ABSTRACT
In this study, cobalt (Co) was recycled from spent lithium ion batteries (LIBs) and used to synthesize cobalt ferrite (CoFe2O4-LIBs), which was applied as a catalyst for heterogeneous photo Fenton reactions that discolored methylene blue (MB) dye. The co-precipitation method was used to synthesize CoFe2O4-LIBs and CoFe2O4-R nanoparticles with spinel structures using as raw materials of the LIB cathodes and commercial reagents. X-ray diffraction (XRD) identified the formation of spinel-type CoFe2O4, which formed clusters that could be seen under scanning electron microscopy (SEM) analysis and nanometric particles seen under transmission electron microscopy (TEM). Inductively Coupled Plasma Optical Emission Spectrometer (ICP OES) analysis was used to determine the concentrations of metals present in the ferrite, which reached 6.5% (w/w) of Co. The optimal conditions for discoloring the dye were evaluated using a factorial design. Using CoFe2O4 as a catalyst, the best conditions for catalytic reaction were pH 3, 30.0 mg of catalyst, and 8.0 mL of H2O2 73% (v/v). Discoloration efficiencies of 87.3% and 87.7% were obtained from CoFe2O4-R and CoFe2O4-LIBs, respectively. Therefore, CoFe2O4-LIBs proved to be an efficient catalyst for discoloring MB dye using heterogeneous photo-Fenton reactions. This work is of scientific, social, economic, and environmental interest. It investigates the process of synthesizing,characterizing CoFe2O4LIBs and the efficiency of degrading MB dye, subjects that have economic and environmental, and therefore, social interest. The work has scientific interest particularly because of the correlation between the structure of the recycled material and its catalytic properties.
Subject(s)
Catalysis , Electric Power Supplies , Ferric Compounds/chemical synthesis , Lithium , Nanostructures/chemistry , Cobalt/chemistry , Ferric Compounds/chemistry , Hydrogen Peroxide/chemistry , Microscopy, Electron, Scanning , Microscopy, Electron, Transmission , Recycling/methods , X-Ray DiffractionABSTRACT
BACKGROUND: Recently, disconnect systems for CAPD that are associated with a reduced frequency of peritonitis have been introduced. Our objective was to compare the incidence of peritonitis using three current CAPD systems in a high-risk population with low educational and socioeconomic levels, and high prevalence of malnutrition. METHODS: In a prospective controlled trial, 147 patients commencing CAPD were randomly assigned to one of three groups: 29 to the conventional, 57 to the Y-set, and 61 to the twin bag systems. The number of peritonitis episodes was registered, and patients were followed up for an average of 11.3 months. RESULTS: The average peritonitis-free interval for the conventional group was 6.1 months, for the Y system was 12.0 months, and for the twin bag was 24.8 months (P < 0.001). By multivariate analysis, the only factor associated with peritonitis was the CAPD system. Peritonitis-related hospitalization was 5.3 +/- 2.0, 2.7 +/- 1.0, and 1.5 +/- 0.9 days/patient/year in the conventional, Y system, and twin bag groups, respectively. The cost per bag was similar for the conventional and Y system, but higher for the twin bag. However, the total costs of treatment (pesos/patient/year) were lower for twin bag (62,159 for the conventional, 70,275 for the Y system, and 54,387 for the twin bag), due to the lower peritonitis incidence and associated hospitalizations. CONCLUSIONS: Y system and twin bag use was associated with a reduction of 50 and 75% peritonitis incidence, respectively, in patients on CAPD. The cost of the twin bag was actually lower, because of savings from a decreased usage of antibiotics and fewer hospitalizations.
Subject(s)
Peritoneal Dialysis, Continuous Ambulatory/adverse effects , Peritoneal Dialysis, Continuous Ambulatory/methods , Peritonitis/prevention & control , Adult , Equipment Design , Female , Health Care Costs , Hospitalization , Humans , Incidence , Length of Stay , Male , Middle Aged , Multivariate Analysis , Peritoneal Dialysis, Continuous Ambulatory/economics , Peritoneal Dialysis, Continuous Ambulatory/instrumentation , Peritonitis/epidemiology , Prospective StudiesABSTRACT
A case of congenital syphilis is reported. It deals with a three-month-old girl suffering from a nephropathy clinically characterized by edema, hematuria, severe proteinuria and slight renal insufficiency. On light an delectron microscopy, a mesangial proliferative and focal extracapillary proliferative glomerulonephritis with abundant intermembranoepithelial deposits was observed.
