Science and Technology Indonesia e-ISSN:2580-4391 p-ISSN:2580-4405 Vol.
No.
July 2022 Research Paper Preparation of Hydrochar from Salacca zalacca Peels by Hydrothermal Carbonization:
Study of Adsorption on Congo Red Dyes and Regeneration Ability Mauizatul Hasanah1,3 .
Alfan Wijaya2 .
Fitri Suryani Arsyad3 .
Risfidian Mohadi3 *.
Aldes Lesbani2,3 1 Department of Pharmacy.
School of Pharmacy Bhakti Pertiwi.
Palembang, 30128.
Indonesia 2 Research Centre of Inorganic Materials and Coordination Complexes.
Faculty of Mathematics and Natural Sciences.
Sriwijaya University.
Palembang, 30139.
Indonesia 3 Doctoral Program.
Faculty of Mathematics and Natural Sciences.
Sriwijaya University.
Palembang, 30139.
Indonesia *Corresponding author: risfidian.
mohadi@unsri.
Abstract Hydrochar of Salacca zalacca peels (HC-SP) is prepared by hydrothermal carbonization treatment of Salacca zalacca peels (SP) obtained from local fruits at Palembang.
South Sumatera.
Indonesia, with the resulting yield weight reaching 90%.
Materials are characterized using the XRD diffraction.
FTIR spectrum, and SEM-EDX.
The XRD pattern shows the characteristics of the formation of amorphous compounds.
The FTIR spectrum confirms the presence of functional groups O-H.
C-H.
C=C, and C-O.
Data of SEM-EDX show that materials have heterogeneous morphologies, form aggregates, and in HC-SP materials there is an increase in carbon content from the initial material.
The capacity of SP in the congo red (CR) adsorption process is 33.
003 mg/g and increases to 133.
mg/g in HC-SP.
The maximum dye adsorbed was achieved at pH 4.
The adsorption kinetics followed PSO with the equilibrium adsorption occurring at 90 minutes, and the adsorption isotherm followed the Langmuir isotherm with the value of R2 closer to the value of 1.
A positive 4H value indicated that the adsorption is an endothermic process.
In contrast, an 4S value suggested that the degree of irregularity in the adsorption process is small in large concentrations.
Based on data regeneration ability, materials of SP and HC-SP can be used in the three cycles regeneration process of the CR adsorption process.
The adsorption process of CR occurs physically and chemically based on enthalpy values and FT-IR data after being adsorbed with CR.
Keywords Hydrochar.
Salacca zalacca Peels.
Adsorption.
Congo Red.
Regeneration Received: 20 March 2022.
Accepted: 14 July 2022 https://doi.
org/10.
26554/sti.
INTRODUCTION
Hydrothermal carbonization (HTC) is a thermochemical process to convert biomass into rich-carbon materials, often referred to as hydrochar.
This process has the advantage of using milder temperatures .
-250AC) and water that acts as a solvent and catalyst.
The favorable reaction conditions make this process more economically feasible compared to other chemical processes (Yu et al.
, 2022.
Camilo et al.
, 2021.
Liu et al.
, 2.
Carbon-based materials such as hydrochar have high chemical stability, porous structure, physical and chemical properties, and surface area (Zulfajri et al.
, 2.
Recently, some literature reported the successful preparation of hydrochar from natural resources such as rice husk (Phan et al.
, 2.
, avocado seed (Dhaouadi et al.
, 2.
, sewage sludge, and coconut shell (Tu et al.
, 2.
, coffee waste (Santana et al.
, 2.
, banana peels (Yusuf et al.
, 2.
, pomelo peels (Wei et al.
, 2.
and orange peels (Espro et al.
, 2.
Salacca zalacca .
nake fruit.
peels one of the biomass pro- duced from agricultural waste easily obtained in Indonesia (Fatimah et al.
, 2.
Research conducted by Fatimah et al.
Arie et al.
, 2018 shows the ability of Salacca zalacca peels in dye removal, to improve its adsorption ability, treatment is carried out through hydrothermal carbonization in this study.
Hydrochar is widely used as an adsorbent and is primarily utilized as an effective and reliable treatment for removing dye pollutants (Haris et al.
, 2022.
Zulfajri et al.
, 2.
Dye pollutants are produced from factories that produce textile clothing, medicines, and food products.
Synthetic dyes are difficult to remove due to the complex aromatic structure.
One of the widely used dyes is congo red (CR).
Dye pollutants are highly toxic, carcinogenic, difficult to biodegrade, and have high solubility in water.
Water contaminated with dyes will adversely affect organisms in the water and is very dangerous if exposed to the human body (Kenawy et al.
, 2.
Therefore, it is necessary to have an effective method for the removal of dye pollutants.
Many ways to remove the dye pollutants like coagulation-flocculation (Ihaddaden et al.
, 2.
, pho- Hasanah et.
Science and Technology Indonesia, 7 .
372-378 for 6 hours.
The obtained material was characterized using XRD.
FTIR, and SEM-EDX.
A schematic representation of hydrochar preparation showed in Figure 1.
Figure 1.
Schematic Representation of Hydrochar Preparation tocatalysis (Mahmoodi et al.
, 2.
, oxidation-precipitation (Anushree and Philip, 2.
, and adsorption (Tran et al.
, 2020.
Wijaya et al.
, 2021.
Palapa et al.
, 2.
Comparing some of these methods, adsorption is one of the economic processes in wastewater treatment and is considered an easy, efficient technique for its operation, high efficiency, and low cost (Karthi et al.
, 2.
According to research by Haris et al.
, hydrochar made from olive waste showed high effectiveness in removing methylene blue and congo red dyes from water.
Hydrochar from straw mushrooms conducted by Zulfajri et al.
and applied to removal of dyes i.
crystal violet and methylene blue, showed excellent removal efficiencies of more than 90%.
In this research, the preparation of hydrochar was retrieved from Salacca zalacca peels which is residual waste, and then materials were analyzed using XRD.
FT-IR, and SEM-EDX.
It will be applied as adsorbents to remove congo red dyes and study the effect of pH, times, adsorption isotherm, adsorption thermodynamics, and regeneration ability.
EXPERIMENTAL SECTION
3 Study of Adsorption The study of adsorption was carried out with 3 treatments: the effect of pH, contact time adsorption, and concentration temperature adsorption.
The effect of pH can be studied by pH pzc treatment and pH adsorption.
pH pzc can be studied by varying the pH of the NaCl solution .
, then adding 0.
g of material to the solution and stirring for 24 hours.
The pH effect of adsorption can be studied by varying the pH of CR .
, and the effect of contact time adsorption on anionic dyes can be studied by varying the contact time .
, 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 120, 150, and 180 minute.
As much as 0.
02 g adsorbents were added to an Erlenmeyer containing 20 mL of dye solution with a concentration of 50 mg/L, and the mixture was stirred.
The effect of concentration and temperature adsorption was studied by varying the concentration .
, 70, 80, 90, and 100 mg/L) and temperature .
, 40, 50, 60, and 70AC).
As much as 0.
02 g adsorbents were added to an Erlenmeyer containing 20 mL of dye solution and stirred for 60 minutes.
The filtrate was measured using a UV-Vis spectrophotometer.
4 Study of Regeneration Ability Regeneration of adsorbent is carried out by adsorption and desorption processes first.
Dyes 50 mg/L were added to 0.
g of adsorbent.
The mixture was stirred for 2 hours, and the absorbance of the filtrate was measured using a UV-Visible Adsorbents that have been used in the adsorption process are carried out the desorption process with ultrasonic systems that use water.
Dried adsorbents are used in the adsorption process for the next cycle.
RESULTS AND DISCUSSION
1 Chemicals and Instrumentation The materials used in this study such as Salacca zalacca peels were obtained from the local fruits at Palembang.
South Sumatera.
Indonesia.
Chemicals include orthophosphoric acid, distilled water.
HCl.
NaOH.
NaCl, and anionic dyes .
ongo red (CR)).
The material was characterized using an X-Ray Rigaku Miniflex-600 diffractometer.
Shimadzu Prestige-21 FTIR Spectrophotometer.
Scanning Electron Microscope Energy Dispersive Spectrometer (SEM-EDS) Quanta 650, and absorbance measurement of solution using UV-Visible Biobase Spectrophotometer UV BK-1800PC.
2 Preparation of Hydrochar from Salacca zalacca Peels Salacca zalacca peels are dried in the sun and then crushed and As much as 2 g of Salacca zalacca peels powder, and 50 mL of orthophosphoric acid were added to the hydrothermal stainless steel autoclave, then heated at a temperature of 150AC for 6 hours.
The mixture was filtered and heated at 110AC A 2022 The Authors.
Figure 2.
Diffraction Patterns of SP .
and HC-SP .
Page 373 of 378 Hasanah et.
Science and Technology Indonesia, 7 .
372-378 Preparation of HC-SP by hydrothermal carbonization treatment (Figure .
results in weight yields up to 90%.
X-ray diffractogram pattern of the Salacca zalacca peels (SP) and hydrochar of Salacca zalacca peels (HC-SP) are shown in Figure A broad peak at a diffraction angle of around 20A with field diffraction .
indicates that the material has low crystallinity and shows the characteristics of the formation of amorphous HC-SP materials have heterogeneous morphologies and form aggregates, and the morphology of HC-SP looks more refined compared to SP.
In HC-SP materials, there is an increase in carbon content from the initial material due to hydrothermal carbonization treatment.
In SP material, the percent of the carbon content weight is 55.
9% increasing to 68% in HC-SP This proves the success of the hydrothermal carbonization process that has been carried out in this research.
Figure 3.
FT-IR Spectrum of SP .
and HC-SP .
Figure 5.
pH pzc of Materials The results of the pH pzc treatment can be seen in Figure Based on the data of pH pzc, it can be seen that the pH pcz of SP and HC-SP materials are 4.
54 and 5.
79, respectively.
In adsorption treatment, if the material is contacted with a solution whose pH is below pH pcz, then the materialAos surface is positively charged and in reverse.
Based on this statement, the adsorption process of anionic dyes such as CR is more suitable to be carried out under pH pzc.
Figure 4.
SEM-EDX of SP .
and HC-SP .
The spectrum FT-IR of SP and HC-SP are shown in Figure 3.
The FT-IR spectrum of SP in Figure 3.
shows that the peak at wavenumber 3448, 2924, 1635, and 1056 cmOe1 corresponds to the presence of O-H.
CAeH.
C=C, and C-O functional groups, respectively.
The functional group of SP in this research is similar to the results of the study reported by Fatimah et al.
The FT-IR spectrum of HC-SP in Figure 3.
experienced a not-so-significant shift in the wavenumber from the starting material due to hydrothermal carbonization Data of SEM-EDX is shown in Figure 4 with a magnification of 250 times.
SEM-EDX data shows that SP and A 2022 The Authors.
Figure 6.
Effect of pH on Adsorption Process Materials of SP and HC-SP were applied as adsorbents to the removal of CR and studying the effect of pH, times, adsorpPage 374 of 378 Science and Technology Indonesia, 7 .
372-378 Hasanah et.
Table 1.
Adsorption Kinetic Parameters Adsorbents Initial Concentration .
g/L) Qeexp .
HC-SP Qecalc .
PFO Qecalc .
PSO Figure 8.
Adsorption Isotherm Models of SP .
and HC-SP .
Figure 7.
Adsorption Kinetic Models tion isotherm, adsorption thermodynamics, and regeneration Based on the data on the development of pH in the CR adsorption process in Figure 6, it can be seen that the highest adsorption concentration is at pH 4.
In contrast, at an increase in pH from 4-9, there is a continuous decrease in the dye absorbed, similar to the reported by Brahma and Saikia .
The results of this adsorption pH are in accordance with the pH pzc statement above, where the CR adsorption process is more suitable to be carried out below the pH pzc.
Adsorption kinetic models and kinetic parameters are shown in Figure 7 and Table 1, respectively.
Based on the results of adsorption kinetic models shown in Figure 7, the equilibrium adsorption of CR occurred at 90 minutes, with an insignificant increase in adsorption concentration at a contact time of more than 90 minutes, and based on data.
Table 1 shows that the adsorption kinetics followed PSO, with the value of the linear regression coefficient (R2 ) which is close to the value 1.
Adsorption isotherm models and isotherm adsorption are shown in Figure 8 and Table 2, respectively.
Based on the adsorption isotherm of SP and HC-SP in Figure 8 indicates that increasing temperature causes the increase in adsorption concentration, and adsorption concentrations in HC-SP are higher than with SP.
Table 2 shows the large adsorption capacity that occurred at an adsorption temperature of 70AC and occurred an increase of adsorption capacity in HC-SP during the CR adsorption process.
The adsorption capacity of SP 003 mg/g to be 133.
333 mg/g in HC-SP.
This proves A 2022 The Authors.
Figure 9.
Regeneration Ability of SP and HC-SP that hydrothermal carbonization treatment will improve the performance of the material.
Based on Figure 8 and Table 2, it can be seen that the Langmuir model is better than the Freundlich model for the adsorption process in this study, with the value of R2 closer to the value of 1.
Adsorption thermodynamic parameters are shown in Table 3.
The enthalpy .
H) value offers the range of 6.
693 to 18.
097 kJ/mol, indicating the physical adsorption process.
Generally, an enthalpy value of less than 21 kJ/mol indicated adsorption physics (Nimibofa et al.
, 2.
A positive 4H value indicated that the adsorption is an endothermic process, while an 4S value suggested that the degree of irregularity in the adsorption process is small in large concentrations.
The regeneration ability of SP and HC SP is shown in Page 375 of 378 Science and Technology Indonesia, 7 .
372-378 Hasanah et.
Table 2.
Adsorption Isotherm Parameters Adsorbents Adsorption
Isotherm
Langmuir
Freundlich
Langmuir
HC-SP
Freundlich
Adsorption
Constant
T (K)
Qmax Qmax Table 3.
Adsorption Thermodynamic Parameters Adsorbents HC-SP Concentration .
g/L) T (K) Qe .
Figure 10.
FT-IR Spectrum of SP .
and HC-SP .
after CR Adsorption Figure 9.
Based on Figure 9, it can be seen that the adsorption ability decreases as the regeneration cycle increases and there is a significant decrease in adsorption ability in the fourth and fifth cycles.
Materials of SP and HC-SP can be used in the A 2022 The Authors.
4H .
J/mo.
4S (J/mol.
4G .
J/mo.
three cycles regeneration process of CR adsorption process.
FT-IR spectrum of SP and HC-SP after CR adsorption is shown in Figure 10.
Based on Figure 10, it can be seen that in SP and HC-SP materials after being adsorbed CR, there is a shift in the wavenumber and a change in intensity from the initial material.
It is caused by the chemical interaction that occurs in the adsorption process between the material and CR, it indicates that the adsorption process that occurs is also The shift in the wavenumber and the change in intensity in the area of about 3400 and 1000 cmOe1 indicate the presence of hydrogen bonds (H-O-H) that occur between the SP and HC-SP materials with CR, while the shift in the wave numbers and changes in the intensity in the wave number areas of about 2300 and 1600 cmOe1 indicate an increase in the C-H and C=C bonds due to the binding of CR to the material.
A comparison of the adsorption capacity of CR by several adsorbents from natural resources or waste can be seen in Table Based on the data in Table 4, it can be seen that HC-SP Page 376 of 378 Science and Technology Indonesia, 7 .
372-378 Hasanah et.
Table 4.
Adsorption Capacity of CR by several Adsorbents Adsorbents Adsorption Capacity .
References Aspergillus carbonarius M333
Penicillium glabrum Pg1
Chemically Modified Egg Shell Membrane Tunics of the Corm of the Saffron
Cabbage Waste Powder
Red Dragon Fruit Peel
Iron Oxide from Steel Waste Recycling Produced with Bottle Cap
Vermicompost
HC-SP
(Dhaouadi et al.
, 2.
(Dhaouadi et al.
, 2.
(Parvin et al.
, 2.
(Dbik et al.
, 2.
(Wekoye et al.
, 2.
(Lima et al.
, 2.
(Borth et al.
, 2.
(Ribeiro et al.
, 2.
This Research has a higher adsorption capacity in the CR adsorption process compared to other adsorbents, thus it can be said that HC-SP is a potential material that can be used in removing CR.
CONCLUSION
The success of the preparation of HC-SP by hydrothermal carbonization was proven by the characterization of XRD.
FTIR, and SEM-EDX.
In this study, the material was applied as an adsorbent for CR by studying the study of adsorption and regeneration ability.
The maximum dye adsorbed was achieved at pH 4.
The adsorption kinetics followed PSO with the equilibrium adsorption occurring at 90 minutes and the adsorption isotherm followed the Langmuir isotherm with the value of R2 closer to the value of 1.
The adsorption capacity of SP in the CR adsorption process is 33.
003 mg/g and increases 333 mg/g in HC-SP.
Adsorption in this study includes an endothermic process and occurs spontaneously.
Based on data regeneration ability, materials of SP and HC-SP can be used in the three cycles regeneration process of the CR adsorption process.
The adsorption process of CR occurs physically and chemically based on enthalpy values and FT-IR data after being adsorbed with CR.
ACKNOWLEDGMENT
The authors thank to Research Center of Inorganic Materials and Coordination Complexes FMIPA Universitas Sriwijaya for support and instrumental analysis.
REFERENCES