The removal of 2,4,6-trichlorophenol in water by Ni/Fe nanoparticles

In this paper, the removal of 2,4,6-trichlorophenol (2,4,6-TCP) by synthesized Ni/Fe nanoparticles were investigated. At the same time, the factors, such as the dosage of Ni/Fe, Ni content in Ni/Fe nanoparticles, sulfate ion, HA, coexisting substances in water which affected the removal of 2,4,6-TCP by synthesized Ni/Fe nanoparticles were also investigated. Under the experimental conditions, the removal efficiency of 2,4,6-TCP by Ni/Fe nanoparticles in water was about 72% for 2 h. The dosage of Ni/Fe, Ni content in Ni/Fe nanoparticles, and Fe3+ all promoted the dechlorination reaction of 2,4,6-TCP by Ni/Fe nanoparticles. Sulfate, oxalic acid and citric acid played an inhibitory role on the removal of 2,4,6-TCP by Ni/Fe nanoparticles in water. Fe2+ had no obvious affect to the removal of 2,4,6-TCP by Ni/Fe nanoparticles in water. In addition, low initial HA concentration was favorable for the removal of 2,4,6-TCP by Ni/Fe nanoparticles, while high concentrations of HA played an inhibitory role.

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Effects of Washing Solution, Washing Time, and Solid-Solution Rate on the Maximum Heavy Metals Removal Efficiency

Applied Sciences ◽

10.3390/app11146398 ◽

2021 ◽

Vol 11 (14) ◽

pp. 6398

Author(s):

Min-Suk Kim ◽

Namin Koo ◽

Jeong-Gyu Kim ◽

Sang-Hwan Lee

Keyword(s):

Solid Solution ◽

Heavy Metal ◽

Citric Acid ◽

Oxalic Acid ◽

Acid Solution ◽

Removal Efficiency ◽

Metal Removal ◽

Heavy Metal Removal ◽

Optimal Operation ◽

Operation Conditions

In Korea, for heavy metal-contaminated soil, there are insufficient basic data as well as field application cases for soil washing. This study was conducted to suggest the significant factors and optimal operation conditions for the maximum heavy metal removal efficiency. Five types of washing solution [acid solution (HCl), citric acid, oxalic acid, EDTA, and CaCl2], washing time (10–360 min), and solid-solution ratio (1:2–1:100) were selected as significant operational factors. Non-observed effect concentration (NOEC) and central composite rotatable design (CCRD) were applied to derive the optimal conditions. The soil pH was slightly alkali, and it was highly contaminated by Cd (17.34 mg kg−1), Cu (307.76 mg kg−1), Pb (714.78 mg kg−1), and Zn (1755.47 mg kg−1), complexly. For all heavy metals, CaCl2, a neutral salt, was difficult to achieve the remediation goal. On the other hand, Cd, Cu, and Pb were removed successfully from the soil by acid solution, citric acid, oxalic acid, and EDTA. For Zn, only acid solution and oxalic acid could meet the remediation goal (300 mg kg−1). As the washing time increased, the heavy metal removal efficiency showed a tendency to increase overall. Especially, oxalic acid and acid solution were able to reach the highest efficiency point within 30 min, whereas citric acid and EDTA took 2 to 4 h at the longest. In the case of 1 M citric acid, through the CCRD experiment, optimal operation conditions (solid-solution ratio and washing time) could be deduced for each heavy metal. Furthermore, this series of processes can be utilized as a useful tool to find the optimal operating conditions and, at the same time, achieve the remediation goal.

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Adsorption Studies on Magnetic Nanoparticles Functionalized with Silver to Remove Nitrates from Waters

Water ◽

10.3390/w13131757 ◽

2021 ◽

Vol 13 (13) ◽

pp. 1757

Author(s):

Yesica Vicente-Martínez ◽

Manuel Caravaca ◽

Antonio Soto-Meca ◽

Miguel Ángel Martín-Pereira ◽

María del Carmen García-Onsurbe

Keyword(s):

Magnetic Nanoparticles ◽

Nitrate Content ◽

Adsorption Efficiency ◽

Experimental Conditions ◽

Dependent Behavior ◽

Before And After ◽

Naoh Solution ◽

High Concentrations ◽

Interference Studies

This paper presents a novel procedure for the treatment of contaminated water with high concentrations of nitrates, which are considered as one of the main causes of the eutrophication phenomena. For this purpose, magnetic nanoparticles functionalized with silver (Fe3O4@AgNPs) were synthesized and used as an adsorbent of nitrates. Experimental conditions, including the pH, adsorbent and adsorbate dose, temperature and contact time, were analyzed to obtain the highest adsorption efficiency for different concentration of nitrates in water. A maximum removal efficiency of 100% was reached for 2, 5, 10 and 50 mg/L of nitrate at pH = 5, room temperature, and 50, 100, 250 and 500 µL of Fe3O4@AgNPs, respectively. The characterization of the adsorbent, before and after adsorption, was performed by energy dispersive X-ray spectroscopy, scanning electron microscopy, Brunauer-Emmett-Teller analysis and Fourier-transform infrared spectroscopy. Nitrates can be desorbed, and the adsorbent can be reused using 500 µL of NaOH solution 0.01 M, remaining unchanged for the first three cycles, and exhibiting 90% adsorption efficiency after three regenerations. A deep study on equilibrium isotherms reveals a pH-dependent behavior, characterized by Langmuir and Freundlich models at pH = 5 and pH = 1, respectively. Thermodynamic studies were consistent with physicochemical adsorption for all experiments but showed a change from endothermic to exothermic behavior as the temperature increases. Interference studies of other ions commonly present in water were carried out, enabling this procedure as very selective for nitrate ions. In addition, the method was applied to real samples of seawater, showing its ability to eliminate the total nitrate content in eutrophized waters.

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Efficient removal of arsenic from water by dielectrophoresis-assisted adsorption

Water Science & Technology Water Supply ◽

10.2166/ws.2018.155 ◽

2018 ◽

Vol 19 (4) ◽

pp. 1066-1072

Author(s):

Q. H. Jin ◽

C. Y. Cui ◽

H. Y. Chen ◽

Y. Wang ◽

J. F. Geng ◽

...

Keyword(s):

Adsorption Capacity ◽

Removal Efficiency ◽

Solution Ph ◽

Residual Concentration ◽

Initial Concentration ◽

Weight Percentage ◽

Before And After ◽

High Concentrations ◽

Plant Ash ◽

Adsorbent Dose

Abstract Adsorption (ADS) and dielectrophoresis (DEP) techniques were combined (ADS/DEP) to efficiently remove As(V) in industrial wastewater. Fly ash, activated carbon, corncob and plant ash were tested to determine the best adsorbent by their adsorption capacity. Plant ash showed the highest adsorption capacity compared with the others. Different parameters such as solution pH and adsorbent dose were explored. The maximum As(V) removal efficiency was 91.4% at the optimized conditions (pH 9.0, adsorbent dose 5 g/L) when the initial concentration of As(V) was 15 mg/L. With the ADS/DEP technique, the plant ash particles with adsorbed As(V) were trapped on the electrodes in a DEP device. The ADS/DEP process could increase the removal efficiency of As(V) to 94.7% at 14 V even when the initial concentration of As(V) was 15 mg/L. And the residual concentration of As(V) decreased to 0.34 mg/L after two series of the ADS/DEP process. The adsorbents before and after DEP were examined by scanning electron microscope (SEM) and energy dispersive X-ray (EDX) analysis. After the DEP process, the weight percentage of As(V) on the adsorbent surface increased to 0.96% from 0.5%. The ADS/DEP process could be a new efficient way to remove arsenic pollutant at high concentrations.

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Activation of human platelets by immune complexes prepared with cationized human IgG

Blood ◽

10.1182/blood.v82.10.3045.bloodjournal82103045 ◽

1993 ◽

Vol 82 (10) ◽

pp. 3045-3051

Author(s):

M Schattner ◽

M Lazzari ◽

AS Trevani ◽

E Malchiodi ◽

AC Kempfer ◽

...

Keyword(s):

Platelet Aggregation ◽

Platelet Activation ◽

Immune Complexes ◽

Platelet Rich Plasma ◽

Human Platelets ◽

Human Igg ◽

Experimental Conditions ◽

Induce Platelet Aggregation ◽

Soluble Immune Complexes ◽

High Concentrations

The present study shows that the ability of soluble immune complexes (IC), prepared with human IgG and rabbit IgG antibodies against human IgG, to trigger platelet activation was markedly higher for IC prepared with cationized human IgG (catIC) compared with those prepared with untreated human IgG (cIC). CatIC induced platelet aggregation and adenosine triphosphate release in washed platelets (WP), gel-filtered platelets (GFP), or platelet-rich plasma (PRP) at physiologic concentrations of platelets (3 x 10(8)/mL) and at low concentrations of catIC (1 to 30 micrograms/mL). On the contrary, under similar experimental conditions, cIC did not induce aggregation in PRP, WP, or GFP. Low aggregation responses were only observed using high concentrations of both WP (9 x 10(8)/mL) and cIC (500 micrograms/mL). Interestingly, catIC were also able to induce platelet activation under nonaggregating conditions, as evidenced by P-selectin expression. Cationized human IgG alone did not induce platelet aggregation in PRP but triggered either WP or GFP aggregation. However, the concentration needed to induce these responses, was about eightfold higher than those required for catIC. The responses induced either by catIC or cationized human IgG were completely inhibited by treatment with heparin, dextran sulphate, EDTA, prostaglandin E1, or IV3, a monoclonal antibody against the receptor II for the Fc portion of IgG (Fc gamma RII). The data presented in this study suggest that IgG charge constitutes a critical property that conditions the ability of IC to trigger platelet activation.

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ChemInform Abstract: Enthalpy of Solution of Oxalic, Succinic, Adipic, Maleic, Malic, Tartaric, and Citric Acids, Oxalic Acid Dihydrate, and Citric Acid Monohydrate in Water at 298.15 K.

Chemischer Informationsdienst ◽

10.1002/chin.198631096 ◽

1986 ◽

Vol 17 (31) ◽

Author(s):

A. APELBLAT

Keyword(s):

Citric Acid ◽

Oxalic Acid ◽

Enthalpy Of Solution ◽

Citric Acid Monohydrate ◽

Oxalic Acid Dihydrate

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Nonadrenergic bronchodilation induced by high concentrations of sulfur dioxide

Journal of Applied Physiology ◽

10.1152/jappl.1990.69.5.1786 ◽

1990 ◽

Vol 69 (5) ◽

pp. 1786-1791

Author(s):

D. C. Thompson ◽

J. L. Szarek ◽

R. J. Altiere ◽

L. Diamond

Keyword(s):

Muscle Tone ◽

Blocking Agent ◽

Lung Compliance ◽

Environmental Pollutant ◽

Inhibitory System ◽

Experimental Conditions ◽

Bronchodilator Response ◽

Cellular Source ◽

High Concentrations ◽

Dynamic Lung Compliance

SO2 is an environmental pollutant known to elicit bronchospasm in susceptible subjects. We observed that brief exposure of artificially bronchoconstricted cats to high concentrations of SO2 induces a bronchodilator response. This study assessed the characteristics of this response and examined various mechanisms that might underlie it. Cats were anesthetized with diallylbarbital-urethan, and airway smooth muscle tone, measured by lung resistance and dynamic lung compliance, was elevated with a continuous infusion of 5-hydroxytryptamine. Administration of 10 breaths of SO2 via a tracheostomy induced concentration-dependent bronchodilation in the range 100-1,000 parts/million. Only infrequently was bronchoconstriction observed before bronchodilation. SO2-induced bronchodilator responses were unaffected by pretreatment with intravenous atropine or propranolol, establishing them as nonadrenergic noncholinergic (NANC) in origin. Neither the ganglionic blocking agent hexamethonium nor the nerve toxin tetrodotoxin influenced the SO2-induced bronchodilation, thus excluding a role for central or local autonomic reflexes in the response. Efforts to modulate the response by pretreatment with the cyclooxygenase inhibitor indomethacin or the mediator release inhibitor cromolyn sodium also were unsuccessful. Administration of acidic aerosols failed to mimic the SO2-induced bronchodilator response. Although the mechanism whereby SO2 induces bronchodilation under these experimental conditions remains unclear, release of a NANC inhibitory transmitter from a neural, epithelial, or other cellular source via a mechanism insensitive to both tetrodotoxin and cromolyn is a distinct possibility. An intrinsic NANC inhibitory system may exist in feline airways functioning as a local regulator of bronchomotor tone and possibly serving to override responses to strong, potentially asphyxial bronchoconstrictive stimuli.

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Treatment of High-Strength Animal Industrial Wastewater Using Photo-Assisted Fenton Oxidation Coupled to Photocatalytic Technology

Water ◽

10.3390/w11081553 ◽

2019 ◽

Vol 11 (8) ◽

pp. 1553 ◽

Cited By ~ 1

Author(s):

Jae Hong Park ◽

Dong Seok Shin ◽

Jae Kwan Lee

Keyword(s):

Light Intensity ◽

Removal Efficiency ◽

Industrial Wastewater ◽

Uv Light ◽

High Strength ◽

Cod Removal ◽

Fenton Oxidation ◽

Optimal Conditions ◽

Experimental Conditions ◽

Animal Wastewater

Animal wastewater is one of the wastewaters that has a color and is difficult to treat because it contains a large amount of non-degradable organic materials. The photo-assisted Fenton oxidation technique was applied to treat animal wastewater, and the optimal conditions of chemical oxygen demands (COD) removal were analyzed according to changes in pH, ferrous ion, H2O2, and ultraviolet (UV) light intensity as a single experimental condition. Experimental results showed that, under the single-factor experimental conditions, the optimal conditions for degradation of animal wastewater were pH 3.5, Fe(II) 0.01 M, H2O2 0.1 M, light intensity 3.524 mW/m2. Under the optimal conditions, COD removal efficiency was 91%, sludge production was 2.5 mL from 100 mL of solution, color removal efficiency was 80%, and coliform removal efficiency was 99.5%.

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