbent for methylene blue, this study offers a practical and eco-friendly approach to wastewater treatment that can be applied in various industrial contexts. The findings of this research are expected to provide valuable insights into the development of sustainable technologies for dye removal and contribute to the preservation of aquatic ecosystems.

The potential of sweet potato peels as a biosorbent for methylene blue removal presents a promising avenue for addressing the environmental challenges posed by synthetic dyes in wastewater. This research underscores the importance of sustainable resource utilization and highlights the role of agricultural waste in developing eco-friendly wastewater treatment technologies. By advancing our understanding of the adsorption process and exploring the practical applications of sweet potato peels, this study aims to contribute to the development of effective and sustainable solutions for water pollution control. The outcomes of this research have the potential to inform future efforts in environmental remediation and promote the adoption of green technologies in industrial wastewater management.

2.1 Preparation of Biosorbent Material

The preparation of sweet potato peels as an adsorbent involved a meticulous process to enhance their efficacy. The process began with thoroughly washing the sweet potato peels with water to remove any dust and residual starch adhering to their surface. After washing, the peels were air-dried in a tray dryer to ensure complete moisture removal. To optimize the adsorption capabilities, the dried sweet potato peels underwent further processing. They were subjected to a controlled temperature of 100°C in an oven for 30 minutes [5]. This heat treatment enhanced the stability of the peels and promoted desirable physical characteristics. After heat treatment, the peels were ground using a pestle and mortar to break down the material into a coarse powder. For a more uniform and finely sized particle structure, the coarse powder was further ground in a grinder, refining the texture and size of the sweet potato peel particles. The ground material was then sieved through a 200-mesh size screen to obtain micro-sized particles [6–8]. This sieving process ensured the removal of larger particles, leaving behind a finely textured, micro-sized sweet potato peel powder ready for application as an adsorbent in wastewater treatment processes. The systematic preparation method was crucial for optimizing the adsorption capacity of sweet potato peels, ensuring their effectiveness in removing Methylene Blue dye from water .

2.2 Utilizing Sweet Potato Peels as a Biosorbent for Methylene Blue Dye Removal

The materials utilized included methylene blue dye, sweet potato peels, and deionized water. Methylene blue with a purity of ≥ 99% was obtained from Sigma Aldrich. The sweet potato peels were sourced from the Southern Punjab region, a byproduct of sweet potato production generated in significant quantities.

2.3 Synthetic Solution of MB

Methylene Blue (MB) is a cationic dye extensively utilized in the textile, printing, and dyeing industries, posing significant environmental concerns [7]. Its widespread use contributes to the release of a toxic, carcinogenic, and mutagenic substance into the environment, resulting in severe ecological issues. MB is characterized by a distinct absorption peak at 663 nm, enabling its detection through spectrophotometric methods[8, 9]. Given its hazardous nature, it is imperative to address MB removal from wastewater to prevent environmental pollution and safeguard human health. Numerous adsorbent materials, including activated carbon, clay minerals, and agricultural wastes, have been studied for their effectiveness in mitigating MB contamination in wastewater.

2.4 Batch Adsorption Experiments

Batch adsorption experiments were conducted to systematically study the removal efficiency of Methylene Blue (MB) dye using sweet potato peels as the adsorbent. The experiments focused on contact time, adsorbent dosage, and temperature. 100 mL Erlenmeyer flasks, each containing 50 mL of MB dye solution, were agitated on a shaker at 150 rpm. To examine the impact of adsorbent dosage, varying amounts of sweet potato peels (ranging from 0.1 to 1.4 g/100 mL) were introduced into the methylene blue dye solution. The influence of contact time was evaluated by adjusting the duration of interaction between the adsorbent and the dye solution, ranging from 10 to 70 minutes.

2.5 Characterization of Adsorbent Material

UV-Vis and FTIR spectroscopies were employed as complementary tools essential for unraveling the intricacies of the Methylene Blue (MB) adsorption process onto sweet potato peels. FTIR spectroscopy, in particular, aided in identifying functional groups engaged in the adsorption process and discerning any chemical transformations occurring on the surface of the sweet potato peel adsorbent [10]. Post-MB adsorption, the intensity of the hydroxyl peak diminished, indicating the participation of hydroxyl groups in the adsorption process. Furthermore, shifts in the carbonyl and carboxylic acid peaks to lower wavenumbers suggested the involvement of these groups in complex formation with MB, illuminating the chemical changes occurring on the sweet potato peel surface during adsorption .

In parallel, UV-Vis spectroscopy served as a crucial tool to validate MB concentration changes in solution pre- and post-adsorption onto sweet potato peels. Quantifying the concentration of MB involved measuring the absorbance of the dye solution at its maximum absorbance wavelength, typically determined by the dye's characteristics. This measurement was done using a calibration curve. By comparing the dye concentration in the solution before and after adsorption, determined through absorbance, the amount of dye adsorbed onto the sweet potato peel surface was calculated.

The combination of FTIR and UV-Vis spectroscopy in characterizing sweet potato peels for the removal of MB from water was invaluable [11–14]. These analytical techniques provided crucial insights into the surface chemistry, adsorption mechanisms, and chemical changes occurring on the sweet potato peel surface during the adsorption process. Additionally, they offered a means to monitor the concentration of dye molecules in solution, facilitating the assessment of adsorption capacity and kinetics.

Continuing the exploration of sweet potato peels as an adsorbent for Methylene Blue (MB) removal, FTIR and UV-Vis spectroscopy played pivotal roles in unraveling the intricate details of the adsorption process. The pseudo-second-order kinetics model suggested a chemically self-controlled process, aligning with the unique surface chemistry of sweet potato peels [14]. Furthermore, adherence to the Langmuir model in the adsorption isotherm underscored a monolayer, identical adsorption process, elucidating the homogeneity of the adsorption mechanism on sweet potato peels .

3.1 Effect of Adsorbent Dosage

The results demonstrate a significant improvement in the removal efficiency of Methylene Blue (MB) dye with an increase in adsorbent dosage. The highest removal efficiency, reaching almost 70%, was attained at an adsorbent dosage of 1.1 g/100mL [15]. The experiment involved the use of various adsorbent dosages in contaminated synthetic water, highlighting a positive correlation between adsorbent dosage and methylene blue removal efficiency. However, it's noteworthy that beyond a certain threshold, removal efficiency starts to decrease. This decline is likely attributed to a saturation point, where the available surface area for methylene blue adherence on the adsorbent becomes limited [15, 16]. Remarkably, the optimal catalyst loading rate, where maximum removal efficiency is achieved, was identified as 1.1 g/50mL

3.2 Effect of Contact Time

The outcomes indicate a progressive enhancement in the removal efficiency of Methylene Blue (MB) dye as the contact time increases, reaching equilibrium at the 50-minute mark. The initial rapid adsorption is attributed to the increased availability of adsorption sites on the surface of the adsorbent material. This abundance of sites enables a rapid interaction between the adsorbent and methylene blue dye molecules. Subsequently, the gradual decrease in the adsorption rate is associated with the desorption of methylene blue dye from the surface of the adsorbent back into the solution [17]. Importantly, optimal removal efficiency is achieved when stirring is conducted for 50 minutes, emphasizing the crucial interplay between contact time and the dynamics of adsorption-desorption [3].

3.3 Effect of Methylene Blue Concentration

The effectiveness of sweet potato peels as an adsorbent for removing Methylene Blue (MB) is contingent on various factors, particularly the concentrations of both methylene blue and the adsorbent itself. In general, a higher concentration of MB requires a corresponding increase in the adsorbent concentration for optimal removal. This investigation highlights that raising the concentration of MB in the solution is associated with a decrease in the removal efficiency of the adsorbent. This trend is attributed to the potential saturation of the adsorbent surface at higher methylene blue concentrations, leading to a reduction in the number of available binding sites crucial for effective adsorption [18, 19].

3.4 FTIR Analysis of adsorbent material

Figure 6 and 7 illustrate the spectroscopic analysis of sweet potato peels, serving as the biosorbent, in both its untreated state and post-treatment following the adsorption of methylene blue on its surface. This technique was employed to discern the presence of functional groups within the sweet potato peel samples. Various peaks are discernible in the spectra of both the untreated and treated sweet potato peel samples. FTIR analysis reveals the existence of several functional groups on the surface of sweet potato peel adsorbent material, notably including hydroxyl, carboxyl, and phenolic groups [20]. Notably, a significant alteration in transmittance behavior is evident in the spectrum of both the untreated sweet potato peel sample and the sweet potato peel sample adsorbed with MB.

The FTIR spectra reveal distinct peaks associated with specific functional groups, including approximately 3350 cm-1 for -O-H groups, 2900 cm-1 for C-H groups, (1650–1750) cm-1 for C = O groups, 1550–1650 cm-1 for C = C groups, 1460 cm-1 for CH2 and CH3 groups,

1375 cm-1 for aromatic CH stretching and carboxyl-carbonate structures, 1150 − 1300 cm-1 for CO groups, 1230 cm-1 for CHOH groups, 1090 cm-1 for Si-O-Si groups, and 860–475 cm-1 for Si-H groups. These distinctive peaks in the FTIR spectra provide valuable insights into the diverse functional groups present on the surface of sweet potato peels, elucidating their potential contributions to the adsorption of methylene blue [21, 22].

The study underscores the remarkable efficacy of sweet potato peels as an exceptional adsorbent material for the removal of methylene blue dye from aqueous solutions. The robust adsorption of methylene blue onto the surface of sweet potato peels was clearly evident, and this phenomenon was systematically assessed using Ultraviolet–Visible spectroscopy. The adsorption process, influenced by factors such as contact time, adsorbent dosage, and stirring rate, revealed its maximum capacity at 1.1g/50mL for methylene blue dye. Complementary FTIR analysis provided insightful confirmation of presence of functional groups associated with methylene blue on surface of the sweet potato peels adsorbent material. The collective findings highlight the potential of sweet potato peels as a highly effective, eco-friendly approach to wastewater treatment. Leveraging the adsorption capabilities of sweet potato peels proves promising for addressing water pollution concerns, offering a sustainable solution that aligns with environmental conservation goals.

Abbas M (2022) Removal of methylene blue pollutant from the textile industry by adsorption onto Zeolithe: Kinetic and thermodynamic study. J Eng Fibers Fabr 17:155892502199369. https://doi.org/10.1177/1558925021993692
Alam Z, Bari N, Kawsari S (2022) Statistical optimization of Methylene Blue dye removal from a synthetic textile wastewater using indigenous adsorbents. Environ Sustain Indic 14:100176. https://doi.org/10.1016/j.indic.2022.100176
Ekinci S (2023) Elimination of Methylene Blue from Aqueous Medium Using an Agricultural Waste Product of Crude Corn Silk (Stylus maydis) and Corn Silk Treated with Sulphuric Acid. ChemistrySelect 8(18). https://doi.org/10.1002/slct.202300284
El-Bery HM, Saleh M, El-Gendy RA, Saleh MR, Thabet SM (2022a) High adsorption capacity of phenol and methylene blue using activated carbon derived from lignocellulosic agriculture wastes. Sci Rep 12(1). https://doi.org/10.1038/s41598-022-09475-4
Hamad HN, Idrus S (2022) Recent Developments in the Application of Bio-Waste-Derived Adsorbents for the Removal of Methylene Blue from Wastewater: A Review. Polymers 14(4):783. https://doi.org/10.3390/polym14040783
Hambisa AA, Regasa MB, Ejigu HG, Senbeto CB (2022) Adsorption studies of methyl orange dye removal from aqueous solution using Anchote peel-based agricultural waste adsorbent. Appl Water Sci 13(1). https://doi.org/10.1007/s13201-022-01832-y
Holliday MC, Parsons D, Zein SHS (2022) Agricultural pea waste as a Low-Cost pollutant biosorbent for methylene blue removal: Adsorption kinetics, isotherm and Thermodynamic studies. Biomass Convers Biorefinery. https://doi.org/10.1007/s13399-022-02865-8
Kausar A, Réhman SU, Khalid F, Bonilla-Petriciolet A, Mendoza-Castillo DI, Bhatti HN, Ibrahim SM, Iqbal M (2022) Cellulose, clay and sodium alginate composites for the removal of methylene blue dye: Experimental and DFT studies. Int J Biol Macromol 209:576–585. https://doi.org/10.1016/j.ijbiomac.2022.04.044
Kavcı E, Erkmen J, Bi̇Ngöl M (2021) Removal of methylene blue dye from aqueous solution using citric acid modified apricot stone. Chem Eng Commun 210(2):165–180. https://doi.org/10.1080/00986445.2021.2009812
Mekuria D, Diro A, Melak F, Asere TG (2022) Adsorptive removal of methylene blue dye using biowaste materials: barley bran and enset midrib leaf. Journal of Chemistry, 2022, 1–13. https://doi.org/10.1155/2022/4849758
Mphuthi BR, Thabede PM, Monapathi ME, Shooto ND (2023) Hemp seed nanoparticle composites for removing lead, methylene blue, and ibuprofen from an aqueous solution and their antimicrobial towards Escherichia coli and Staphylococcus aureus. Case Stud Chem Environ Eng 8:100436. https://doi.org/10.1016/j.cscee.2023.100436
Ofgea NM, Tura AM, Fanta GM (2022) Activated carbon from H3PO4 -activated Moringa Stenopetale Seed Husk for removal of methylene blue: Optimization using the response surface method (RSM). Environ Sustain Indic 16:100214. https://doi.org/10.1016/j.indic.2022.100214
Oladoye PO, Ajiboye TO, Omotola EO, Oyewola OJ (2022) Methylene blue dye: Toxicity and potential elimination technology from wastewater. Results Eng 16:100678. https://doi.org/10.1016/j.rineng.2022.100678
Omer AS, Naeem GaEE, Abd-Elhamid AI, Farahat OO, El-Bardan AA, Soliman HMA, Nayl A (2022a) Adsorption of crystal violet and methylene blue dyes using a cellulose-based adsorbent from sugercane bagasse: characterization, kinetic and isotherm studies. J Mater Res Technol 19:3241–3254. https://doi.org/10.1016/j.jmrt.2022.06.045
Zhu H, Chen S, Luo Y (2023) Adsorption mechanisms of hydrogels for heavy metal and organic dyes removal: A short review. J Agric Food Res 100552. https://doi.org/10.1016/j.jafr.2023.100552
Sah MK, Edbey K, El-Hashani A, Almshety S, Luisetto M, Alomar TS, AlMasoud N, Bhattarai A (2022) Exploring the Biosorption of Methylene Blue Dye onto Agricultural Products: A Critical Review. Separations 9(9):256. https://doi.org/10.3390/separations9090256
Sawalha H, Bader A, Sarsour J, Al-Jabari M, Rene ER (2022) Removal of Dye (Methylene Blue) from Wastewater Using Bio-Char Derived from Agricultural Residues in Palestine: Performance and Isotherm Analysis. Processes, 10(10), 2039. https://doi.org/10.3390/pr10102039
Xue H, Wang X, Xu Q, Dhaouadi F, Sellaoui L, Seliem MK, Lamine AB, Belmabrouk H, Bajahzar A, Bonilla-Petriciolet A, Li Z, Li Q (2022) Adsorption of methylene blue from aqueous solution on activated carbons and composite prepared from an agricultural waste biomass: A comparative study by experimental and advanced modeling analysis. Chem Eng J 430:132801. https://doi.org/10.1016/j.cej.2021.132801
Yadav SK, Dhakate SR, Singh BP (2022) Carbon nanotube incorporated eucalyptus derived activated carbon-based novel adsorbent for efficient removal of methylene blue and eosin yellow dyes. Bioresour Technol 344:126231. https://doi.org/10.1016/j.biortech.2021.126231
Wang K, Ding J, Shi J, Deng J, Huang H (2023) Multi-Scale characteristics of coal secondary spontaneous combustion under different Pre-Heating oxygen concentrations by TG and FTIR analysis. Combust Sci Technol 1–16. https://doi.org/10.1080/00102202.2023.2248367
Hambisa AA, Regasa MB, Ejigu HG et al (2023) Adsorption studies of methyl orange dye removal from aqueous solution using Anchote peel-based agricultural waste adsorbent. Appl Water Sci 13:24. https://doi.org/10.1007/s13201-022-01832-y
Bourahla S, Nemchi F, Belayachi H et al (2023) Removal of the AO7 dye by adsorption on activated carbon based on grape marc: equilibrium, regeneration, and FTIR spectroscopy. J Iran CHEM SOC 20:669–681. https://doi.org/10.1007/s13738-022-02705-6

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Novel Biosorption Method for Eliminating Methylene Blue Dye from Wastewater Using Sweet Potato Peels.

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Abstract

Figures

1 Introduction

2 Materials and Methods

2.1 Preparation of Biosorbent Material

2.2 Utilizing Sweet Potato Peels as a Biosorbent for Methylene Blue Dye Removal

2.3 Synthetic Solution of MB

2.4 Batch Adsorption Experiments

2.5 Characterization of Adsorbent Material

3 Results and Discussion

3.1 Effect of Adsorbent Dosage

3.2 Effect of Contact Time

3.3 Effect of Methylene Blue Concentration

3.4 FTIR Analysis of adsorbent material

4 Conclusion

References

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