FeSO4 Research Articles

Antioxidant Activity, Antiproliferative Activity, Antiviral Activity, NO Production Inhibition, and Chemical Composition of Essential Oils and Crude Extracts of Leaves, Flower Buds, and Stems of Tetradenia riparia.

The chemical composition of extracts (CEs) and essential oils (EOs) from Tetradenia riparia leaves, flower buds, and stems was analyzed. Antiproliferative activity against tumor cell lines, NO production inhibition, and antioxidant and antiviral activities were assessed. The CEs contained flavonoids, phenolic acids, coumarins, and saturated fatty acids. The EOs included monoterpenes, oxygenated sesquiterpenes, and diterpenes. NO production inhibition ranged from 76 to 247 µg mL-1, and antiproliferative activity exhibited GI50 between 20 and >204 µg mL-1, with low cytotoxicity (SI: 1.08 to 4.75). Reactive oxygen species inhibition ranged from 45 to 82%. Antioxidant activity varied when determined by the 2,2-diphenyl-1-picrylhydrazyl radical scavenging assay (IC50: 0.51 to 8.47 mg mL-1) and ferric reducing antioxidant power (0.35 to 0.81 µM ferrous sulfate per mg). The reduction in β-carotene-linoleic acid co-oxidation varied between 76.13 and 102.25%. The total phenolic content of CEs and EOs was 10.70 to 111.68 µg gallic acid mg-1. Antiviral activity against herpes simplex virus type 1 (HSV-1) showed an EC50 between 9.64 and 24.55 µg mL-1 and an SI between 8.67 and 15.04. Leaf EOs exhibited an EC50 of 9.64 µg mL-1 and an SI of 15.04. Our study unveils the diverse chemical composition and multifaceted pharmacological properties of T. riparia, demonstrating its potential as a valuable source of bioactive compounds for therapeutic applications.

Establishment of a promising vitiligo mouse model for pathogenesis and treatment studies

AimsVitiligo is a chronic dermatological condition characterized by the progressive loss of melanocytes, for which traditional therapy has shown limited efficacy. This study aimed to establish a vitiligo model with easy operability, high repeatability, and stable depigmentation to provide a foundation for studying the pathogenesis and developing novel therapies for vitiligo.Methods(1) Establishing vitiligo model: Firstly, deliver B16F10 cells to the back skin of C57BL/6 J via intradermal injection (day 0), and the CD4 depletion antibody was injected intraperitoneally on day 4 and 10. Secondly, the melanoma was surgically removed on day 12. Thirdly, CD8 antibody was administered intraperitoneally every fourth day till day 30. (2) Identification of vitiligo model: H&E staining, immunohistochemistry, and immunofluorescence were used to detect the melanocytes. The melanin was detected by transmission electron microscopy (TEM), Lillie ferrous sulfate staining and L-DOPA staining.Results(1) The back skin and hair began to appear white on day 30. Melanin loss reached peak on day 60; (2) Hematoxylin and eosin (H&E) staining, immunohistochemistry and immunofluorescence results showed melanocytes were reduced. L-DOPA staining, Lillie ferrous sulfate staining and TEM results showed that melanin decreased in the epidermis.ConclusionWe successfully establishment a vitiligo mouse model which can be more capable to simulate the pathogenesis of human vitiligo and provide an important basis for the study of pathogenesis and therapy of vitiligo.

Study the Effect and Safety of Oral Lactoferrin Therapy for Functional Iron Deficiency Anemia in Prevalent Hemodialysis Patients

Abstract Background Anemia is one of the main problems in hemodialysis patients, which is caused by inadequate production of erythropoietin. Functional iron deficiency (FID) anemia is a kind of anemia, which lack of functional iron therein leads to resistance and inappropriate response to erythropoietin in hemodialysis patients. Aim of the Work The aim of the present study was to study the effect and safety of oral lactoferrin therapy for functional iron deficiency anemia in prevalent hemodialysis patients. Patients and Methods This was Randomized clinical trial, was conducted at El Demerdash hemodialysis unit on 70 prevalent hemodialysis patients divided into 2 groups: (Group A): included 35 patients with functional iron deficiency anemia, received lactoferrin together with the recommended dose of ESA therapy for 3 months, (Group B): included 35 patients with functional iron deficiency anemia, received no lactoferrin apart from the recommended dose of ESA therapy for 3 months. Results There was no statistically significant difference between the two studied groups (group A and group B) as regard sex, occupation, residence and age. There was no statistically significant difference between the two studied groups (group A and group B) as regard height, weight and BMI. There was no statistically significant difference between the two studied groups (group A and group B) as regard history. There was no statistically significant difference between the two studied groups (group A and group B) as regard hemoglobin and WBCs. There was no statistically significant difference between the two studied groups (group A and group B) as regard PLT and Reticulocyte %. There was no statistically significant difference between the two studied groups (group A and group B) as regard ferritin, serum iron and TSAT. There was highly statistically significant difference between the two studied groups (group A and group B) as regard KT/V and URR at 3 months. There was nostatistically significant difference between the two studied groups (group A and group B) as regard KT/V and URR at baseline. Conclusion Oral lactoferrin could not be used as a substitute to totally replace IV ferrous sulphate in treating iron deficiency anemia in end stage renal disease (ESRD) on dialysis. Oral lactoferrin could not even control Hb level constant without dropping in patients with end stage renal disease (ESRD). Oral lactoferrin had some gastrointestinal effects on some patients which did not allow compliance on the medication.

Recurrence of Hepatocellular Carcinoma after Living Donor Liver Transplantation Prevalence, Patterns, Perioperative Factors and Outcome

Abstract Background Hepatocellular carcinoma (HCC) is the sixth most common cancer and the third cause of cancer-related mortality world- wide. The incidence of HCC is on the increase, and it is a major threat to our modern life. Epidemiological studies have indicated that HCC are related to chronic hepatitis B virus (HBV) and chronic hepatitis C virus (HCV) infection. Aim of the Work To detect prevalence, patterns, perioperative factors and outcome of recurrence of HCC after living donor liver transplantation. Patients and Methods This was a cross sectional study based on the review of medical records of all patients undergoing LT at Ain Shams Centre of Transplantation, between January 1, 2010, and December 31, 2018. Results we detected prevalence, patterns, perioperative factors and outcome of recurrence of HCC after living donor liver transplantation. Conclusion Oral lactoferrin could not be used as a substitute to totally replace IV ferrous sulphate in treating iron deficiency anemia in end stage renal disease (ESRD) on dialysis. Oral lactoferrin could not even control Hb level constant without dropping in patients with end stage renal disease (ESRD). Oral lactoferrin had some gastrointestinal effects on some patients which did not allow compliance on the medication.

Preparation of thermochromic ink from anthocyanidin-encapsulated alginate nanoparticles for anticounterfeiting applications.

In order to make commercial products less vulnerable to counterfeiting, thermochromic inks have proven to be a viable authentication strategy. Herein, we developed a thermochromic ink for authentication by combining an anthocyanidin (ACYD) extract with alginate (ALG). To increase the anthocyanidin/alginate ink stability, a mordant (ferrous sulfate) was employed to tie up the anthocyanidin biomolecules with alginate. ACYD was extracted from red-cabbage and then immobilized into alginate to serve as an environmentally friendly spectroscopic probe. Thermochromic composite inks (ACYD@ALG) were made by adjusting the content of anthocyanidin. A homogenous blue film (608 nm) was printed on a paper surface and investigated by the CIE Lab coordinate system. The blue color transformed into reddish (477 nm) when heated from 35°C to 65°C. Nanoparticles (NPs) of anthocyanidin/mordant (ACYD/M) were examined for their size and morphology to indicate diameters of 80-90 nm, whereas the ACYD/M-encapsulated alginate nanoparticles showed diameters of 120-150 nm. Multiple analytical techniques were utilized to examine the printed papers. The mechanical and rheological performance of both stamped sheets and ink fluid were explored. The cytotoxicity and antimicrobial efficacy of ink (ACYD@ALG) were investigated.

Reaction Mechanism in Standardized α-Cellulose Content Test: Study from Boehmeria nivea Fiber

In defense industry, α-cellulose is the main component of nitrocellulose propellant. However, a detailed description of the reaction mechanism of each treatment step in SNI 0444-2009 is still very scarce. This study addresses this gap by presenting the reaction mechanisms of each treatment and the symbols used in the SNI 0444-2009 procedure. The separation of lignin from α-cellulose occurred by breaking the C‒O bond linking them. This bond was broken by the ‒OH group of NaOH via a hydrolysis reaction. The reaction was initiated with the elimination of a hydrogen atom from the lignin structure by the hydroxyl ion (‒OH), and the C‒O bond was broken by a hydrolysis reaction. The breaking of this bond was indicated by the disappearance of the IR peaks at wavenumbers 1049 and 1190 cm–1 in the filtrate after extraction. The SNI 0444-2009 method for the α-cellulose content test was carried out by a redox back titration of Cr(VI) with Fe(II) from ferrous ammonium sulfate. This titration was conducted to calculate the amount of Cr(VI) ions in potassium dichromate or Cr(VI) that did not react with lignin or beta cellulose in the filtrate. Understanding the contribution and reaction mechanisms of each compound involved in the SNI 0444-2009 procedure contributed to obtaining accurate data on α-cellulose content. In this study, the calculated α-cellulose content of the flax fiber was 96.75%. Furthermore, the detailed mechanism of the redox reaction was discussed in detail in this paper.

Effect of Mordants on Percentage Absorption of Rubia Cardifolia Dye

This study examines the impact of various mordants on the absorption of Indian Madder Root dye by cotton fabric. The Indian Madder Root dye, derived from the roots of the Indian madder plant, is a natural, eco-friendly alternative to synthetic dyes. The mordants used in this investigation include ferrous sulfate, copper sulfate, zinc sulfate, magnesium sulfate, aluminum potassium sulfate, and potassium dichromate. The absorption of the dye was measured using a colorimeter at a wavelength of 680 nm. The results show that the transition metal mordants, such as copper sulfate and ferrous sulfate, exhibit the highest percentage absorption, while magnesium sulfate shows the least absorption. The study highlights the significance of mordants in enhancing the binding of dyes to fabric, resulting in improved colorfastness and retention of color. The findings of this research have implications for the textile industry, particularly in the development of sustainable and environmentally friendly dyeing processes.

Enhancement of heat transfer through alloys and nanoparticle over a melted sheet: A Koo and Kleinstreuer (K-K) model

Alloys are used in a wide variety of contexts, including aircraft building, the military, industry, medicine, and manufacturing. Alloys including tools, equipment, cars, and structures. Furniture, shipping containers, and medical supply storage containers are among products that benefit from the usage of aluminium alloys. To further enhance simultaneous heat transmission, scientists have developed nano-fluids, which are essentially nano-particle suspensions in a regular fluid. Ferric Sulfate may be added to soil to improve its quality and is also used to clean water. Iron (3+) sulphate is an iron (III) and sulfate (III) combination with a 3:2 ratio of iron (III) to sulfate (III) ions. As a catalyst, mordant, and astringent, it serves several purposes. It is a sulphate of a metal and a molecule of iron. Due of these purposes, we employ the K-K model to study how alloys and nanoparticles affect surface flow and heat transfer. By making use of the boundary layer approach and the flow assumptions, the partial differential equations (PDEs) were generated by approximating the Navier-Stokes equation. This system is transformed into ordinary differential equations (ODE's) using similarity transformations. Using the BVP4C method, a system with non-dimensions is defined. Mathematical and pictorial explanations are provided for the consequences of the key physical variables. It is founded that the magnitude of the temperature field is directly proportional to the R value; a higher value indicates more heat conduction to the liquid. Additionally, the velocity of the fluid lessened by the impact of melting effect.

Dyeing of Silk Yarn With Natural Dye from Teak Leaves

Objective: This study investigated the impacts of using teak leaf-derived natural dye for dyeing silk yarn. Theoretical Framework: This research uses a conceptual framework for the development of natural fibers for application in textile production. By testing the properties of dyed fibers obtained from teak trees cultivated in Thailand. which tests the properties of the fibers and the adhesion of colors obtained from teak trees. Method: This research explored two mordanting methods (pre-mordanting and post-mordanting) across varying conditions. The study documented the ideal parameters for dyeing, as well as color values, color strength, and fastness properties of the silk yarn. Results and Discussion: by dyeing at 90°C for 60 minutes with a pH of 3. Silk yarn treated with a mixture of teak leaf extract and a mordant substance displayed a yellowish-brown color, except when dyed with ferrous sulfate, which produced a dark gray-brown shade. The silk yarn exhibited fair color fastness when subjected to washing and perspiration, while its resistance to light was rated as poor–moderate. On the other hand, the results in terms of rubbing and water fastness showed a good to very good level. Research Implications: The fibers obtained from the research process have the properties of fibers and color adhesion on the yarn that are highly resistant to washing. Moreover, dyed yarn is beautiful and durable. Originality/Value: These findings underscore the potential utility of teak leaf extract-based natural dyes for silk yarn dyeing.

Impact of Partial Substitution of Soybean Meal by Cottonseed Meal with Iron Sulfate Supplementation in Nile Tilapia Diet

Aquatic meals participate in food security and nutrition. The economic dimension greatly influences the sustainability of the aquaculture industry. This study aimed to assess the effects of partial substitution of soybean meal (SBM) with cottonseed meal (CSM) supplemented with ferrous sulfate (FS) on the growth performance and health status of Nile tilapia. One hundred and fifty Nile tilapia (Oreochromis niloticus) were split equally into five group (triplicated). Each group was fed one of the following isonitrogenous isolipid diet; diet1 (0% CSM), diet2 (20% CSM), Diets3 (20% CSM with 580 mg/kg (FS), diet4 (50% CSM), and diet5 (50% CSM with 580 mg/kg FS) of total protein for two months. In comparison to the control group, Statistically significant (p<0.05) improvements in growth performance, hemogram, and leukogram, as well as, the levels of ALT, AST, urea, creatinine, total protein, MDA, and GSH-px were observed in the third treatment . Histopathologically, it showed the highest values of villus height, width, and surface absorption area with normal architecture and cellular details. On the other hand, fish fed diet4 had the lowest growth rat with microcytic normochromic anemia and decreased villus height and width. The groups that fed CSM showed lower cholesterol levels. In conclusion, CSM inclusion with FS supplementation enhanced growth and health parameters.

Effect of Tempering Temperature on Microstructure and Intergranular Corrosion Property of 2205 Duplex Stainless Steel

The effect of tempering temperature on the microstructure and intergranular corrosion property of 2205 duplex stainless steel (DSS2205) was determined using a boiling acid intergranular corrosion test (boiling 65% nitric acid and 50% sulfuric acid–ferric sulfate), an optical microscope, a transmission electron microscope, and a double-loop electrochemical potentiokinetic reactivation (DL-EPR) test. The results show that the ferrite content of the DSS2205 is about 50% in a specimen close to a solid solution state (1050 °C for 1 h, then water-quenched) when tempered at 675 °C–725 °C for 1 h. As the tempering temperature rises to 750 °C–800 °C for 1 h, the ferrite content drops gradually from 49% to 35%. M23C6, FeCr (σ phase), and Cr2N phases are precipitated when the specimen is tempered at 675°C–800 °C for 1 h. When the tempering temperature rises to 750 °C–800 °C for 1 h, the content and size of σ phase increase significantly. In the boiling acid intergranular corrosion test, when the specimen is tempered at 675 °C–725 °C for 1 h, the corrosion rate is higher than when it is tempered at 750 °C–800 °C for 1 h. In the DL-EPR test, when the specimen is tempered at 675 °C–800 °C for 1 h, the intergranular corrosion sensitivity rises gradually. External polarization is added during the DL-EPR test, and the test principle is different from that of the boiling acid intergranular corrosion test, resulting in a different sensitivity to intergranular corrosion compared to boiling acid intergranular corrosion.

Fe2TiO5 nanoparticle-based novel gas sensor with high response to ethanol and acetone

This paper presents a novel Fe2TiO5 sensing material for ethanol and acetone detection. Pure Fe2TiO5 nanomaterial was synthesized by a combined solvothermal and calcination method using ferrous sulfate as precursor and urea as a surfactant. The microstructure and surface morphology indicate that Fe2TiO5 belongs to the orthorhombic crystal structure with a Bbmm space group and is composed of loose aggregates of irregular nanoparticles (20–30nm) and abundant pores. X-ray photoelectron spectroscopy analysis indicates that the Fe2TiO5 aggregates contain mixed valence states of Fe2+ and Fe3+ and abundant oxygen vacancies. Examination of gas sensing properties suggests that Fe2TiO5 is an excellent gas-sensitive material. Particularly, at a low optimum operating temperature (240 °C), the gas response of the Fe2TiO5 aggregates to 100 ppm ethanol and acetone is as high as 84.1 and 220.9, respectively. The linear relationship between log(S-1) and logC indicates that Fe2TiO5 can accurately detect ethanol and acetone over a wide concentration range. The gas-sensing performance of the novel Fe2TiO5 nanomaterial can be explained based on the synergistic effect of oxygen vacancy defects and the characteristic surface morphology.

Adsorption-coupled Fenton type reduction of bromate in water by high-yield polymer-derived ceramic-supported nano-zerovalent iron

Nano-zerovalent iron (nZVI) is a promising material for the removal of both organic and inorganic pollutants from contaminated water. This study investigates the potential of a novel composite of nZVI on a polymer-derived supporting ceramic (nZVI-PDC) synthesized via the liquid-phase reduction method for the simultaneous adsorption and Fenton-type reduction of bromate anion (BrO3−) in water. The nZVI nanoparticles were effectively anchored onto the PDC by impregnating high-yield carbon in a ferrous sulfate solution. The PDC facilitated the uniform dispersion of nZVI nanoparticles due to its multiple active sites distributed within mesocarbon cavities. The developed nZVI-PDC composite exhibited a high specific surface area of 837 m2 g−1 and an ordered mesoporous structure with a pore volume of 0.37 cm3 g−1. As an adsorbent, the nZVI-PDC composite exhibited a maximum adsorption capacity (qe) of 842 mg g−1 and a partition coefficient (KH) of 10.2 mg g−1 μM−1, as calculated by the pseudo-second-order model. As a catalyst, the composite demonstrated a reaction kinetic rate of 43.5 μmol g−1 h−1 within 6 h at pH 4, using a dosage of 60 mg L−1 nZVI-PDC and a concentration of 0.8 mmol L−1 H2O2. Comparatively, PDC exhibited a qe of 408 mg g−1, KH of 1.67 mg g−1 μM−1, and a reaction rate of 20.8 μmol g−1 h−1, while nZVI showed a qe of 456 mg g−1, KH of 2.30 mg g−1 μM−1, and a reaction rate of 27.2 μmol g−1 h−1. The modelling indicated that the nZVI-PDC composite followed pseudo-second-order kinetics. The remarkable removal efficiency of the nZVI-PDC composite was attributed to the synergistic effects between PDC and nZVI, where PDC facilitated charge transfer, promoting Fe2+ generation and the Fe3+/Fe2+ cycle. Overall, this work introduces a promising adsorption technology for the efficient removal of BrO3− from contaminated aqueous solutions, highlighting the significant potential of the nZVI-PDC composite in water purification applications.

Hyaluronic acid as a pulpotomy material in primary molars: an up to 30 months retrospective study

BackgroundThe aim of this retrospective study was to determine the long-term clinical and radiographic success of our previous randomized clinical trial and to compare the success of hyaluronic acid, with the widely used formocresol and ferric sulphate agents.MethodsThis retrospective study is the extension of the 1-year survey of our randomized clinical trial that had compared the effectiveness of a hyaluronic acid pulpotomy over formocresol and ferric sulphate pulpotomies and included clinical and radiographic evaluations with a follow-up period of over 24 months for 44 children who applied to our clinic between May 2019 and September 2019. Long-term clinical and radiographic data were obtained from the periodic files of our department, wherein each tooth’s file was examined to identify any clinical and radiographic findings. Descriptive statistics and Pearson’s chi-square tests were used to evaluate the data. Statistical significance was considered as p < 0.05.ResultsThe clinical and radiographic success rates of the hyaluronic acid, formocresol, and ferric sulphate groups were not statistically different at > 24 months. None of the teeth in the hyaluronic acid group showed any clinical findings at > 24 months.ConclusionsHyaluronic acid pulpotomies exhibited comparable success rates to formocresol and ferric sulphate materials spanning over 24 months examinations. Because of convenient accessibility and applicability of hyaluronic acid, it may be recommended as a promising alternative medicament for pulpotomy treatments of primary molars. However, further long-term follow-up human studies are needed to better understand the effect of hyaluronic acid on the dental pulp of human primary molars.

Comparison of chemical and biological leaching methods with the effect of chloride on the recovery of nickel, cobalt and copper from a pentlandite-pyrrhotite concentrate

In this study, a finely ground nickel sulphide concentrate, consisting mainly of pyrrhotite, pentlandite and chalcopyrite, was leached in shake flask and batch reactor experiments. The objective was to determine the optimal method to recover nickel and cobalt, both hosted in pentlandite, and copper hosted in pentlandite and chalcopyrite respectively. The selected leaching methods tested were sulphuric acid leaching, ferric sulphate leaching and bioleaching. In addition, the effect of chloride ions on the leaching efficiency was evaluated with different concentrations. The results of the chemical leaching experiments showed increase in nickel, cobalt and copper recovery with chloride addition as a result of increased leaching rate for pentlandite and chalcopyrite. The highest yields in the 8-hour reactor experiment (70 % Ni, 66 % Co and Cu 87 %) were obtained in ferric sulphate leaching with chloride concentration of 20 g/L at the temperature of 90 °C. The mineralogical analysis showed that pyrrhotite was dissolved almost completely in all the experiments. Pentlandite and chalcopyrite leaching was clearly improved by the addition of Cl− at similar temperatures.

Grinding siderite with ferric sulfate to generate an active ferrous source for Cr(VI) reduction

Activated siderite, endowed with excellent properties, was simply prepared by co-grinding with Fe sulfate to enhance its high reducing ability for Cr(VI). Batch experiments were conducted to investigate the main affecting parameters, such as material ratio, pH, temperature, etc. The removal of Cr(VI) by activated siderite was completed within 4 h of the reaction. The activated siderite maintained a high removal effect of Cr(VI) within a wide pH range (3–9). Various analytical methods, including XRD, SEM/EDS, XPS, etc., were employed to characterize the samples and discover variations before and after the reaction. The Fe (Ⅱ) in activated siderite becomes highly active, and it can even be released from the solid phase in the mildly acidic liquid phase to efficiently reduce Cr(VI) and mitigate its toxicity. These findings introduce an innovative approach for activating various minerals widely distributed in nature to promote the recovery of the ecological system.

Study on the Influence of Calcination Temperature of Iron Vitriol on the Coloration of Ancient Chinese Traditional Iron Red Overglaze Color.

Iron red, a traditional Jingdezhen overglaze color, is primarily colored with iron oxide (Fe2O3). In traditional processes, the main ingredient for the iron red overglaze color, raw iron red, is produced by calcining iron vitriol (FeSO4·7H2O). Analysis of ancient iron red porcelain samples indicates that the coloration is unstable, ranging from bright red to dark red and occasionally to black. Addressing this, the present study, from a ceramic technology standpoint, conducts a series of calcination experiments on industrial iron vitriol at varying temperatures. Utilizing methodologies such as differential scanning calorimetry-thermogravimetry (DSC-TG), Raman spectroscopy, X-ray diffraction (XRD), scanning electron microscopy with X-ray energy dispersive spectrometry (SEM-EDS), and optical microscopy (OM), this research scientifically explores the impact of iron vitriol's calcination temperature on the coloration of traditional Jingdezhen iron red overglaze color. The findings indicate that from room temperature to 550 °C, the dehydration of iron vitriol resulted in the formation of Fe2(SO4)3 and a minimal amount of α-Fe2O3, rendering the iron red overglaze color a yellowish-red shade. At 650 °C, the coexistence of Fe2(SO4)3 and α-Fe2O3 imparted a brick-red color to the iron red. As the temperature was elevated to 700 °C, the desulfurization of Fe2(SO4)3 produced α-Fe2O3, transitioning the iron red to an orange red. With further temperature increase to 750 °C, the particle size of α-Fe2O3 grew and the crystal reflectivity decreased, resulting in a purplish-red hue. Throughout this stage, the powder remained in a single α-Fe2O3 phase. Upon further heating to 800 °C, the crystallinity of α-Fe2O3 enhanced, giving the iron red overglaze color a dark red or even black appearance.

Microplastics removal from natural surface water by coagulation process

The present study aimed to compare the efficiency of microplastic removal from natural surface water by coagulation with ferrous and aluminum sulfate in the presence and without the selected coagulant aids. Coagulation with Fe(II) and Al(III) sulfates at doses conventionally used for drinking water treatment (10 – 80 mg.L−1) was effective in polystyrene and polyvinyl chloride removal. Fe(II) salts showed up to 5 % efficiency higher in microplastic removal under the conditions of the experiment. The addition of the flocculating agent to support the aggregation of flocs allowed for the improvement of microplastic removal efficiency at the same dose of up to 10 %. Based on the results, flocculating agents are recommended for microplastic removal. Coagulation without flocculating agent amendment is enough to remove most microplastics if filtration is applicable.

Effect of porous media heterogeneity and FeS re-generation for multiple cycles on arsenic immobilization under in-situ conditions

Arsenic (As) contamination in groundwater is a well-established concern. Several studies have explored the possibility of immobilizing arsenite [As (III)] in-situ within the aquifer. Recent studies show a uniform distribution of ferrous sulfate (FeS) synthesized within homogenous porous media and demonstrated promising performance in immobilizing As(III). Upscaling from bench-scale to field-scale systems involves the integration of physical and chemical heterogeneities. Thus, the distribution of reducing agent (i.e., FeS), subsequent capturing of As(III) in the upscaled heterogeneous porous media system is a complex and uncertain phenomenon. Therefore, this study focuses on assessing the performance of FeS when synthesized for multiple cycles under constant flow and constant head conditions for immobilization of As(III) through a heterogeneous porous media system. A 3-D heterogenous porous media system is first simulated using a sequential indicator simulator model (SISIM). Then, the same heterogeneous media is prepared in the laboratory by packing three different-sized sand within a 3-D tank (0.67 m × 0.40 m × 0.40 m) which is subdivided into a total of 150 grids (0.096 m × 0.08 m × 0.08 m). FeS is synthesized in-situ by sequential injection of sodium sulfide (Na2S) and ferrous sulfate (FeSO4‧6H2O), as detailed in the previous study. The outcome of the study suggests that flow within the model subsurface porous media is non-uniform and follows an inter-connected preferential flow path. The progression of in-situ synthesized FeS is faster in the areas of higher hydraulic conductivity. The immobilization of As (88%) is promising by FeS synthesized within heterogeneous porous media. An overall reduction of porosity (7.7%) and hydraulic conductivity (68.3%) are observed, which is more predominant along the preferential flow path where deposition of FeS is significantly higher. To maintain constant flow rate, 60% increase in head difference is required. Whereas the flow rate decreases by 47.2% when constant head condition is adopted. Overall, the newly synthesized FeS shows promising performance in immobilizing As(III) within heterogeneous model subsurface porous media; however, there might be some possibility of pore-clogging and bypassing of flow due to deposition and subsequent retention of As, which may impact the As removal efficiency in the longer run.

Granular activated carbon supported polyethylene glycol modified nano-zero-valent iron immobilized microbial removal of 2,4-dichlorophenol in water

In recent years, the remediation of 2,4-DCP pollution using immobilized microbial technology has attracted increasing attention. Using granular activated carbon (GAC), polyethylene glycol 4000 (PEG-4000), ferrous sulfate, and sodium borohydride as raw materials, granular activated carbon loaded polyethylene glycol modified nano zero-valent iron composite material (PEG-nZVI/GAC) was prepared via a liquid-phase reduction method. Bacillus marisflavi, capable of degrading phenolic compounds, was immobilized on PEG-nZVI/GAC using an adsorption method to prepare immobilization of microorganisms by granular activated carbon loaded polyethylene glycol modified nano zero-valent iron (PEG-nZVI/GAC@B) for 2,4-DCP removal. Characterization analysis of immobilized microbes was conducted using transmission electron microscopy (TEM) and other methods to determine their physicochemical properties. Response surface methodology (RSM) was employed to optimize the conditions for 2,4-DCP removal, and the performance and mechanism of 2,4-DCP removal by PEG-nZVI/GAC@B were studied. The results indicate that nanoscale zero-valent iron (nZVI) was uniformly distributed in granular activated carbon, Bacillus marisflavi was successfully loaded onto PEG-nZVI/GAC, PEG-nZVI/GAC@B had a higher content of oxygen-containing groups on its surface, and exhibits good dispersibility, stability, and reusability. When the immobilized microbial dosage was 270.32 mg/L, the initial concentration of 2,4-DCP was 50.51 mg/L, and pH was 6.58, the predicted removal rate of 2,4-DCP was 96.53 %. Under these conditions, the actual removal rate of 2,4-DCP was 94.68 %. The removal of 2,4-DCP by PEG-nZVI/GAC@B involved adsorption by granular activated carbon, reductive dechlorination by nanoscale zero-valent iron, and degradation by Bacillus marisflavi. In conclusion, PEG-nZVI/GAC@B is an excellent immobilized microorganism for the removal of 2,4-DCP.