Rodrigo Fernando dos Santos Salazar

Design of Experiments Applied to Antibiotics Degradation by Fenton’s Reagent

Advanced oxidation technologies (AOTs) are processes affected by a large number of parameters such as iron (Fe) and H2O2 concentrations, pH, temperature, light intensity and chemical composition (organics and inorganics). In addition, for different industrial chemical processes, there are different effluents, which greatly vary in chemical composition from each other, not allowing a unique approach for all of them. Thus, it is necessary to adjust AOT parameters to the specific effluent to be treated. In such context, statistical design of experiments (DoE) and response surface methodology (RSM) emerge as important and widely used tools to determine the effects of multiple variables on wastewater treatment processes such as photo-Fenton. A revision of academic studies based on degradation of antibiotics-containing effluents is presented. The chapter also presents commercial cases of AOT and electrical efficiency considerations.

EVALUATION OF THE QUALITY OF WATER IN THE REGION OF SANTA MARIA

This study aims to assess the water quality of the central region of Rio Grande do Sul State, through xa0chemical analyzes (conductivity, color, nitrogen, dissolved oxygen, hardness, pH, temperature,xa0 total dissolved solids, iron content and turbidity) . The samples were divided into thirty-seven points, corresponding to twenty- two collections in neighborhoods and fifteen districts in the Santa Maria area during 2014 2 nd semester. After performing experimental procedures we compared the results with the values u200bu200baccepted by law. It was found that most samples are in accordance with the water quality parameters of class 2.

State-of-the-Art and Trends in Atomic Absorption Spectrometry

Atomic Absorption Spectrometry, or AAS, is an analytical technique commonly used for the quantitative and qualitative determination of elements in samples such as aqueous solutions, waters, sea-waters, metals and alloys, glass, drugs, food, environmental samples, industrial wastes, biological samples among others. This technique is based on measuring the amount of electromagnetic energy of a particular wavelength (ultraviolet or visible region), which is absorbed as it passes through a cloud of atoms of a particular chemical element (the analyte) coming from samples and standards. An appropriate mathematical treatment allows relating the amount of absorbed energy to the number of absorbed atoms by providing a measurement of the element concentration in the sample. This technique is established, relatively quickly, economically affordable and allows to determine more than 60 chemical elements from a huge type of samples. It is used by most of research laboratories and industry quality control around the world. The aim of this text is to present concisely this powerful technique providing basic information about fundamental concepts, instrumentation and application. Relevant and effective techniques will be shown including flame atomization, hydride generation, cold vapor and electrothermic atomization or graphite furnace. Fundamental and theoretical details will not be presented on mechanical components, electronic, software and data processing. They are deeply discussed in specific literature.