Sorption Studies

Hydraulics and Dynamics of Backwash in Filtration with Activated Carbon to Reduce Iron and Manganese in Groundwater

Nur Iswanto — 2025-06-18

Well water used by the community often does not meet quality standards because it contains high levels of iron (Fe) and manganese (Mn). This study was intended to reduce Fe and Mn levels in well water by using filtration technique with activated charcoal media. The effect of hydraulics and backwash dynamics on the efficiency of filtration process was also investigated. The filtration apparatus was made of PVC pipe with the diameter of 4 inches and 120 cm height. The determination of optimum hydraulic conditions of filtration was carried out by varying the size of the activated carbon filter media (8-10, 12-14, and 16-18 mesh) and flow rate (1, 2, and 3 L/min) at the service time of 10 hours. The results showed that the size of filter media has significant effect on removal efficiency of Fe and Mn, with the most effective size was 16-18 mesh with the removal efficiency of 83.33% (Fe) and 93.33% (Mn). The highest head loss value in the filtration column was 0.15 cm, which occurred at the flow rate 3 L/min. Backwash should be performed after filtering process of 35 hours, 44 hours and 55 hours at the flow rate 1 L/min, 2 L/min, and 3 L/min repectively. The single filter design in this study reduced Fe and Mn concentration to meet clean water quality standards.

Kinetic Study of Mg(II) Adsorption on Activated Coal Bottom Ash

Dwi Putra Wijaya — 2025-06-30

The research of sadsorption of Mg(II) ions on coal bottom ash as adsorbent has been carried out. The research was conducted by activating the coal bottom ash using concentrated HCl. Characterization of activated coal bottom ash was done by using Fourier Transform Infra-Red (FTIR) spectroscopy and X-Ray Difraction (XRD) analysis. Parameters of metal adsorption examined in this study include the effect of pH, mass of adsorbent, and interaction time. The concentration of each metal ion remaining in the solution after adsorption and desorption was determined using atomic absorption spectrophotometer. The result showed that activated coal bottom ash has been carried out. The optimum conditions for Mg(II) adsorption using 0.3 g coal bottom ash are at pH 5 with 60 minute contact. The Adsorption kinetics follow Ho model pseudo-second order with the rate constant 0.6182 and 0.998 correlation coefficient. These results highlight the potential of activated coal bottom ash as a low-cost, effective adsorbent for water treatment applications.

Adsorption Ni(II) on Magnetic Fulvic Acid-Chitosan: Kinetics and Isotherm Study

Raihansyah Raja Hutama — 2025-06-30

Indonesia, as one of the most populous countries in the world, requires clean water sources. Industrial waste that is improperly discharged pollutes water bodies with hazardous metals. Adsorption is one of the effective methods for reducing the concentration of harmful metals in water. This study utilized fulvic acid extracted from goat manure compost and combined it with chitosan and magnetite as an adsorbent material for Ni(II). The FTIR results for the magnetite-fulvic acid-chitosan composite showed a peak at 1627 cm⁻¹, indicating the presence of aromatic C=C, aromatic ring -OH, and quinone C=O groups, which confirm the binding of fulvic acid. BET analysis was performed on magnetite and magnetite-fulvic acid-chitosan, and the pore volume and pore size were found to be 0.177488 cm³/g and 6.5394 nm, respectively. The composite exhibited magnetic behavior due to the attraction between the magnetite-fulvic acid-chitosan and an external magnet. Adsorption tests using isotherm and kinetic models revealed that Ni(II) adsorption followed a multilayer mechanism and pseudo-second-order kinetics, with a b value of 121.68 mg/g and an experimental qe of 6.28 × 10⁻⁵ mol/g. This shows that the magnetite-fulvic acid-chitosan composite is a promising, sustainable, and magnetically separable adsorbent for the effective removal of nickel ions from contaminated water.

Radar Absorber Composite Graphene Oxide/Magnetite/Zinc Oxide in Polypyrole Matrix

Allodya Nadra Xaviera — 2025-06-30

The development of stealth technology in modern defense systems demands superior radar absorbing material (RAM) innovation. This study aims to synthesize and characterize Fe₃O₄/ZnO modified carbon-based RAM composites in a polypyrrole (PPy) matrix using graphite oxide (GiO). The composites were synthesized via a modified Hummer method as well as a one-pot technique, and characterized using FTIR, XRD, SEM-EDX, and VNA. The FTIR characterization results showed that the C=C peak decreased in intensity after the oxidation process, indicating the breaking of the aromatic double bond and the formation of new functional groups such as C–O and C=O. This change was detected in both pGiO and kGiO samples. XRD data showed a shift in the main peaks to 2θ = 11.25° and 42.20° for pGiO and 2θ = 11.56° and 42.40° for GiO-k, respectively. This shift indicates the formation of a more amorphous graphite oxide structure compared to the original graphite.The results show that GiO/Fe₃O₄/ZnO has the highest reflection loss value of -9.20 dB at 10.91 GHz (GiO-p/Fe₃O₄/ZnO 66%-PPy) with an absorption value of 88.03% and rGO/Fe₃O₄/ZnO/PPy the highest RL value reached -7.51 dB at 11.57 GHz (rGO-k/Fe₃O₄/ZnO 66%-PPy) with an absorption value of 82.21%. This research proves that Fe₃O₄/ZnO modified carbon-based composites in a polypyrrole matrix have high potential as an efficient radar absorbing material and can support the needs of domestic defense technology.

Synthesis of Magnetite/Chitin/Fulvic Acid Derived from Goat Manure Compost and Adsorption Study of Zn(II) for Water Security Enhancement

Audrey Nur Aisyah — 2025-06-30

Water pollution due to heavy metals such as Zn(II) poses a risk to the environment and health. This study aims to synthesize Magnetite/Chitin/Fulvic Acid (AF)-based composite adsorbent from goat feces compost and evaluate its effectiveness in adsorbing Zn(II) ions. Fulvic acid was extracted through alkaline-acid method and synthesized together with chitin and magnetite using one pot coprecipitation method. Characterization using FTIR, XRD, and BET showed successful synthesis with mesoporous structure for BET (average pore size 6.15 nm, surface area 41.77 m²/g). Isotherm studies showed that the adsorption of Zn(II) showed a good fit with the Freundlich (R² = 0.9967) and Temkin (R² = 0.9968) models, indicating multilayer adsorption on the heterogeneous surface. The composite also shows good adsorption ability and can be magnetically separated, making it an environmentally friendly and efficient potential adsorbent for wastewater treatment applications.