• Title/Summary/Keyword: Spontaneous removal

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Enhancement effect of phosphate and silicate on water defluoridation by calcined gypsum

  • Al-Rawajfeh, Aiman Eid;Alrawashdeh, Albara I.;Aldawdeyah, Asma;Hassan, Shorouq;Qarqouda, Ruba
    • Advances in environmental research
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    • v.2 no.1
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    • pp.35-49
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    • 2013
  • Research work on removal of fluoride from water, referred to as water defluoridation, has resulted into the development of a number of technologies over the years but they suffer from either cost or efficiency drawbacks. In this work, enhancement effects of phosphate and silicate on defluoridation of water by low-cost Plaster of Paris (calcined gypsum) were studied. To our knowledge, the influence of silicate on defluoridation was not reported. It was claimed, that the presence of some ions in the treated water samples, was decreasing the fluoride removal since these ions compete the fluoride ions on occupying the available adsorption sites, however, phosphate and silicate ions, from its sodium slats, have enhanced the fluoride % removal, hence, precipitation of calcium-fluoro compounds of these ions can be suggested. Percentage removal of $F^-$ by neat Plaster is 48%, the electrical conductance (EC) curve shows the typical curve of Plaster setting which begins at 20 min and finished at 30 min. The addition of phosphate and silicate ions enhances the removal of fluoride to high extent > 90%. Thermodynamics parameters showed spontaneous fluoride removal by neat Plaster and Plaster-silicate system. The percentage removal with time showed second-order reaction kinetics.

Foreign Body Ingestion in Children: Should Button Batteries in the Stomach Be Urgently Removed?

  • Lee, Jun Hee;Lee, Jee Hoo;Shim, Jung Ok;Lee, Jung Hwa;Eun, Baik-Lin;Yoo, Kee Hwan
    • Pediatric Gastroenterology, Hepatology & Nutrition
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    • v.19 no.1
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    • pp.20-28
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    • 2016
  • Purpose: Foreign body (FB) ingestion is common in children, and button battery (BB) ingestion has been increasing in recent years. This study was to identify factors related to outcomes of FB ingestion, particularly BBs in the stomach. We evaluated whether the current recommendations are appropriate and aimed to suggest indications for endoscopic removal of BB in the stomach in young children. Methods: We investigated patient age, shape, size, location of FBs, spontaneous passage time and resulting complications among 76 children. We observed types, size, location of BB and outcomes, and analyzed their associations with complications. Results: Coins and BB were the two most common FBs. Their shapes and sizes were not associated with the spontaneous passage time. Size, spontaneous passage time, and age were also not associated with any specific complications. For BB ingestion, all 5 cases with lithium batteries (${\geq}1.5cm$, 3 V) presented moderate to major complications in the esophagus and stomach without any symptoms, even when the batteries were in the stomach and beyond the duodenum, while no complications were noted in 7 cases with alkaline batteries (<1.5 cm, 1.5 V) (p=0.001). All endoscopies were conducted within 24 hours after ingestion. Conclusion: The type and voltage of the battery should be considered when determining whether endoscopy is required to remove a BB in the stomach. For lithium battery ingestion in young children, urgent endoscopic removal might be important in order to prevent complications, even if the child is asymptomatic and the battery is smaller than 2 cm.

Exceptional removal capacity of clenbuterol from aqueous solution by mechano-synthesized [Cu (INA)2]-MOF via ball-mill

  • Marinah Mohd, Ariffin;Usman, Armaya'u;Saw Hong, Loh;Wan Mohd Afiq Wan Mohd, Khalik;Hanis Mohd, Yusoff
    • Membrane and Water Treatment
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    • v.13 no.6
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    • pp.321-335
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    • 2022
  • Copper-based Metal-organic framework (MOF) namely ([Cu (INA)2]-MOF) is synthesized by ball milling and characterized using scanning electron microscopy (SEM) for the topography, microstructure, and elemental evidence determination, powdered X-ray diffraction (XRD) for the crystallinity measurement, thermogravimetric (TG) analysis was performed to determine the thermal stability of the material, and Fourier transformed infrared (FTIR) spectroscopy for functional groups identification. The use of [Cu (INA)2]-MOF as hazardous removal material of β-agonists as persistent hazardous micro-pollutants in our environmental water is first reported in this study. The removal efficiency of the Cu-MOF is successfully determined to be 97.7% within 40 minutes, and the MOF has established an exceptional removal capacity of 835 mg L-1 with 95 % percent removal on Clenbuterol (CLB) even after the 5th consecutive cycle. The Langmuir model of the adsorption isotherms was shown to be more favourable, while the pseudo-second-order model was found to be favoured in the kinetics. The reaction was exothermic and spontaneous from a thermodynamic standpoint, and the higher temperatures were unfavourable for the adsorption study of the CLB. As a result, the studied MOF have shown promising properties as possible adsorbents for the removal of CLB in wastewater.

Preparation of PVC-D2EHPA beads by Immobilization of D2EHPA on Polyvinyl Chloride as Solid Phase Extractant and Removal Characteristics of Cu(II) (고체상 추출제로서 Polyvinyl Chloride에 D2EHPA를 고정화한 PVC-D2EHPA의 제조와 Cu(II) 제거 특성)

  • Kam, Sang-Kyu;You, Hae-Na;Lee, Dong-Hwan;Lee, Min-Gyu
    • Journal of Environmental Science International
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    • v.23 no.6
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    • pp.1157-1163
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    • 2014
  • The solid phase extractant (PVC-D2EHPA bead) was prepared by immobilizing di-2-ethylhexyl-phosphoric acid (D2EHPA) with polyvinyl chloride (PVC). The prepared PVC-D2EHPA beads were characterized by using fourier transform infrared spectrometer (FTIR) and scanning electron microscopy (SEM). The removal experiments of Cu(II) by PVC-D2EHPA beads conducted batchwise. The removal kinetics of Cu(II) was found to follow the pseudo-second-order model. The equilibrium data fitted well with Langmuir isotherm model and the maximum removal capacity was 2.6 mg/g at $20^{\circ}C$. The optimum pH region was in the range of 3.5 to 6. and the standard free energy (${\Delta}G^{\circ}$) was between -4.67~-4.98 kJ/mol, indicating the spontaneous nature of Cu(II) removal by PVC-D2EHPA beads.

Spontaneous Regression of Liver Metastasis in Stage IV-S Neuroblastoma after Adrenalectomy - Case Report - (간 전이가 동반된 Stage IV-S 신경모세포종에서 부신절제 후 간 전이의 자연소실 - 1예보고 -)

  • Seo, Hak-Jun;Jung, Jae-Hee;Song, Young-Tack
    • Advances in pediatric surgery
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    • v.7 no.1
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    • pp.68-72
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    • 2001
  • Prenatally diagnosed neuroblastomas have been reported in increasing numbers over the past several years. The vast majority are in favorable stages of the disease (stage I, II, IV-S). The authors experienced one case of stage IV-S neuroblastoma of the adrenal gland with liver metastasis, which regressed spontaneously after removal by adrenalectomy. This patient was noticed to have an abdominal mass at prenatal ultrasonography performed at 36weeks of gestation. This tumor was a neuroblastoma of the left adrenal gland with multiple liver metastases. Left adrenalectomy and liver biopsy were performed at 3 months of age. Thirty-eight months after surgery, an MRI demonstrated that the hepatic metastatic lesions had completely regressed without chemotherapy or radiation.

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Ni Nanoparticle-Graphene Oxide Composites for Speedy and Efficient Removal of Cr(VI) from Wastewater

  • Wang, Wan-Xia;Zhao, Dong-Lin;Wu, Chang-Nian;Chen, Yan;Oh, Won-Chun
    • Korean Journal of Materials Research
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    • v.31 no.6
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    • pp.345-352
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    • 2021
  • In this study, Ni nanoparticle supported by graphene oxide (GO) (Ni-GO) is successfully synthesized through hydrothermal synthesis and calcination, and Cr(VI) is extracted from aqueous solution. The morphology and structure of Ni-GO composites are characterized by scanning electron microscopy (SEM), trans mission electron microscopy (TEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). High-resolution transmission electron microscopy (HRTEM) and XRD confirms the high dispersion of Ni nanoparticle after support by GO. Loading Ni on GO can obviously enhance the stability of Ni-GO composites. It can be calculated from TGA that the mass percentage of Ni is about 60.67 %. The effects of initial pH and reaction time on Cr(VI) removal ability of Ni-GO are investigated. The results indicate that the removal efficiency of Cr(VI) is greater than that of bared GO. Ni-GO shows fast removal capacity for Cr(VI) (<25 min) with high removal efficiency. Dynamic experiments show that the removal process conforms to the quasi-second order model of adsorption, which indicates that the rate control step of the removal process is chemical adsorption. The removal capacity increases with the increase of temperature, indicating that the reaction of Cr(VI) on Ni-GO composites is endothermic and spontaneous. Combined with tests and characterization, the mechanism of Cr(VI) removal by rapidly adsorption on the surface of Ni-GO and reduction by Ni nanoparticle is investigated. The above results show that Ni-GO can be used as a potential remediation agent for Cr(VI)-contaminated groundwater.

Adsorption of lisinopril and chlorpheniramine from aqueous solution on dehydrated and activated carbons

  • El-Shafey, El-Said I.;Al-Lawati, Haider A. J.;Al-Saidi, Wafa S. H.
    • Carbon letters
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    • v.19
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    • pp.12-22
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    • 2016
  • Date palm leaflets were used as a precursor to prepare dehydrated carbon (DC) via phosphoric acid treatment at 150℃. DC, acidified with H3PO4, was converted to activated carbon (AC) at 500℃ under a nitrogen atmosphere. DC shows very low surface area (6.1 m2/g) while AC possesses very high surface area (829 m2/g). The removal of lisinopril (LIS) and chlorpheniramine (CP) from an aqueous solution was tested at different pH, contact time, concentration, and temperature on both carbons. The optimal initial pH for LIS removal was 4.0 and 5.0 for DC and AC, respectively. However, for CP, initial pH 9.0 showed maximum adsorption on both carbons. Adsorption kinetics showed faster removal on AC than DC with adsorption data closely following the pseudo second order kinetic model. Adsorption increases with temperature (25℃–45℃) and activation energy (Ea) is in a range of 19–25 kJ mol/L. Equilibrium studies show higher adsorption on AC than DC. Thermodynamic parameters show that drug removal is endothermic and spontaneous with physical adsorption dominating the adsorption process. Column adsorption data show good fitting to the Thomas model. Despite its very low surface area, DC shows ~70% of AC drug adsorption capacity in addition of being inexpensive and easily prepared.

Aqueous phase removal of ofloxacin using adsorbents from Moringa oleifera pod husks

  • Wuana, Raymond A.;Sha'Ato, Rufus;Iorhen, Shiana
    • Advances in environmental research
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    • v.4 no.1
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    • pp.49-68
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    • 2015
  • Chemically activated and carbonized adsorbents were prepared from Moringa oleifera pod husks (MOP), characterized and evaluated for their ability to remove a common antibiotic - ofloxacin (OFX) from aqueous solution. The pulverized precursor was steeped in a saturated ammonium chloride solution for a day to give the chemically activated adsorbent (AMOP). A portion of AMOP was pyrolyzed in a muffle furnace at 623 K for 30 min to furnish its carbonized analogue (CMOP). The adsorbents showed favorable physicochemical attributes. The effects of operational parameters such as initial OFX solution pH and concentration, adsorbent dosage, temperature and contact time on OFX removal were investigated. At equilibrium, optimal removal efficiencies of 90.98% and 99.84% were achieved at solution pH 5 for AMOP and CMOP, respectively. The equilibrium adsorption data fitted into both the Langmuir and Freundlich isotherms. Gibbs free energy change (${\Delta}G^o$), enthalpy change (${\Delta}H^o$) and entropy change (${\Delta}S^o$) indicated that the adsorption of OFX was feasible, spontaneous, exothermic and occurred via the physisorption mode. Adsorption kinetics obeyed the Blanchard pseudo-second-order model. The results may find applications in the adsorptive removal of micro-contaminants of pharmaceutical origin from wastewater.

Removal of different anionic dyes from aqueous solution by anion exchange membrane

  • Khan, Muhammad Ali;Khan, Muhammad Imran;Zafar, Shagufta
    • Membrane and Water Treatment
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    • v.8 no.3
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    • pp.259-277
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    • 2017
  • Adsorption is a widely used technique for the removal of dyes from wastewaters by variety of adsorbents. In this work, the main focus is on the potential assessment of anion exchange membrane for the removal of different dyes using batch system and investigation of experimental data by applying various kinetic and thermodynamic models. The removal of anionic dyes i.e., Eosin-B, Eriochrome Black-T and Congo Red by anion exchange membrane BII from aqueous solution was carried out and effect of various parameters such as contact time, membrane dosage, temperature and ionic strength on the percentage removal of anionic dyes was studied. The experimental data was assessed by kinetic models namely pseudo-first-order, pseudo-second-order, Elovich liquid film diffusion, Bangham and the modified Freundlich models equation have been used to analyze the experimental data. These results indicate that the adsorption of these anionic dyes on BII follows pseudo-second-order kinetics with maximum values of regression coefficient (0.992-0.998) for all the systems. The adsorption of dyes was more suitable to be controlled by a liquid film diffusion mechanism. The adsorptive removal of dye Eosin-B and Eriochrome Black-T were decreased with temperature and thermodynamic parameters such as free energy (${\Delta}G^o$), enthalpy (${\Delta}H^o$) and entropy (${\Delta}S^o$) for adsorption of dyes on membrane BII were calculated at 298 K, 308 K and 318 K. The values of enthalpy and entropy were negative for EB and EBT representing that the adsorption of these dyes on BII is physiosorptive and exothermic in nature. Whereas the positive values of enthalpy and entropy for CR adsorption on BII, indicating that its adsorption is endothermic and spontaneous in nature. It is evident from this study that anion exchange membrane has shown good potential for the removal of dyes from aqueous solution and it can be used as adsorbent for dues removal on commercial levels.

Spontaneous Perinephric Urinoma after the Removal of a Foley Catheter in a Girl with Acute Kidney Injury (급성 신부전 환아에서 유치 도뇨관 제거 후 발생한 신 주위 요낭종 1례)

  • Yang, Tae Hwan;Yim, Hyung Eun;Yoo, Kee Hwan
    • Childhood Kidney Diseases
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    • v.17 no.2
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    • pp.127-131
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    • 2013
  • Urinomas can occur after renal trauma or perforation of the collecting system during an endosurgical procedure. However, spontaneous urinomas are very rare. Here we report a case of a spontaneous perinephric urinoma following the removal of a Foley catheter in an 18-year-old girl with acute kidney injury caused by septic shock. The patient had been treated for septic shock, acute kidney injury, and acute respiratory distress syndrome, and had a Foley catheter in place for seven days. After Foley catheter removal, the patient complained of consistent voiding difficulty. An abdominal computed tomography scan showed a large amount of left perinephric fluid, and the aspirated fluid included urothelial cells, confirming the diagnosis of a urinoma. The urinoma was successfully treated by insertion of a double-J stent into the left ureter. This report discusses the available literature on urinomas, and their clinical features, diagnosis, and treatment.