Oxidation Process Research Articles

Mechanism of removal of Sb from printing and dyeing wastewater by a novel titanium-manganese binary oxide.

Antimony (Sb) is a toxic heavy metal that endangers both the environment and human health. In response to the growing need for efficient Sb removal from printing and dyeing wastewater (PDW), this study introduces a novel titanium-manganese binary oxide adsorbent (T2M1BO) synthesized via precipitation. Experimental results show that T2M1BO exhibited higher absorption efficiency for Sb(III) compared to Sb(V), with maximum adsorption capacities recorded at 323.19mg/g for Sb(III) and 273.65mg/g for Sb(V) at pH 5. The findings emphasize the synergistic interaction between titanium and manganese oxides, which enhances the adsorption of antimony. Adsorption followed a pseudo-second-order kinetic model, consistent with the Freundlich isotherm model. While Sb(V) adsorption involved surface metal hydroxyl group replacement and inner-sphere complex formation, Sb(III) removal required a more complex approach, incorporating adsorption and oxidation processes. The straightforward synthesis, high efficiency, and recyclability of T2M1BO position it as a cpromising candidate for antimony removal in recyclability wastewater treatment.

NH2-MIL-125(Ti)/TiO2 heterojunction with non-disturbed dual reactive centers for synchronous photocatalytic removal of Cr(VI) and organic dyes.

Chromium (VI) (Cr(VI)) generally coexists with organic dyes in industrial effluents, posing a formidable challenge in water purification. Herein, NH2-MIL-125(Ti)/TiO2 Z-scheme heterojunction with intimate interfacial contact was synthesized for synchronous removal of pollutant in coexisting Cr(VI)/dyes system under simulated solar irradiation. Structural and optical investigations indicated that a well-defined interface was formed by establishing a Ti-N-C bond, facilitating the spatial separation of the photoexcited carriers of the Z-scheme heterojunction. The optimum NH2-MIL-125(Ti)/TiO2 nanocomposites show superior performance in photocatalytic removal of the pollutants in the Cr(VI) (5mg/L, 97.2%)/MB (40mg/L, 100%) coexistence systems within 120min, which is comparable to that in the single system. The electron spin resonance (ESR) tests, radicals scavenging experiments, and density functional theory (DFT) cannulations unveiled that TiO2 could serve as oxidation centers to generate hydroxyl radicals (•OH) for MB oxidation, while the NH2-MIL-125(Ti) with exposed Ti nodes could act as reduction centers to effectively adsorb Cr2O72- and inject photo-generated electrons (e-) to accomplish the in-site photoreduction of Cr(VI) into Cr(III) under illumination. Particularly, owing to the spatial separation and non-disturbed dual reactive centers, the reduction and oxidation processes could be well accommodated, which could allow MB and Cr(VI) to be removed synchronously. This work demonstrated the great potential of applying duel reactive centers to eliminate multipollutant simultaneously in the actual scenarios for wastewater treatment.

Study on electromagnetic characteristics and microwave sintering process of iron oxides

Study on electromagnetic characteristics and microwave sintering process of iron oxides

Start-up of Anammox-HAP in IC reactors: Revelation of sludge characteristics and microbial community structure.

The scarcity of seed sludge poses a significant barrier to the advancement of anaerobic ammonia oxidation (anammox) process. In this investigation, two alternative sludge (anaerobic granular sludge (AGS) and activated flocculent sludge (AFS)) were employed to start up the anammox process in internal circulation (IC) reactors with the hydroxyapatite (HAP) strategy. Both reactors achieved rapid start-up on days 83 and 53, respectively. Subsequently, a nitrogen removal rate (NRR) of 1.34 gN/L/d was attained at a nitrogen loading rate (NLR) of 1.39 gN/L/d on days 107 and 81 correspondingly. The analysis of granular properties revealed that the anammox granular sludge (AMXGS) transformed from AGS exhibited superior granular size distribution and settling performance. Furthermore, the assessment of microbial community structure demonstrated that inoculating AFS was capable of enriching anammox bacteria (AnAOB) in a shorter time. Last but most importantly, this study provides a comprehensive analysis of the distinct granulation routes of AGS and AFS. AGS predominantly underwent a "broken-adsorption-granulation" process, whereas AFS exhibited not only a typical "adsorption-granulation" process but also a "biofilm growth-granulation" cycle process. The findings of this study offer a novel approach for quickly initiating anammox process when inoculating alternative sludge.

Research note: Reduction of Salmonella enterica in simulated wastewater using electrochemical and photochemical processes.

Salmonella is a poultry-borne pathogen causing numerous human outbreaks in the U.S. Consequently, Salmonella, along with other pathogens, can be found in wastewater generated from poultry processing. It is essential to treat this wastewater before discharge, recycle, or reuse. Hence, this study investigated the utility of Advanced Oxidation Processes (AOPs) like electrochemical (EC) and photochemical processes (PC) to disinfect Salmonella in simulated wastewater (contaminated water). Three Salmonella serotypes: Kentucky (SK), Infantis (SI), and Typhimurium (ST) were chosen based on their ability to persist in poultry processing environments and cause infection. These serotypes, prepared in water at 6 to 7 Log10 CFU/mL were exposed to alternating current in EC with a voltage demand of 30 V, 40 V, and 50 V where ammonium sulfate was added as an electrolyte and ferrous sulfate to facilitate AOP production; and PC with curcumin, a photosensitizer at 0.40 % (1X) and 0.80 % (2X) to produce singlet oxygen and hydrogen peroxide that are lethal to pathogens. During the disinfection process, samples were collected every 20 min for 180 min and plated on XLD agar to assess Salmonella reduction. The data were analyzed using ANOVA in SAS. Bacterial reduction differed (P < 0.0001) between serotypes at 30 V and SK had the greatest reduction (3.13 Log10 CFU/mL), whereas there was no difference in reduction between the serotypes at 40 V (P = 0.98) where all the serotypes had more reduction than at 30 V. Complete attenuation of the serotypes was seen at 50 V (P < 0.0001), where SI reduced the most (5.96 Log10 CFU/mL) followed by ST (5.15 Log10 CFU/mL) after 140 min. SK was also attenuated (3.34 Log10 CFU/mL) after 60 min due to a lower starting concentration. This preliminary result suggests that Salmonella in poultry processing wastewater can be effectively attenuated through AOPs, offering a potential solution for enhancing poultry wastewater treatment.

High performance ozone nanobubbles based advanced oxidation processes (AOPs) for degradation of organic pollutants under high pollutant loading.

Advanced Oxidation Processes (AOPs) have proven to be an effective solution for chemical wastewater treatment, particularly for degradation of organic pollutants, especially dyes. Ozonation is recognized as one of the most prevalent AOPs. Nevertheless, some cases show a lowered efficiency of O3 utilization which is attributed to its inadequate distribution in the treated water causing low residence time, low mass transfer coefficient as well as shorter half-life. This study demonstrates the application of ozone nanobubbles to enhance the degradation of organics under high pollution load conditions. We propose an integrated method that utilizes bulk nanobubbles to enhance the reactivity of ozone for the degradation of organics. We examined the degradation of organic pollutants under parameters such as varying pH levels, ozone concentrations and presence of salts and surfactants. The degradation of the organic pollutant by ozone nanobubbles (0.177 L mg-1min-1) demonstrated a threefold increase in reaction rate constants compared to microbubbles (0.025 L mg-1min-1). The plausible reason for these findings is (i) higher mass transfer coefficient (ii) higher ozone solubility (iii) NBs may act as a surface for chemical reaction (iv) NBs may increase the half-life of ozone. The presence of reactive oxygen species was verified using scavenging tests. This part of the studies revealed contribution of reactive oxygen species (ROSs) such as hydroxyl radical (•OH), superoxide radical anion (O2•-) and singlet oxygen (1O2) in the degradation process. The conditions that provide total degradation of 100% in 300s for both organic pollutants (Green rit and methylene blue dye) are: 5 LPM (Litre per minute) ozone flow rate, acidic pH, monovalent salts (NaCl, 2mM) and lower concentration of surfactants (CTAB and SDS, 0.3 CMC). A degradation mechanism has been outlined based on intermediates identified by LC-MS. This work presents a new method that combines AOPs with nanobubbles, which should lead to increased environmental sustainability and efficiency.

Degradation of azo dye (direct red 89) using H2O2/periodate process-parameter optimization and mixture composition evaluation.

As a fast and efficient process, a periodate (PI)-based advanced oxidation process was used to degrade direct red 89 (DR89), wherein hydrogen peroxide (H2O2) was employed to activate PI (H2O2/PI process) to investigate the effect of operating parameters and mixture composition. The PI was efficiently activated by H2O2 to degrade 67% of DR89 within 1min. Acidic pH was more favorable to high-efficiency degradation than the basic pH; at pH 3 degradation rate was 94.31%, while it was only 20.92% at pH 11. The degradation rates were further enhanced with increasing H2O2 and PI dose up to certain optimum values, later it decreased which was dependent upon the amount of hydroxyl (●OH) and iodyl (IO3●) radicals produced. The quenching experiments suggested that IO3●, ●OH, 1O2, and O2●- are the predominant reactive species during H2O2/PI process, while O2●- radicals are the primary precursor of other reactive oxygen species. The results of this study suggested that H2O2/PI is the efficient and rapid treatment method to degrade persistent organic pollutants (POPs) from polluted wastewater sources.

Green chemistry in chemical mechanical planarization through a comparison of amino acid degradability with benzotriazole in advanced oxidation processes

Green chemistry in chemical mechanical planarization through a comparison of amino acid degradability with benzotriazole in advanced oxidation processes

Enhanced adsorption of tetracycline by lanthanum/iron co-modified rice shell biochar: Synthesis, adsorption performance, site energy distribution and regeneration

A novel La/Fe co-modified biochar derived from rice shell (La/Fe@RSBC) was prepared and employed in tetracycline (TC) adsorption from water. The characterizations, kinetics, isotherms, thermodynamics, and site energy distribution (SED) were studied to investigate TC adsorption behaviors. La/Fe@RSBC exhibited the maximum adsorption capacity towards TC of 414.84 mg/g, which was 1.27 ∼ 2.41 folds than that of RSBC, La@RSBC, and Fe@RSBC. The possible adsorption mechanism of TC dominantly involved H bond, surface complexation, pore filling, electrostatic attraction, and π-π electron donor-acceptor (EDA) interaction. Moreover, TC adsorption behavior was spontaneous and endothermic, significantly related to the compositions and dosage of La/Fe@RSBC, initial pH, and solution temperature. Additionally, SED results promulgated that co-loaded Fe and La synergistically enhanced the affinity of biochar and provided more adsorption sites for TC at a higher temperature. The residual TC after regeneration by ethanol dominantly inhibited the third stage of adsorption, that is, the adsorption of TC on the inner surface of La/Fe@RSBC in next run. Importantly, H2O2 combined with La/Fe@RSBC-mediated advanced oxidation process could effectively clear residual TC after ethanol desorption, which obviously improved the service life of La/Fe@RSBC. In addition, the swine wastewater treatment demonstrated that La/Fe@RSBC had a promising potential application in practical application.

Bifunctional sulfur-doped biochar for efficient removal of tetracycline and resistant bacteria via adsorption and peroxydisulfate activation

Sulfur-doped biochar (SBC) was prepared for the efficient removal of tetracycline (TC) and TC-resistant bacteria via the dual functions of adsorption and peroxydisulfate (PDS) activation. One of the prepared SBC/PDS systems was found to remove 93.89 % of TC with 3.11 times the removal efficiency of the system without sulfur doping (i.e., BC/PDS). The SBC/PDS system inactivated approximately 105 CFU/mL of the TC-resistant bacterium Escherichia coli within 90 min, corresponding to 1.14 times the inactivation efficiency of the BC/PDS system. The introduction of sulfur improved the adsorption rate by 3.09 times, likely due to pore filling and hydrogen bonding. The PDS activation of the SBC/PDS system primarily removed TC and E. coli through nonradical oxidation dominated by 1O2 generation, and the main active sites were vacancy defects. TC adsorption may be the key step for determining the reaction rate of nonradical oxidation. A high correlation (R2 = 0.98) was observed between the adsorption capacity and degradation rate constant of different activator systems, which indicated a synergistic effect between the adsorption and oxidation of TC. This study provides a theoretical basis for the development of advanced oxidation processes utilizing bifunctional materials with a nonradical oxidation pathway for the removal of antibiotics and antibiotic-resistant bacteria.

Advances and challenges in the application of confined catalysts in heterogeneous advanced oxidation processes: A review

Advances and challenges in the application of confined catalysts in heterogeneous advanced oxidation processes: A review

Dual action of non-metal doped C2N and Ti3C2T2 heterojunction enhances the catalytic activity of electrochemical simultaneous oxidation of hydrogen peroxide and peroxymonosulfate:A theoretical study.

Electrochemical advanced oxidation processes (EAOPs) are energy-efficient methods for generating activated radicals like HO• and SO4•-, which enable the degradation of difficult-to-mineralize chlorinated organic compounds. This study explored the catalytic activity and reaction mechanism of EAOPs under a dual strategy involving non-metal doped C2N (X@C2N (X = O, F, Si)) and a heterostructured build(X@C2N/Ti3C2T2) using first principles calculation. The non-metal doping and the heterojunction construction can make H2O2 and PMS spontaneously adsorb (Eads< 0), with negative Gibbs free energy for their oxidation to HO• and SO4•-, significantly enhancing catalytic activity. The catalytic activity of the X@C2N catalysts was in the order of O@, F@, and Si@C2N. The loading of Ti3C2T2 improved the stability and activity of the material, while Ti3C2F2 and Ti3C2O2 proved superior as heterojunction carriers compared to Ti3C2(OH)2. Notably, O@C2N/Ti3C2F2 is proved to be an appropriate catalyst for simultaneous hydrogen peroxide (ΔGmax = -0.90 eV) and peroxymonosulfate (ΔGmax = -0.99 eV) oxidation reactions, achieving non-selective generation of oxidants in electrochemistry. 2,4-D can be effectively degraded by surface-generated HO• and SO4•-, with the reactivity of SO4•- towards 2,4-D greater than that of HO•. This research highlights the potential of combining heteroatom doping with heterojunction catalyst formation to enhance EAOPs for environmental remediation.

Electrochemical Advanced Oxidation Processes as a feasible approach towards treatment of pesticides contaminated water and environmental sustainability: A review

Electrochemical Advanced Oxidation Processes as a feasible approach towards treatment of pesticides contaminated water and environmental sustainability: A review

Confinement of reactive species in close proximity to pollutants achieves ultrafast advanced oxidation processes in core-shell CoOx@FeOx/pC

Confinement of reactive species in close proximity to pollutants achieves ultrafast advanced oxidation processes in core-shell CoOx@FeOx/pC

Effect of surface iodine atom on dissolved oxygen activation for enhanced photocatalytic advanced oxidation processes over Bi2WO6 nanosheet

Effect of surface iodine atom on dissolved oxygen activation for enhanced photocatalytic advanced oxidation processes over Bi2WO6 nanosheet

Titanomagnetite Rims on Hornblende Phenocrysts in Intermediate Subvolcanic Intrusions, Torud–Ahmad Abad Magmatic Belt, Iran: Examination of Devolatilization and Oxidation Processes

Titanomagnetite Rims on Hornblende Phenocrysts in Intermediate Subvolcanic Intrusions, Torud–Ahmad Abad Magmatic Belt, Iran: Examination of Devolatilization and Oxidation Processes

Bibliometric analysis and research progress on hydrogen peroxide and persulfate oxidation processes in the remediation of actual oil-contaminated soil.

Oil pollution poses significant harm to both the ecological environment and human health. The primary sources of oil pollutants in soil are leaks that occur during the extraction, transportation, and production phases. In the face of the severe situation of global soil pollution, chemical oxidation technology has shown potential in the remediation of oil-contaminated soil. However, most current research on chemical oxidation technology remains in the laboratory stage, with limited discussion on its characteristics and application conditions in the actual treatment of oil-contaminated sites. To address this gap, this paper applies bibliometric methods to analyze the development trends of chemical oxidation technology and provides a comprehensive review from the perspective of its real-world applications in remediating oil-contaminated soil. It explores commonly used activators, enhancement measures, and key influencing factors of advanced oxidation processes, focusing particularly on those based on hydrogen peroxide and persulfate. The study highlights significant advantages, such as improving remediation efficiency, reducing treatment time, and compatibility with other remediation methods. Nevertheless, challenges remain, including soil acidification, limited pollutant targeting, and high operational costs. To address these issues, this paper proposes innovative directions such as the development of green and efficient activators, optimization of oxidant application strategies, and integration of chemical oxidation with other remediation technologies. These findings aim to establish a robust theoretical foundation and provide strong technical support for future chemical oxidation treatments of such soils. Through this research, we aspire to develop more scientific and effective strategies and methods for the remediation of oil-contaminated soil.

Near Infrared-Mediated Intracellular NADH Delivery Strengthens Mitochondrial Function and Stability in Muscle Dysfunction Model.

Mitochondrial transfer emerges as a promising therapy for the restoration of mitochondrial function in damaged cells, mainly due to its limited immunogenicity. However, isolated mitochondria rapidly lose function because they produce little energy outside cells. Therefore, this study investigates whether near infrared (NIR)-mediated nicotinamide adenine dinucleotide (NADH) pre-treatment enhances mitochondrial function and stability in mitochondria-donor cells prior to transplantation. Clinical applications of NADH, an essential electron donor in the oxidative phosphorylation process, are restricted due to the limited cellular uptake of NADH. To address this, a photo-mediated method optimizes direct NADH delivery into cells and increases NADH absorption. L6 cells treated with NADH and irradiated with NIR enhanced NADH uptake, significantly improving mitochondrial energy production and function. Importantly, the improved functional characteristics of the mitochondria are maintained even after isolation from cells. Primed mitochondria, i.e., those enhanced by NIR-mediated NADH uptake (P-MT), are encapsulated in fusogenic liposomes and delivered into muscle cells with mitochondrial dysfunction. Compared to conventional mitochondria, P-MT mitochondria promote greater mitochondrial recovery and muscle regeneration. These findings suggest that NIR-mediated NADH delivery is an effective strategy for improving mitochondrial function, and has the potential to lead to novel treatments for mitochondrial disorders and muscle degeneration.

Polyphenol-Rich Extract of Roselle Improves Oxidative Stress Status, Renal Function and Structure of Diabetic Rat

Diabetic nephropathy is a progressive chronic renal disease, that leads to renal failure mediated by oxidative stress. Roselle or Hibiscus sabdariffa is well-known for its health benefits and is rich in polyphenols with high antioxidant activities. Limited studies evaluate the effects of polyphenol-rich extract of roselle (HPE) on the development of diabetic nephropathy. Hence, this study aimed to determine the effect of HPE in the renal of diabetic rats focusing on oxidative stress, renal function, and structural changes. Type 1 diabetes mellitus was induced in adult male Sprague-Dawley rats which were then divided into three groups: untreated diabetes (DM), HPE-supplemented diabetic rats (DM+HPE), and metformin-treated diabetic rats (DM+MET). Non-diabetic rats (NDM) served as normal controls. All rats were left untreated for four weeks followed by another four weeks of treatment, respectively. At the end of the study, all rats were sacrificed whereby blood was collected for creatinine level analysis, and kidneys were collected for oxidative stress and antioxidant markers as well as histological analyses. Data showed that HPE reduced blood glucose and creatinine levels significantly and improved catalase (CAT) activity. HPE supplementation also reduced the lipid and protein oxidation process, marked by significant reductions in malondialdehyde (MDA) and advanced oxidation protein products (AOPP). Moreover, HPE supplementation improved renal structure, especially in reducing glomerulus degeneration and renal tubule damage. In conclusion, this study suggests that HPE is able to reduce renal damage by mitigating oxidative stress and improving antioxidant status that potentially prevents the progression of diabetic nephropathy in diabetic rat model.

Characteristics and Treatment of Effluent from a Ceramic Fiber Products Manufacturing Factory

Abstract: Wastewater generated from Ceramic Fiber industry poses serious environmental pollution due to its high chemical load and complex composition. This study investigates the wastewater generated from the production of various ceramic fiber products, such as ceramic fiber paper, board, and vacuum formed shapes. As ceramic fiber products provide excellent thermal insulation and are helpful in energy savings, growth of this industry in future is obvious. Though ceramic fiber production uses water in a considerable amount, comprehensive wastewater treatment is a necessity to reduce environmental footprint of this industry. The primary objective of this study was to analyze and characterize wastewater parameters such as Biochemical Oxygen Demand (BOD), Chemical Oxygen Demand (COD), and Total Dissolved Solids (TDS). In this study, the chemical treatment utilizes poly aluminum chloride as a coagulant and poly electrolyte as a flocculant. Chemical treatment yields BOD and COD removal by 70.12% and 73.9% respectively. Further, the aerobic biological treatment provides a reduction of BOD by 77.1% and COD by 63.21%. An advanced oxidation process, ozonation trial was also employed for the evaluation of further reduction of pollutants to bring them within regulatory limits. The ozonation trail yields BOD and COD reduction by 75.2% and 55.8% respectively.