INVESTIGADORES
DOMINI Claudia Elizabeth
artículos
Título:
Trivalent manganese as an environmentally friendly oxidizing reagent
Autor/es:
CLAUDIA E. DOMINI ; LORENA VIDAL ; ANTONIO CANALS
Revista:
ULTRASONICS SONOCHEMISTRY.
Editorial:
ELSEVIER SCIENCE BV
Referencias:
Lugar: Coventry; Año: 2009 vol. 16 p. 686 - 691
ISSN:
1350-4177
Resumen:
In the present work manganese(III) has been used as oxidant and microwave radiation and ultrasound
energy have been assessed to speed up and to improve the efficiency of digestion step for the determination
of chemical oxygen demand (COD). Microwave (MW) and ultrasound-assisted COD determination
methods have been optimized by means of experimental design and the optimum conditions are: 40 psi
pressure, 855W power and 1 min irradiation time; and 90% of maximum nominal power (180 W), 0.9 s
(s1) cycles and 1 min irradiation time for microwaves and ultrasound, respectively. Chloride ion interference
is removed as hydrochloric acid gas from acidified sample solutions at 150 C in a closed reaction
tube and captured by bismuth-based adsorbent suspended above the heated solution. Under optimum
conditions, the evaluated assisted digestion methods have been successfully applied, with the exception
of pyridine, to several pure organic compounds and two reference materials. COD recoveries obtained
with MW and ultrasound-assisted digestion for five real wastewater samples were ranged between
8697% and 6891%, respectively, of the values obtained with the classical method (open reflux) used
as reference, with relative standard deviation lower than 4% in most cases. Thus, the Mn(III) microwave-
assisted digestion method seems to be an interesting and promising alternative to conventional
COD digestion methods since it is faster and more environmentally friendly than the ones used for the
same purpose.
is removed as hydrochloric acid gas from acidified sample solutions at 150 C in a closed reaction
tube and captured by bismuth-based adsorbent suspended above the heated solution. Under optimum
conditions, the evaluated assisted digestion methods have been successfully applied, with the exception
of pyridine, to several pure organic compounds and two reference materials. COD recoveries obtained
with MW and ultrasound-assisted digestion for five real wastewater samples were ranged between
8697% and 6891%, respectively, of the values obtained with the classical method (open reflux) used
as reference, with relative standard deviation lower than 4% in most cases. Thus, the Mn(III) microwave-
assisted digestion method seems to be an interesting and promising alternative to conventional
COD digestion methods since it is faster and more environmentally friendly than the ones used for the
same purpose.
is removed as hydrochloric acid gas from acidified sample solutions at 150 C in a closed reaction
tube and captured by bismuth-based adsorbent suspended above the heated solution. Under optimum
conditions, the evaluated assisted digestion methods have been successfully applied, with the exception
of pyridine, to several pure organic compounds and two reference materials. COD recoveries obtained
with MW and ultrasound-assisted digestion for five real wastewater samples were ranged between
8697% and 6891%, respectively, of the values obtained with the classical method (open reflux) used
as reference, with relative standard deviation lower than 4% in most cases. Thus, the Mn(III) microwave-
assisted digestion method seems to be an interesting and promising alternative to conventional
COD digestion methods since it is faster and more environmentally friendly than the ones used for the
same purpose.
1) cycles and 1 min irradiation time for microwaves and ultrasound, respectively. Chloride ion interference
is removed as hydrochloric acid gas from acidified sample solutions at 150 C in a closed reaction
tube and captured by bismuth-based adsorbent suspended above the heated solution. Under optimum
conditions, the evaluated assisted digestion methods have been successfully applied, with the exception
of pyridine, to several pure organic compounds and two reference materials. COD recoveries obtained
with MW and ultrasound-assisted digestion for five real wastewater samples were ranged between
8697% and 6891%, respectively, of the values obtained with the classical method (open reflux) used
as reference, with relative standard deviation lower than 4% in most cases. Thus, the Mn(III) microwave-
assisted digestion method seems to be an interesting and promising alternative to conventional
COD digestion methods since it is faster and more environmentally friendly than the ones used for the
same purpose.