H2O2 Dosage Research Articles

Preparation and utilization of Zn-La oxide nanocatalyst as a binary composite for photocatalytic degradation of methylene blue dye: Optimization through RSM-BBD

In this research, the photocatalytic degradation of methylene blue (MB) dye was explored by employing Zn-La (zinc-lanthanum) oxide nanocatalysts under UV irradiation. Preparation of Zn-La oxide nanocatalysts was executed utilizing the co-precipitation technique, and the surface and morphology of the fabricated nanocatalyst were examined via X-Ray diffraction analysis (XRD), Fourier-transform infrared spectroscopy (FTIR), Brunauer-Emmett-Teller (BET), Barrett-Joyner-Halenda (BJH), Field emission scanning electron microscopy (FESEM), Transmission electron microscopy (TEM), and energy dispersive X-ray (EDX) methods. BET-BJH analysis demonstrated that the specific surface area of the Zn-La oxide nanocatalyst was 20.43 m2/g. Moreover, the response surface methodology (RSM) procedure was utilized to influence the operational factors i.e., catalyst amount, pH, H2O2 dose, and UV power. The quadratic model proposed via the RSM technique with a high R2 value of 0.89, demonstrates its reliability. Besides, the maximum percentage of MB dye removal reached 75.18% under optimal conditions, which include a catalyst amount of 12.05 mg, pH of 9, H2O2 dose of 0.44 mL, UV power of 23 W, and a reaction time of 45 min. Further, under the mentioned conditions, after 120 min, the MB degradation efficiency reached 98.8%. The kinetic study exhibited that the reaction rate constant was 0.0363 min−1. According to the outcomes, Zn-La oxides have a higher ability to remove MB. After 5 consecutive reuse rounds, the reduction in the yield of MB removal using Zn-La oxide nanocatalysts was 5.4%. This study demonstrates that the Zn-La oxide nanocatalyst can be promisingly utilized for the degradation of MB dye suspension solution.

Amperometry for real-time and on-site monitoring of phenol and H2O2 during the treatments

In conventional wastewater treatment processes, a predetermined quantity of chemicals is introduced at the onset, without ongoing monitoring of the treatment progress. Thus, it is difficult to perform timely intervention in the treatment process. Herein, we develop an amperometry-guided wastewater treatment strategy based on a green oxidation process with H2O2 and an iron-tetraamidomacrocyclic ligand (Fe-TAML) catalyst. During the process, users can monitor both phenol and H2O2 concentrations in real time and then intervene by adding more H2O2 to accelerate the reaction. As a proof of concept, a wastewater sample containing 9.3 ppm of phenol is treated by using the amperometry-guided strategy with 1 dosage of Fe-TAML (0.45 ppm) and 3 dosages of H2O2 (1.86 ppm). After the treatment, phenol concentration in the wastewater decreases to 0 ppm after 21 min. In contrast, with only 1 dosage of Fe-TAML (0.45 ppm) and 1 dosage of H2O2 (1.86 ppm), the reaction slows down after 5 min and stops prematurely. After that, the reaction kinetics of ppb-level phenol are investigated, in which the phenol rate and the rate constant are estimated. Compared to conventional detections, the designed amperometry shows faster response, lower limit of detection (LOD, phenol: 11 ppb, H2O2: 80 ppb) and consumable cost, easier operation, and no pollution generated. This example demonstrates the importance of early intervention during wastewater treatment with the help of real-time information.

A new sustainable wastewater management: Simultaneous mineralization and dehalogenation treatment of high salinity dye wastewater

Sustainable management of refractory dye wastewater has become an important operational and environmental issue. Catalytic ozonation is commonly used in dye wastewater treatment to enhance the removal efficiency of TOC. However, it is still a challenge to control the formation of adsorbable organic halogens (AOX) during the oxidation process in high salinity dye wastewater. In order to simultaneously remove TOC and AOX, this study developed an innovative O3+MnOx/GAC + H2O2 treatment process. After optimizing the operating factors such as initial pH and H2O2 dosage, the removal rates of TOC and AOX in dye wastewater reached over 70 % and 80 %, respectively. The possible oxidation mechanism was analyzed through kinetic model, free radical detection and scavenging experiments. The results indicated that MnOx/GAC and H2O2 contributed to the decomposition of ozone, the generation of hydroxyl, and the reduction of reactive halogen species. The toxicity experiments of luminescent bacteria, chlorella and zebrafish eggs showed that the acute toxicity of dye wastewater significantly decreased after O3+MnOx/GAC + H2O2 treatment. This study offered novel insights into the sustainable management of high salinity wastewater through simultaneous mineralization and dehalogenation treatment.

Telomere Length, Mitochondrial DNA, and Micronucleus Yield in Response to Oxidative Stress in Peripheral Blood Mononuclear Cells.

Telomere shortening, chromosomal damage, and mitochondrial dysfunction are major initiators of cell aging and biomarkers of many diseases. However, the underlying correlations between nuclear and mitochondrial DNA alterations remain unclear. We investigated the relationship between telomere length (TL) and micronucleus (MN) and their association with mitochondrial DNA copy number (mtDNAcn) in peripheral blood mononuclear cells (PBMCs) in response to 100 μM and 200 μM of hydrogen peroxide (H2O2) at 44, 72, and 96 h. Significant TL shortening was observed after both doses of H2O2 and at all times (all p < 0.05). A concomitant increase in MN was found at 72 h (p < 0.01) and persisted at 96 h (p < 0.01). An increase in mtDNAcn (p = 0.04) at 200 µM of H2O2 was also found. In PBMCs treated with 200 µM H2O2, a significant inverse correlation was found between TL and MN (r = -0.76, p = 0.03), and mtDNA content was directly correlated with TL (r = 0.6, p = 0.04) and inversely related to MN (r = -0.78, p = 0.02). Telomere shortening is the main triggering mechanism of chromosomal damage in stimulated T lymphocytes under oxidative stress. The significant correlations between nuclear DNA damage and mtDNAcn support the notion of a telomere-mitochondria axis that might influence age-associated pathologies and be a target for the development of relevant anti-aging drugs.

Tuning the carboxyl content of carbon quantum dots by an electrochemical exfoliation method to enhance Fenton-like reactions for contaminants removal in a wide pH range

The complexation of CQDs with Fe(III) through -COO-Fe bond in the CQDs-Fe(III)/H2O2 system can accelerate the Fe(III)/Fe(II) cycle and broaden the pH range for application. However, the yield and carboxyl content of CQDs prepared by conventional electrochemical exfoliation were limited, which hampered the application of CQDs and the enhancement of CQDs Fenton-like process. Hence, in this study, carboxyl-rich and high-yield CQDs were successfully prepared by electrochemical exfoliation of graphite rods in hydrogen peroxide (H2O2) solution. The results suggested that the yield and carboxyl content of the optimal CQDs (CQD@5) were 1.49 and 2.01 times those of CQDs prepared by the conventional electrochemical exfoliation method (CQD@0), respectively. Subsequently, the CQDs were applied in CQDs-Fe(III)/H2O2 systems for phenol degradation. Due to 1.73 times the carboxyl of CQD@ 5 complexing with Fe(III) than that of CQD@ 0, the kinetic constant and removal of the CQD@ 5-Fe(III)/H2O2 system for phenol degradation were 2.36 and 1.44 times those of the CQD@ 0-Fe(III)/H2O2 system at pH= 6, respectively. Under the same condition, Fe(III)/H2O2 and Fe(II)/H2O2 showed negligible degradation performance. Furthermore, the removals of phenol in the CQD@ 5-Fe(III)/H2O2 system were 1.08–7.77 times those of the CQD@ 0-Fe(III)/H2O2 system at pH= 4–8, respectively. Finally, the effect of Fe(III), CQDs, and H2O2 dosages on the phenol degradation, reusability, and universality of CQD@ 5-Fe(III)/H2O2 were investigated individually. In summary, this work provides a new method for tuning the CQDs yield and carboxyl content, which enhances pollutant degradation in CQDs-Fe(III)/H2O2 systems at a wide pH range.

The interplay of low H2O2 doses, lytic cyanophage, and Microcystis aeruginosa: Implications for cyanobacterial bloom control and microcystin production/release

Low H2O2 doses can suppress cyanobacterial blooms without damaging non-target species but enable undesirable regrowth. Besides, the role of cyanophage in preventing regrowth after low H2O2 exposure remains unclear. Applying phages to cyanobacteria pre-exposed to low H2O2 in early growth stages may improve host removal and reduce microcystin (MC) production/release. Lytic cyanophage MDM-1 with a 172 PFU/cell burst size, 2-day short latent period against MCs-producing Microcystis, shows high H2O2 stability. Low H2O2 (1 to 2.5 mg/L) doses significantly (p < 0.05) inhibited Microcystis aeruginosa growth rate, biofilm and MCs concentration reduction in a dose-dependent manner but regrowth occurred at all concentrations. Phage treatment eliminated cells without H2O2 pretreatment within 3 days and reduced MC production. H2O2-pretreated M. aeruginosa cells altered the phage dynamics, affecting adsorption, latency, production, and cell lysis in response to H2O2-induced oxidative stress. At 1.5 mg H2O2/L pretreatment, cells were eliminated with reduced MC production, like untreated cells. H2O2 pretreatment with 2.0 and 2.5 mg/L resulted in an extension of the phage absorption phase and the latent period. This was accompanied by a reduction in lysis efficacy, attributed to the increased ROS production. At 2.5 mg H2O2/L, 17.10 % of phages remain un-adsorbed, with cell lysis rate dropped from 0.89 d−1 to 0.26 d−1 compared to the untreated control. The highest phage titer (70 %) was obtained with 1.5 mg/H2O2 pretreated cells. This study emphasizes that low-dose H2O2 eliminates Microcystis but severely affects phage lysis and MCs release depending on H2O2-induced ROS levels. It is a crucial consideration when using phages to control cyanobacterial blooms with H2O2-induced stress.

Exploiting a dosage model to enhance Photo‐Fenton process performance

The performance of Photo-Fenton treatments is reported to heavily rely on how hydrogen peroxide is supplied. Rigorously optimizing the dosage profile of hydrogen profile is a challenge that has been hardly addressed. Although some model-based approaches have been explored, solutions of practical significance have not been produced. However, model-based approaches can be used to explore new dosage schemes and identify practical sub-optimal improvements. This work addressed the photo-Fenton degradation of Paracetamol (PCT) in an annular photoreactor, and used a kinetic model including variable H2O2 dosage previously fit and reported for simulating new dosage schemes for unexplored operational conditions. Preliminary results allowed understanding trends and proposing new simulations, which in turn allowed identifying promising operation alternatives. Finally, experimental validation confirmed that significant reduction of TOC levels (20 percent points, beyond 80%) are possible. Furthermore, alternatives that could reach total mineralization were also identified for larger processing times (beyond 20 h). Thus, the work has once again demonstrated that model exploitation allows producing significant practical outcomes with a much-reduced experimental effort, and has produced unexplored hydrogen peroxide dosage schemes that increase the process performance reported previously and indicates the way to total mineralization.

COMBINATION OF PHOTOCATALIST TiO2 (Titanium Dioxide) AND H2O2 (Hydrogen Peroxide) IN LAUNDRY WASTEWATER TREATMENT

Any laundry operation will discharge the waste water directly to the water surface, which can lead to pollution in the water. One method that can be used to treat laundry wastewater is a photocatalytic method with TiO2 (Titanium Dioxide) as an UV-assisted catalyst that is combined with a strong H2O2 oxidizer to produce OH (hydroxyl radical) to oxidize pollutants. The study aims to determine the differences in pH, TSS, BOD, COD, and Phosphate separation values with combination of TiO2 and H2O2 doses with variations in UV exposure time for 30, 60, and 90 minutes. A good quality TSS level obtained in the 60th minute with a dose of 1 g TiO2 and in combination with 10 ml H2O2 can reduce TSS levels by 20 mg/l from the initial TSS with a residual weight of 180 mg/L. A decrease in the quality COD level at a 90 minute clearance time with a dosage of 1 gr TiO2, in a combination of 10 ml H2O2, can reduce the COD levels by 32.5 mg/ l from the original COD value of 89.1 mg/l. A reduction in the phosphate level achieved at the cleaning time of 30 minutes at a combined dose of 4 gr TiO2 in a 40 ml combination, can lower the phosphatic level by 0.05 mg /l from the starting value of 5.61 mg/l and already meet the quality standard of laundry waste water.

Degradation of the cytostatic drug bicalutamide by photo-assisted catalytic wet peroxide oxidation

The presence of cytostatic drugs, such as bicalutamide (BICA), in aquatic compartments reveals the necessity of developing efficient processes for their elimination in wastewater treatment plants (WWTP). This work explores for the first time the use of natural magnetite as a low-cost catalyst in the photo assisted — catalytic wet peroxide oxidation (UV-CWPO) of BICA. For this purpose, real WWTP secondary effluents were spiked with 100 μg/L BICA and subjected to UV-CWPO. Preliminary runs comparing UV photolysis, UV/H2O2, CWPO and UV-CWPO confirmed the synergistic effect of UV radiation and the CWPO process employing magnetite. Afterwards, a parametric study was performed evaluating the influence of the pH, catalyst load, H2O2 dosage, temperature and water matrix. Under optimum operating conditions (pH 0: 6, [magnetite]: 375 mg/L and [H2O2]: 75 mg/L), 99.7 % BICA degradation and 60.7 % mineralization were reached after 30 min in WWTP effluent. UV-CWPO also proved to be effective in hospital wastewater. Catalyst activity was studied in 5 consecutive runs, showing great stability for both BICA removal and TOC elimination. Finally, phytotoxicity tests revealed a lower toxicity in the UV-CWPO effluent compared to the untreated stream. Hence, UV-CWPO proved to be a feasible to eliminate risky cytostatic drugs in relevant environmental matrices.

Efficient nickel extraction from nickel matte by combined atmospheric-oxygen pressure acid leaching: Thermodynamic analysis and sulfur conversion mechanism

Atmospheric acid leaching was prevalently employed in extraction nickel from nickel matte owing to its gentle effect, but the leaching efficiency of nickel still remains limited. In this paper, the efficient nickel leaching from nickel matte and sulfur conversion mechanism through the combined atmospheric-oxygen pressure acid leaching process were investigated. Factors affecting nickel leaching and sulfur conversion from nickel matte were systematically investigated on the basis of thermodynamic calculations. The results showed that the nickel leaching rate after atmospheric acid leaching could reach 79.91 % under the optimized conditions of H2SO4 concentration of 300 g/L, H2O2 dosage of 7 %, 80 °C, liquid–solid ratio of 8 mL/g, and 3 h. X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD) and scanning electron microscopy (SEM-EDS) analyses indicated that the S8-coating produced during atmospheric acid leaching and the small amount of NiO passivation film on the surface of the nickel matte impeded the further leaching of nickel. The S8-coating and NiO passivation film were converted to H2SO4 and water-soluble NiSO4, respectively, after the oxygen pressure leaching process. The Ni3S2 and NiS in the nickel matte were released to continue leaching, and the nickel extraction rate reached 99.11 %. The specific optimized process parameters were H2SO4 concentration of 90 g/L, operating pressure of 1.5 MPa, 180 °C, L/S of 10 mL/g and 3 h. This provided a green economical and efficient method for the extraction of nickel from nickel matte.

Emulsified oil fouling resistant cellulose acetate-MoS2-nanocomposite membrane for oily wastewater remediation

This study evaluated the performance stability of amphiphilic cellulose acetate-MoS2-nanocomposite membranes (CMN) on oil removal and flux, oil fouling trends, as well as MoS2's catalytic peroxidase-like efficiency for oily wastewater treatment. When H2O2 was present in the feed, the membrane consistently achieved oil removal rates as high as 83.12 %, with only <10 % flux decline over an 80-minute filtration. During longer-term filtration of 4–6 h, the CMN membrane also exhibited significantly lower overall flux decline rates compared to the neat membrane with flux decline rates of 16.27 %, which was half of the cellulose membrane flux of 39.38 %. The fouling resistant performance was underpinned by the generation of reactive oxygen species (ROS) via catalytic reactions of MoS2 and H2O2. Coumarin was use as ROS scavenging agent and confirmed that the ROS amount was affected by the MoS2 and H2O2 dosages. The CMN membrane achieved the oil removal to the permissible discharge limit for low concentration wastewater. As a low-pressure membrane, it offered advantages of less energy consumption and continuously operating mode without frequent chemical cleaning and desorption. These findings support the CMN membrane's potential as a promising solution for treating industrial oily wastewater.

Cheese wastewater treatment through combined coagulation-flocculation and photo-Fenton-like advanced oxidation processes for reuse in irrigation: effect of operational parameters and phytotoxicity assessment.

The present study aims to investigate the efficiency of a combined cheese wastewater treatment approach involving coagulation with ferric chloride coupled with a photo-Fenton-like oxidation process for potential reuse in irrigation. Laboratory-scale tests were conducted, examining the effect of various operational parameters on the treatment process. Specifically, the effects of initial wastewater pH, coagulant dosage, decantation time for the coagulation process, and initial pH, chemical oxygen demand (COD) concentration, and Fe3+ and H2O2 dosages for photo-Fenton-like oxidation were studied. Coagulation was found effective at natural pH of 6 and showed a highest removal efficiency in terms of COD (50.6%), biological oxygen demand BOD5 (42.1%), turbidity (99.3%), and least sludge volume generation (11.8% v/v) for an optimum coagulant dose of 400mg Fe3+ L-1 and 8h of decantation time. Thereafter, photo-Fenton-like oxidation (Fe3+/H2O2/UVA-300W) of the pretreated cheese effluent enhanced the removal of COD, BOD5 and TOC to 91.2%, 91.4%, and 97.5%, respectively, using the optimized conditions (pH = 3; [Fe3+] = 5.0 × 10-4mol L-1; [H2O2] = 0.2mol L-1 and tirr = 24h). This study also shows that the proposed combined process allowed a significant phytotoxicity reduction toward lentil seed germination. The obtained outcome was encouraging and supports the possible use of the treated cheese wastewater as an additional water source for agricultural irrigation.

Transforming waste brake pads from automobiles into Nano-Catalyst: Synergistic Fe-C-Cu triple sites for efficient fenton-like oxidation of organic pollutants

The arbitrary disposal of used brake pads from motor vehicles has resulted in severe heavy metal pollution and resource wastage, highlighting the urgent need to explore the significant untapped potential of these discarded materials. In this study, The in-situ growth of highly dispersed Fe2O3 nanocrystals was achieved by simple oxidation annealing of brake pad debris(BPD). Interestingly, Cu remained unoxidized and acted as a “valence state transformation bridge of Fe2O3” to construct the “triple Fe-C-Cu sites”. The Fenton degradation experiment of pollutants was conducted under constant temperature conditions at 40 °C, a stirring rate of 1300 rpm, a pH value of 3, a catalyst dosage of 0.5 g/L, pollutant dosage ranging from 50 to 400 mg/L, and H2O2 dosage of 0.25 g/L. Experimental results showed that BPD treated at 300 °C for 2 h exhibited optimal Fenton-like oxidation activity, achieving rapid degradation of over 90 % of refractory antibiotics, such as tetracycline and ciprofloxacin, in organic wastewater within 10 min. This remarkable performance was mainly attributed to the synergistic effect of “Fe-C-Cu triple sites”, where the electron-donating role of C in the Fe-C and Cu-C interfaces facilitated the conversion of the Fe(III) to Fe(II) and Cu(II) to Cu(I). In addition, the ability of Cu2+ to accept electrons at the Fe-Cu interface promoted the transition from Fe (II) to Fe (III). This “balance of electron gain and loss” accelerated the interfacial electron transfer and the recycle of dual Fenton sites, Fe(II)/Fe(III) and Cu(I)/Cu(II), to generate more ·OH from H2O2. Therefore, this strategy of functionalizing BPD as Fenton-like catalysts without the addition of external Fe provides intriguing prospects for understanding the construction of Fe-based Fenton catalysts and resource utilization of Fe-containing solid waste materials.

Highly efficient removal of Direct Red 89 from aqueous solution by homogeneous catalyst produced during electrocoagulation for PS/H2O2 activation

The study explored the simultaneous use of peroxydisulfate (PS) and hydrogen peroxide (H2O2) in the electrocoagulation process for efficient removal of direct red 89 (DR89) from aqueous solutions. The study examined the effect of various parameters, including electrode type, electrolyte type and dosage, initial pH, current density, PS and H2O2 dosage, and initial DR89 concentration. The highest efficiency was achieved in acidic conditions using AL-Fe electrodes and Na2SO4 as a supporting electrolyte and applying the highest studied current density (20 mA/cm2). The study found that DR89 removal followed second-order reaction kinetics, and singlet oxygen played a significant role in DR89 degradation.

Combining pretreatments and co-fermentation as successful approach to improve biohydrogen production from dairy cow manure

The present paper is focused on enhancing the production of biohydrogen (bioH2) from dairy cow manure (DCM) through dark fermentation (DF). Two enhancement production strategies have been tested: i) the combination of H2O2 with sonification as pretreatment and ii) the co-fermentation with cheese whey as co-substrate. Concerning the pretreatment, the best combination was investigated according to the response surface methodology (RSM) by varying H2O2 dosage between 0.0015 and 0.06 g/gTS and ultrasonic specific energy input (USEI) between 35.48 and 1419.36 J/gTS. The increase of carbohydrates concentration was used as target parameter. Results showed that the combination of 0.06 g/gTS of H2O2 with 1419.36 J/gTS of USEI maximized the concentration of carbohydrates. The optimized conditions were used to pretreat the substrate prior conducting DF tests. The use of pretreatment resulted in obtaining a cumulative bioH2 volume of 51.25 mL/L and enhanced the bioH2 production by 125% compared to the control test conducted using raw DCM. Moreover, the second strategy, i.e. co-fermentation with cheese whey (20% v/v) as co-substrate ended up to enhancing the DF performance as the bioH2 production reached a value of 334.90 mL/L with an increase of 1372% compared to the control DF test. To further improve the process, dark fermentation effluents (DFEs) were valorized via photo fermentation (PF), obtaining an additional hydrogen production aliquot.

Synergistic potency of ultrasound and solar energy towards oxidation of 2,4-dichlorophenol: a chemometrics approach.

Industrial units based on chemical processes-the textile and paper industries-are major sources of chlorophenols in the environment, and chlorophenolic compounds persist within the environment for a long time with high toxicity levels. The photo-assisted Fenton's and photocatalysis processes were investigated for the degradation of chlorophenols in the present study. Response surface methodology was employed to get optimised conditions for photocatalysis and photo-Fenton process-governing factors, thus, yielding a profound removal efficiency. Under optimised conditions, with a photocatalyst dose of 0.2 g/L, oxidant concentration of 10.0 mM and pH 5.0, complete removal of 2,4-dichlorophenol (2,4-DCP) was observed in 210 minutes in photocatalytic treatment. In the case of the photo-Fenton process, at an H2O2 dose of 5.0 mM and Fe2+ concentration of 0.5 mM, the organic pollutant was eliminated within 5 minutes of reaction time under acidic conditions (pH 3.0). The RSM model reported the perfect fit of experimental data with the predicted response. Among different isotherm models, the Langmuir isotherm was the best fit. The process followed pseudo-first order rate kinetics among various kinetics models. For the obtained optimised conditions, sonication and solar energy-driven processes were incorporated to study enhanced mineralisation. The solar-assisted Fenton process reported maximum mineralisation (90%) and cost-effective ($0.01/litre for 100 mg/L 2,4-DCP) treatment among different hybrid oxidation processes. The work provides insight into harnessing the naturally available solar energy, reducing the overall treatment cost and opting for a sustainable treatment method.

Removal of organic pollutants from sugarcane stillage using UV-assisted Fenton process

Stillage or distillery wastewater have been reported as industrial effluent that are difficult to be treated as its discharge in the water bodies presents contamination with recalcitrant and non-degradable pollutants. Due to their complicated structure, stillage treatment process using traditional methods such as adsorption, coagulation, and flocculation is challenging. Fenton reaction has been found as an effective method to degrade these contaminants through hydroxyl radicals. In this study, the removal of pollutants in stillage was investigated using UV-assisted Fenton process. Experiments was conducted for 60 minutes in a batch reactor with initial pH of stillage 4.5, UV lamp of 395-400 nm, and constant speed of 250 rpm, while the dosages of H2O2 and Fe (II) were kept constant at 3.3 g/L and 0.6 g Fe/L, respectively. The profile of chemical oxygen demand (COD) removal, pH, temperature, and oxidation-reduction potential (ORP) was evaluated under three dilution factors of raw stillage (1/10; 1/25; and 1/50) during treatment process to investigate the effects of these parameters on treatment efficiency. It has been observed that initial COD of stillage had considerable effect on the performance of UV-photo-Fenton treatment, as higher dilution factor increases the removal efficiency of COD from stillage. The degradation of COD by UV-assisted Fenton was found to be suitably described by the pseudo-first-order kinetics. The results obtained from this work indicated that UV-Fenton can be introduced as a successful advanced treatment process for efficient degradation of stillage.

Efficiency and Cost of the “Fenton+Recapter” Combined Process for Treating the Electroplating Nickel Wastewater

The aim of this work was to investigate the “Fenton+Recapter” combined process for treating electroplating nickel wastewater. Firstly, five commonly used dithiocarbamate heavy recapters (DTC types) were compared and selected through trial tests. Then, the optimization of the sole Fenton process was carried out, including the dosing molar ratio of Fe2+/H2O2, the dosage of H2O2 and the reaction time. At last, the optimization and cost analysis of the combination process was carried out to meet the nickel wastewater treatment standards and to determine the optimal fit point. The experimental results showed that DTC-2 was a more suitable heavy recapter, with advantages of wide pH adaptation range (3.0-11.0), strong anti-interference, fast Ni removal rate, and low cost (1.20 ¥/t). The optimal molar ratio of Fe2+/H2O2 in the sole Fenton process was determined to be 0.8, which resulted in the optimum breaking effect and a 98.5% removal rate of Ni. The optimization of the combined process parameters showed that when the dosage of heavy recapter DTC-2 (1%) was 0.08 mg/L, 0.19 mg/L, 0.5 mg/L, 1.25 mg/L, 7.5 mg/L, and 25 mL/L respectively, the residual concentration of Ni in Fenton effluent was 0.2 mg/L, 0.3 mg/L, 0.5 mg/L, 0.7 mg/L, 1.0 mg/L, and 1.5 mg/L, which all could meet the discharge standards (concentration of Ni ≤0.1 mg/L). The best fit for the “Fenton+Recapter” combined process was to first treat nickel wastewater with Fenton until the Ni concentration was about 1.0 mg/L, and then use heavy recapter DTC-2 to capture and treat the wastewater until it meets the standard discharge. Under this condition, the treatment cost of the combined process was the lowest (7.79 ¥/t).

Exploring the toxicity and carcinogenic potential of 300 KDA “Mito Organelles”™ cellular extracts through MTT and BALB/C-3T3 cell transformation assays: a vital component of peptide and protein biomedical research and safety study

The MTT assay, an essential component of our research, evaluates cellular metabolic activity to indicate cell viability, proliferation, and the cytotoxic effects of therapeutic products utilized as cellular therapy agents. The objectives of this study were: to investigate and assess the potential cytotoxicity and carcinogenesis of the selected range of the medicinal biological products - 300 kDa cellular extracts “Mito Organelles” of the following types: heart, brain, kidney, cartilage, thymus, placenta, lungs, connective tissue, and a combo LPPSIMKE (liver, pancreas, placenta, kidney, intestines, retina); evaluate carcinogenic potential; compare toxicity; provide recommendations for biomedical research and application. Materials and methods: The MCF-7 human breast cancer cell line was used for the MTT assay. Cells were cultured in standard MCF-7 medium (DMEM supplemented with 10% fetal bovine serum and 1% penicillin-streptomycin) under controlled conditions at 37°C and 5% CO₂ in a humidified incubator. Different protein solutions (designated as MOs) were tested for their effects on MCF-7 cells. The BALB-CTA offers essential information to assess cell viability and carcinogenic potential following treatment with MOs 300 kDA cellular peptide/protein extracts. Material processing was carried out using MS Excel and Statistica EZR version 1.62-2023 statistical programs. Dunn's test, Kruskal-Wallis rank univariate analysis, Scheffe, Student's parametric t-test were used to assess differences between groups. The difference was considered statistically significant at p &lt;0.05. Results: According to MTT assays, the 300 kDA peptide/protein cellular extracts “MitoOrganelles” (MOs) tested did not affect the viability of MCF-7 cells. In addition, cells that were stressed with low doses of H2O2 were able to improve their vitality through the addition of MOs 300 kDa. The BALB/c-3T3 two-stage in vitro transformation assay (CTAs), a model for studying carcinogenesis, is another important tool in our research. It showed chemical transformation with morphologically aberrant foci after treatment with MCA and TPA. In contrast, various 300 kDA peptide/protein cellular extracts were tested, and no carcinogenic activity was observed, reinforcing the safety profile of these cellular extracts. The confidence in our research methods, particularly the MTT and BALB/c-3T3 assays, is crucial in understanding the safety profile of these cellular extracts. Conclusion: The comparative study conducted on the cytotoxicity and potential adverse effects of these extracts on cell viability and metabolic activity revealed that the selected range of medicinal biological products-specifically, the cellular extracts known as "Mito Organelles" from heart, brain, kidney, cartilage, thymus, placenta, lungs, connective tissue, and the combo LPPSIMKE (liver, pancreas, placenta, kidney, intestines, retina)-showed no cytotoxic effects on human cells. Additionally, no potential for malignant transformation or morphological changes were observed in the treated cell lines, and there were no negative impacts on cell viability or transformation rates. The results of these assays support recommendations for the safe use of Mito Organelles cellular extracts in biomedical research and therapeutic applications within regenerative medicine.

Optimizing the micro/mesoporous structure of hierarchical graphene aerogel for CO2 capture by controlling the oxygen functional groups of graphene oxide

BackgroundGraphene aerogels as solid porous adsorbents are great candidates for CO2 adsorption based on their tunable hierarchical pore structure and oxygenated groups on graphene oxide can control the self-assembly and pore structure of graphene aerogels. MethodsModified Hummer's method was used to synthesize graphene oxides by using various levels of H2SO4, KMnO4, and H2O2 and 3D graphene aerogels were synthesized via the hydrothermal and freeze-drying method. FTIR, RAMAN, XRD, FE-SEM, and BET analysis were used for characterizations. Significance findingsThe effect of graphite oxidation conditions on the hierarchical porous structure of graphene aerogel for CO2 adsorption was investigated. The graphene aerogel with the high meso and micro surface areas and the highest Sm/ST value (micro surface area/total micro and meso surface area) of 33% and also, the adequate macropores was achieved using high dosage of H2SO4 in the graphene oxidation process led to the highest CO2 adsorption capacity of 1.72 mmol/g. increasing the H2O2 dosages increased the macropores in the aerogel structure and improved the value of Sm/ST leading to an increase in the CO2 adsorption capacity. The high content of KMnO4 led to low Sm/ST value and fewer macropores and decreased the CO2 adsorption capacity (1.04 mmol/g).