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Adsorption of Phenol Using Hydrochar Modified Layered Double Hydroxide – Kinetic, Isotherm, and Regeneration Studies

Palapa Neza Rahayu, Ahmad Nur, Utami Hasja Paluta, Zahara Zaqiya Artha, Mohadi Risfidian, Lesbani Aldes

Ecological Engineering & Environmental Technology

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2023

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Vol. 24, iss. 5

275--281

EN

In this work, hydrochar using to modified nickel aluminum layered double hydroxide (hydrochar@NiAl LDH). The collected data by XRD indicate that 2θ of material at 11.38°, 22.90°, 35.20°, and 61.60°. The FTIR spectrum of hydrochar@NiAl LDH at wavenumber 3448, 1650, 1500–1600, 1348, 1056, and 500–800 cm-1. NiAl LDH and hydrochar have surface areas of 3.288 m2/g and 7.366 m2/g, respectively. The precursors enhance the composite’s surface area by 11.879 m2/g. NiAl LDH, hydrochar, and hydrochar@NiAl LDH have optimal pH values of 3, 6, and 6 respectively. The adsorption process is determined by the kinetic model of pseudo-second order and the model of Freundlich isotherm. NiAl LDH, hydrochar, and hydrochar@NiAl LDH had respective maximum adsorption capacities of 25.445, 21.008, and 25.773 mg/g. The increase in regeneration cycles decreases the percentage of adsorbed.

2

Improving the Performance of Mg/Cr LDH by Forming Metal Oxides Mg/Cr-Ni Using Coprecipitation Method as Adsorbent for Cationic Dyes

Yuliasari Nova, Badri Arini Fousty, Siregar Patimah Mega Syah Bahar Nur, Palapa Neza Rahayu, Mardiyanto, Mohadi Risfidian, Lesbani Aldes

Journal of Ecological Engineering

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2022

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Vol. 23, nr 6

67--74

EN

This study aimed to determine the adsorption capacity of rhodamine-B (Rh-B) and methylene blue (MB) on Mg/Cr-Ni adsorbents. The Mg/Cr-Ni adsorbent was synthesized by the coprecipitation method. The results of the characterization of Mg/Cr-Ni using XRD analysis showed the formation of oxides at an angle of 2θ = 31.726°, 33°, and 45.44°. The surface area of Mg/Cr-Ni is 23.139 m2/g. The adsorption capacity test for Mg/Cr-Ni for Rh-B and MB were 85.470 mg/g and 166.667 mg/g, respectively. The adsorption kinetics model followed the pseudo second order (PSO). The adsorption process is endothermic and occurs spontaneously at any temperature. Mg/CrNi showed stability in the adsorption process of Rh-B and MB for 5 regeneration cycles.

3

Development of Renewable Material Hydrochar-Based CaAl Layered Double Hydroxide to Overcome Methyl Red Dyes Contaminant

Mohadi Risfidian, Juleanti Novie, Palapa Neza Rahayu, Hidayati Nurlisa, Lesbani Aldes

Journal of Ecological Engineering

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2022

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Vol. 23, nr 3

17--25

EN

The preparation of the CaAl/HC composite was carried out with a supporting material in the form of hydrochar from duku skin. The success of the preparation was demonstrated by XRD, FT-IR, and BET analysis. The diffractogram of CaAl/HC showed diffraction peaks at 2θ = 10.16° (003), 18.0° (002), 20.15° (006) and 65.4° (110). The diffraction showed similarity to diffraction in CaAl and hydrochar double layer hydroxyl. The FT-IR spectrum of CaAl/HC also showed similarity to the CaAl/HC double layer hydroxyl at 3448, 1635, and 1381 cm-1. The characteristic spectrum of the hydrochar also appeared in CaAl/HC at 20.15. BET analysis showed an increase in the surface area of CaAl/HC before modification of 11.842 m2/g and increased to 22.635 m2/g of CaAl/HC. The ability of CaAl/HC as an adsorbent is determined through several parameters including selectivity, regeneration, isotherm, and thermodynamics. The results of dye selectivity showed that CaAl/HC was more likely to absorb MR dyes in a mixture of dyes (DG, MO, PR, MR, CR, and DR). The regeneration results showed the ability of CaAl/HC which lasted up to 73.26% in the fifth cycle.

4

Layered Double Hydroxide/Chitosan Composite (Mg-Al/CT) as a Selective Adsorbent in Congo Red Adsorption from Aqueous Solution

Mohadi Risfidian, Siregar Patimah Mega Syah Bahar Nur, Palapa Neza Rahayu, Taher Tarmizi, Lesbani Aldes

Ecological Engineering & Environmental Technology

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2022

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Vol. 23, iss. 2

144--152

EN

Layered double hydroxide (LDH) can be used as an adsorbent to remove pollutants from aqueous solutions, but it drawbacks where the structure is easily damaged so that it cannot be reused in the adsorption process and has a low adsorption capacity. This can be overcome through the development of layered double hydroxide material composited with chitosan support material. In addition to untilizing waste, chitosan is selected as supporting material in the layered double hydroxide modification process, because it is cheap, has high selectivity, and is biodegradable. In this study, the adsorbent was applied in the process of removing Congo Red (CR). The LDH modification process using chitosan was successfully carried out, as seen from XRD analysis which resembled the base material (Mg-Al) and support (CT), the BET analysis which showed an increase in surface area, as well as from the large adsorption capacity value and the regeneration process which tends to be stable after compositing is done.

5

Soft Ion Divalent Metals toward Adsorption on Zn/Al-POM Layered Double Hydroxide

Silaen Luna, Elfita, Mohadi Risfidian, Normah, Juleanti Novie, Palapa Neza Rahayu, Lesbani Aldes

Journal of Ecological Engineering

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2021

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Vol. 22, nr 10

109--120

EN

Development of Zn/Al layered double hydroxide by intercalation using polyoxometalate (POM) K4 [α-SiW12O40] to Zn/Al-POM was investigated. The success of the modification is evidenced by the XRD, FT-IR, and BET characterization data. XRD characterization showed an increase in the interlayer distance from 8.59 Å in Zn/Al LDHs to 10.26 Å in Zn/Al-POM. This success is also supported by the FT-IR data with the appearance of vibrations around 779–979 cm-1 which indicates the vibration of the polyoxometalate compound in Zn/Al-POM. Other supporting data in the form of BET also prove an increase in surface area from 1.968 m2/g in Zn/Al LDHs to 14.042 m2/g Zn/Al-POM. The ability of Zn/Al-POM as an adsorbent is proven through several parameters such as kinetics, isotherm, thermodynamics, and regeneration for Cd2+, Pb2+, Ni2+, and Co2+. Adsorption kinetics showed that Zn/Al-POM was more likely to follow the pseudo-second-order adsorption kinetics model for Cd2+, Pb2+, Ni2+, and Co2+. The results of determining the adsorption isotherm parameters of Zn/Al-POM tend to follow the Freundlich isotherm model with a maximum adsorption capacity of 74.13 mg/g on Pb2+. The regeneration process showed that Zn/Al-POM was more resistant than Zn/Al LDHs up to 3 cycles. It was proven that Zn/Al-POM was able to survive in the last cycle up to 69.19% on Ni2+.

6

High Structural Stability and Adsorption Capacity of Zn/Al-Biochar and Cu/Al-Biochar Toward Adsorption of Cr(VI)

Palapa Neza Rahayu, Taher Tarmizi, Siregar Patimah Mega Syah Bahar Nur, Normah, Juleanti Novie, Wijaya Alfan, Badri Arini Fousty, Lesbani Aldes

Journal of Ecological Engineering

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2021

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Vol. 22, nr 4

213--223

EN

Layered double hydroxide (LDH) Zn/Al and Cu/Al was synthesized by using the coprecipitation method under base condition at pH 10 following with formation of composites based on biochar (BC) to form Zn/Al-BC and Cu/ Al-BC. The materials were characterized by XRD, FTIR, BET, and thermal analyses. Furthermore, materials was applied as adsorbent of Cr(VI) on aqueous solution. The performance of composites as adsorbent was evaluated by reusability of adsorbent toward Cr(VI) adsorption process. The results showed that Cu/Al-BC and Zn/Al-BC can reuse the re-adsorption process with the adsorption ability of more than 60%. The adsorption capacity of Cu/ Al-BC and Zn/Al-BC was higher than that of starting materials and up to 384.615 mg/g for Cu/Al-BC and 666.667 mg/g for Zn/Al-BC. Both composites showed the potential adsorbents to remove Cr(VI) from aqueous solution.

7

Oxalate Intercalated Mg/Cr Layered Double Hydroxide as Adsorbent of Methyl Red and Methyl Orange from Aqueous Solution

Badri Arini Fousty, Juleanti Novie, Palapa Neza Rahayu, Hanifah Yuliza, Mohadi Risfidian, Mardiyanto, Lesbani Aldes

Ecological Engineering & Environmental Technology

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2021

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Vol. 22, iss. 3

71--81

EN

Mg/Cr layered double hydroxide (LDH) has been successfully synthesized by means of the coprecipitation method followed by the intercalation process using oxalate to form Mg/Cr-oxalate. The materials were characterized using XRD, BET, and FTIR and then applied as an adsorbent of anionic dyes i.e. methyl red (MR) and methyl orange (MO). MR and MO adsorption was studied through variations of adsorption time, concentration, temperature, desorption process, and adsorbent regeneration. The XRD characterization results showed an increase in the interlayer distance from 7.62 Å to 11.35 Å after the intercalation process. The increase of interlayer space of Mg/Cr-oxalate is also equal to the BET data, which shows an increase in surface area from 21.511 m2/g to 49.270 m2/g. The kinetics and isotherm parameters of MR and MO adsorption using Mg/Cr LDH and Mg/Cr-oxalate showed the same results following the PFO kinetics model and Langmuir isotherm model with R2 close to one. Mg/Cr LDH has the adsorption capacity for MR and MO up to 61.728 mg/g 54.645 mg/g, respectively. In turn, the highest adsorption capacity is achieved by Mg/Cr-oxalate for MR adsorption at 81.235 mg/g and MO at 71.429 mg/g. The thermodynamic parameters of MR and MO adsorption using Mg/Cr LDH and Mg/Cr-oxalate indicate that the adsorption process is endothermic and spontaneous.

8

Competitive Removal of Cationic Dye Using NiAl-LDH Modified with Hydrochar

Normah, Palapa Neza Rahayu, Taher Tarmizi, Mohadi Risfidian, Arsyad Fitri Suryani, Priambodo Aldi, Lesbani Aldes

Ecological Engineering & Environmental Technology

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2021

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Vol. 22, iss. 4

124--135

EN

In this study, NiAl-LDH was modified with hydrochar using the NiAl-Hydrochar composite coprecipitation method. Materials were characterized by XRD and FT-IR analysis. XRD diffractogram and FT-IR spectra show that the NiAl-Hydrochar composite material has the characteristics of the precursors. NiAl- Hydrochar composite materials have a large adsorption capacity to adsorb cationic dyes. The adsorption follows the Langmuir adsorption isotherm model with the maximum capacity (Qmax) of the NiAl-Hydrochar composite material reaching 256.410 mg/g for malachite green and the adsorption process takes place spontaneously and endothermically. The regeneration process of NiAl-Hydrochar composites was more stable and the decrease was not significant (>70%). The selectivity of the dye mixture showed that the adsorbent was more selective for malachite green dye compared to methylene blue and rhodamine-B.

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Effective Removal of Iron (II) from Aqueous Solution by Adsorption using Zn/Cr Layered Double Hydroxides Intercalated with Keggin Ion

Oktriyanti Melantina, Palapa Neza Rahayu, Mohadi Risfidian, Lesbani Aldes

Journal of Ecological Engineering

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2020

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Vol. 21, nr 5

63--71

EN

Zn/Cr and Zn/Cr layered double hydroxides (LDHs) intercalated with Keggin ion [α-SiW12O40]4-were successfully synthesized at room temperature and pH value of 10. The synthesized materials were characterized by means of the XRD, BET, and FT-IR analyses and used as an adsorbent iron(II). The adsorption process was investigated by studying pH, the kinetics, and thermodynamic properties of the adsorption process. The results showed the interlayer Zn/Cr LDHs was 7.53 Å and increase to 10.26 Å on Zn/Cr LDHs intercalated with Keggin ion [α-SiW12O40]4-. The BET analysis showed that the pore volume of both materials increased from 0.063 cm3 g-1 to 0.163 cm3 g-1. The pH point zero charge measurement for the Zn/Cr LDHs material was 10 while LDHs Zn/Cr intercalated with Keggin ion [α-SiW12O40]4- was 8. Zn/Cr LDHs intercalated with Keggin ion [α-SiW12O40]4- has higher adsorption capacity than Zn/Cr LDHs without intercalation. Desorption of iron (III) was successfully conducted using HCl as reagent showing the involvement of ion exchange in the adsorption.