Vol. 2 No. 3 (2024): November

In order to ensure the availability of pure water free from contaminants, we focused on developing different laboratory-made filters and applying the ready-made nanosilver type Ag1 and the prepared type Ag2 prepared in the laboratory and loading them on the filters. We evaluated their effectiveness in removing and inhibiting bacteria based on the filter type and pore size, and we observed an increase in inhibition efficiency. In addition, we subjected the samples to UV testing within the wavelength range of 200-800, which is the range of nanosilver. We used EDX to confirm the presence of nanosilver in the samples. AFM examination, which shows the surface roughness values, pressure and grain size distribution of the prepared particles, and SEM examination, which shows the particle distribution, shapes and size measurement. To verify the stability of Nano silver and its strong negativity and confirm its size, a Zet test was performed to determine the negativity of the material and the nano size. The resulting water was analyzed with a TDS device to measure the dissolved salts in the water resulting from the different manufactured filters and to evaluate the drinking water and ensure that it is within acceptable levels. Then we used the Atomic Assay (AAS) to measure the percentage of nano silver in the drinking water resulting from the prepared filters and that the silver present does not affect the water because its percentage is very small and the silver loaded on the different filters has a moderate toxicity percentage that does not affect the water.

In this research, zinc nanoparticles were prepared using pulsed laser ablation in liquids. A pulsed Nd+:YAG laser with wavelength (532 nm) was applied to a pure zinc target immersed in deionized water, and the structural and optical properties of the prepared zinc nanoparticles were studied. The behavior of the UV absorption spectra of zinc nanoparticles was studied as a function of pulse number and ablation energy. The UV-vis absorption spectra showed absorption peaks in the ultraviolet region and in the visible region, the latter being responsible for the formation of zinc nanoparticles, and an increase in the intensity of the absorption peaks with increasing number of laser pulses was observed. Scanning electron microscopy results measured after examining drops of zinc nanoparticle solution showed that the nanoparticles were predominantly spherical in shape with nanoparticle sizes ranging from (42.49, 42.42, and 39.31 nm) respectively, and decreasing in size with increasing ablation pulses, with the best results at higher ablation pulses, the formation of zinc nanoparticles was confirmed by infrared spectroscopy, which confirmed the formation of nanoparticles.

This study successfully prepared longan peel hydrochar via hydrothermal carbonization, characterized and evaluated for its adsorption capacity of cationic dyes malachite green (MG) and rhodamine B (RhB) in aqueous solution. Material characterization through XRD analysis revealed diffraction peaks indicative of carbonaceous content, supported by FTIR results showing OH, C-O, and C-O-C functional groups. The BET analysis showed a surface area of 18.712 m²/g, and SEM images displayed a heterogeneous, irregular surface morphology with spherical particles. The longan peel hydrochar exhibited adsorption capacities of 117.647 mg/g for MG and 50.505 mg/g for RhB, with MG showing greater selectivity, as demonstrated through dye mixture adsorption tests. The adsorption process was spontaneous, endothermic, and conformed to the pseudo-second-order kinetic model. Adsorption of MG followed the Freundlich isotherm, while RhB adsorption conformed to the Langmuir isotherm. Additionally, the hydrochar exhibited reusability for up to two adsorption cycles, indicating its potential as an effective adsorbent for cationic dye removal from aqueous solutions.

This study investigates the adsorption characteristics of phenol on rice husk biochar (BC) and microcrystalline cellulose (MC), with a focus on their structural, kinetic, isotherm, and thermodynamic properties. XRD and FTIR analyses reveal that BC and MC possess similar carbon-based structures. Nitrogen adsorption-desorption isotherms highlight BC’s higher surface area and pore volume, which likely contribute to its superior adsorption performance. Adsorption kinetics are best described by the PSO model, indicating chemisorption as the rate-limiting step. Isotherm studies show that the Langmuir model provides a better fit, suggesting monolayer adsorption on homogeneous surfaces. Thermodynamic parameters indicate that phenol adsorption onto BC is endothermic and spontaneous, with adsorption capacity increasing with temperature, while MC shows minimal temperature sensitivity. The adsorption capacity of phenol using BC and MC was obtained as 28.50 mg/g and 13.25 mg/g, respectively. The reusability tests reveal that BC retains significant adsorption capacity over multiple cycles compared to MC. Overall, BC is identified as a more efficient and reusable adsorbent for phenol removal in aqueous solutions.

This study investigates the effectiveness of ZnAl-LDH modified with polyoxometalate (POM) as an adsorbent material in the competitive adsorption of heavy metal ions Cr(VI) and Fe(II). The material was synthesized using the co-precipitation method, resulting in ZnAl-LDH@POM with enhanced interlayer spacing, a specific surface area 14 times more significant, and increased surface-active sites. Characterization using XRD, FT-IR, and BET confirmed the successful structural modification and improved adsorption properties. Kinetic studies revealed that adsorption followed a pseudo-second order kinetic model, achieving maximum efficiency within 50 minutes. Isothermal analysis demonstrated maximum adsorption capacities (???????????????? ) of 92.95 mg/g for Fe(II) and 44.44 mg/g for Cr(VI). These findings highlight the potential of ZnAl-LDH@POM as an effective adsorbent for treating heavy metal-contaminated wastewater.