Contact Period Research Articles

Sustainable removal of methylene blue dye from textile effluents by magnetized Tea waste and Peanut shells

Methylene blue finds numerous applications across various industries but its prolonged exposure to living organisms can result in significant health risks. In this study, the adsorption of magnetized Peanut shells and Tea waste for methylene blue dye removal has been reported. The biosorbents were synthesized by co-precipitation method and their suitability for methylene blue adsorption was confirmed through characterization techniques including Scanning Electron Microscope, Fourier Transfer Infrared Spectroscopy and X-Ray Diffraction analysis. After optimizing for pH (8.0), temperature (312 k), biosorbents dosage 25 mg/L with contact periods (35 min for Tea waste@Fe3O4 and 40 min for Peanut shells@Fe3O4), and initial methylene blue concentrations (5 ppm), the removal percentages of 95.88 % for Tea waste@Fe3O4 and 84.11 % for Peanut shells@Fe3O4 were achieved effectively. The equilibrium data for MB dye adsorption fitted well with the Langmuir model (R2 = 0.99) for Tea waste@Fe3O4 which indicated the formation of monolayer formation of adsorbate at the surface of adsorbent and the Freundlich model (R2 = 0.98) for Peanut shells@Fe3O4 confirmed the multilayers formation of MB dye at the material surface. Kinetic studies specified that both Tea waste@Fe3O4 (R2 = 0.99) and Peanut shells@Fe3O4 (R2 = 0.99) followed the pseudo-second order. Thermodynamic analysis showed that the adsorption process on Tea waste@Fe3O4 and Peanut shells@Fe3O4 was spontaneous (−ΔG) and endothermic. Tea waste@Fe3O4 exhibited ΔH (27.97 kJ/mol) and entropy ΔS (93.69 kJ/mol) while ΔH = 208.9 kJ/mol and ΔS 62 kJ/mol were found for Peanut shells@Fe3O4. The performance of the proposed biosorbent in industrial effluent demonstrated their effectiveness, highlighting their potential as a cost effective and sustainable solution for wastewater treatment.

Empowering children as messengers of peace: time matters

ABSTRACT This study explores the potential of empowering children as peace agents through education by using the case of the TEC4Schools program. The program is based on Allport’s Contact Theory and promotes prolonged exposure to the ‘other’ culture among culturally diverse groups of students. It is based on the hypothesis that extended contact periods encourage more positive attitudes towards different cultures. The study involved three groups of mainly 5th and 6th grade students: The first group participated in the program for the first time, and we call them first-year participants and some of them participated in the program for second year and we call them second-year program participants, and the control group who never participated. Surveys were distributed at the beginning and end of the year, exploring attitudes, proximity, and friendships with peers from the other group. The results showed that second-year participants improved their attitudes towards and willingness to be close to children from other cultures. These findings suggest that the TEC4Schools project and the TEC Model effectively improve attitudes towards children from other cultures among second-year participants. Further research is needed to understand these differences and refine the project to be more effective for all participants.

Experimental analysis of the kinematics in the elastic collision between two bodies during the contact time

The elastic collision between two bodies is a fleeting event challenging to observe due to its infinitesimally short contact time, usually lasting mere hundredths or even thousandths of a second. This brief duration poses significant challenges for accurately measuring velocities and impulsive forces and establishing representative functions. Consequently, this study aims to address these challenges. Experimental measurements of velocity, acceleration, and force changes during the contact period are crucial for validating theoretical models and functions that accurately represent the dynamics of collisions under realistic conditions. These measurements are critical in optimizing the activation response of airbag and restraint systems in vehicles and are fundamental in reconstructing physical scenarios of accidents. The experiments were conducted in a practical computer-assisted laboratory, utilizing wireless sensors embedded within the test vehicles and positioned on a low-friction track. The collision setup was designed to be horizontal and frontal, ensuring that the bodies involved did not undergo permanent deformations. The primary methodology adopted in this analysis integrates both quantitative and qualitative approaches, focusing on collecting and analyzing numerical data to identify patterns and establish mathematical relationships between variables. This integrated approach offers a more comprehensive understanding of the kinematics of colliding vehicles during the contact period.

Frequency Identification using Resonance Curve-Based Drive-by Monitoring: Field Validation

Railway bridges have a long service life - in Germany, for example, the average is 122 years. During this time, vehicles are constantly evolving, leading to innovative axle configurations and higher speeds. This leads to loads for which the bridges were not originally designed, which can lead to resonant structural responses. A key parameter for calculating and evaluating the dynamic behaviour of bridge structures, is the resonance frequency. Due to the large number of bridges in the network, conventional methods using sensors on the structure would be very laborious. A cost-effective alternative would be drive-by monitoring, using sensors on a passing train. In railway bridge contexts, drive-by monitoring to identify frequencies faces challenges from short spans and high speeds, leading to brief contact periods. The brief periods cause a low resolution of the signals in the frequency domain. An approach to overcome this issue is the use of resonance curve-based drive-by monitoring. The term resonance curve describes the maximum structural responses as a function of speed. In conjunction with the known axle configuration of the train, the resonance frequency can be determined from the resonance curve. In this paper, data from two field tests are analysed, in which synchronised acceleration measurements were conducted on the main girders of the bridges and the axle boxes of the trains. An ICE 4 was used on a bridge with a 19.5-metre span, and an ICE TD on a bridge spanning 16.4 metres. The analyses show that frequency identification using indirect resonance curves is feasible under real operating conditions. Thus, this approach enables the determination of a key parameter essential for calibrating structural models. Furthermore, this method enables the avoidance of resonance crossings by speed adaptation, either by acceleration or deceleration. This strategy has the potential to significantly increase the service life of bridges.

Decolourization and detoxification of Reactive Red-195 azo dye by Staphylococcus caprae isolated from textile effluent.

Azo dyes are used as coloring agent in textile industries at larger scale. As a result, large quantity of dye-enriched waste water is generated which subsequently poses environmental problems. Biological tool involving bacteria having azoreductase enzyme has proved to be more effective and efficient in dye effluent treatment. Current work focuses on Staphylococcus caprae (S. caprae) for degradation and decolorization of Reactive Red-195 (RR-195) azo dye. For this purpose, factors such as pH, temperature, inoculums, carbon and nitrogen sources, and dye concentrations have been optimized for maximum decolorization and degradation. S. caprae (4mg/mL) efficiently resulted into 90% decolorization of RR-195 dye under static condition at 100µg/mL concentration, 30°C and pH 7.0 at a 12-h contact period. FTIR analysis has revealed the formation of new functional groups in the treated dye such as O-H stretch at 3370cm-1, C-H band stretching at 2928cm-1, and new band at 1608cm-1 which specify the degradation of aromatic ring, 1382 and 1118cm-1 represents desulfonated peaks. Biodegraded metabolites of RR-195 dye such as phenol, 3, 5-di-tert-butylphenol, and phthalic acid have been identified respectively that find industrial applications. Phytotoxicity test has shown non-toxic effects of treated dye on germination of Vigna radiata and Triticum aestivum seeds. Further, antibiotic diffusion assay has confirmed the biosafety of S. caprae.

A Novel Nanogold Composite Fabrication, Its Characterization, and Its Application in the Removal of Methylene Blue Dye from an Aqueous Solution

A unique aspect of this research lies in the combination of polyethylene terephthalate (PET) nanofibers with Auo@PPh2-PIILP to create a nanogold composite (NGC). This NGC has proven to be highly efficient in removing methylene blue (MB) from wastewater. The prepared nanogold composite NGC was characterized by Fourier-transform infrared spectroscopy (FTIR), Field Emission Scanning Electron Microscopy (FE-SEM), transmission electron microscopy (TEM), Energy Dispersive X-ray Spectroscopy (EDAX), and Elements Distribution Mapping (EDM). Several factors were examined in batch adsorption experiments to determine their impact on dye adsorption. These factors included the initial pH range of four to eight, the dosage of NGC adsorbent ranging from 0.001 to 0.008 g, the initial concentration of MB dye ranging from 10 to 50 mg L−1, and the contact period ranging from 10 to 80 min. It has been observed that NGC is more efficient in removing MB from polluted water. The results of the pseudo-second-order model show good agreement between the calculated adsorption capacity (qe)cal. (4.3840 mg g−1) and the experimental adsorption capacity (qe)exp. (4.6838 mg g−1) values. Experimental findings suggest a monolayer capping of MB dye on the NGC surface with a maximum adsorption capacity Qm of 18.622 mg g−1 at 20 °C, indicating that it is well-fitted to the Langmuir isotherm.

Polypyrrole-coated zinc/nickel oxide nanocomposites as adsorbents for enhanced removal of Pb(II) in aqueous solution and wastewater: An isothermal, kinetic, and thermodynamic study

One common heavy metal that is extremely harmful to the kidneys, reproductive system, and nervous system of humans is lead (Pb). This study aimed to investigate the effectiveness of a novel nanocomposite adsorbent, synthesised from polypyrrole, zinc oxide, and nickel (PPy/ZnO-NiO), in eliminating Pb(II) ions from a water-based solution. This adsorbent offers excellent metal selectivity, environmental stability, ease of manufacture, and reusability. Several techniques, namely XRD, FTIR, TGA, SEM, TEM, EDX, and BET, were employed to characterize the synthesised nanocomposite adsorbent. The study examined the impact of multiple factors influencing the adsorption process, including pH, temperature, contact period, metal ion concentration, and adsorbent dose, along with isotherms, kinetics, and thermodynamics processes. The adsorption of Pb ions was examined via various isotherm models, including the Temkin, Freundlich, and Langmuir, and thus various factors inherent to pseudo-first-order, pseudo-second-order, and Elovich kinetics were determined. The data revealed that both the Langmuir sorption model and pseudo-second-order kinetics match the adsorption data well. The highest adsorption capacities of the PPy/ZnO-NiO nanocomposite adsorbent for Pb(II) metal ions were 436.48, 450.48, and 469.56 mg/g at 298, 305, and 310 K, respectively, and the optimal pH was 5. An actual water sample that had been tainted with Pb(II) ions was used to test the applicability of the PPy/ZnO-NiO nanocomposite for the removal of Pb(II) ions. Based on the available data, the PPy/ZnO-NiO nanocomposite appears to be effective in terms of elimination of Pb(II) from five different raw water samples, such as tap water, surface water, groundwater, sewage plant wastewater, and domestic wastewater.

Variant patterns of sibilant debuccalization in Camuno

Abstract Some varieties of Camuno, an Eastern Lombard variety spoken in Valcamonica, Italy, show clear evidence of what appears to be an unconditioned sound change of S > h, where S had [s] and [θ] variants (Bonfadini 1995a; Cresci 2014). However, neighboring varieties in the upper parts of the valley retain inherited S and, in at least one village, Cerveno, debuccalization is limited to intervocalic position. In this study, we attempt to explain dialect variation in Camuno in terms of s-debuccalization as a lenition process within the general framework of Evolutionary Phonology (Blevins 2004a, 2006, 2015) building on the typology established by Ferguson (1990). The probability of articulatory undershoot is greatest in the V_V environment, and all dialects with S > h show the sound change in this context. In medial clusters like rS, lS, nS, where there is articulatory overlap and longer sustained constriction, articulatory undershoot is less likely, and S is most likely to be maintained, as it is in Cerveno. A treatment of S > h as lenition implies that [s] and [θ] were produced with spread vocal folds in languages where this sound change has been observed. Here we offer additional evidence for aspiration as an active feature in Camuno phonology and suggest possible origins of this feature during the long period of contact with Longobardic. Another central issue explored in this study are phonetic factors that might differentiate intervocalic s > h from s > h that originates in the syllable coda, as in many varieties of Spanish.

Does nuclear DNA support the recognition of three species within the Splendid Fairywren Malurus splendens?

ABSTRACT The Splendid Fairywren Malurus splendens has four distinct phenotypic forms currently recognised as subspecies, although three species have been recognised within the group in the past. Here, we use multilocus nuclear DNA to test the recent hypothesis that the Splendid Fairywren represents three allopatric taxa with little to no modern-day contact, despite phenotypic evidence of periods of past contact and gene flow. Our nuclear dataset is concordant with earlier mtDNA-based data in supporting three distinct genetic groups within M. splendens. These genetic groups align with the three phenotypically distinct forms recently hypothesised to be allopatric and previously described at species-level – western M. splendens, central M. callainus and eastern M. melanotus. Nuclear gene flow does not appear to be rampant between the three forms; however, several individuals show signals of admixed nuclear ancestry, which we cannot distinguish as having resulted from incomplete lineage sorting, poor phylogenetic signal, or gene flow. Given changing modern taxonomic interpretations of the significance of gene flow in speciation, we argue that recognising three distinct species within the M. splendens complex might better represent their evolutionary distinctiveness, rather than continuing to treat these genetically and morphologically distinct forms as subspecies of a widespread polytypic species. Our study highlights the interesting complexity of determining species status when taxa are in the ‘grey zone’ near the subspecies/species continuum, and the value gained from adding perspectives from nuclear DNA.

Research on the influence of mineral heterogeneity under different CO2 injection schemes in low permeability reservoirs

In the pursuit of sustainable oil and gas resource extraction, the innovative integration of carbon capture, utilization, and storage (CCUS) technology has emerged as the most promising approach. During the CCUS process, intricate physicochemical interactions between the injected CO2, facilitated through various injection strategies (Water Alternative Gas: WAG/Continue Gas Injection: CGI) and the formation fluids and heterogeneous mineral assemblages within the reservoir trigger alterations in mineral structures, consequently impacting permeability and recovery factors, constituting a pivotal aspect. Precisely delineating and quantifying these interactions is paramount for optimizing process design and evaluating reservoir dynamics in the successful implementation of CCUS operations. This study has carried out qualitative and quantitative characterization of mineral heterogeneity, different pore types, and mineral combination characteristics from a low-permeability sandstone reservoir. Additionally, the effect on the physical properties of minerals from different development methods (WAG/CGI) was investigated using numerical simulation for CCUS applications. The results indicate that the saturated CO2 fluid selectively dissolves the potassium feldspar (orthoclase) in intergranular pores, while the intergranular pores are filled with illite and secondary precipitated clay minerals. It initially dissolves the sensitive mineral (ankerite) in the intergranular pores. The decrease of ankerite and increase of illite result from the prolonged contact period between saturated CO2 and minerals, which changes the mineral cementation to argillaceous type, thus affecting permeability in the context of CCUS. The spatial impact on reservoir physical properties depends on the spatial heterogeneity of the original sensitive minerals (ankerite, anorthite, illite, etc.) distributed in the study area. In the WAG scheme, the physicochemical interaction between saturated CO2 and reservoir minerals is more intense than in the CGI scheme for CCUS operations, significantly impacting cumulative production.

Peach seed shell and Aspergillus oryzae as adsorbents for the uptake of acid violet 90 dye from wastewater

In this study, Aspergillus oryzae (A. Oryzae) biomass and waste peach seed shells (PPSS) were used to create alternative and effective adsorbents. Acid Violet 90 (AVD) dye was removed from wastewater using the as-prepared adsorbents. Different process variables like pH (2–11), contact period (0–180 min), and adsorbent mass (0.2–2.0 g/L) were examined. The solution pH had a synergistic effect on the improved removal of AVD and the optimal adsorption removal for the PPSS and the A. Oryzae adsorbent occurred at pH 2.0 and pH 5.0, respectively. The findings demonstrated that, in comparison to A. Oryzae, PPSS reported a greater AVD adsorption (mg/g). The equilibrium time for the adsorption process was attained within 180 min for both adsorbents. The adsorption kinetics modelling results showed a good fit with pseudo-second-order kinetics, for both adsorbents, with average R2 values of 0.999 (for PPSS) and 0.997 (for A. Oryzae). Similarly, the isotherm modelling results confirmed the good fitting of the Langmuir isotherm model for A. Oryzae (R2 = 0.999) and the Freundlich model for PPSS (R2 = 0.997). The maximum adsorption capacity (qmax) of 55.0 and 94.92 mg/g was recorded for A. Oryzae and PPSS, respectively. Mechanistic investigation of the present system suggests that both intraparticle diffusion and surface sorption mechanisms control the adsorption rate. As agro materials, both adsorbents are composed of mostly oxygen-based surface functional groups like the –OH, –C = O, -C-O-C, and multiple carbon-carbon bonds, all contributed to the synergistic mechanism interaction between the adsorbent and AVD dye in this study. This study, therefore, revealed that the PPSS and A. Oryzae may be very helpful for removing anionic dye from contaminated wastewater, indicating its potential for useful application in the removal of other major pollutants.

Porous sodium alginate/poly (acrylic acid) composites cross-linked with FeCl3 for acid black 1 dye removal from aqueous solution

This study developed a polymeric composite, sodium alginate (SA)/poly (acrylic acid) (PAA) cross-linked with FeCl3 (SA/PAA-Fe), for its function as adsorbent to eliminate acid black 1 dye (AB1) from an aqueous solution. The structural analysis of SA/PAA-Fe revealed a porous structure. To comprehensively evaluate the adsorption of AB1 onto SA/PAA-Fe and gain insight into its mechanism, we examined the effects of solution’s pH, initial dye concentration, adsorbent dosage, contact time, and adsorption temperature. The best adsorption conditions for achieving a highly effective removal percentage of 95.43 % were a pH of 8.9, contact period of 90 min, and a temperature of 45 °C. Pseudo-second-order and Langmuir models were fitted for the isotherm and kinetic model parameters, respectively. Thermodynamic analyses strongly suggested that the adsorption process occurred was endothermic and spontaneous. The adsorption of AB1 was primarily observed on the solid surface, as confirmed by the SEM-EDS and FTIR measurements.

Sequestration of an Azo Dye by a Potential Biosorbent: Characterization of Biosorbent, Adsorption Isotherm and Adsorption Kinetic Studies.

This study explores the detailed characterization of a biosorbent (Hen Feather) and its efficient use in eradicating the azo dye Metanil Yellow (MY) from its aqueous solutions. Effects of a range of experimental parameters, including pH, initial dye concentration, biosorbent dosage and contact time on the adsorption, were studied. A detailed physical and chemical characterization of the biosorbent was made using SEM, XRD, XPS and FTIR. During the optimization of adsorption parameters, the highest dye uptake of almost 99% was recorded at pH 2, dye concentration 2 × 10-5 M, 0.05 g of biosorbent and a contact period of 75 min. Various adsorption isotherm models were studied to gather different adsorption and thermodynamic parameters. The linearity of the Langmuir, Freundlich and D-R adsorption isotherms indicate homogeneous, multilayer chemisorption with high adsorption affinity between the dye and biosorbent. Values of the changes in the Gibbs free energy (ΔG°) and the enthalpy (ΔH°) of the adsorption process have been calculated, these values indicate that it is a spontaneous and endothermic process. Kinetics of the adsorption were also measured, and it was established that the adsorption of MY over Hen Feather follows a pseudo-second-order kinetic model at temperatures 30, 40 and 50 °C. The findings of this investigation clearly indicate that the studied biosorbent exhibits a high affinity towards the dye (MY), and it can be effectively, economically and efficiently used to sequestrate and eradicate MY from its aqueous solutions.

Removal of Methylene blue dye from contaminated wastewater using lignocellulosic biomasses: A comparative study

In this study, lupine seed (Lu-SP) and pumpkin seed shells (PSSP) biomasses were used to create alternative and effective adsorbents. Methylene blue (MB) dye was removed from wastewater using the as-prepared adsorbents at variables solution pH 2.0 –11.0, contact period (0–180 min), and adsorbent mass (0.2–2.0 g/L). The solution pH had a synergistic effect on the improved removal of MB and the optimal adsorption removal for both adsorbents occurred at pH 8.0 and 120 min. The adsorption isotherm modelling results showed a good fit with the Langmuir model, with a maximum monolayer adsorption capacity of 48.98 and 77.48 mg/g for PSSP and Lu-SP, respectively. Similarly, the pseudo-first-order (PFO) model is regarded as the best-fit kinetic model for both adsorbents and suggests the predominance of physisorption via interfacial diffusion. Mechanistic investigation of the present system suggests that both intraparticle diffusion and surface sorption mechanisms control the adsorption rate. Notably, the Lu-SP with a lower surface area (54.013 m2/g) outperformed the PSSP (235.992 m2/g) in terms of adsorption capacity under varying pH. Therefore, in addition to electrostatic interaction, adsorption into the micropores via volume filling is considered one of the adsorption mechanisms. This study, therefore, revealed that the PSSP and Lu-SP may be very helpful for removing cationic MB dye from contaminated wastewater.

Maternal behavior of dairy cows and suckling behavior of dairy calves in different cow-calf contact conditions

Cow-calf contact (CCC) has been suggested as an alternative to the common practice of early separation of dairy cow and calf. Increasing CCC poses challenges by reducing the machine milk yield and increasing separation stress. Part-time CCC may prove more feasible than full-time contact for farmers but may affect the maternal behavior of the cows. Gradually reducing the daily contact could gradually wean the calf off milk, preparing it for separation. This study aims to investigate 1) how cows' maternal behaviors toward their own calf are affected by part-time contact, and 2) whether calves' suckling behavior is reduced by reducing daily cow contact. Fifty-six dairy cows and their calves were assigned to either full-time (23 h/d) or part-time (10 h/d) cow-calf contact for 7 weeks (main rearing period). This was followed by 2 weeks of either reduced contact (50% in wk 8, then 25% of original contact time in wk 9) or unchanged contact. First, the maternal behavior of full and part-time cows was observed for 24 h in the third week of the main rearing period. Part-time cows spent less time nursing and grooming their own calf than full-time cows did. However, the amount of nursing in the inverse parallel position and the probability of a cow nursing a calf other than her own did not differ between the 2 treatments. Second, calf suckling behavior was observed for 24 h in both weeks of the reduced contact period. Averaged across both observations, total suckling time (i.e., time spent suckling any cow) was lower in part-time calves that experienced reduced contact compared with part-time calves with unchanged contact. In wk 9, time spent suckling only the dam was lower for full-time calves with reduced contact compared with part-time calves with unchanged contact. In conclusion, although we found a lower nursing and grooming time in part-time cows compared with full-time, we found no difference between treatments with regards to nursing in the inverse parallel position and nursing a calf other than the cow's own. The effect of gradually reducing cow-calf contact on calves' suckling time requires more research.

Valorization of sugarcane bagasse cellulose to synthesize novel graphene oxide-based composite for remediation of atrazine – Optimization studies

Atrazine (AZE) is a hazardous herbicide that pollutes drinking water and wastewater at an alarming rate, posturing a somberhazard to the environment and human being. This research is aimed to investigate the valorization of biomass for the synthesis and applicationof novel Sugarcane Bagasse Cellulose (SCBC) - Graphene oxide (GO) nanocomposite for remediation of atrazine. The novel nanocomposite is characterized using Fourier transform infrared spectroscopy (FTIR), Particle size distribution, Raman spectra analysis, X-ray analysis (XRD), Scanning electron microscope analysis (SEM) and Transmission electron microscopy (TEM). The prepared GOSCBC had high surface area of 189 m2/g, pore volume of 0.13 cm3/g, and inter-particle pore width of 17 nm. The impact of operating constraints such as adsorbent dose (50–150 mg), medium pH (4.5–8.5), contact period (3 h), temperature (15–45°C), and atrazine concentration (10–50 mg/L) were varied and optimum conditions were examined with the help of Box-Behnken statistical design (BBD). The optimum conditions identified were: 90.84 mg/L nanocomposite; pH 5.51; time 180 min; temperature 34.64°C and feed concentration 27.77 mg/L. The adsorption statistical analyses were performed and the values were determined using the isotherms and kinetic models; the optimal parameters were evaluated using sum of normalised errors approach. The maximum adsorption capacity of AZE was found to be 143.29 mg/g. The mechanism of sorption is well represented by PSO model. The exothermic nature of removal process was confirmed through thermodynamic parameters. The reusability of the nanocomposite was identified to be efficient for six cycles.

Co-Al layered double oxide activated carbon composite for eliminating lead ions from water

In the current study, preparation of cobalt-aluminum layered double oxide doped activated carbon (Co-Al LDO/AC) was achieved by the co-precipitation technique and utilized for the remediation of lead (Pb2+) from water. Various methods were employed to examine the properties of the composite material, including BET, XRD, FTIR, SEM, and EDS analysis. The material characterization outcomes indicated that the LDO structure was successfully incorporated into the AC matrices with a surface area of 189.4 m2/g. The influence of adsorption parameters including Co-Al LDO/AC dosage, period of contact, initial Pb2+ loading, and initial solution pH were investigated. Moreover, the isotherm and kinetic models were investigated to provide a deeper understanding of the elimination mechanism of Pb2+ ions. The adsorption results illustrated that pH has a substantial influence on Pb2+ removal with a highest removal effectiveness at pH = 6 and a fast adsorption rate within 7 h. The kinetic data were well aligned with the pseudo-second-order model while the isotherm data obeyed the Sips model (R2>0.966). The highest adsorption uptake, estimated by the Sips model was 25.09 mg/g. Considering the modeling and characterization of the spent Co-Al LDO/AC, a chemical interaction process was involved in the elimination process and mainly controlled by ion exchange, electrostatic interactions, and surface complexation mechanisms. Accordingly, the Co-Al LDO/AC could have great potential as a promising hybrid for the purification of toxic Pb2+ ions from contaminated water streams.

The adsorption behaviour of biochar derived from Prosopis juliflora with surface modified by KOH against Allura red dye

This study examined the efficacy of ProsopisJuliflora with surface changes as a bioadsorbent for the removal of Allura Red dye. The effects of adsorptive dosage, pH, and contact period with starting dye attentiveness on adsorption were examined in the batch adsorption study. The study demonstrated that the Allura Red dye may be absorbed by surfaces that had been treated with KOH compound.The percentages of Allura Red dye eliminated were 67.18 %, 75.88 %, and 94.37 %, respectively. UV–visible adsorption spectroscopy is used to quantify the extent of dye decolorization. The modified surface characteristics of the adsorbent produced by ProsopisJuliflora were reported using XRD, FTIR, and SEM. The Adams-Bohart mathematical models are employed in the computation and assessment of adsorption efficiency. The adsorption-derived R2 values for the equilibrium isotherm data model were 94.63, 86.67, and 96.35. Diffusion and intraparticle regeneration were investigated to bolster the adsorption investigation.

Dithiocarbamate functionalised crosslinked polyacrylamide for separation and pre-concentration of uranium (VI) ions from sulphate medium

ABSTRACT This article introduces a novel approach for extracting and concentrating uranium (VI) ions from water-based solutions using two dithiocarbamate functionalised cross-linked polyacrylamide adsorbents, CPAAm-DETA-CS2 and CPAAm-EDA-CS2. The adsorbents were synthesised and characterised through techniques like Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM), X-ray Diffraction (XRD), and elemental analysis. The efficacy of these adsorbents in removing U(VI) species from solution matrices was systematically investigated, yielding maximum adsorption capacities of approximately 57.8 mg/g and 60.2 mg/g for CPAAm-EDA-CS2 and CPAAm-DETA-CS2, respectively. The optimised operational parameters encompassed a solution pH of 4.0, a contact period of 60 minutes, and an adsorbent dosage of 1.7 g/L, all conducted at ambient temperature. The adsorption adhered to the Langmuir isotherm and pseudo-second order kinetics, with a spontaneous and exothermic nature. Notably, the adsorbents displayed potential for regeneration and reuse. CPAAm-DETA-CS2 sorbent which exhibits the highest sorption capacity was applied successfully for the removal of uranium(VI) removal from sulphate leach liquor of Sella uranium ore. The adsorption capacity of the prepared sorbent was ≈ 45.3 mg/g. These aforementioned findings underscore the viability of a sustainable approach for uranium extraction, highlighting the notable importance of dithiocarbamate functionalised cross-linked polyacrylamide as a proficient adsorbent within the realm of environmental and industrial uranium separation processes.

STATISTICAL OPTIMIZATION AND EVALUATION OF IN SITU GEL FOR THE OCULAR DELIVERY OF CROMOLYN SODIUM

Objective: The study aimed to develop and optimize cromolyn sodium-based ocular in situ gel to improve the ophthalmic contact period and provide sustained drug release for treating allergic conjunctivitis. Methods: Formulations were prepared using sodium alginate and HPMC K4M (Hydroxypropyl Methylcellulose) polymers and were characterized and evaluated for viscosity, gelling time, in vitro drug release, and optimized using a factorial 32 DOE design (Version 11; Design Expert® software). The resulting cromolyn sodium-based formulation was tested for hyperemia and eye-scratching behavior in Wistar albino rats. Results: Increased polymer concentrations resulted in higher viscosity with decreased gelling time and in vitro drug release. The optimized formulation achieved a viscosity of 15.350 cps, a gelling time of 55.137 s, and sustained drug release of 92.61% over 12 h. The in vivo pharmacodynamic study of the optimized formulation showed a significant decrease in the frequency of eye-scratching behaviour (7.525) at a significance level of (**p<0.01) and hyperemia (1.125) (***p<0.001, *p<0.05) compared to negative and positive control indicating that the developed in situ formulation improved the drug's therapeutic effectiveness by extending its duration within the cul de sac. Conclusion: In light of these findings, this optimized cromolyn sodium in situ gel holds promise as a viable alternative to conventional eye drops