Tubular microreactor-based Fe(II)-driven advanced oxidation: comparative assessment of percarbonate and persulfate systems for toxic dye removal

Promoted elimination of antibiotic sulfamethoxazole in water using sodium percarbonate activated by ozone: Mechanism, degradation pathway and toxicity assessment

Degradation of tetracycline antibiotics by Fe2+-catalyzed percarbonate oxidation

Mechanism of PCE oxidation by percarbonate in a chelated Fe(II)-based catalyzed system

Heterogeneous catalytic activation of percarbonate by ferrocene for degradation of toxic amaranth dye in water

Non-thermal plasma activated peroxide and percarbonate for tetracycline and oxytetracycline degradation: Synergistic performance, degradation pathways, and toxicity evaluation

Activation of sodium percarbonate by vanadium for the degradation of aniline in water: Mechanism and identification of reactive species

Sodium percarbonate (SPC) is a widely used oxidant with applications in environmental remediation, especially within advanced oxidation processes (AOPs). Despite its prevalence, traditional methods for SPC quantification are often limited by complexity, cost, or lack of adaptability, creating a need for rapid, reliable, and scalable analytical approaches. This study presents a novel method for SPC quantification using a modified high-performance liquid chromatography with visible detection (HPLC-VIS) system. The key innovation lies in replacing the conventional separation column with a narrow-diameter loop reactor made of simple PEEK tubing, allowing SPC to react with acidified potassium iodide directly within the system. This modification eliminates the need for separate sample pretreatment, simplifies the analytical workflow, and enables real-time reaction monitoring while using standard HPLC equipment available in most laboratories. The method demonstrated high repeatability, reproducibility, and strong linearity (R 2 > 0.99) across a range of pH values and in complex matrices, including highly saline and organic pollutant-containing samples. The method effectively monitored residual SPC levels in AOP-treated tramadol samples, where it confirmed continued SPC activity post-degradation of the target compound, indicating potential for comprehensive degradation of byproducts. Additionally, tests on a commercial SPC-based detergent (Vanish) validated the method's applicability for real-world samples. Overall, this HPLC-based technique provides a streamlined, environmentally friendly, and robust solution for SPC quantification, offering significant advantages for both research and industrial applications involving SPC in various water matrices.

Activation of sodium percarbonate by micro amounts of copper for highly efficient degradation of acid orange 7

Ozonation of textile effluents and dye solutions under continuous operation: Influence of operating parameters

Decomposition and mineralization of cefaclor by ionizing radiation: Kinetics and effects of the radical scavengers

Investigation of biosorption of Gemazol Turquise Blue-G reactive dye by dried Rhizopus arrhizus in batch and continuous systems

Efficiency assessment of municipal landfill leachate treatment during advanced oxidation process (AOP) with biochar adsorption (BC)

Percarbonate promoted antibiotic decomposition in dielectric barrier discharge plasma.

1. The effect of eight salts, NaCl, Na2SO4, Na4Fe(CN)6, CaCl2, LaCl3, ThCl4, and basic and acid fuchsin on the cataphoretic P.D. between solid particles and aqueous solutions was measured near the point of neutrality of water (pH 5.8). It was found that without the addition of electrolyte the cataphoretic P.D. between particles and water is very minute near the point of neutrality (pH 5.8), often less than 10 millivolts, if care is taken that the solutions are free from impurities. Particles which in the absence of salts have a positive charge in water near the point of neutrality (pH 5.8) are termed positive colloids and particles which have a negative charge under these conditions are termed negative colloids. 2. If care is taken that the addition of the salt does not change the hydrogen ion concentration of the solution (which in these experiments was generally pH 5.8) it can be said in general, that as long as the concentration of salts is not too high, the anions of the salt have the tendency to make the particles more negative (or less positive) and that cations have the opposite effect; and that both effects increase with the increasing valency of the ions. As soon as a maximal P.D. is reached, which varies for each salt and for each type of particles, a further addition of salt depresses the P.D. again. Aside from this general tendency the effects of salts on the P.D. are typically different for positive and negative colloids. 3. Negative colloids (collodion, mastic, Acheson's graphite, gold, and metal proteinates) are rendered more negative by low concentrations of salts with monovalent cation (e.g. Na) the higher the valency of the anion, though the difference in the maximal P.D. is slight for the monovalent Cl and the tetravalent Fe(CN)6 ions. Low concentrations of CaCl2 also make negative colloids more negative but the maximal P.D. is less than for NaCl; even LaCl3 increases the P.D. of negative particles slightly in low concentrations. ThCl4 and basic fuchsin, however, seem to make the negative particles positive even in very low concentrations. 4. Positive colloids (ferric hydroxide, calcium oxalate, casein chloride—the latter at pH 4.0) are practically not affected by NaCl, are rendered slightly negative by high concentrations of Na2SO4, and are rendered more negative by Na4Fe(CN)6 and acid dyes. Low concentrations of CaCl2 and LaCl3 increase the positive charge of the particles until a maximum is reached after which the addition of more salt depresses the P.D. again. 5. It is shown that alkalies (NaOH) act on the cataphoretic P.D. of both negative and positive particles as Na4Fe(CN)6 does at the point of neutrality. 6. Low concentrations of HCl raise the cataphoretic P.D. of particles of collodion, mastic, graphite, and gold until a maximum is reached, after which the P.D. is depressed by a further increase in the concentration of the acid. No reversal in the sign of charge of the particle occurs in the case of collodion, while if a reversal occurs in the case of mastic, gold, and graphite, the P.D. is never more than a few millivolts. When HCl changes the chemical nature of the colloid, e.g. when HCl is added to particles of amphoteric electrolytes like sodium gelatinate, a marked reversal will occur, on account of the transformation of the metal proteinate into a protein-acid salt. 7. A real reversal in the sign of charge of positive particles occurs, however, at neutrality if Na4Fe(CN)6 or an acid dye is added; and in the case of negative colloids when low concentrations of basic dyes or minute traces of ThCl4 are added. 8. Flocculation of the suspensions by salts occurs when the cataphoretic P.D. reaches a critical value which is about 14 millivolts for particles of graphite, gold, or mastic or denatured egg albumin; while for collodion particles it was about 16 millivolts. A critical P.D. of about 15 millivolts was also observed by Northrop and De Kruif for the flocculation of certain bacteria.

In this study, the combined effects of initial dye (40-700 mg/L) and initial reducing sugar concentration (1-15 g/L) on the bioaccumulation of Violet 90 metal-complex dye by growing cells of Candida tropicalis yeast were investigated in growth media containing sugar beet molasses as a carbon and energy source. The bioaccumulation experiments were performed at pH 3 at 30 $^{\circ}$C and at 140 rpm agitation rate in a batch system. The highest uptake was obtained as 61.46% at 14.9 g/L reducing sugar concentration and at 38 mg/L dye concentration while the maximum uptake capacity was achieved as 56.28 mg/g at 3.2 g/L reducing sugar concentration and at 711.1 mg/L dye concentration. Higher uptakes were obtained at lower dye concentrations; higher uptake capacities were observed at higher initial dye concentrations. The combined effects of the initial dye (100-500 mg/L) and initial reducing sugar concentration (5-15 g/L) on dye uptake capacity and growth rate of Candida tropicalis yeast were also investigated by response surface methodology (RSM). Optimum design variables from RSM were calculated by numerical optimization with the Design Expert program. The optimum values of the variables to maximize uptake capacity were estimated as 5.1 g/L reducing sugar concentration and 499 mg/L dye concentration. The maximum uptake capacity was achieved as 41.3 mg/g at these optimized conditions.