ABSTRACT
Nano zero-valent iron (nZVI) is a promising phosphate adsorbent for advanced phosphate removal. However, the rapid passivation of nZVI and the low activity of adsorption sites seriously limit its phosphate removal performance, accounting for its inapplicability to meet the emission criteria of 0.1 mg P/L phosphate. In this study, we report that the oxalate modification can inhibit the passivation of nZVI and alter the multi-stage phosphate adsorption mechanism by changing the adsorption sites. As expected, the stronger anti-passivation ability of oxalate modified nZVI (OX-nZVI) strongly favored its phosphate adsorption. Interestingly, the oxalate modification endowed the surface Fe(III) sites with the lowest chemisorption energy and the fastest phosphate adsorption ability than the other adsorption sites, by in situ forming a Fe(III)-phosphate-oxalate ternary complex, therefore enabling an advanced phosphate removal process. At an initial phosphate concentration of 1.00 mg P/L, pH of 6.0 and a dosage of 0.3 g/L of adsorbents, OX-nZVI exhibited faster phosphate removal rate (0.11 g/mg/min) and lower residual phosphate level (0.02 mg P/L) than nZVI (0.055 g/mg/min and 0.19 mg P/L). This study sheds light on the importance of site manipulation in the development of high-performance adsorbents, and offers a facile surface modification strategy to prepare superior iron-based materials for advanced phosphate removal.
Subject(s)
Iron , Oxalates , Phosphates , Water Pollutants, Chemical , Phosphates/chemistry , Adsorption , Iron/chemistry , Water Pollutants, Chemical/chemistry , Oxalates/chemistry , Water Purification/methods , Models, ChemicalABSTRACT
Nitrate (NO3-) is a widespread pollutant in high-salt wastewater and causes serious harm to human health. Although electrochemical removal of nitrate has been demonstrated to be a promising treatment method, the development of low-cost electro-catalysts is still challenging. In this work, a phosphate modified iron (P-Fe) cathode was prepared for electrochemical removal of nitrate in high-salt wastewater. The phosphate modification greatly improved the activity of iron, and the removal rate of nitrate on P-Fe was three times higher than that on Fe electrode. Further experiments and density functional theory (DFT) calculations demonstrated that the modification of phosphoric acid improved the stability and the activity of the zero-valent iron electrode effectively for NO3- removal. The nitrate was firstly electrochemically reduced to ammonium, and then reacted with the anodic generated hypochlorite to N2. In this study, a strategy was developed to improve the activity and stability of metal electrode for NO3- removal, which opened up a new field for the efficient reduction of NO3- removal by metal electrode materials.
Subject(s)
Electrodes , Iron , Nitrates , Phosphates , Waste Disposal, Fluid , Wastewater , Water Pollutants, Chemical , Wastewater/chemistry , Nitrates/chemistry , Iron/chemistry , Phosphates/chemistry , Water Pollutants, Chemical/chemistry , Waste Disposal, Fluid/methods , Electrochemical Techniques/methodsABSTRACT
Glass ionomer cements (GICs) are the common materials employed in pediatric dentistry because of their specific applications in class I restorations and atraumatic restoration treatments (ART) of deciduous teeth in populations at high risk of caries. Studies show a limited clinical durability of these materials. Attempts have thus been made to incorporate nanoparticles (NPs) into the glass ionomer for improving resistance and make it like the tooth structure. An in vitro experimental study was conducted using the required samples dimensions and prepared based on the test being carried out on the three groups with or without the modification of light-cured glass ionomer. Samples were grouped as follows: control group (G1_C), 2% silver phosphate/hydroxyapatite NPs group (G2_SPH), and 2% titanium dioxide NPs group (G3_TiO2). The physical tests regarding flexural strength (n = 10 per group), solubility (n = 10 per group), and radiopacity (n = 3 per group) were performed. The data were analyzed by Shapiro Wilks test, and one-way analysis of variance (one-way ANOVA), and multiple comparisons by post hoc Tukey's test. The p-value of < 0.05 was considered significant. No statistically significant difference was observed between the control group (G1_C) and (G2_SPH) (p = 0.704) in the flexural strength test, however differences were found between G2_SPH and G3_TiO2 groups, ANOVA (p = 0.006); post hoc Tukey's test (p = 0.014). Pertaining to the solubility, G2_SPH obtained the lowest among the three groups, ANOVA (p = 0.010); post hoc Tukey's test (p = 0.009). The three study groups obtained an adequate radiopacity of >1 mm Al, respectively. The resin-modified glass ionomer cement (RMGIC) was further modified with 2% silver phosphate/hydroxyapatite NPs to improve the physical properties such as enhancing the solubility and sorption without compromising the flexural strength and radiopacity behavior of modified RMGIC. The incorporation of 2% titanium dioxide NPs did not improve the properties studied.
Subject(s)
Durapatite , Glass Ionomer Cements , Nanoparticles , Phosphates , Titanium , Titanium/chemistry , Glass Ionomer Cements/chemistry , Durapatite/chemistry , Nanoparticles/chemistry , Phosphates/chemistry , In Vitro Techniques , Materials Testing , Humans , Silver Compounds/chemistry , Solubility , Flexural StrengthABSTRACT
The manufacturing of fossil-based fertilizers by extraction of rock phosphate has contributed to carbon emissions and depleted the non-renewable phosphorus reserves. Sewage sludge, which is a waste product from Sewage Treatment Plants (STPs), is rich in phosphorus. The existing techniques for sludge management contribute to carbon emissions and ecological footprint. Struvite (raw fertilizer) and biochar recovery from sludge has emerged as viable methods to reduce carbon emission and ensure economic sustainability of STPs. In this work, the potential for phosphorus recovery and revenue generation is discussed for Rajasthan state in India. The fate of phosphorus and heavy metals in STPs is evaluated which indicates that about 70% of the phosphorus and trace amounts of metals end up in sewage sludge. Further, the power consumption is high in STPs due to industrial wastewater ingress. There is a need to bridge the gap between sewage treatment and generation in Rajasthan, improve STP performance before resource recovery inclusion at policy-level and scale-up. Mixing struvite with biochar can lead to safe application of struvite as raw fertilizer as heavy metals are sequestered by biochar. A business framework is developed to serve as a blueprint and potential model for linking technical and market viability.
Subject(s)
Magnesium Compounds , Phosphates , Phosphorus , Sewage , Struvite , Sewage/chemistry , Struvite/chemistry , India , Phosphorus/chemistry , Phosphorus/analysis , Phosphates/chemistry , Magnesium Compounds/chemistry , Fertilizers/analysis , Chemical Precipitation , Charcoal/chemistry , Metals, Heavy/analysis , Waste Disposal, Fluid/methodsABSTRACT
Phosphogypsum, a typical by-product in the phosphorus chemical industry, could generate a large amount of leachate containing phosphate and fluoride in the process of rainfall and long-term stacking, which not only causes serious environmental pollution, but also leads to a waste of resources. In this study, a united treatment of calcium hydroxide precipitation and lanthanum zeolite (La-ZFA) adsorption was proposed to achieve the recovery of phosphate and fluoride from phosphogypsum leachate. In phosphogypsum, most phosphorus could be leached except P in the residual occurrence form, while for fluoride, only water-soluble F could be effectively leached. The optimum leaching amounts of phosphate and fluoride were 22.59 and 4.64 mg/g, respectively, at liquid-solid ratio of 400:1, leaching time of 120 min, pH of 6.0, particle size of >200 mesh (<0.075 mm), and leaching temperature of 25°C. Using Ca(OH)2 as the precipitant, the phosphate could be precipitated selectively from phosphogypsum leachate by controlling pH and time, and the concentrations of it decreased significantly to 0.29 mg/L at pH 10.0, with a removal efficiency of 99.48%. XRD, SEM and Visual MINTEQ software analysis proved that the main component of the precipitate was hydroxyapatite (Ca5(PO4)3(OH)). After P precipitation, a series of sorbents for fluoride were investigated, and La-ZFA sorbent was chosen and utilized to recover the fluoride from the leachate through a cyclic fixed-bed column. The efficiency of La-ZFA was basically not affected by the high concentration sulfate, and it can selectively adsorb fluoride from phosphogypsum leachate, leading to a final fluoride concentration of 0.29 mg/L in the effluent. The characterization demonstrated that fluoride might be adsorbed onto the La-ZFA via ligand exchange with hydroxy groups. The proposed method in this study is expected to sequentially recover phosphate and fluorine from the leachate of phosphogypsum, and it has great guiding significance for resource utilization and management of phosphogypsum.
Subject(s)
Calcium Sulfate , Fluorides , Phosphates , Phosphorus , Adsorption , Fluorides/chemistry , Phosphorus/chemistry , Calcium Sulfate/chemistry , Phosphates/chemistry , Water Pollutants, Chemical/chemistry , Zeolites/chemistryABSTRACT
We have functionally characterized the high-affinity phosphate transporter (PiPT) from the root endophyte fungus Piriformospora indica. PiPT belongs to the major facilitator superfamily (MFS). PiPT protein was purified by affinity chromatography (Ni-NTA) and Size Exclusion Chromatography (SEC). The functionality of solubilized PiPT was determined in detergent-solubilized state by fluorescence quenching and in proteoliposomes. In the fluorescence quenching assay, PiPT exhibited a saturation concentration of approximately 2 µM, at a pH of 4.5. Proteoliposomes of size 121.6 nm radius, showed transportation of radioactive phosphate. Vmax was measured to be 232.2 ± 11 pmol/min/mg protein. We have found Km to be 45.8 ± 6.2 µM suggesting high affinity towards phosphate.
Subject(s)
Basidiomycota , Phosphate Transport Proteins , Basidiomycota/metabolism , Basidiomycota/chemistry , Phosphate Transport Proteins/metabolism , Phosphate Transport Proteins/genetics , Phosphate Transport Proteins/chemistry , Fungal Proteins/chemistry , Fungal Proteins/isolation & purification , Fungal Proteins/metabolism , Endophytes/metabolism , Endophytes/chemistry , Plant Roots/microbiology , Plant Roots/chemistry , Phosphates/metabolism , Phosphates/chemistryABSTRACT
Tropomyosin (TM) is the main allergen in shrimp (Litopenaeus vannamei). In this study, the effects of allergenicity and structure of TM by glycosylation (GOS-TM), phosphate treatment (SP-TM), and glycosylation combined with phosphate treatment (GOS-SP-TM) were investigated. Compared to GOS-TM and SP-TM, the IgG/IgE binding capacity of GOS-SP-TM was significantly decreased with 63.9 ± 2.0 and 49.7 ± 2.7%, respectively. Meanwhile, the α-helix content reduced, surface hydrophobicity increased, and 10 specific amino acids (K30, K38, S39, K48, K66, K74, K128, K161, S210, and K251) were modified by glycosylation on six IgE linear epitopes of GOS-SP-TM. In the BALB/c mice allergy model, GOS-SP-TM could significantly reduce the levels of specific IgE, IgG1, and CD4+IL-4+, while the levels of IgG2a, CD4+CD25+Foxp3+, and CD4+IFN-γ+ were increased, which equilibrated Th1 and Th2 cells, thus alleviating allergic symptoms. These results indicated that glycosylation combined with phosphate treatment can provide a new insight into developing hypoallergenic shrimp food.
Subject(s)
Allergens , Immunoglobulin E , Penaeidae , Phosphates , Tropomyosin , Animals , Female , Humans , Mice , Allergens/immunology , Allergens/chemistry , Arthropod Proteins/immunology , Arthropod Proteins/chemistry , Food Hypersensitivity/immunology , Glycosylation , Immunoglobulin E/immunology , Immunoglobulin G/immunology , Immunoglobulin G/chemistry , Mice, Inbred BALB C , Penaeidae/immunology , Penaeidae/chemistry , Phosphates/chemistry , Shellfish/analysis , Shellfish Hypersensitivity/immunology , Th2 Cells/immunology , Th2 Cells/drug effects , Tropomyosin/immunology , Tropomyosin/chemistryABSTRACT
In this study, the protein and salts distribution (Ca, P, Na and Mg) in processed cheese (PC) samples prepared with 180 or 360 mEq/kg of the calcium sequestering salts (CSS) disodium phosphate (DSP), disodium pyrophosphate (DSPP), sodium hexametaphosphate (SHMP) and trisodium citrate (TSC) was studied. For this purpose, a water-soluble extract (WSE) of PC samples was prepared. All PC samples contained 45-46% moisture, 26-27% fat and 20-21% protein and had a pH of 5.2 or 5.7. Ultracentrifugation slightly reduced the protein content of the WSE of PC, indicating that most protein in the WSE was non-sedimentable. At equal concentration of CSS, the protein content of the WSE was higher for PC at pH 5.7 compared to PC at pH 5.2. Approximately 55-85% of the Ca and P in the WSE of samples was 10 kDa-permeable for PC prepared with DSPP and SHMP. This suggests that the formation of non-permeable Ca-polyphosphate-casein complexes. For PC prepared with TSC, >90% of Ca in the WSE was 10 kDa-permeable, indicating that micellar disruption arises from sequestration of micellar Ca. These results indicate that the WSE method is an appropriate method to understand how salts present in PC are distributed. However, the WSE and ultracentrifugal supernatant of the WSE can include both soluble and protein-associated salts. Therefore, determining levels of salts in 10 kDa permeate of ultracentrifugal supernatant of the WSE is most appropriate.
Subject(s)
Cheese , Diphosphates , Phosphates , Salts , Solubility , Cheese/analysis , Phosphates/chemistry , Salts/chemistry , Diphosphates/chemistry , Calcium/chemistry , Citrates/chemistry , Hydrogen-Ion Concentration , Food Handling/methodsABSTRACT
The use of green methods to treat industrial waste and waste reuse has become a key environmental issue. In order to achieve this goal, this study treated waste phosphogypsum (PG) and produced modified PG biochar to adsorb and remove phosphorus from PG leachate, so that the PG pollution problem was controlled. In this study, PG was modified with sodium carbonate (Na2CO3) to prepare a modified PG biochar that was used for the removal of phosphorus-containing wastewater. An X-ray diffraction (XRD) analysis of the modified PG revealed that the main component was calcium carbonate (CaCO3), and a suitable amount of modified PG could load calcium oxide (CaO) onto the biochar and improve its physical properties. The experimental results showed that the modified PG biochar had a maximum phosphorus adsorption capacity of 132 mg/g. A further investigation of the mechanism of adsorption revealed the importance of electrostatic attraction and chemical precipitation, and it was found that the CaO in the modified PG biochar could effectively facilitate the conversion of phosphate to hydroxylapatite (Ca5(PO4)3OH) in water. The phosphorus removal rate from leachate obtained from a landfill containing PG was 99.38% for a specific dose of the modified PG biochar. In this study, a PG pollution control technology was developed to realize the goal of replacing waste with waste.
Subject(s)
Calcium Sulfate , Charcoal , Phosphates , Phosphorus , Adsorption , Charcoal/chemistry , Phosphorus/chemistry , Calcium Sulfate/chemistry , Phosphates/chemistry , Water Pollutants, Chemical/chemistry , Wastewater/chemistry , Waste Disposal, Fluid/methods , X-Ray DiffractionABSTRACT
Research on the observation of nutrient release rates from slow-release and regular fertilizers combined with the percolation rate in the soil is scarce. This work aims to observe potassium and phosphate release behavior from slow-release and regular fertilizer, followed by the percolation of that nutrient in the soil. The characteristics of the soil were analyzed using X-ray Diffraction (XRD), X-ray Fluorescence (XRF), and Scanning Electron Microscope (SEM). The concentration of potassium and phosphate in soil is analyzed using Atomic Absorption Spectroscopy (AAS) and Ultraviolet-Visible Spectroscopy (UV-Vis), respectively. The release rate of nutrients from slow-release fertilizer is 6 to 8 times slower than regular fertilizer. Meanwhile, the rate of nutrients released from slow-release and regular fertilizer followed by soil percolation matches the quadratic equation. Potassium adsorption on the soil surface is significantly higher than that of potassium. The negativity of soil polarity contributed to the high level of potassium adsorption on soil particle surfaces. The low phosphate adsorption capability of magnetite and the negativity of soil polarity contributed to the soil's low phosphate adsorption.
Subject(s)
Fertilizers , Potassium , Soil Pollutants , Soil , Soil/chemistry , Potassium/analysis , Soil Pollutants/analysis , Soil Pollutants/chemistry , Phosphates/analysis , Phosphates/chemistry , Nutrients/analysis , Environmental Monitoring , Adsorption , X-Ray DiffractionABSTRACT
Iron minerals in nature are pivotal hosts for heavy metals, significantly influencing their geochemical cycling and eventual fate. It is generally accepted that, vivianite, a prevalent iron phosphate mineral in aquatic and terrestrial environments, exhibits a limited capacity for adsorbing cationic heavy metals. However, our study unveils a remarkable phenomenon that the synergistic interaction between sulfide (S2-) and vivianite triggers an unexpected sulfidation-reoxidation process, enhancing the immobilization of heavy metals such as cadmium (Cd), copper (Cu), and zinc (Zn). For instance, the combination of vivianite and S2- boosted the removal of Cd2+ from the aqueous phase under anaerobic conditions, and ensured the retention of Cd stabilized in the solid phase when shifted to aerobic conditions. It is intriguing to note that no discrete FeS formation was detected in the sulfidation phase, and the primary crystal structure of vivianite largely retained its integrity throughout the whole process. Detailed molecular-level investigations indicate that sulfidation predominantly targets the Fe(II) sites at the corners of the PO4 tetrahedron in vivianite. With the transition to aerobic conditions, the exothermic oxidation of CdS and the S sites in vivianite initiates, rendering it thermodynamically favorable for Cd to form multidentate coordination structures, predominantly through the Cd-O-P and Cd-O-Fe bonds. This mechanism elucidates how Cd is incorporated into the vivianite structure, highlighting a novel pathway for heavy metal immobilization via the sulfidation-reoxidation dynamics in iron phosphate minerals.
Subject(s)
Metals, Heavy , Oxidation-Reduction , Metals, Heavy/chemistry , Sulfides/chemistry , Water Pollutants, Chemical/chemistry , Phosphates/chemistry , Minerals/chemistry , Iron/chemistry , AdsorptionABSTRACT
A parallel hybrid ordinary differential equation (ODE) integrating the Activated Sludge Model No. 2d (ASM2d) and an artificial neural network (ANN) was developed to simulate biological phosphorus removal (BPR) with high accuracy and interpretability. Two novelties were introduced; first, the involved supporting data (i.e., phosphate-release activity) were incorporated as an input in the ANN. Second, the outputs of the ANN were selective. Three models were implemented using different ANN outputs, and all three outperformed ASM2d in phosphate estimation for anaerobic/aerobic sequencing batch reactor operation. In particular, the incorporation of four variables responsible for BPR into the ANN enabled the highest performance (R2 = 0.93) owing to the capture of increasing phosphate-accumulating organisms (PAOs). The ANN with the supporting data worked satisfactorily to compensate for ASM2d by adding proper PAOs, resulting in improvement in phosphate estimation. The novel parallel hybrid ODE can simulate BPR while maintaining physical meaning.
Subject(s)
Neural Networks, Computer , Phosphates , Wastewater , Water Purification , Phosphates/chemistry , Wastewater/chemistry , Water Purification/methods , Bioreactors , Sewage , Waste Disposal, Fluid/methods , Phosphorus , Models, Theoretical , CitiesABSTRACT
In this work, an atomistic-scale investigation of the phosphodiester P-O bond cleavage reaction by the enzyme ribonuclease A was carried out using computer simulation techniques. It is shown that during the reaction the network of non-covalent interactions in the active center of the ribonuclease changes significantly, while the role of these non-covalent interactions is different: coordination of the corresponding groups, electron density transfer, and ligand holding in the active center. It is shown that the process of proton transfer from Asp121 to His119 is the first stage of this reaction; at the same time, the hydrogen bond between the phosphate ligand and the imino group of Arg39 is broken, which, although keeping the ligand in the active center, does not allow the ligand to orient itself more conveniently for subsequent proton transfers. Furthermore, the key step of this reaction occurs: proton transfer with the participation of imidazole rings His12 and His119, in which the guiding role is played by several hydrogen bonds with the participation of Phe120, and the role of an electron density carrier is played by the pnictogen bond between the oxygen of the phosphate ligand and the pyridine-like nitrogen of the imidazole ring His119, which was detected for the first time.
Subject(s)
Hydrogen Bonding , Ribonuclease, Pancreatic , Ribonuclease, Pancreatic/chemistry , Ribonuclease, Pancreatic/metabolism , Molecular Dynamics Simulation , Protons , Catalytic Domain , Phosphates/chemistry , LigandsABSTRACT
Large bone defects resulting from fractures and diseases have become a significant medical concern, usually impeding spontaneous healing through the body's self-repair mechanism. Calcium phosphate (CaP) bioceramics are widely utilized for bone regeneration, owing to their exceptional biocompatibility and osteoconductivity. However, their bioactivities in repairing healing-impaired bone defects characterized by conditions such as ischemia and infection remain limited. Recently, an emerging bioceramics zinc-strontium phosphate (ZSP, Zn2Sr(PO4)2) has received increasing attention due to its remarkable antibacterial and angiogenic abilities, while its plausible biomedical utility on tissue regeneration is nonetheless few. In this study, gallic acid-grafted gelatin (GGA) with antioxidant properties was injected into hydrogels to scavenge reactive oxygen species and regulate bone microenvironment while simultaneously incorporating ZSP to form GGA-ZSP hydrogels. The GGA-ZSP hydrogel exhibits low swelling, and in vitro cell experiments have demonstrated its favorable biocompatibility, osteogenic induction potential, and ability to promote vascular regeneration. In an in vivo bone defect model, the GGA-ZSP hydrogel significantly enhanced the bone regeneration rates. This study demonstrated that the GGA-ZSP hydrogel has pretty environmentally friendly therapeutic effects in osteogenic differentiation and massive bone defect repair.
Subject(s)
Bone Regeneration , Gallic Acid , Gelatin , Hydrogels , Osteogenesis , Gallic Acid/chemistry , Gallic Acid/pharmacology , Bone Regeneration/drug effects , Gelatin/chemistry , Hydrogels/chemistry , Hydrogels/pharmacology , Animals , Osteogenesis/drug effects , Phosphates/chemistry , Phosphates/pharmacology , Strontium/chemistry , Strontium/pharmacology , Zinc/chemistry , Zinc/pharmacology , Mice , Humans , Bone and Bones/drug effects , Male , Biocompatible Materials/chemistry , Biocompatible Materials/pharmacologyABSTRACT
This study explores the impact of electrostatic interactions and hydrogen bonding on tear film stability, a crucial factor for ocular surface health. While mucosal and meibomian layers have been extensively studied, the role of electrolytes in the aqueous phase remains unclear. Dry eye syndrome, characterized by insufficient tear quantity or quality, is associated with hyperosmolality, making electrolyte composition an important factor that might impact tear stability. Using a model buffer solution on a silica glass dome, we simulated physiologically relevant tear film conditions. Sodium chloride alone induced premature dewetting through salt crystal nucleation. In contrast, trace amounts of solutes with hydroxyl groups (sodium phosphate dibasic, potassium phosphate monobasic, and glucose) exhibited intriguing phenomena: quasi-stable films, solutal Marangoni-driven fluid influx increasing film thickness, and viscous fingering due to Saffman-Taylor instability. These observations are rationalized by the association of salt solutions with increased surface tension and the propensity of hydroxyl-group-containing solutes to engage in significant hydrogen bonding, altering local viscosity. This creates a viscosity contrast between the bulk buffer solution and the film region. Moreover, these solutes shield the glass dome, counteracting sodium chloride crystallization. These insights not only advance our understanding of tear film mechanics but also pave the way for predictive diagnostics in dry eye syndrome, offering a robust platform for personalized medical interventions based on individual tear film composition.
Subject(s)
Electrolytes , Hydrogen Bonding , Tears , Tears/chemistry , Electrolytes/chemistry , Humans , Viscosity , Sodium Chloride/chemistry , Phosphates/chemistry , Surface Tension , Static Electricity , Dry Eye Syndromes/metabolism , Wettability , Potassium CompoundsABSTRACT
The recycling of spent lithium iron phosphate batteries has recently become a focus topic. Consequently, evaluating different spent lithium iron phosphate recycling processes becomes necessary for industrial development. Here, based on multiple perspectives of environment, economy and technology, four typical spent lithium iron phosphate recovery processes (Hydro-A: hydrometallurgical total leaching recovery process; Hydro-B(H2O2/O2): hydrometallurgical selective lithium extraction process; Pyro: Pyrometallurgical recovery process; Direct: Direct regeneration process) were compared comprehensively. The comprehensive evaluation study uses environment, economy and technology as evaluation indicators, and uses the entropy weight method and analytic hierarchy process to couple the comprehensive indicator weights. Results show that the comprehensive evaluation values of Hydro-A, Hydro-B (H2O2), Hydro-B (O2), Pyro and Direct are 0.347, 0.421, 0.442, 0.099 and 0.857, respectively. Therefore, the technological maturity of Direct should be further improved to enable early industrialization. On this basis, this study conducted a quantitative evaluation of the spent lithium iron phosphate recycling process by comprehensively considering environmental, economic and technical factors, providing further guidance for the formulation of recycling processes.
Subject(s)
Lithium , Phosphates , Recycling , Phosphates/chemistry , Lithium/chemistry , Iron/chemistryABSTRACT
Phosphorus (P) scarcity and eutrophication have triggered the development of new materials for P recovery. In this work, a novel magnetic calcium-rich biochar nanocomposite (MCRB) was prepared through co-precipitation of crab shell derived biochar, Fe2+ and Fe3+. Characteristics of the material demonstrated that the MCRB was rich in calcite and that the Fe3O4 NPs with a diameter range of 18-22 nanometers were uniformly adhered on the biochar surface by strong ether linking (C-O-Fe). Batch tests demonstrated that the removal of P was pH dependent with an optimal pH of 3-7. The MCRB exhibited a superior P removal performance, with a maximum removal capacity of 105.6 mg g-1, which was even higher than the majority lanthanum containing compounds. Study of the removal mechanisms revealed that the P removal by MCRB involved the formation of hydroxyapatite (HAP-Ca5(PO4)3OH), electrostatic attraction and ligand exchange. The recyclability test demonstrated that a certain level (approximately 60%) was still maintained even after the six adsorption-desorption process, suggesting that MCRB is a promising material for P removal from wastewater.
Subject(s)
Charcoal , Nanocomposites , Phosphates , Water Pollutants, Chemical , Charcoal/chemistry , Nanocomposites/chemistry , Water Pollutants, Chemical/chemistry , Phosphates/chemistry , Adsorption , Hydrogen-Ion Concentration , Calcium/chemistry , Water Purification/methods , Wastewater/chemistryABSTRACT
This study explores the enhancement of phosphate rock (PR) solubilization through solid-state fermentation (SSF) by optimizing oxalic acid production using Aspergillus niger. Key process parameters, including the use of agro-industrial by-products (sugarcane bagasse (SCB), wheat bran (WB), soybean bran (SB)), pH levels, sucrose supplementation, and methanol addition, were systematically evaluated through sequential experimental designs. The results identified SCB and SB in a 1:1 ratio as the most effective substrate. Remarkably, the inclusion of methanol (7 %) and sucrose (0.5 %) resulted in a 3-fold increase in oxalic acid production. Under these optimized conditions, significant phosphorus solubilization of Bayóvar, Itafós, and Registro PRs was achieved, with Bayóvar rock releasing up to 12.1 g/kgds of soluble P (63.8 % efficiency). Additionally, the SSF process effectively released organic phosphorus from the agro-industrial substrates. These findings hold promise for advancing the bio-based economy and developing future industrial biofertilizers.
Subject(s)
Aspergillus niger , Fermentation , Oxalic Acid , Phosphates , Solubility , Oxalic Acid/chemistry , Phosphates/chemistry , Aspergillus niger/metabolism , Hydrogen-Ion Concentration , Cellulose/chemistry , Glycine max/metabolism , Methanol/chemistry , Sucrose/metabolism , Saccharum/chemistryABSTRACT
This study aims to enhance the physical properties and color stability of anthocyanin-based intelligent starch films. Three dual-modified starches, namely crosslinked-oxidized starch (COS), acetylated distarch phosphate (ADSP), and hydroxypropyl distarch phosphate (HDSP), were utilized as film matrices. Aronia melanocarpa anthocyanins were incorporated through three different pre-treatments (free, spray-drying microencapsulation, and freeze-drying microencapsulation) to assess the prepared films' functionality, stability, and applicability. The results indicate that the ADSP film exhibited an approximately two-fold increase in elongation at break (EAB) compared to native starch film. Specifically, the ADSP film's water contact angle (WCA) reached 90°, demonstrating excellent flexibility and hydrophobicity. Scanning electron microscopy (SEM) revealed stronger interactions between anthocyanins and the film matrix after microencapsulation. Furthermore, after 30 days of exposure to 37 °C heat and light radiation, the freeze-dried anthocyanin-based intelligent film (FDA film) exhibited minimal fading, displaying the highest stability among the tested films. Notably, during beef freshness monitoring, the intelligent films underwent significant color changes as the beef deteriorated. In conclusion, the developed FDA film, with its outstanding stability and responsive pH characteristics, holds immense potential as a novel packaging material for food applications.
Subject(s)
Anthocyanins , Photinia , Starch , Photinia/chemistry , Starch/chemistry , Capsules/chemistry , Anthocyanins/chemistry , Phosphates/chemistry , Hydrogen-Ion Concentration , Color , Spectroscopy, Fourier Transform Infrared , Thermodynamics , Smart Materials/chemistry , Hydrophobic and Hydrophilic Interactions , Freeze DryingABSTRACT
The breeding of livestock raises substantial environmental concerns, especially the efficient management of nutrients and pollution. This research is designed to assess the potency of char and modified char in diluting nutrient concentrations in livestock wastewater. The characteristics of graphene oxide, struvite, and calcium-modified char were inspected, defining their efficacy in both batch and bed-column investigations of nutrient sorption. Various factors, including sorption capacity, time of contact, ion levels, a decrease in ion levels over time, and sorption kinetics, have been considered, along with their appropriateness for respective models. The first evaluation of the options concluded that 600 °C char was better since it exhibited higher removal efficiency. Modified char sorption data at 600 °C was used to adjust the models "PSOM, Langmuir", and "Thomas". The models were applied to both batch and bed-column experiments. The maximum phosphate sorption was 110.8 mg/g, 85.73 mg/g, and 82.46 mg/g for B-GO, B-S, and B-C modified chars respectively, in the batch experiments. The highest phosphate sorption in column experiments, at a flow rate of 400 µl/min, was 51.23 mg per 10 g of sorbent. This corresponds to a sorption rate of 5.123 mg/g. B-GO and B-S modified chars showed higher sorption capacities; this was observed in both the batch and bed-column studies. This displayed the capability of graphene oxide and struvite-modified chars for efficient ion and nutrient uptake, whether in single or multi-ion environments, making them a very good candidate for nutrient filtration in livestock wastewater treatment. Additionally, B-GO char enhanced the sorption of phosphate, resulting in augmented seed germination and seedling growth. These results reveal that B-GO char can be used as a possible substitute for chemical fertilizers.