KOVALEN: Jurnal Riset Kimia, 11.
, 2025: 73-80 https://bestjournal.
id/index.
php/kovalen Modification of Areca Nut (Areca catechu L.
) Peel Hydrochar for Photodegradation of Methylene Blue Eva Musifa.
Neza Rahayu PalapaA.
Titah Maharti Nugraheni.
Miftahun Naimah Chemistry Department.
Faculty of Mathematics and Natural Sciences.
Universitas Sriwijaya.
PalembangInderalaya Street Km.
Inderalaya.
South Sumatera.
Indonesia Abstract.
Synthetic dyes such as methylene blue (MB) are persistent pollutants that pose serious environmental risks due to their toxicity and resistance to biodegradation.
This study investigates the development of sustainable photocatalysts derived from Areca catechu L.
peel through hydrothermal carbonization, followed by activation, zeolite impregnation, and magnetic modification using FeAA/FeAA ions.
XRD and FTIR analyses confirmed the successful formation of FeCEOCE, increased porosity, and the presence of functional groups that facilitate adsorption and photocatalytic activity.
The results indicate that photodegradation is significantly more effective than adsorption, with magnetic hydrochar and hydrocharAezeolite composites achieving degradation efficiencies above 90%.
Optimal performance was observed at a catalyst mass of 0.
20 g and an irradiation time of 150 minutes.
The high removal efficiency is attributed to synergistic interactions including AAeA stacking, hydrogen bonding, and electrostatic attraction between MB molecules and the modified hydrochar surface.
Overall, this study demonstrates that Areca catechu L.
peel waste can be valorized into an efficient, low-cost, and magnetically recoverable photocatalyst for dye-contaminated wastewater treatment.
Keywords: Hydrochar.
Areca catechu L.
Photodegradation.
Methylene blue Abstrak.
Zat warna sintetis seperti metilen biru (MB) merupakan polutan persisten yang menimbulkan risiko lingkungan serius karena sifatnya yang toksik dan resisten terhadap biodegradasi.
Penelitian ini mengkaji pengembangan fotokatalis berkelanjutan yang berasal dari kulit buah pinang melalui proses karbonisasi hidrotermal, diikuti aktivasi, impregnasi zeolit, serta modifikasi magnetik menggunakan ion FeAA/FeAA.
Analisis XRD dan FTIR mengonfirmasi keberhasilan pembentukan FeCEOCE, peningkatan porositas, serta keberadaan gugus fungsi yang mendukung aktivitas adsorpsi dan fotokatalisis.
Hasil penelitian menunjukkan bahwa fotodegradasi jauh lebih efektif dibandingkan adsorpsi, dengan hidrochar magnetik dan hidrocharAezeolit mencapai efisiensi degradasi lebih dari 90%.
Kinerja optimal diperoleh pada massa katalis 0,20 g dan waktu iradiasi 150 menit.
Efisiensi tinggi ini disebabkan oleh interaksi sinergis seperti AAeA stacking, ikatan hidrogen, dan gaya elektrostatik antara molekul MB dan permukaan hidrochar termodifikasi.
Secara keseluruhan, penelitian ini menunjukkan bahwa limbah kulit buah pinang dapat divalorisasi menjadi fotokatalis efisien, berbiaya rendah, dan mudah dipisahkan secara magnetik untuk pengolahan limbah zat warna.
Kata kunci: Hidrokar, kulit Areca catechu L, fotodegradasi, metilen biru Received: November 30, 2025.
Accepted: December 28, 2025 Citation: Musifa.
Palapa.
Nugraheni.
, dan Miftahun.
Modification of Areca Nut (Areca catechu L.
) Peel Hydrochar for Photodegradation of Methylene Blue.
KOVALEN: Jurnal Riset Kimia, 11.
: 73-80.
INTRODUCTION
and printing industries, but their excessive use Water pollution caused by industrial and untreated disposal lead to water pollution effluents containing synthetic dyes is a serious (Palapa et al.
, 2.
Dyes can be toxic at high environmental issue.
Dyes such as methylene concentrations, are not readily biodegradable, blue (MB) are widely used in the textile, paper, and can harm aquatic life and human health if A accumulated over the long term.
Exposure to Corresponding Author E-mail: nezarahayu@mipa.
these dyes can cause health problems such as https://doi.
org/10.
22487/kovalen.
2477-5398/ A 2025 Musifa et al.
This is an open-access article under the CC BY-SA license.
KOVALEN: Jurnal Riset Kimia, 11.
, 2025: 73-80 Musifa et al.
enhanced by the addition of FeAA/FeAA ions, resulting in magnetic hydrochar with strong carcinogenic and teratogenic effects (He et al.
magnetic properties, a larger surface area, and ease of separation after the reaction.
Magnetic With hydrochar has been shown to exhibit higher environmental sustainability, various methods have been developed to treat dye waste from hydrochar because the presence of iron oxide industrial wastewater, such as adsorption, increases electron transfer, surface reactivity, coagulation, biodegradation, bioremediation, and the number of active sites involved in the and photodegradation (Aragaw & Bogale, dye degradation process.
(Huabin Wang et al.
Among these methods, adsorption and In this context, this study addresses the environmentally friendly approaches because optimization of the photodegradation process they produce no secondary waste, have low using magnetic areca nut hydrochar for the energy consumption, and are highly efficient in decomposition of methylene blue.
Optimizing the adsorbent mass is crucial because the However, photodegradation requires the assistance of light and semiconductor materials capable of degradation efficiency.
Too low a mass limits absorbing photon energy and generating free the number of active sites, while too high a radicals to chemically destroy the pollutant mass can lead to light saturation and reduce structure (Khan et al.
, 2.
The resistance of the effectiveness of photocatalysis.
Therefore, dyes to biodegradation also necessitates more this study focuses on determining the optimum mass of magnetic hydrochar capable of conventional methods such as coagulation and Therefore, alternative technologies compounds into simpler, more environmentally MATERIAL AND METHODS friendly compounds are needed.
(Zavahir et Material Preparation Areca nut peels were separated from the , 2.
The use of biomass-based catalysts is seeds, cut into small pieces, and oven-dried at gaining popularity due to their abundant 100 AC for 24 h.
A total of 2.
5 g of the dried peels was mixed with 50 mL of distilled water Areca nut peel is a very abundant agricultural waste in Indonesia but remains hydrothermal autoclave.
The autoclave was placed in an oven at 250 AC for 4 hours.
The process, areca nut peel can be converted into black powder, which was the hydrochar, was washed with distilled water and then oven- material with good adsorption capacity and dried at 105 AC for 24 hours (Adawiyah et al.
potential as an alternative catalyst.
However.
Through the hydrochar's performance can be further KOVALEN: Jurnal Riset Kimia, 11.
, 2025: 73-80 Musifa et al.
Procedure experiments were conducted to assess the Impregnation process optimum conditions to determine the range of hydrochar raw material was first activated with degradation process.
The photodegradation KOH process was carried out in a dedicated reactor The activated hydrochar was equipped with a UV lamp (Philips TUV then dried at 80AC overnight.
The activated 15W/G15 T8 Ae wavelength 280 n.
for 150 hydrochar was then immersed in a zeolite minutes with stirring to maintain solution suspension at a ratio of 1:10 .
The After the irradiation process was soaking was carried out for 2 hours.
Afterward, completed, the solids were separated using the biomass-zeolite mixture was dried in an centrifugation at 7000 rpm for 15 minutes.
The oven at 80 A 5AC.
absorbance of the remaining solution was then H2SO4 The zeolite-impregnated modified with magnetics The zeolite-impregnated hydrochar was then magnetically modified using Fe ions.
First, 1 g of FeSOCEA7HCCO .
2 M) and 2 g of FeClCEA6HCCO .
4 M), in a 2:1 molar ratio, were dissolved in 100 mL of distilled water.
The solution was then vigorously stirred and heated to 80 AC, after which approximately 40 mL of a 25% NHCEOH solution was slowly added until the pH reached 12.
The resulting solids were separated using a magnet and dried at 75 AC for 3 h.
Natural zeolite was prepared by grinding and sieving through a 110-mesh sieve, followed by washing and oven-drying at 110 AC for 4 h.
SEM-EDS
analysis was then performed on the zeolite surface profile before activation.
100 g of the prepared zeolite was activated with 300 ml of 5 M HCl for 30 minutes using a water bath shaker at 200 rpm, and then dried for 24 After reaching a neutral pH, it was oven-dried for 5 hours at 160 AC.
were conducted at the optimum pH with varying irradiation times of 90, 120, 150, 180, and 210 minutes.
Meanwhile, the effect of photocatalyst mass was tested at the optimum pH and irradiation time, with variations in mass 05, 0.
10, 0.
15, 0.
20, and 0.
25 grams.
RESULT AND DISCUSSION
Material Preparation Results The hydrochar produced from areca nut peels turned brown after heating and washing.
The resulting hydrochar was subsequently modified with zeolite, transforming the fibrous and nonporous raw biomass into porous, heterogeneous hydrocarbon fragments.
Zeolite is a porous hydrated mineral with an anionic composed of silicon .
and oxygen its pores are formed by various tetrahedral arrangements (Zheqi Wang et al.
In addition to changes in color and magnetic behavior, the magnetization process indicates the formation of bonds between Dye photodegradation The measured using UVAeVis.
Contact time tests FeAA/FeAA AeOH AeCOOH functional groups on the hydrochar surface.
Methylene Blue (MB) was conducted by studying three main parameters: irradiation Initial KOVALEN: Jurnal Riset Kimia, 11.
, 2025: 73-80 Musifa et al.
X-Ray Diffraction Spectrum
(XRD)
Infrared HCP is area nut hydrochar.
HC peaks at 88A, 22.
92A, and 34.
74A indicate increased The XRD diffractogram in Figure 1 shows the structural characteristics of areca nut husk, carbonization, with a prominent peak at 22.
hydrocarbons (HC).
HCZ is magnetic zeolite indicating partially ordered carbon, although impregnated areca nut hydrochar.
AZ is the structure remains HCPZ is zeolite acera nut hyrochar.
(Sabzoi et al.
, 2.
HCPM is magnetic areca nut hydrochar nut Figure 1.
XRD diffractogram Figure 2.
FTIR spectrum Magnetic hydrochar, on the other hand, correspond to the .
, .
, .
, .
, exhibits much sharper and more defined and .
planes of magnetite (FeCEOCE).
The These peaks are located at positions appearance of these peaks indicates that the around 2 30A, 35A, 43A, 57A, and 62A, which iron impregnation and hydrothermal heating KOVALEN: Jurnal Riset Kimia, 11.
, 2025: 73-80 Musifa et al.
processes successfully formed the FeCEOCE this study compared the effectiveness of the adsorption and photodegradation processes XRD HCl- zeolite-impregnated Determination of maximum wavelength of methylene blue The zeolite-impregnated hydrochar Measurements were made using a UV-Vis exhibited 2 angles at 15.
9A and 22.
These spectrophotometer in the range of 500Ae700 diffraction peaks were identified as solullose The scan results showed the highest These diffraction results are absorption peak at 664 nm, which is the typical consistent with the data provided in ICDD PDF max 00-060-1501 (Montoya-escobar et al.
, 2.
Odoemelam also reported a max value for Research The FTIR spectra presented in Figure 2 methylene blue at 660Ae664 nm, thus these illustrate the functional group compositions of results are consistent with the literature HCPMZ.
HCPM.
HCPAZ, and HCPZ.
In HC, (Odoemelam et al.
, 2.
the absorption band at 1650Ae1600 cmAA corresponds to the C=C stretching vibration of aromatic rings, indicating an increase in aromaticity during hydrothermal carbonization.
In addition, the band at 1400 cm-1 corresponds to C-H bending vibration, while the peak at C-O-C characteristic of ether bonds in carbohydrate The peak at 600-800 cm-1 indicates Figure 3.
UV-VIS spectra the presence of out-of-plane aromatic bending, which confirms the retention of aromatic The structures in the adsorbent material (Mara conducted by adding 0.
02 g of areca nut peel Olivares.
Silvia Romyn, 2.
After the and hydrochar (HC) adsorbents to a 100 mL magnetization process, which involves the Erlenmeyer addition of FeAA/FeAA ions, the FTIR spectrum methylene blue solution with a concentration of shows a new peak at 500 cmAA, which is a 50 mg/L, without pH adjustment.
The mixture characteristic band for Fe-O bonds, indicating was stirred using a magnetic stirrer for varying the formation of a magnetite phase (FeCEOCE) on After stirring, the adsorbent was the hydrochar surface (Herbei et al.
, 2.
separated from the solution by filtration, and This magnetization process does not remove the resulting filtrate was analyzed using a UV- active functional groups such as -OH and - Vis spectrophotometer to measure absorbance COOH, so the adsorption properties of the (Herbei hydrochar are maintained.
adsorption times are shown in Table 1 and Material Application in Adsorption and Photodegradation Processes In this study, hydrochar material was Data for Figure 4, showing the % adsorption versus % degradation of areca nut peel, and HC, analyzed using UV-VIS spectroscopy.
utilized primarily for the adsorption process, as KOVALEN: Jurnal Riset Kimia, 11.
, 2025: 73-80 Musifa et al.
Table 1.
Comparison of adsorption and photodegradation methods at 150 Adsorbent Initial Concentration .
g/L) Area Peel Adsorption Degredation hydrocarbons from areca nut shells were impregnated with zeolite at a mass of 0.
showed a lower decomposition rate than activated zeolite.
At a mass of 0.
1 g, hydrocarbons from zeolite-impregnated areca nut shells (HCP Z) tended to be slightly more effective or equivalent to activated zeolite (AZ).
Hydrochar Even at a mass of 0.
2 g, hydrocarbons from zeolite-impregnated areca nut shells showed Figure Percentage Figure 4 shows a comparison of the percentages of adsorption and degradation calculated from the residual concentrations.
These calculations were based on UVAeVIS characteristic wavelength of methylene blue and the final concentrations obtained for each Figure 4 and Table 1 indicate that the raw material being tested is more effective in the photodegradation process than in the adsorption process at the same time and dye Figure 5.
Mass variation graph Based The application of the modified variation data, it was found that increasing the material is then carried out through the mass of magnetic hydrochar and hydrochar photodegradation process.
had a significant effect on the degradation Effect of material mass variation on the amount of MB degradation In magnetic hydrochar material, a The results of photodegradation tests at and at a mass of 0.
05 g the degradation different adsorption masses, namely with percentage was 78.
When the mass was zeolite activated with HCl and hydrocarbons increased to 0.
10 g, the degradation reached from areca nut shells impregnated with zeolite 90%, then increased to 93.
79% at a mass (Figure .
Based on the data in the graph, 20 g and stabilized at 93.
17% at 0.
25 g.
mass of 0.
025 g showed 55.
69% degradation.
KOVALEN: Jurnal Riset Kimia, 11.
, 2025: 73-80 Musifa et al.
Meanwhile, in hydrochar, the degradation photodegradation performance tests, it can be percentage was 68.
57% at a mass of 0.
025 g.
concluded that areca nut peelAebased materials At a mass of 0.
05 g, the degradation were successfully modified into hydrochar, decreased slightly to 67.
16%, but increased magnetic hydrochar, and hydrocharAezeolite.
again at 0.
10 g to 78.
The highest These degradation value was achieved at a mass of physicochemical properties that are more 20 g, namely 93.
85%, and slightly decreased suitable for applications as adsorbents and 81% at 0.
25 g.
Overall, both materials Activation and modification showed an increasing trend of degradation with increasing adsorbent mass, with the photodegradation efficiency.
Application tests demonstrated that photodegradation was more value before stabilizing at subsequent masses.
Hydrochar-based hydrocharAezeolite, percentage degradation reached its highest Effect of variation in material contact time on the amount of MB dye degraded The percentage degradation increased degradation performance at an optimum mass with time, up to 150 minutes (Figure .
, 20 g, achieving degradation efficiencies indicating a percentage degradation of 91.
exceeding 90%.
In addition, contact time had a for HCP.
0% for HCP-M.
8% for HCP Z.
positive effect, with maximum degradation and 93% for AZ, respectively.
observed at 150 min.
ACKNOWLEDGMENT
The Universitas Sriwijaya supporting this research through the PDP Unsri 0027/UN9/SK.
LPPM.
PT/2025.
This serves as an output publication within the broader scope of the project.
The authors also thank the Inorganic Chemistry Laboratory.
Department of Chemistry for their support in the analytical work.
REFERENCES