The study’s aim was to develop a novel sorbent for removing the color Congo red (CR) from water by precipitating (Mg/Al)-layered double hydroxide (LDH) at the nanoscale onto the waterworks sludge surface as a byproduct. To achieve an effective sorbent with the removal of over 91.19%, The utilization of nanoparticles, the addition of 1 g of sludge to 50 mL of water, and a molar ratio of 2 (Mg/Al) were the optimal production conditions for sorbent. In batch experiments, the optimal operating parameters were found to be 0.5 g of adsorbent in 50 mL of CR, pH of CR solution equal to 3, and a contact time of 3 hours at 200 rpm with 25 mg/L dyes. According to the study, the adsorption capacity was 23.576 mg/g. Additionally, the pseudo-second-order and Langmuir models provided accurate descriptions of the sorption data.
The possibilities of using a natural sorbent – peat for the wastewater treatment of ammonium ions and phosphates discharged from runoff into natural reservoirs at high concentrations were investigated. The peat of from the Vereshchytsya-Yanovske deposit of Ukraine of two depths: lowland and upland, was studied. It was established that the lowland samples of peat have higher sorption properties to the investigated pollutants from the aquatic environment than the upland ones. A greater moisture loss in the lowland peat species was observed, as well as the major part of the plant fibers in its structure, which explains its sorption properties. Due to the high content of humic substances, the extraction of cations from the water by peat can occur due to the ion exchange. The adsorption isotherms of both ammonium and phosphate ions on the top and lowland peat species of the Vereshchytsya-Yanovske deposit were constructed and presented. The adsorption isotherm obtained in the experimental studies was used to mathematically establish the isotherm equation, using the Langmuir and Freundlich models to describe the equilibrium of the sorption processes under study. The degree of appropriation of linear equations to the experimental data was evaluated on the basis of the deterministic coefficient, which enabled to determine that in each case the Langmuir equations describe the adsorption isotherms more adequately.
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Removal of phenol (Phen) andp-nitrophenol (p-NPhen) from aqueous solutions onto sodium modified (ZG-Na) and surface modified (ZG-HDTMA) natural zeolite has been investigated. X-ray diffraction (XRD) and scanning electron microscopy (SEM) technique characterizations show that clinoptilolite is the major phase in zeolitic rock. Batch system was considered to determine the kinetics and isotherm type of the adsorption of NOJ by the ZG-Na and ZG-HDTMA. Results suggest a better fit to the adsorption data than the pseudo-first order kinetic model. It seems that the Langmuir model best describes the experimental data. p-NPhen is selectively adsorbed by both ZG-HDTMA and ZG-Na.
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Removal of cationic dyes, rhodamine B and methylene blue, from aqueous solutions by unmodified beech sawdust was investigated. The adsorption kinetics and equilibrium data were fitted by various models. The pseudosecond order kinetics and the Langmuir model described biosorption data reasonably well. The maximum adsorption capacity was 70.40 mg.dm.3 and 52.66 mg.dm.3 for rhodamine B and methylene blue, respectively. The study shows that beech sawdust has the potential off application as an efficient sorbent for removal of cationic dyes.
PL
Sprawdzono skuteczność zastosowania niemodyfikowanych trocin bukowych do usuwania barwników kationowych . rodaminy B i błękitu metylenowego - z roztworów wodnych. Kinetykę i równowagę biosorpcji opisano za pomocą różnych modeli. Najlepszy opis procesu uzyskano, stosując model pseudodrugorzędowy oraz izotermę Langmuira. Pojemność sorpcyjna trocin względem rodaminy i błękitu metylenowego wynosiła odpowiednio 70,40 i 52,66 mg.dm.3. Trociny bukowe okazały się efektywnym sorbentem w usuwaniu barwników kationowych z roztworów wodnych.
Sorption of Methylene Blue (MB) and Malachite Green (MG) dyes onto barks and leaves of four trees was examined with a batch method. The obtained sorption isotherms are well described by the Langmuir equation. The examined barks proved to have quite different sorption capacities. The highest values were recorded for the walnut tree bark (512 and 307 mg/g towards the MB and MG dyes, respectively) and the lowest capacities were observed for the birch tree bark (68 and 22 mg/g towards the MB and MG dyes, respectively). The studied leaves proved to have rather similar sorption capacities, i.e., from 210 to 286 mg/g for the MB dye and from 152 to 189 mg/g for the MG dye. The specific surface values calculated from the MB monolayer capacity are substantially higher than those obtained by the BET method, probably because of swelling of the test materials in an aqueous medium.
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