Competitive adsorption of heavy metals by two different types of soils

Soil is a key element in human survival and can be described by various definitions according to its main utility. Nowadays, it is accepted that soil is a very complex heterogeneous medium which consists of solid phases containing minerals and organic matter and soil solution, defined as the fluid phase where soil reactions, transport and adsorption occurs (Alloway, 1995). Unfortunately, in the last decades, soils have been used as a deposit of residues. Therefore, the contamination and pollution of soils, sediments, surface and groundwater are of main concern. There are several ions and compounds of organic or inorganic nature that can contaminate soil and water. The inorganic contaminants include heavy metals like cadmium, chromium, cooper, lead and zinc, which are focused in this study. These metals are commonly present in industrial wastes (electroplating, textile and dyes, etc.), in fertilizers or in sewage sludge, but they can also contaminate soils through atmospheric deposition or runoff water (Serrano et al., 2005). Since adsorption is well recognized as the main process affecting the mobility of heavy metals through soils (Bradl, 2004), the aim of this work is the study the non competitive adsorption of these five metals, as well as the competitive adsorption in two different typical soils of the North of Portugal The soil samples were collected in Póvoa de Varzim, from O-horizon and A-horizon (0 cm -30 cm), one from a culture land and another from a beach land. To evaluate the adsorption equilibrium, batch tests were performed by adding to 2 g of air dried soil, 20 mL of 0.01 M CaCl2 solution, containing different initial concentrations of Pb [Pb(NO3)2], Cd [CdN2O6·4H2O], Cu [Cu(NO3)2·3H2O], Zn [Zn(NO3)2·6H2O] and Cr [K2Cr2O7], isolated (non-competitive system) and coupled (competitive system).To eliminate the mass effect, the multi-metal solutions were prepared in terms of molar concentrations (Echeverría et al., 1998). To avoid precipitation the pH of initial solution was adjusted to 2. Isotherm models like Freundlich and Langmuir equations were adjusted to experimental data. Batch tests are useful for the understanding of the adsorption process. However, advection and dispersion may occur in dynamic systems justifying the need of flow experiments (Miretzky et al., 2006). For continuous experiments, soil samples were packed in a column (25 cm × 3.2 cm) and a single – or multi – element solution of 50 mg/L was pass upwards during seven days. Then, using the CXTFIT code, the convection-dispersion equation was adjusted to the breakthrough curves in order to determine the retardation factor (R) and to compare the behavior of the different ions and soils

Effects of consumption of galactooligosaccharides obtained through whey enzymatically modified on the faecal flora and nutritional parameters of hamsters

The aim of this research was to evaluate the influence of wheyenzymatically modified rich in galactooligosaccharides in thenutritional characteristics and effects in the microflora of cecumcontents by the study with Golden Syrian hamsters (Mesocricetusauratus) for 28 days (controlled conditions). Three isoproteic dietswere prepared (20% w/w): C (casein), W (whey) and G (wheymodified). The groups studied differed positively from the C regardingfeed and protein efficiency ratio. The relationships (w/w) oforgan/body were found proportional in all diets. The counts ofprobiotics from the cecum contents the groups showed no difference.The pHs of studied groups were lower than C, this acidity can atimpairs the ability of pathogens to grow in the intestine. Resultssuggest that using whey enzymatically modified rich ingalactooligosaccharides could replace the standard diet withnutritional efficiency and possible inhibit the microorganismspathogenic without induce damage in health.Fil: Dos Santos Da Fonseca, Renata Aline. Universidade Federal Do Rio Grande; Brasil. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario; ArgentinaFil: Rodrigues Machado, Adriana. Universidade Federal Do Rio Grande; BrasilFil: Muniz Moreira, Lidiane. Universidade Federal Do Rio Grande; BrasilFil: Rodrigues, Rosane S.. Universidade Federal de Pelotas; BrasilFil: Machado, Mirian. Universidade Federal de Pelotas; BrasilFil: Souza Soares, Leonor A.. Universidade Federal Do Rio Grande; BrasilFil: Burkert, Carlos André V.. Universidade Federal Do Rio Grande; BrasilFil: Burkert, Janaína Fernandes de Medeiros. Universidade Federal Do Rio Grande; Brasi

Multidisciplinary Scientific Cruises for Environmental Characterization in the Santos Basin – Methods and Sampling Design

The Santos Basin (SB) is the main petroliferous basin in the Brazilian continental margin and one of the most studied marine areas in Brazil. However, historical data suggest that new efforts should be carried out to acquire quantitative biological data, especially in the deep sea, to establish the baseline of essential ocean variables in different ecosystems for future monitoring programs. The Brazilian energy company Petrobras planned and executed 24 oceanographic cruises over a period of 2 years to assess the benthic (SANSED cruise) and pelagic (SANAGU cruise) systems of the SB (356 days at sea in 2019 and 2021/2022). These efforts were part of the Santos Project, which comprised a comprehensive environmental study aimed at investigating benthic and pelagic variables to characterize ecology, biogeochemistry, thermohaline properties of water masses, and ocean circulation patterns, geomorphology, and sedimentology, as well as organic and inorganic chemistry. Here we present the detailed sampling designs and the field methods employed on board, during the SB scientific cruises. All sampling protocols were based on standardized approaches. For the benthos analyses, triplicate sediment samples were performed using a GOMEX-type box corer (0.25 m²) or a large modified Van Veen grab (0.75 m²) at 100 stations ranging from 25 to 2400 m depth. At each station, 25 geochemical and physico-chemical parameters were analyzed in addition to micro-, meio-, and macrofauna and living foraminifera samples. For the pelagic system, 60 stations were selected to investigate the plankton community, ranging in size from pico- to macroplankton, through vertical, horizontal, and oblique net hauls (20, 200, and 500 μm mesh size), as well as 25 biogeochemical parameters collected with an aid of a CTD-rosette sampler. Part of this scientific information also serves the Regional Environmental Characterization Project (PCR-BS) in support of Petrobras’ Santos Basin drilling licensing process led by the Brazilian Environmental Agency – IBAMA. This project contributes to the sustainable development of the SB, in line with the guidelines of the United Nations Decade of Ocean Science for Sustainable Development