Biosorption of cadmium using the fungus Aspergillus niger

Sorption experiments using the Aspergillus niger fungus for cadmium removal were carried out to study the factors influencing and optimizing the biosorption of this metal. The effects of pH, time, biomass concentration, and initial concentration of the heavy metal on the rate of metallic biosorption were examined. An experimental design was also used to determine the values of the under study variables that provided the greatest biosorption efficiency. A technique for biomass recovery was also developed with the objective of determining the capacity of the regenerated biomass to biosorb the metals in solution. This research proved that with a pH of 4.75, a biomass concentration of 0.7 g/L, and a heavy metal concentration varying between 5 and 10 mg/L a biosorption process of biosorption with Aspergillus niger could be successfully used for heavy metal removal from oil field water in the oil industry

Household Sampling In Slums In Surveys

Objective: To identify the advantages and disadvantages of using segments compared to a complete address list, for the selection of households in a multistage cluster sampling in slums. Methodological Procedures: A qualitative study was performed in four slums selected by the São Paulo Municipal Health Survey of 2008, and the two selection techniques were applied. Focal groups were performed with fi eld researchers, including the persons making the list of addresses and the interviewers. The content of the conversations were analyzed, grouped in categories and organized in themes. Analysis of Results: Use of household segments was associated with several advantages and few disadvantages. The advantages included: speed and facility in developing the sampling frame and in locating and identifying households when performing interviews, increased safety for interviewers and the population, greater access to interviewees, greater stability and coverage of the frame, and fewer errors in the identifi cation of selected households. Conclusions: The construction of a household registry by creation of segments is advantageous compared to the complete listing of addresses, when undertaken in slums. Due to its economy and ease, the technique is an option for simplifying the sampling process in areas characterized by high density and disorganized housing.45610991109Alves, M.C.G.P., Silva, N.N., Simplifi cação do método de estimação da densidade larvária de Aedes aegypti no Estado de São Paulo (2001) Rev Saude Publica, 35 (5), pp. 467-473. , DOI: 10.1590/S0034-89102001000500010Anker, M., Epidemiological and statistical methods for rapid health assessment: introduction (1991) World Health Sta Q, 44 (3), pp. 94-97Bardin, L., (1977) Análise de conteúdo, , Lisboa: Edições 70Barros, M.B.A., Inquéritos domiciliares de saúde: potencialidades e desafi os (2008) Rev Bras Epidemiol, 11 (SUPPL. 1), pp. 20-37. , DOI:10.1590/S1415-790X2008000500002Bennet, S., A simplifi ed general method for cluster -sample surveys of health in developing countries (1991) World Health Sta Q, 44 (3), pp. 98-106Caraveo-Anduaga, J.J., Bermúdez, E.C., The epidemiology of obsessive-compulsive disorder in México City (2004) Salud Mental, 27 (2), pp. 1-6Herderson, R.H., Sundaresan, T., Cluster sampling to assess immunization coverage: a review of experience with a simplifi ed sampling method (1982) Bull World Health Organ, 60 (2), pp. 253-260Kish, L., (1965) Survey sampling, , New York: John Wiley & SonsKuper, H., Polack, S., Limburg, H., Rapid assessment of avoidable blindness (2006) Community Eye Health J, 19 (60), pp. 68-69Morgan, D., (1997) Focus group as qualitative research, , London: Sage Publications. (Qualitative Research Methods Series, 16)Passos, M.C., Lamounier, J.A., Silva, C.A.M., Freitas, S.N., Baudson, M.F.R., Práticas de amamentação no município de Ouro Preto, MG, Brasil (2000) Rev Saude Publica, 34 (6), pp. 617-622. , DOI:10.1590/S0034-89102000000600009Rogers, E.M., Takegami, S., Yin, J., Lessons learned about technology transfer (2001) Technovation, 21 (4), pp. 253-261. , DOI:10.1016/S0166-4972(00)00039-0Trindade, E., A incorporação de novas tecnologias nos serviços de saúde: o desafi o da análise dos fatores em jogo (2008) Cad Saude Publica, 24 (5), pp. 951-964. , DOI:10.1590/S0102-311X2008000500002Turner, A.G., Magnani, R.J., Shuaib, M., A not quite as quick but much cleaner alternative to the Expanded Programme on Immunization (EPI) Cluster Survey Design (1996) Int J Epidemiol, 25 (1), pp. 198-203. , DOI:10.1093/ije/25.1.198White, L.L., Golberg, H.I., Ballew, C., Mendlein, J.M., Peter, D.G., Percy, C.A., Rationale, design and methodology for the Navajo Health and Nutrition Survey (1997) J Nutr, 127 (10 SUPPL.), pp. 2078-208