Potassium Persulfate Concentration Research Articles

Eco-friendly natural rubber-based hydrogel loaded with nano-fertilizer as soil conditioner and improved plant growth

This study addresses the dual challenge of agricultural cost and waste management by harnessing agrarian waste to produce nano-fertilizers (NF) to enhance crop yield while mitigating environmental impacts. Recognizing the limitations of traditional hydrogels' non-biodegradability and their inability to sustain root zone moisture and nutrient levels, we developed an LNR/AAc/pectin hydrogel. This innovative hydrogel offers a viable solution that provides a consistent NF supply and improves water retention efficiently. Additionally, we utilized Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy-energy dispersive x-ray (SEM-EDX), and thermogravimetric analysis (TGA) to analyze the hydrogel's structure, stability, and form. Transmission electron microscopy (TEM) and X-ray fluorescence spectroscopy (XRF) were employed to ascertain the NF concentration. The optimization of the hydrogel's swelling and NF release was conducted through a 5-level, 2-factor Response Surface Methodology (RSM), focusing on the effects of the AAc: LNR ratio and pectin weight while maintaining constant concentrations of potassium persulfate (KPS) and MBA. Results revealed a high correlation between predicted and experimental values, with determination coefficients (R2) of 0.9982 for swelling and 0.9979 for NF release. Furthermore, the hydrogel exhibited a 96.30 % biodegradation rate after 120 days of soil burial. Our findings demonstrate the hydrogels' potential to significantly impact farming and gardening by ensuring a sustainable supply of nutrients to enhance soil moisture retention.

Potassium persulfate enhances humification of chicken manure and straw composting: The perspective of rare and abundant microbial community structure and ecological interactions

Improper disposal of organic solid waste results in serious environmental pollution. Aerobic composting provides an environmentally friendly treatment method, but improving humification of raw materials remains a challenge. This study revealed the effect of different concentrations of potassium persulfate (PP) on humification of chicken manure and straw aerobic composting and the underlying microbial mechanisms. The results showed that when 0.6 % PP was added (PPH group), humus and the degree of polymerization were 80.77 mg/g and 2.52, respectively, which were significantly higher than those in 0.3 % PP (PPL group). As the concentration of PP was increased, the composition of rare taxa (RT) changed and improved in evenness, while abundant taxa (AT) was unaffected. Additionally, the density (0.037), edges (3278), and average degree (15.21) in the co-occurrence network decreased compared to PPL, while the average path (4.021) and modularity increased in PPH. This resulted in facilitating the turnover of matter, information, and energy among the microbes. Interestingly, cooperative behavior between microorganisms during the maturation period (24–60 d) occurred in PPH, but competitive relationships dominated in PPL. Cooperative behavior was positively correlated with humus (p < 0.05). Because the indices, such as higher degree, betweenness centrality, eigenvector centrality, and closeness centrality of the AT, were located in the microbial network center compared to RT, they were unaffected by the concentration of PP. The abundance of carbohydrate and amino acid metabolic pathways, which play an important role in humification, were higher in PPH. These findings contribute to understanding the relative importance of composition, interactions, and metabolic functionality of RT and AT on humification during chicken manure and straw aerobic composting under different concentrations of PP, as well as provide a basic reference for use of various conditioning agents to promote humification of organic solid waste.

Fe, Mn-Prussian blue analogue@MXene composites for efficient photocatalytic peroxydisulfate-activated degradation of tetracycline hydrochloride and photoelectrochemical desalination

The utilization of wastewater or saline as a source of clean and safe freshwater is a potential solution to address water pollution and scarcity. In this study, we synthesized a composite material, i. e. Fe, Mn-Prussian blue analogue@MXene, which is highly responsive to visible light and serves as an innovative activator for peroxydisulfate (PDS) in the degradation of tetracycline hydrochloride (TCH). The FeMn-PBA@MXene-0.30 composite, with its unique metal-organic framework (MOF) structure, exhibited excellent photocatalytic activity in the degradation of TCH by activating PDS through dual redox cycles of Mn(II)–C≡N–Fe(III) and Mn(III)–C≡N–Fe(II). A remarkable 93.41% removal of TCH can be achieved at a concentration of 30 mg·L−1 within 120 min. The presence of MXene in the composite may facilitate the efficient electron transportation owing to its excellent conductivity. The influences of various reaction conditions are also investigated, such as the concentration of potassium persulfate (KPS), TCH concentration, and solution pH value. Electron spin resonance (ESR) analysis and trapping experiments revealed the presence of reactive species, including 1O2, ∙OH, and h+, in the FeMn-PBA@MXene-0.30/visible light/PDS system. Furthermore, we demonstrated the application of the FeMn-PBA@MXene-0.30 composite as the photoanode of a solar-assisted photoelectrochemical desalination (SA-PED) device, which combines the TCH degradation with photoelectrochemical desalination. This novel approach enabled simultaneous degradation and desalination, resulting in a significant reduction of 4000-ppm brine to 240 ppm (lower than the freshwater threshold of 500 ppm), with a salt removal efficiency (SRE) of 94.00%. Meanwhile, the degradation rate of TCH (900 mg·L−1) reached up to 98.91% under visible light irradiation. This work not only provides valuable insights into the development of PDS-activated catalysts but also explores new avenues for the multifunctional application of photocatalysts in addressing water pollution and scarcity.

Ph–CN as a novel ECL emitter combining catalysis and luminescence in one

Graphitic-phase carbon nitride (CN) has attracted extensive interest in the direction of electrochemiluminescence (ECL) due to its peculiar properties, inexpensive cost and easy synthesis. However, they are often limited by unsatisfactory ECL performance, such as low luminescence efficiency and poor electrical cycling stability, among other characteristics. Here, phenyl-doped carbon nitride (Ph–CN) is prepared by a simple and controllable supramolecular pre-assembly route for high-brightness and high-stability electrochemiluminescence. The variation of phenyl content plays a key role in tailoring the optical behavior, triggering a change in the material energy level and further facilitating the electron transfer between Ph–CN and the co-reacting reagents. Surprisingly, Ph–CN also exhibits high stability of ECL intensity at low concentrations of potassium persulfate (K2S2O8) solution, effectively avoiding oxidative damage to biomolecules caused by high concentrations of co-reactive reagents, and large Stokes shifts have potential applications in bioimaging. To validate the proposed novel luminescent material, Ph–CN is used as a new generation ECL emitter with carcinoembryonic antigen (CEA) as the detection molecule, and the proposed biosensor can analyze tumor markers sensitively and quantitatively. The construction of this work will considerably promote the development of novel ECL materials and have broad application prospects in early diagnosis and biological imaging.

Fabrication of adhesive hydrogels based on poly (acrylic acid) and modified hyaluronic acid

Hydrogel wound dressings with good flexibility and adhesiveness to resist deformation during wound movement are urgently needed in clinical application. In this work, the hydrogels based on poly (acrylic acid) and N-hydroxysuccinimide grafted hyaluronic acid (PAA/HA-NHS) with good elasticity and adhesiveness were prepared by chemical cross-linking and hydrogen bonding. The elastic and adhesive properties within the PAA hydrogels could reach a balance by adjusting the concentration of potassium persulfate (KPS) and N, N′-methylenebisacrylamide (MBA). Subsequently, HA-NHS was incorporated into the PAA hydrogel system. The mechanical test revealed that the elongation at break and interfacial toughness of the PAA/HA-NHS hydrogels could reach 265.79 ± 21.93% and 52.88 ± 3.51 J/m2, respectively. In addition, the hydrogels possess a connected porous network and well water absorption ability (with porosity of 51.90 ± 0.11% and swelling ratio in wet state of 122.17 ± 2.78%). In vitro experiment demonstrates that the PAA/HA-NHS hydrogels exhibit nontoxic and cell in-adhesive properties. The PAA/HA-NHS hydrogels could cover the wound spots directly, stretch with the skin movement and gently remove from the wound tissue due to the suitable adhesiveness and poor cell adhesion. In conclusion, the PAA/HA-NHS hydrogels show great application value in the field of wound dressing.

Chitosan capped trimetallic nanoparticles: Synthesis and their Congo red adsorbing activities

Chitosan capped Fe0-based Fe-Pd-Ir (Chi-Fe-Pd-Ir) tri-metallic nanoparticles were fabricated using metal displacement method in presence of sodium borohydride. The preliminary indications of Fe0 production were the appearance of pale yellow color with ferric nitrate, NaBH4, and chitosan. Chitosan was detected by using ninhydrin color test, thermal gravimetric analysis and measurement of relative viscosity. The average molecular weight of chitosan and Chi-Fe-Pd-Ir decreased with increased potassium persulfate concentration. Chi-Fe-Pd-Ir used as an adsorbent for the removal of Congo red. The sorption equilibrium data were fitted into Langmuir, Freundlich, Temkin, and Dubinin-Radushkevich isotherms (DRK). The maximum monolayer adsorption capacity (Q0max), and sorption intensity (n) were estimated to be 93.4 mg/g and 2.0, respectively, from Langmuir and Freundlich adsorption isotherm models. The mean free energy was calculated by using DRK isotherm to be 0.15 kJ/mol. Sorption parameters indicate that the Congo red adsorbed on the surface of Chi-Fe-Pd-Ir through monolayer formation via physisorption process. The adsorption of CR on Chi-Fe-Pd-Ir was in good agreement with the Langmuir adsorption isotherm and pseudo-second-order kinetic model. Protonated amino group of chitosan was also responsible for the adsorption of anionic CR along with the Fe-Pd-Ir NPs.

Synthesis of PMMA-HoVO4 nanocomposites by emulsifier-free emulsion polymerization: radical effects

Abstract Poly(methyl methacrylate)-holmium orthovanadate (PMMA-HoVO4) nanocomposites were synthesized using emulsifierfree emulsion polymerization system in two ways. In the first one, the HoVO4 nanoparticle dispersion was added to the emulsion system before or after polymerization start (in situ polymerization). In the other one, nanoparticle dispersion and polymeric latex were mixed together at room temperature (blending). Crystalline HoVO4 nanoparticles (about 60 nm) were synthesized by coprecipitation method. Three different composite latexes were synthesized by varying the potassium persulfate concentration and the time of HoVO4 nanoparticles addition. According to the dynamic light scattering analysis, the size of the polymer beads in the latexes is between 244.8 nm and 502.5 nm and the PDI values are in the range of 0.005 to 0.206. Infrared spectral analysis showed that HoVO4 caused some changes in the structure of the polymer. Luminescence measurements attempted to determine optical properties of the nanocomposites. The results have shown that HoVO4 nanoparticles do not protect their structure due to the reaction with persulfate radicals but that they enter the polymer beads and change the luminescence properties of the polymer forming a new material with different properties.

Green Preparation of Hyphaene thebaica Fiber Grafted Acrylic Acid for Adsorption of Pb (II) ions from Aqueous Solution

In this study, a green chemistry approached was employed in the preparation of Hyphaene thebaica fiber grafted polyacrylic acid via microwave assisted method using potassium persulfate as chemical initiator. The optimum percentage grafting 92% was achieved under 5g concentration of acrylic acid, 0.2g concentration of potassium persulfate (KPS) and 2 minutes reaction time. The grafted sample was characterized using the following techniques, FTIR, SEM and XRD. The prepared graft copolymer was examined for adsorption of Pb (II) ions from aqueous solution in batch mode systems. The adsorption parameters such as pH, initial metal ion concentration and contact time were also studied. The Langmuir and Freundlich isotherm models were applied to simulate the equilibrium adsorption experimental data. The Langmuir model fitted well with experimental data with maximum adsorption capacity (qmax) of 20.37 mg/g at 45 minutes. Higher regression coefficient obtained confirmed the suitability of the Langmuir isotherm model which assumed monolayer coverage on the adsorbent surface. The adsorption studies revealed the efficacy of the grafted fiber for removal of Pb (II) ions from dilute aqueous solutions.

Construction of Fe2O3/Co3O4/exfoliated graphite composite and its high efficient treatment of landfill leachate by activation of potassium persulfate

Landfill leachate, as one of high-ammonia nitrogen organic pollutants, has been characterized to be potentially dangerous on ground water and soil. However, traditional technologies cannot deal with these substances swiftly. Thus, in this study, exfoliated graphite (EG) immobilized ferric oxide and cobaltosic oxide species has been successfully constructed by a facile heating-precipitation strategy. Subsequently, physicochemical properties of Fe2O3/Co3O4/EG were investigated by scanning electron microscope, X-ray diffraction, N2 adsorption/desorption, X-ray photoelectron spectroscopy measurements. Results indicated that Fe2O3 and Co3O4 nano-particles were successfully deposited onto the surface and interstice of EG substrate. In addition, activation performance of Fe2O3/Co3O4/EG composite was evaluated by activating potassium persulfate (PS) to degrade the landfill leachate. In addition, effect of some critical operating parameters on the removal of landfill leachate was studied systematically. The experimental results showed that 90.6% of NH4+-N and 67.1% of COD in landfill leachate could be removed at the optimized conditions of pH 5, PS concentration 0.05 M and Fe2O3/Co3O4/EG dosage 0.1 g. Furthermore, Fe2O3/Co3O4/EG sample also displayed good recycle and reusable capacities. Besides these, high-efficient removal mechanism of Fe2O3/Co3O4/EG was proposed. This study provides a feasible strategy to prepare catalyst which could be potentially applied in refractory contaminants elimination.

Preparation and Characterization of Potato Starch Nanoparticles with Acrylamide by Microwave Radiation.

In this study on decreasing the particle size of the potato starch, ultrasound and acid hydrolysis methods were carried out at the same time. The starch nanoparticles obtained were modified with acrylamide(AM) monomer by microwave irradiation, employing a small concentration of chemical initiator. It was found that, with a low concentration of potassium persulfate (PPS) in aqueous medium and microwave assistance, starch nanoparticles grafted with acrylamide could be prepared quickly. Native starch, starch nanoparticles and grafted copolymers were characterized by various analytical techniques. The Fourier transform infrared spectroscopy (FT-IR) analysis demonstrates group acrylamide attachment to starch nanoparticles chains. X-ray diffraction (XRD) and scanning electron microscopy (SEM) demonstrate an increased amorphous region of starch nanoparticles and grafted copolymers, while the thermogravimetric analysis (TGA) highlighted the increase in thermal stability of the copolymers in comparison to potato starch nanoparticles.

Persulfate based pretreatment to enhance the enzymatic digestibility of rice straw

Oxidation induced by potassium persulfate was evaluated as an economic substitute for the Fenton-like reaction for the purpose of rice straw pretreatment in terms of temperature (80–140°C), potassium persulfate concentration (5–100mM) and process time (0.5–3h), an optimal pretreatment condition was identified: 120°C for 2 h with 75mM potassium persulfate concentration and yielded 91% enzymatic digestibility using 25.2FPU/g of biomass. Crystallinity index, SEM and SEM-EDS analyses revealed that biomass was indeed disrupted and components like silica were exposed. All this suggested that this persulfate-based pretreatment method, which is distinctively advantageous in terms of effectiveness and economics, can indeed be a competitive option.

Determination of the latex particle size in emulsion polymerization of methyl methacrylate with low emulsifier concentrations

The mean size of the latex particles formed in emulsion polymerization of methyl methacrylate under definite conditions (water: monomer volume ratio 15: 1, 80°C, potassium persulfate concentration 0.07 wt %) decreases from 200 to 9–10 nm as the concentration of an ionic surfactant (anionic Disponil AES 60, SDS, cationic C19H42BrN) is increased from 0.0 to 1.0 wt %. The nonionic surfactants studied influence the size of the latex particles formed differently: with ALM-10, the particle size decreases from 200 to 150–190 nm, whereas with ALM-7 and ALM-2 it increases from 200 to 320 nm as the surfactant concentration is increased from 0.0 to 1.0 wt %. An increase in the concentration of F127 amphiphilic ternary block copolymer from 0.0 to 1.0 wt % leads to a monotonic decrease in the size of the poly(methyl methacrylate) latex particles formed from 200 to 53 nm.

Effects of Monocarboxylic Acids and Potassium Persulfate on Preparation of Chitosan Nanoparticles

In this research, we studied the preparation of nanochitosan from the addition of potassium persulfate as an initiator for monomer polymerization and monocarboxylic acid—namely acetic acid, lactic acid, and formic acid—to a chitosan solution. To obtain the dried form of chitosan nanoparticles, we investigated the effects of oven and spray drying systems toward the physicochemical properties and morphology of chitosan nanoparticles. Successfully prepared chitosan nanoparticles were characterized by Fourier transform infrared spectroscopy (FTIR), Field Emission Scanning Microscopy/Energy Dispersive X-ray Analysis (FESEM-EDX), and a particle size analyzer (PSA). The structures of nanochitosan prepared in different acids were quite similar based on the FTIR spectra. By increasing the concentrations of potassium persulfate, the yields of chitosan nanoparticles also increased. The concentration of potassium persulfate had a significant influence on the production of chitosan nanoparticles. The lowest concentration of potassium persulfate (0.6 mmol) did not produce an observable formation of chitosan nanoparticles. By using formic acid and potassium persulfate in various concentrations from 1.2–3.0 mmol, chitosan nanoparticles were obtained. A particle size distribution of chitosan nanoparticles was produced from a formic acid solution having a smaller size compared to others. The acidity effect of monocarboxylic acids in the formation of chitosan nanoparticles was better compared to the addition of other acids. Furthermore, synthesized chitosan nanoparticles (50–110 nm) produced from formic acid solutions have potential applications for drug carrier purposes.

Application of full factorial design for methylene blue dye removal using heat-activated persulfate oxidation

In this study, a thermally activated persulfate oxidation process was investigated to treat aqueous methylene blue (MB) dye. Effects of temperature (55–80°C), initial pH (2.3–9.3), and potassium persulfate concentration (500–2000 (mg/L)) on MB color removal were examined. Results showed that acidic and neutral pH values were more favorable for MB oxidation than basic pH values. Based on experimental results, increasing the temperature from 55 to 80 (°C), and oxidant dose from 500 to 2000 (mg/L) enhanced the color removal efficiency (CR%) from 36% to 99.5% and from 55% to 98%, respectively. Kinetic study indicated that MB dye removal was a pseudo first-order reaction with respect to the various concentrations of MB and persulfate. Activation energy for the hot persulfate oxidation of MB was obtained as 112.3 (kJ/mol). To analyze the experimental data, an experimental design was applied by considering four operating parameters, including initial dye concentration, oxidant dosage, temperature and reaction time as input variables. A model was proposed for the statistical analysis of color removal prediction. Model predictions were found to be in good agreement (R2=0.96, adjusted R2=95.6%) with experimental data.

Preparation of monodispersed polystyrene microspheres and self-assembly of photonic crystals for structural colors on polyester fabrics

Monodispersed polystyrene (PS) microspheres with perfect sphericity and the spherical diameter ranging from 200 to 400 nm were prepared by soap-free emulsion polymerization. The spherical size of PS microspheres can be regulated by controlling the styrene concentration, potassium persulfate concentration, and polymerization time. The monodispersed PS microspheres were self-assembled by gravity into photonic crystals on polyester fabrics to generate bright structural colors. Scanning electron microscopy (SEM) observation and crystallographic analysis confirmed a face-centered cubic structure (FCC structure) of the photonic crystals. The structural color of the photonic crystals is governed by the photonic band gap dependent upon the viewing angle and the size of PS microspheres. The resultant polyester fabrics with the photonic crystals showed bright structural colors changing with the viewing angle, displaying a biomimetic variable color effect on the textiles.

Study on Preparation and Application as Organic Particulate Retention Agent of Chitosan-AM-DMDAAC Inverse Latex

Graft copolymerization of acrylamide (AM) and diallyl dimethyl ammonium chloride (DMDAAC) onto chitosan in inverse emulsion was studied. The effect on Zeta potential and average granularity of synthetic inverse latex of the main reaction conditions such as the proportion of cationic monomer in total monomers, concentration of potassium persulfate (KPS) used as initiating agent were investigated in detail. It was shown that when the weight ratio of chitosan, AM and DMDAAC was 1:6:2, KPS concentration was 4.0mmol/L, NaHSO3concentration was 2.0mmol/L, stable inverse latex which had optimal performance could be gained. Good retention effect was obtained when a novel organic microparticle retention system composed of the above-mentioned chitosan-AM-DMDAAC inverse latex and anicnic polyacryamide (APAM) was applied to the deink pulp. First Pass Retention retention percentage of deink pulp was improved from 83.2% to 95.0% with the organic microparticle retention system when the dosage of inverse latex was from 0 to 0.4% of absolute dry pulp.

Homogeneously distributed magnetite in the polystyrene spherical particles using the miniemulsion polymerization

The polystyrene spherical particles with homogeneously distributed magnetites were prepared using the conventional miniemulsion polymerization. In the first, the magnetite nanoparticles were coated with oleic acid in aqueous Fe 3+/Fe 2+ solution using excess ammonium hydroxide via co-precipitation method. In the second, the miniemulsion polymerization of styrene was carried out using various concentrations of potassium persulfate (KPS) as an initiator, H-08E as an emulsifier, hexadecane as a co-emulsifier and acrylic acid as a dispersing agent in the presence of oleic acid coated magnetite at 70 °C for 24 h. The particle size and its distribution of the homogeneously embedded magnetites were influenced by the concentration of the initiator (KPS) and acrylic acid (AAc). In addition, the emulsifier, H-08E, affects the size and the shape of the PS particles. The optimum conditions for the homogeneously distributed magnetite in the spherical PS particles with the narrow distribution were 5 wt.% styrene, 0.2 g KPS, 0.2 g AAc, and 0.12 g H-08E by inducing 364 nm in diameter, 12.04% in the coefficient of variation ( C v) and 22.1% of the maximum magnetite content.

Effect of surface treatment with potassium persulfate on dispersion stability of multi-walled carbon nanotubes

Muti-walled carbon nanotubes (MWCNTs) were treated with different concentrations of potassium persulfate (KPS; K 2S 2O 8) to improve their dispersion stability, which were characterized by thermal gravimetric analysis, ultraviolet/visible spectroscopy, field emission scanning electron microscopy and field emission transmission electron microscopy. The amount of sulfate groups on the MWCNTs increased with increasing KPS concentration, which enhanced the hydrophilicity, but deteriorated the dispersion stability. The optimal KPS concentration for the best dispersion stability of the KPS-treated MWCNTs was 0.01 M.

Hg 0 oxidative absorption by K 2S 2O 8 solution catalyzed by Ag + and Cu 2+

The aqueous phase oxidation of gaseous elemental mercury (Hg 0) by potassium persulfate (K 2S 2O 8, KPS) catalyzed by Ag + and Cu 2+ was investigated using a glass bubble column reactor. Concentrations of gaseous Hg 0 and aqueous Hg 2+ were measured by cold vapor generation atomic absorption spectrometry (CVAAS). The effects of several experimental parameters on the oxidation were studied; these include different types of catalysts, pHs and concentrations of potassium persulfate, temperatures, Hg 0 inlet concentrations and tertiary butanol (TBA). The results showed that the removal efficiency of Hg 0 increased with increasing concentration of potassium persulfate and catalysts Ag +, Cu 2+ and Ag + provided better catalytic effect than Cu 2+. For example, in the presence of 5.0 mmol l −1 KPS, the mercury removal efficiency could reach 75.4 and 97.0% for an Ag + concentration of 0.1 and 0.3 mmol l −1, respectively, and 69.8 and 81.9% for 0.1 and 0.3 mmol l −1 Cu 2+. On the other hand, high temperature and the introduction of TBA negatively affect the oxidation. Furthermore, the removal efficiency of Hg 0 was much greater in neutral solution than in either acidic or alkaline solution. But the influence of pH was almost eliminated upon the addition of Ag + and Cu 2+, and high Hg 0 inlet concentration also has positive impact on the removal efficiency of Hg 0. The possible catalytic oxidation mechanism of gaseous mercury by KPS was also proposed.

Catalytic Polymerization of Acrylonitrile by Khulays Bentonite

The aqueous polymerization of acrylonitrile (AN) catalyzed with exchanged Khulays bentonite . The influence of various polymerization parameters ( e.g., concentrations of Potassium Persulfate (K2S2O8) and monomer , various of organic solvents, and different temperature has been investigated. It was found that the rate of polymerization of AN was found to be dependent on monomer concentration, initiator and temperature. The activation energy of polymerization was calculated .Thermal properties of the polymer were studied by TGA and DSC techniques. © 2007 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0)