title: Abatement of toxicity of effluents containing Cr(VI) by heterogeneous photocatalysis. Toxicity assessment by AMPHITOX assay.
abstract: Toxicity of a Cr(VI) solution before and after treatment by TiO2 heterogeneous photocatalysis (HP) was performed with AMPHITOX bioassay. Changes in toxicity on Rhinella arenarum larvae for 10-d were monitored after exposure to an untreated Cr(VI) solution and to the same solution after HP treatment. The HP treatment of a 41.60 mg L(-1) Cr(VI) solution reduced to 37.5% the concentration of the metal ion. A 10-fold reduction in toxicity at acute exposure (72 h) and 150-fold reduction in toxicity after 240 h was found. Further, the LOEC value increased from 0.001% for the untreated solution to 0.153% after HP treatment. Moreover, the safe concentration in untreated solution corresponded to 0.0001% sample, and it was 0.01% after the treatment, i.e., 100 times higher. A saving of water of about 100,000 L per L of effluent would be possible through dilution to allow safer concentrations for discharge; the saving would reach the highest value (1,000,000 L per L) at 240 h. Sub-lethal effects were completely absent in larvae exposed to the treated solution. The AMPHITOX test allowed to detect chronic effects at low Cr concentrations, i.e. at environmentally relevant levels.
authors.affiliation: Instituto de Investigación e Ingeniería Ambiental, Universidad Nacional de Gral. San Martín, Campus Miguelete, Av. 25 de Mayo y Martín de Irigoyen, 1650 San Martín, Prov. de Buenos Aires, Argentina.
authors.forename: Jonatan Y
authors.initials: JY
authors.lastname: Hojman
authors.affiliation: Gerencia Química, Comisión Nacional de Energía Atómica, Av. Gral. Paz 1499, 1650 San Martín, Prov. de Buenos Aires, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas, Av. Rivadavia 1917, 1033 Ciudad Autónoma de Buenos Aires, Argentina.
authors.forename: J Martín
authors.initials: JM
authors.lastname: Meichtry
authors.affiliation: Instituto de Investigación e Ingeniería Ambiental, Universidad Nacional de Gral. San Martín, Campus Miguelete, Av. 25 de Mayo y Martín de Irigoyen, 1650 San Martín, Prov. de Buenos Aires, Argentina; Gerencia Química, Comisión Nacional de Energía Atómica, Av. Gral. Paz 1499, 1650 San Martín, Prov. de Buenos Aires, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas, Av. Rivadavia 1917, 1033 Ciudad Autónoma de Buenos Aires, Argentina.
authors.forename: Marta I
authors.initials: MI
authors.lastname: Litter
authors.affiliation: Instituto de Investigación e Ingeniería Ambiental, Universidad Nacional de Gral. San Martín, Campus Miguelete, Av. 25 de Mayo y Martín de Irigoyen, 1650 San Martín, Prov. de Buenos Aires, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas, Av. Rivadavia 1917, 1033 Ciudad Autónoma de Buenos Aires, Argentina.
authors.forename: Cristina S
authors.initials: CS
authors.lastname: Pérez Coll
mesh_terms: D000818:Animals; D001681:Biological Assay; D002025:Bufonidae / Q000254:growth & development; D002384:Catalysis; D002857:Chromium / Q000032:analysis / Q000633:toxicity*; D007814:Larva / Q000187:drug effects; D012996:Solutions; D014025:Titanium / Q000737:chemistry*; D018675:Toxicity Tests; D014466:Ultraviolet Rays; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000633:toxicity*; D018508:Water Purification / Q000379:methods*
chemical_list: D012996:Solutions; D014874:Water Pollutants, Chemical; D002857:Chromium; C009495:titanium dioxide; C074702:chromium hexavalent ion; D014025:Titanium
keywords: AMPHITOX test; Heterogeneous photocatalysis; Hexavalent chromium