Epithelial myoepithelial carcinoma of the parotid gland: A rare tumor with oncocytic changes.

Epithelial myoepithelial carcinoma (EMC), a very rarely seen, low-grade, malignant, salivary gland tumor is most commonly located in the parotid gland followed by the submandibular gland. It is more often observed in females and in the 6th decade of life. Although primary treatment of the tumor is surgical resection, adjuvant radiotherapy may be applied to the adjacent area or close follow-up can be done if the surgical margin is closed. Patients must be followed up closely for recurrence and metastasis. Physical and radiological examinations (USG and MRI) should be performed to see for any recurrence in the operated area during the first year for every 2-3 months. This study presents the clinical, radiological, and pathological characteristics of a 59-year-old female patient with low-grade, oncocytic variant of EMC located in the left parotid gland.

Clinoptilolite: a possible support material for nitrifying biofilms for effective control of ammonium effluent quality?

Ammonium selective natural zeolite clinoptilolite is suggested as a possible support material for nitrifying biofilms to help improve effluent ammonium quality through its high capacity of ammonium removal in the process of ion exchange. This will especially be helpful in cases where the biofilter receives peak or variable loads routinely or occasionally. At the time of peak loads or shocks of ammonium, ion exchange capacity will provide a buffer for the effluent ammonium quality. Data to support this suggestion is presented.

Water quality factors affecting bromate reduction in biologically active carbon filters.

Biological removal of the ozonation by-product, bromate, was demonstrated in biologically active carbon (BAC) filters. For example, with a 20-min EBCT, pH 7.5, and influent dissolved oxygen (DO) and nitrate concentrations 2.1 and 5.1 mg/l, respectively, 40% bromate removal was obtained with a 20 microg/l influent bromate concentration. In this study, DO, nitrate and sulfate concentrations, pH, and type of source water were evaluated for their effect on bromate removal in a BAC filter. Bromate removal decreased as the influent concentrations of DO and nitrate increased, but bromate removal was observed in the presence of measurable effluent concentrations of DO and nitrate. In contrast, bromate removal was not sensitive to the influent sulfate concentration, with only a slight reduction in bromate removal as the influent sulfate concentration was increased from 11.1 to 102.7 mg/l. Bromate reduction was better at lower pH values (6.8 and 7.2) than at higher pH values (7.5 and 8.2), suggesting that it may be possible to reduce bromate formation during ozonation and increase biological bromate reduction through pH control. Biological bromate removal in Lake Michigan water was very poor as compared to that in tapwater from a groundwater source. Bromate removal improved when sufficient organic electron donor was added to remove the nitrate and DO present in the Lake Michigan water, indicating that the poor biodegradability of the natural organic matter may have been limiting bromate removal in that water. Biological bromate removal was demonstrated to be a sustainable process under a variety of water quality conditions, and bromate removal can be improved by controlling key water quality parameters.