Application of ozonation to reduce biological sludge production in an industrial wastewater treatment plant.

Biosolids production in the activated sludge process generates an additional cost to wastewater treatment plants due to the growing requirements for sludge treatment and disposal. This work focuses on the application of ozonation to reduce sludge production in an industrial wastewater treatment plant. The results show that ozonation was able to promote cell wall rupture, releasing intracellular matter into the liquid medium. This effect was observed by the increase in concentrations of DNA (1.14 to 7.83 mg/L) and proteins (0.5 to 45.602 mg/L) in the liquid phase, when ozonation was applied during 10 min, using 30 mg/L of ozone. Reduction of sludge production was assessed by calculating the observed sludge yield coefficient (Y) in bench-scale continuous experiments conducted with varying proportions of ozonated sludge in the recycle stream and recycle ratios. Reduction of sludge production ranged from 14 to 39%, depending on the experimental conditions. The best result in terms of sludge excess reduction was achieved when 20% of the recycle sludge was ozonated and the recycle ratio was 0.67.

[Qualification needs of the nursing team for care provided to HIV and AIDS patients]. / Necessidades de qualificação da equipe de enfermagem para a assistência aos clientes portadores do HIV e da AIDS.

This study discourses about the especific training needs of the nursing teams of the Centers of Reference of Sexual Transmissible Diseases (STD) and Aids from the STD/Aids Program of the Health Secretary of the Township of São Paulo for the assistance of clients with HIV and Aids. From a total of 671 nursing workers, 453 answered the questionnaire. They identified the following training needs: contents related to standard precautions, preparation and administration of specific drugs and other general nursing care to HIV + clients.