Zeolite Clinoptilolite Research Articles

Hydrogel nanocomposite based on alginate/zeolite for burn wound healing: In vitro and in vivo study.

The main objective of the current assay was to evaluate the antibacterial and regenerative effects of hydrogel nanocomposite containing pure natural zeolite (clinoptilolite) integrated with alginate (Alg) as wound healing/dressing biomaterials. The zeolites were size excluded, characterized by SEM, DLS, XRD, FTIR, and XRF, and then integrated into Alg hydrogel followed by calcium chloride crosslinking. The Alg and alginate zeolite (Alg/Zeo) hydrogel was characterized by swelling and weight loss tests, also the antibacterial, hemocompatibility, and cell viability tests were performed. In animal studies, the burn wound was induced on the back of rats and treated with the following groups: control, Alg hydrogel, and Alg/Zeo hydrogel. The results showed that the hydrodynamic diameter of zeolites was 367 ± 0.2 nm. Zeolites did not show any significant antibacterial effect, however, the hydrogel nanocomposite containing zeolite had proper swelling as well as hemocompatibility and no cytotoxicity was observed. Following the creation of a third-degree burn wound on the back of rats, the results indicated that the Alg hydrogel and Alg/Zeo nanocomposite accelerated the wound healing process compared with the control group. Re-epithelialization, granulation tissue thickness, collagenization, inflammatory cell recruitment, and angiogenesis level were not significantly different between Alg and Alg/Zeo nanocomposite. These findings revealed that although the incorporation of zeolites did not induce a significant beneficial effect in comparison with Alg hydrogel, using zeolite capacity in hydrogel for loading the antibiotics or other effective compounds can be considered a promising wound dressing.

Application of natural zeolite clinoptilolite for the removal of ammonia in wastewater

This work intends the characterization of the natural zeolite clinoptilolite and its capability in removing the ammonia in wastewater. The natural zeolite clinoptilolite was characterized using transmittance electron microscopy (TEM), X-ray diffraction (XRD), Fourier-transform infrared (FTIR) spectroscopy, X-ray fluorescence (XRF) and zeta potential prior to the adsorption process. The results showed that the natural zeolite clinoptilolite possessed the lamellar and needle-like structure thus giving the highest surface area for effective adsorption. The main constituent of the element consisted of natural zeolite clinoptilolite is known to have a high affinity towards ammonia. Additionally, the zeta potential analysis has shown that natural zeolite clinoptilolite is negatively charged in all media pH with the highest negative potential of −30 mV recorded at pH 7 thus, contributing to the highly effective electrostatic interaction with the contaminants’ cations. Consequently, the excellent performance in removing ammonia of up to 82.97 % has revealed that the natural zeolite clinoptilolite has a great potential to be developed as a synergized adsorptive ceramic membrane that is combining the adsorption and the filtration of water simultaneously.

Effect of sulfur dioxide on adsorption capacity of zeolite sorbents for carbon dioxide

The article discusses a rather serious problem limit-ing the use of adsorption for the CO2 capture from flue gas, in the presence of sulfur dioxide. An apparatus with a vertical batch adsorber was constructed to study adsorption under elevated pressure in a wide range of temperatures and evaluation of CO2 breakthrough curves with an infrared analyzer. The article summarizes the results of experiments conducted with zeolite clinoptilolite, which represented natural materials, and molecular sieve 13X as a representative of synthetic sorbents. Adsorption capacities achieved during cyclically repeated tests with a model gaseous mixture free of SO2 and a mixture of the same composition but enriched with a low volume fraction of SO2 (0.3 %) were compared. Adsorption took place at a temperature of 20 °C and at two overpressures (200 and 500 kPa) of the gas with a 13 % volume fraction of CO2. Each sub-experiment consisted of five adsorption and desorption cycles, where desorption was based on depressurization followed by temperature increase to 120 °C under nitrogen atmosphere. There were no changes in capacities when tested with the gaseous mixture without SO2. Relative to the weight of the sample, the 13X sample at an overpressure of 500 kPa had a capacity of 11.3 % and clinoptilolite 3.8 %. Tests in the presence of SO2 led to a permanent reduction of the equilibrium capacities for both samples and at both pressures. At the overpressure of 500 kPa, the capacity decreased to 7.4 % for the 13X and to 2.5 % for the clinoptilolite. A more intensive desorption involving a thermal and vacuum step did not lead to any improvement for the 13X sample. In contrast, the effect for clinoptilolite was very positive. Its capacity in the fifth cycle reached 3.4 % close to the state without SO2 exposition. In the case when SO2 in the gas was accompanied with 40 % relative humidity, vacuum desorption did not lead to positive results in any case. After five cycles, the capacity of 13X dropped to 3.2 % and clinoptilolite to 1.4 %. When moisture, SO2 and the presence of O2 (volume fraction of 6 %) in the model mixture were further combined, the capacity of 13X decreased to 1.4 % and clinoptilolite to 0.4 % after five cycles. Tests with SO2 (dry gas) caused a decrease in the specific surface area from 512 to 211 m2.g‒1 for the 13X sample. On the other hand, for clinoptilolite it decreased from only 29 to 28 m2.g‒1 under the same conditions. Ac-cording to XRF, it was not possible to remove sorbed SO2 from the 13X sample even by evacuation followed by heating up to 200 °C. Using the XRD method, it was found that SO2 remains in the matrix, although it does not undergo transition to the crystalline phase. The study verified that synthetic molecular sieve 13X, unlike natural clinoptilolite, is not applicable for CO2 adsorption from SO2 containing flue gas.

Evaluation of high‐performance adsorbents for separation of CO2 from industrial effluent gases

AbstractThe aim of this work is the investigation of several CO2 adsorbents such as three synthetic zeolites (4A, 5A, and 13X), a natural zeolite (clinoptilolite), an activated carbon (AC), and a metal organic framework (MOF‐MIL‐53) for the postcombustion CO2 capture via temperature‐pressure swing adsorption. The adsorbents were evaluated in terms of the CO2 adsorption capacity and performance during successive adsorption–desorption cycles at different conditions (1–6 bar and 120–180°C) using different mixtures of gases simulating a combustion process stream (N2/CO2/O2/CO). The 13X zeolite showed excellent adsorption capacity of 4.3 mmolCO2/g zeolite and very stable performance during successive cycles. © 2022 Society of Chemical Industry and John Wiley & Sons, Ltd.

Adsorptive Desulfurization of Crude Oil with Clinoptilolite Zeolite

Crude oil; is a fossil fuel containing carbon, hydrogen, sulfur and many other components and is one of the world's largest and most widely used energy sources. However, in order for crude oil to be used as an energy source, it must be refined. With the use of petroleum products obtained as a result of refining, very high amounts of SOx gas are released into the atmosphere. These gases seriously harm both the environment and human health. This study aimed to reduce the amount of sulfur in crude oil and reduce its possible damages by using clinoptilolite zeolite (CZ). For this purpose, first of all, CZ; was characterized by SEM and XRF. Then, 0.1 g, 0.5 g, 1 g, 2 g and 5 g of the characterized CZ were weighed and added to the 50 mL crude oil samples separately. The mixture was mixed with a magnetic stirrer at 400 rpm for 60 and 120 minutes at room temperature before going through with an adsorptive desulfurization step. Afterwards, it was separated from the adsorbent by centrifugation and the residual sulfur amount was determined by ASTM D 1552-03 method. As a result of this study, which was carried out in an experimental laboratory environment; it has been observed that the desulfurization efficiency varies between 0.75 and 5.76 % (w/v) with the use of CZ adsorbent. Moreover; it was determined that the highest sulfur removal was obtained by using 5 g CZ.

Adsorption of Methylene Blue and Tetracycline by Zeolites Immobilized on a PBAT Electrospun Membrane

The detection of emerging contaminants in bodies of water has steadily increased in recent years, becoming a severe problem threatening human and ecosystem health. Developing new materials with adsorption properties to remove these pollutants represents an important step toward a potential solution. In this paper, a polybutylene adipate terephthalate (PBAT) nanofibrous membrane incorporating clinoptilolite zeolite was developed and its excellent performance in removing tetracycline (TC) and methylene blue (MB) from water was demonstrated. The composite membrane was prepared in two steps: firstly, a homogeneous dispersion of clinoptilolite (1 wt% respect to polymer) in a PBAT solution (12.6 wt%) was electrospun; secondly, the electrospun membrane was subjected to an acid treatment that improved its wettability through the protonation of the surface silanol groups of clinoptilolite. The resulting membrane was hydrophilic and showed higher adsorption for TC (800 mg/g) and MB (100 mg/g), using a low dose (90 mg/L) powdered zeolite. The maximum removal capacity was obtained at neutral pH, being the cation exchange reaction the main adsorption mechanism. Pseudo-second-order kinetics and Henry's law agree well with the proposed chemisorption and the high affinity of TC and MB for the adsorbent. The material can be reused after the removal process without generating additional contamination, although losing some effectivity.

Reduction of CO2 emission through a photocatalytic process using powder and coated zeolite-supported TiO2 under concentrated sunlight irradiation.

The efficiency of a novel synthetic zeolite (Ze) prepared from stone cutting sludge and a natural zeolite (clinoptilolite, Cp) as the support of TiO2 photocatalyst was examined for the CO2 removal under solar irradiation using a designed parabolic trough collector (PTC). The used samples were characterized using XRF, BET, SEM/EDS, and XPS analyses. The enhanced sunlight irradiation obtained by PTC increased the performance of CO2 photocatalytic removal. The maximum CO2 adsorption by TiO2-Ze and TiO2-Cp composites was 21.1% and 28.4% which increased to 61.8% and 78.9% under sunlight irradiation, respectively. The efficiency of zeolite-TiO2 composites for CO2 removal was approximately two times higher than zeolites and TiO2 alone. The performance of TiO2-Ze-coated composite with lower use of photocatalyst for CO2 adsorption and photocatalytic removal was better than that of powder one. Regeneration of TiO2-Ze using NaOH solution improved its removal efficiency. The adsorption behavior of CO2 on TiO2-Ze composite was well described by the Langmuir isotherm and the pseudo-first-order kinetic model. This work promises CO2 reduction using natural and synthetic zeolite as an efficient photocatalyst support under solar irradiation.

Utilisation of waste Cu-, Mn- and Fe-loaded zeolites generated after wastewater treatment as catalysts for air treatment.

Disposal of copper, manganese and iron is particularly problematic in wastewater of metallurgical and galvanization plants, the electronics industry and agriculture. On the other hand, volatile organic compounds (VOCs), emitted from industrial processes, transportation and consumer products are the main class of air pollutants. The study revealed the potential of waste metal-loaded zeolite, generated through wastewater treatment procedures, to be utilised as an effective VOC removal catalyst for air treatment. In the first step, we have evaluated the sorption performance of natural zeolite clinoptilolite (HEU type), and synthetic zeolite 4A (LTA type) for the simultaneous removal of Cu2+, Mn2+ and Fe3+ species from aqueous solution. By a detailed sorption study, we determined the optimum sorption conditions and maximum metal concentrations in wastewater that can be after treatment disposed of in rivers or municipal plants. The efficiency of both zeolites for metal immobilization was demonstrated for concentrations up to 5mg metals/1g zeolite. These waste Cu-, Mn- and Fe-loaded zeolites were thermally treated at 540°C before the second step, where we evaluated their catalytic performance in removing VOC. The thermally treated waste Cu-, Mn- and Fe-loaded natural zeolite clinoptilolite showed good catalytic performance in total toluene oxidation as a model VOC (conversion rate up to 96% at 510°C) and cycling stability (less than 15% drop in conversion rate in 4h). In contrast, this is not the case for thermally treated waste Cu-, Mn- and Fe-loaded synthetic zeolite 4A.

Sodium aluminate activated geopolymers based on natural zeolite clinoptilolite

Geopolymers based on natural zeolite clinoptilolite were activated with different concentration of sodium aluminate and potassium hydroxide and the influence on compressive strength, density and water absorption were evaluated. The microstructure was analyzed by XRD, FTIR and SEM. The obtained geopolymers are comprised of newly formed zeolite phases – phillipsite, zeolite A.

Power generation by means of a prototype microcell using bioethanol as fuel and clinoptilolite-type zeolite

Currently, technological alternatives are being sought for the substitution of fossil fuels for different reasons.One of the most relevant is the protection of the environment, to have an improvement in this aspect, the generation of energy through clean sources is sought. The PEMFC (Proton Exchange Membrane Fuel Cell) type fuel cells are an excellent alternative for the generation of clean energy because the residues of the fuel cell are mainly water and heat. In the present work, clinoptilolite zeolite was used to produce clean energy by a fuel cell using bioethanol as fuel. Zeolite showed promising results when used in combination with carbon and hydrogel as a solid electrolyte. The material was characterized by scanning electron microscopy and x-ray electron microscopy. The result showed a maximum power of 0.00589241 mW in a surface of 900 mm2 , which is considered a positive result. The catalyst is functional to produce energy by an electrooxidation reaction using bioethanol in a fuel cell at a low cost compared to traditionally platinum-based catalysts.

Conversion of Nyamplung Oil into Green Diesel through Catalytic Deoxygenation using NiAg/ZH Catalyst

Nyamplung oil (Calophyllum inophyllum L) can be converted into green diesel by the catalytic deoxygenation method. Bimetallic catalyst NiAg supported by hierarchical natural zeolite (NiAg/ZH) can be used in this method. This study aims to determine the characteristics of the NiAg/ZH catalyst and the optimal conditions for the catalytic deoxygenation of nyamplung oil into green diesel. The NiAg/ZH catalyst was synthesized by wet impregnation with a total metal concentration of 10% and a mass ratio of Ni/Ag of 4. X-Ray Diffraction, Surface Area Analyzer and NH3-TPD characterized the catalyst. Catalytic deoxygenation of Nyamplung oil was carried out by varying the temperature (325, 350 and 375 °C) and reaction time (1, 2 and 3 hours) with a catalyst dosage of 5%. The composition of the product was analyzed using Gas Chromatography-Mass Spectroscopy. The catalyst XRD spectrum showed a peak at 2θ = 22.38° (clinoptilolite zeolite), 44.42° (Ni) and 38.21° (Ag). The surface area of the catalyst is 46.7024 m2/g, the pore volume is 0.0813 cc/g, the average pore diameter is 6.9632 nm, and the deposit is 1.6882 mmol/g. The optimum catalytic deoxygenation of nyamplung oil was obtained at 350 °C and 3 hours with a gasoline selectivity of 3.51%, kerosene 4.73%, and 62.02% green diesel.

Synthesis, characterization and optimization of PVA/SA hydrogel functionalized with zeolite (clinoptilolite): Efficient and rapid color removal from complex textile effluents

This study aims to determine the synthesis of zeolite-based hydrogel composites and their decolorization potential by adsorption method from real textile wastewater containing dye mixture. Initial bridging was used to create the cross-linked hydrogel with polyvinyl alcohol (PVA) and sodium alginate (SA), and then natural zeolite (clinoptilolite) particles were uniformly distributed throughout the polymer matrix. Investigations were also conducted into the impacts of adsorption correlation parameters such as pH, adsorbent concentration, reaction time, temperature, zeolite (%) content and drying time (particle size) by using the Response Surface Methodology. SEM and FTIR techniques were used to analyze changes in the parental hydrogel polymer's property profile following the addition of zeolite. It was found that the adsorption process applied for color removal with Zeolite/PVA/SA hydrogel composite was a chemical process that could achieve 86% optimum color removal and 166 Pt–Co/g adsorption capacity, respectively. Adsorption kinetics was most effectively explained using a pseudo-second-order model, and the adsorption isotherm followed the Langmuir model with a 559.47 mg/g adsorption capacity. Intraparticle and liquid film diffusion mechanisms worked together to control the diffusion of dye molecules into the ZDH's internal structure. In addition, when the change in the performance of ZDHs after it was activated and applied five times was examined, it was determined that the activation did not have a significant effect on the reusability of the ZDH particles. When the same particles were subjected to color adsorption in wastewater five times in a row, the adsorption efficiency of ZDHs decreased significantly after the third application. It was also demonstrated that the ZDH particles did not desorb color in three consecutive cycles without the need for any activation. This study also revealed that zeolite doped hydrogel particles could be used as an alternative, environmentally friendly, low-cost adsorbents for color removal from industrial wastewater containing dyestuffs like those in the textile industry.

Shaped natural and synthetic zeolites for CO2 capture in a wide temperature range

The CO2 adsorption performances of a Linde-Type A (LTA) zeolite and a natural Clinoptilolite (Clino) zeolite, both in shaped form, were investigated as such or after an ion-exchange procedure and compared to assess their potential application as solid adsorbents for Carbon Capture and Storage (CCS). The samples were characterized following a multi-technique approach. Their structural and textural properties were evaluated to investigate the accessibility of the different ions present inside the microporous structure and the strength of their interaction with the adsorbates. The CO2 adsorption tests were carried out performing pure CO2 adsorption/desorption isotherms and dynamic breakthrough measurements in a wide range of temperature (298–423 K). The ion-exchange enhanced the adsorption capacity of the synthetic zeolite, while no significant increment in the CO2 adsorption performances is observed for the natural one. Nonetheless, the CO2 adsorption reversibility is affected by the cation exchange process in both synthetic and natural zeolites. The CO2 adsorption capacities of LTA zeolites are higher at lower temperatures, whereas the CO2 adsorption performances of natural Clino are interesting also at medium-high temperature, being the most performant material at 423 K. By performing IR experiments with specific probe molecules, the presence of a consistent number of Fe2+ ions in the framework of natural Clino, responsible for the capacity of this material to strongly interact with CO2 also at medium-high temperatures, was proved. The peculiar adsorption behavior of natural Clino, its low cost and availability in shaped form are some of the essential features for its possible implementation in real CCS technologies.

Natural Zeolite Clinoptilolite Application in Wastewater Treatment: Methylene Blue, Zinc and Cadmium Abatement Tests and Kinetic Studies.

In recent decades, several abatement techniques have been proposed for organic dyes and metal cations. In this scenario, adsorption is the most known and studied. Clinoptilolite was considered, since it is a zeolite with a relatively low cost (200-600 $ tons-1) compared to the most well-known adsorbent used in wastewater treatment. In this work, Clinoptilolite was used for the adsorption of Methylene Blue (MB) at three different concentrations, namely, 100, 200, and 250 ppm. Furthermore, the adsorption capacity of the natural zeolite was compared with that of Activated Charcoal (250 ppm of MB). The two adsorbents were characterized by complementary techniques, such as N2 physisorption at -196 °C, X-ray diffraction, and field emission scanning electron microscopy. During the adsorption tests, Clinoptilolite exhibited the best adsorption capacities at 100 ppm: the abatement reached 98% (t = 15 min). Both Clinoptilolite and Activated Charcoal, at 250 ppm, exhibited the same adsorption capacities, namely, 96%. Finally, at 250 ppm MB, the adsorption capacity of Clinoptilolite was analyzed with the copresence of Zn2+ and Cd2+ (10 ppm), and the adsorption capacities were compared with those of Activated Charcoal. The results showed that both adsorbents achieved 100% MB abatement (t = 40 min). However, cation adsorption reached a plateau after 120 min (Zn2+ = 86% and 57%; Cd2+ = 53% and 50%, for Activated Charcoal and Clinoptilolite, respectively) due to the preferential adsorption of MB molecules. Furthermore, kinetic studies were performed to fully investigate the adsorption mechanism. It was evidenced that the pseudo-second-order kinetic model is effective in describing the adsorption mechanism of both adsorbents, highlighting the chemical interaction between the adsorbent and adsorbate.

Improving Nitrogen Availability and Ananas comosus L. Merr var. Moris Productivity in a Tropical Peat Soil Using Clinoptilolite Zeolite

Pineapple cultivation in nitrogen deficient and acidic peat soils leads to poor growth, yield, and fruit quality of pineapples. A study was conducted to determine whether clinoptilolite zeolite (CZ) could improve soil nitrogen availability, growth, yield, and fruit quality of pineapples grown in drained peat soils. Laboratory leaching experiments were conducted to determine the effectiveness of CZ in controlling nitrogen loss from peat soils, whereas an ion-exchange resin method was used to determine nitrogen availability in pineapple cultivation. Treatments evaluated were: (i) different amounts of CZ (25, 50, 70, and 100%) + NPK fertilizer, (ii) NPK fertilizer, and (iii) peat soil only. The peat soils with CZ reduced ammonium and nitrate losses because of the sorption of ammonium within the lattices of the CZ via ion exchange. Co-application of CZ (25%) and NPK fertilizers was more effective in increasing soil ammonium availability, whereas the use of CZ (25% to 100%) improved nitrogen uptake and use efficiency, growth, yield, and fruit quality of pineapple because CZ could regulate the availability of nitrogen ions for pineapple uptake. The buffering capacity of CZ increased soil pH and facilitated organic nitrogen mineralization. The co-application of CZ and NPK fertilizers can be used to improve nitrogen availability and pineapple productivity in tropical peat soils.

Retraction Note: Optimization of dyes and toxic metals removal from environmental water samples by clinoptilolite zeolite using response surface methodology approach

Retraction Note: Optimization of dyes and toxic metals removal from environmental water samples by clinoptilolite zeolite using response surface methodology approach

Synthesis of porous magnetic zeolite-based material and its performance on removal of Cd2+ ion and methylene blue from aqueous solution

In this study, the natural clinoptilolite zeolite was hydrothermally treated and then combined with porous silica-coated magnetic particles to prepare a porous magnetic zeolite-based material. Process parameters such as NaOH concentration, hydrothermal temperature and time, pH value, and Fe3O4/Na2SiO3 ratio were optimized. XRD, XPS, N2 adsorption-desorption technique, SEM-EDX, TEM, FTIR, etc. were employed to investigate the composition and structure of the materials. Cd2+ ion and methylene blue were adopted to evaluate the contamination removal performance of the materials. The results showed that hydrothermal treatment under an alkaline environment could transform clinoptilolite to Na–P zeolite with a low Si/Al ratio and relatively high Cd2+ adsorption capacity. Porous silica-coated magnetite loading could significantly increase the specific surface area of the material and render it magnetic. The as-prepared porous magnetic zeolite-based material exhibited much higher Cd2+ ion and methylene blue removal performance than the raw natural clinoptilolite zeolite.

PSII-B-20 Altering the Particle Size of Supplemental Zeolite (Clinoptilolite) in Finishing Cattle Diets: Manure Characteristics and Ammonia Emissions

Abstract A potential strategy to limit ammonia (NH3) emissions from feedlots is the feeding of supplemental clinoptilolite (CLN), which has a high affinity for ammonium (NH4+). The particle size of CLN could influence its efficacy in binding NH4+ in the rumen and manure. Therefore, our objective was to determine the effects of feeding CLN (2% of diet DM) of two different particle sizes (30 and 40 µm) on manure N profile and NH3 emissions. Six beef heifers were used in a replicated 3 × 3 Latin square design with 21 d periods. Dietary treatments were: 1) finishing ration with no supplement (CON), 2) CON + 30-µm CLN (CL-30), and 3) CON + 40-µm CLN (CL-40). Grab fecal and spot urine samples were collected (d 19 to 21) for analysis. To determine NH3 emissions, six rectangular vented, non-steady state, closed chambers interfaced with a Fourier Transform Infrared Spectroscopy analyzer were used. Soil was added to chambers to a depth of 10 cm before addition of manure and incubated over a 7-d period. Data were analyzed using SAS. There was no diet effect (P ≥ 0.78) on urinary total nitrogen (N) and urea-N concentrations. However, urinary NH3-N concentration, which was less (P = 0.03) for CON than CL-40 heifers did not differ between CON and CL-30 heifers. Fecal N concentration, which tended to greater (P = 0.07) for CL-30 than CL-40 heifers did not differ between CON and CL-40 heifers. However, there was no diet effect (P = 0.25) on fecal NH3-N concentration. Ammonia emissions, which were less (P = 0.02) for manure from CL-40 than CL-30 heifers, did not differ between CON and CL-30 heifers during the first 48 h of incubation. In summary, feeding CL with different particle sizes resulted in changes in the manure N profile and NH3 emissions.

Efficient removal of non-steroidal anti-inflammatory ibuprofen by polypyrrole-functionalized magnetic zeolite from aqueous solution: kinetic, equilibrium, and thermodynamic studies

ABSTRACT This study investigated the adsorption performance of ibuprofen onto magnetic zeolite clinoptilolite modified with polypyrrole (Clino/Fe3O4/Ppy). The synthesized nanocomposite was characterized by scanning electron microscope, Fourier-transform infrared spectroscopy, Energy-dispersive X-ray analysis, Brunauer-Emmett-Teller, and X-ray powder diffraction analysis. The obtained results demonstrated that the high surface area of zeolite could significantly impact the adsorption process. Various parameters were studied to determine the optimum condition, including contact time, pH, adsorbent dosage, initial ibuprofen concentration, temperature, and mixing speed. The optimization of contact time revealed a high performance in the first 5 min of the adsorption process. Furthermore, when the temperature rose, the efficiency increased as well, with the highest efficiency being achieved at 45°C. Some isotherm models and kinetics equations were used to analyze equilibrium data. The kinetic study revealed that the adsorption process followed pseudo-second-order (R2 = 0.9972), and the isotherm investigations showed that Langmuir (R2 = 0.9941) was an appropriate model for explaining the equilibrium of the adsorption process. Based on the obtained thermodynamic factors, it was represented that the adsorption process was endothermic and spontaneous. Based on the research findings, Clino/Fe3O4/PPy nano-adsorbent developed in this study might be a helpful strategy for removing ibuprofen from various water sources.

Performance Enhancement of Specific Adsorbents for Hardness Reduction of Drinking Water and Groundwater

One of the most advantageous methods for lowering water hardness is the use of low-cost adsorbents. In this research, the effectiveness of natural zeolite (clinoptilolite type), activated carbon, and activated alumina was evaluated. These adsorbents were sequentially modified by NaCl, HCl, and NaCl-HCL to improve their ability to adsorb. The contact time and the amount of adsorbent used in the adsorption process were investigated experimentally to determine their effects. The results indicated that the best contact time for hardness reduction was 90 min, and the best concentrations of adsorbents in drinking water for zeolite, activated carbon, and activated alumina were 40, 60, and 60 g/L, respectively. In addition, for groundwater, these figures were 60, 40, and 40 g/L, respectively. The greatest possible decreases in total hardness under the best conditions by natural zeolite, activated carbon, and activated alumina adsorbents were 93.07%, 30.76%, and 56.92%, respectively, for drinking water and 59.23%, 15.67 %, and 39.72% for groundwater. According to the results obtained from experiments, NaCl-modified zeolite, natural zeolite, and NaCl-HCl-modified activated carbon performed better in terms of parameter reduction. The equilibrium data were well fitted by the Langmuir isotherm model, whereas the kinetic data for the adsorption process were consistent with the pseudo-second-order model. The equilibrium study of the adsorption process by the Morris–Weber model revealed that both chemical and physical adsorption are involved.