UV/H2O2 oxidation of arsenic and terbuthylazine in drinking water.

Arsenic is a widespread contaminant in the environment. The intake of water containing high concentrations of arsenic could have serious impact on human health, such as skin and lung cancer. In the European Union, thus, also in Italy, the arsenic limit in drinking water is 10 µg L(-1). Several water remediation treatment technologies are available for arsenic removal. For some processes, the removal efficiencies can be improved after an oxidation step. Most full-scale applications are based on conventional oxidation processes for chemical micropollutant removal. However, if water contains arsenic and refractory organic contaminants, the advanced oxidation processes could be considered. The aim of this work was to investigate the effectiveness of ultraviolet (UV) radiation alone and in combination with hydrogen peroxide for the oxidation of arsenic and terbuthylazine (TBA). The experimental tests were performed in groundwater at the laboratory scale (0.1 mg L(-1) As(III) and 10 µg L(-1) TBA). Hydrogen peroxide alone (15 mg L(-1)) was ineffective on both arsenic and TBA oxidation; the 253.7-nm radiation alone did not oxidize arsenic(III), but photolyzed efficiently TBA (52 % removal yield at a UV dose of 1,200 mJ cm(-2)). The UV/H2O2 advanced oxidation (UV dose 600-2,000 mJ cm(-2), 5-15 mg L(-1) H2O2) was the most effective process for the oxidation of both arsenic and TBA, with observed oxidation efficiencies of 85 and 94 %, respectively, with 5 mg L(-1) H2O2 and a UV dose of 2,000 mJ cm(-2).

Arsenic oxidation by UV radiation combined with hydrogen peroxide.

Arsenic is a widespread contaminant in the environment around the world. The most abundant species of arsenic in groundwater are arsenite [As(III)] and arsenate [As(V)]. Several arsenic removal processes can reach good removal yields only if arsenic is present as As(V). For this reason it is often necessary to proceed with a preliminary oxidation of As(III) to As(V) prior to the removal technology. Several studies have focused on arsenic oxidation with conventional reagents and advanced oxidation processes. In the present study the arsenic oxidation was evaluated using hydrogen peroxide, UV radiation and their combination in distilled and in real groundwater samples. Hydrogen peroxide and UV radiation alone are not effective at the arsenic oxidation. Good arsenic oxidation yields can be reached in presence of hydrogen peroxide combined with a high UV radiation dose (2,000 mJ/cm(2)). The quantum efficiencies for As(III) oxidation were calculated for both the UV photolysis and the UV/H(2)O(2) processes.

[Liposarcoma of the oral cavity: description of a case and review of the literature]. / Liposarcoma del cavo orale: descrizione di un caso e revisione della letteratura.

A case of well differentiated lipoma like and sclerosing liposarcoma in a 66 years old women is reported. The review of literature showed the rare occurrence of this neoplasia in the head and neck region especially in the floor of the mouth. C-T Scans and MRI can be helpful in addressing to the diagnosis of a fot tissue neoplasia, but only microscopic examination of a wide incisional biopsy makes the differential diagnosis from a liposarcoma possible. The elective treatment fundamental to present any relapses, as stressed in literature, is the complete removal of the lesion.

[Surgical protection: anatomic and diagnostic contribution of a new CT techniques in preoperative study of the temporal bone]. / La proiezione chirurgica: l'apporto anatomo-diagnostico di una nuova proiezione TC nello studio preoperatorio del temporale.

In the last ten years, CT study of the temporal bone has become, finer and has enriched itself with new projections. The objective of this paper fruit of collaboration between radiologist and otologist, is the search for CT projections, which evidentiate, with the same order and progression, the most important reference points that otologists find in temporal bone surgery. The study was conducted on fresh temporal bone extracted from cadavers which underwent tomography according to a projection very similar to a surgical plane defined precisely as "surgical". The Authors comment on what they consider the three most significant tomographies: those taken from the cortical mastoid at 15, 23 and 32 mm. The various anatomical structures and the relationships between them are identified with an operatory logic; this would afford in the surgical planning phase a better evaluation of the most appropriate approach, of the risks this approach would involve and of the length of the surgical procedure. The Authors also studied and developed an accessory that allows the application of surgical projection in living patients.