RESUMEN
OBJECTIVE: In this study, we aimed to investigate the diagnostic availability of oxidant and antioxidant parameters in ascites for spontaneous bacterial peritonitis (SBP). MATERIAL AND METHODS: This study was carried out between July and October 2018 with 25 patients with SBP and 24 patients without SBP. Patients with acute infection, those taking vitamin supplements and antioxidant medication, smoking and drinking alcohol, and patients without ascites culture were excluded from the study. RESULTS: In patients with SBP compared those without SBP median paraoxonase (3.1 vs 15.6 ; p <0.001), median stimulated paraoxonase (12.6 vs 53.1 ; p <0.001), median arylesterase (769,9 vs 857,5 ; p = 0,003) and median catalase (10 vs 22,2 ; p = 0,003) were found to be lower and median myeloperoxidase (8.1 vs 1.1 ; p <0.001) were found to be higher. There was a positive correlation between paraoxonase levels and stimulated paraoxonase levels, arylesterase levels and catalase levels, there was a negative correlation between paraoxonase levels and myeloperoxidase levels. Paraoxonase levels 3.7 and lower, stimulated paraoxonase levels 25.8 and lower, arylesterase levels 853.4 and lower, catalase levels 11.8 and lower and myeloperoxidase levels 2.7 and more predicted the the presence of SBP with high specificity and high sensitivity. Paraoxonase and stimulated paraoxo-nase levels were found to have superior performance in predicting the presence of SBP compared to arylesterase levels (p <0.05). CONCLUSION: In this study it was shown that paraoxonase, stimulated paraoxonase, arylesterase, catalase and myeloperoxidase activities can be used for the diagnosis and severity of SBP.
Asunto(s)
Ascitis , Peritonitis , Arildialquilfosfatasa , Ascitis/diagnóstico , Biomarcadores , Humanos , Estrés Oxidativo , Peritonitis/diagnósticoRESUMEN
In the present study, a new adsorbent was produced from spent bleaching earth by H2SO4 impregnation method. The sorption of arsenic(III) by acid treated spent bleaching earth was studied to examine the possibility of utilizing this material in water treatment systems. The effect of time, pH, initial concentration, temperature on the adsorption of arsenic(III) was studied. Maximum adsorption was found to occur at pH 9.0. The adsorption process followed the first order Lagergren equation. Mass transfer coefficients and rate constants of intraparticle diffusion were calculated. The experimental data points were fitted to the Langmuir equation in order to calculate the adsorption capacity (Q0) of the adsorbent and the value of Q0 was found to be 0.46 mmol g(-1). In order to understand the adsorption mechanism, Dubinin-Radushkevich (DR) isotherm was used. The magnitude of E calculated from DR equation was found to be 5.12 kJ mol(-1). The heat of adsorption (deltaH0 = -30367 J mol(-1)) implied that the adsorption was physical exothermic adsorption. The column studies were also carried out to simulate water treatment processes. The capacity values obtained in column studies were found to be greater than the capacity values obtained in batch studies. This result was explained by the difference between batch system and column system. The factors that affect the capacity values of column and batch systems were explained. The effect of other anions on the adsorption of arsenic(III) in the presence of NO3-, SO4(2-), Cl-, Br- was studied. The presence of these anions did not affect the adsorption of arsenic(III) significantly.
Asunto(s)
Arsenitos/química , Purificación del Agua/métodos , Adsorción , Aniones , Arsenitos/aislamiento & purificación , Cromatografía/métodos , Contaminación Ambiental/prevención & control , Concentración de Iones de Hidrógeno , Residuos Industriales , Aceites , Soluciones/química , Ácidos Sulfúricos , Termodinámica , Eliminación de Residuos Líquidos/métodos , Contaminantes Químicos del AguaRESUMEN
The adsorption of free- and bound-metal ions (metal complexes) as well as of ligands onto various hydrous oxide type sorbents have been extensively modelled using EDTA as the model ligand. This type of modelling uses metal ion-EDTA mixture solutions containing stoichiometrically equivalent or excessive amounts of either constituent. Consequently, for mixture solutions equilibrated with the sorbent, the aim was to develop a suitable method for determining either metal complex+free ligand (MY(2-)+H(2)Y(2-)) or metal complex+free metal (MY(2-)+M(2+)) in the aqueous filtrate, the metal M being lead or cadmium. The conventional method of analyzing such filtrates is exchanging different metal-EDTA complexes with Fe(NO(3))(3) followed by HPLC using UV detection. The developed method utilizes Vis- and AA-spectrometry widespread in common laboratories, eliminating the need for HPLC and UV techniques that require higher operational cost, expertise and contaminant-free media. The developed procedure is based on the following analyses for the possible constituents of equilibrated solution (with the sorbent). All EDTA (free or bound, as H(2)Y(2-) or MY(2-)) species are converted into FeY(-) by adding Fe(NO(3))(3), and heating at 80 degrees C for 1 h. All metal (free or bound, as M(2+) or MY(2-)) species are determined by AAS. All unbound (free) Fe(3+) species are determined by the thiocyanate spectrophotometric method at 480 nm. Then 'EDTA-bound iron (III)' is defined as added Fe minus colorimetrically (thiocyanate method) found Fe, and 'AAS-found metal' (lead or cadmium) corresponds to M(2+) and/or MY(2-), depending on the analyzed solution. If EDTA-bound Fe(III) is greater than AAS-found metal, then one has a (MY(2-)+H(2)Y(2-)) mixture where AAS-found metal is (MY(2-)), and free EDTA, i.e. (H(2)Y(2-)), is calculated from the difference. If EDTA-bound Fe(III) is smaller than AAS-found metal, then one has a (M(2+)+ MY(2-)) mixture where EDTA-bound Fe(III) is (MY(2-)), and the free metal, i.e. (M(2+)), is calculated from the difference. If the two compared quantities are equal, then one has a pure MY(2-) solution. Since surface complexes on the hydrous oxide sorbent ( approximately SOH) as bound metal ( approximately SOM), bound ligand ( approximately SOL) or bound metal complex ( approximately SOML) are much more difficult to desorb and analyze, the simple procedure developed here applicable to more conventional instruments carried out in sorbent equilibrated solutions (filtrates) may effectively aid heavy metal adsorption modelling in realistic environmental simulations.
RESUMEN
The adsorption of toxic heavy metal cations, i.e., Cu(II), Cd(II), and Pb(II), from metal-EDTA mixture solutions on a composite adsorbent having a heterogeneous surface, i.e., bauxite waste red mud, has been investigated and modeled with the aid of a modified surface complexation approach in respect to pH and complexant dependency of heavy metal adsorption. EDTA was selected as the modeling ligand in view of its wide usage as an anthropogenic chelating agent and abundance in natural waters. The adsorption experiments were conducted for metal salts (nitrates), metal-EDTA complexes alone, or in mixtures containing (metal+metal-EDTA). The adsorption equilibrium constants for the metal ions and metal-EDTA complexes were calculated. For all studied cases, the solid adsorbent phase concentrations of the adsorbed metal and metal-EDTA complexes were found by using the derived model equations with excellent compatibility of experimental and theoretically generated adsorption isotherms. The model was useful for metal and metal-EDTA mixture solutions either at their natural pH of equilibration with the sorbent, or after pH elevation with NaOH titration up to a certain pH. Thus adsorption of every single species (M(2+) or MY(2-)) or of possible mixtures (M(2+)+MY(2-)) at natural pH or after NaOH titration could be calculated by the use of simple quadratic model equations, once the initial concentrations of the corresponding species, i.e., [M(2+)](0) or [MY(2-)](0), were known. The compatibility of theoretical and experimental data pairs of adsorbed species concentrations was verified by means of nonlinear regression analysis. The findings of this study can be further developed so as to serve environmental risk assessment concerning the expansion of a heavy metal contaminant plume with groundwater move ment in soil consisting of hydrated-oxide type minerals. Copyright 2000 Academic Press.