Revista Ambiente & Água - An Interdisciplinary Journal of Applied Science

1-18

Authors: Marcos Tavares Carneiro; Myriam Bandeira Vianna Cortes; Julio Cesar Wasserman*

The Escherichia coli T90 parameter is widely employed in outfall plume hydrodynamic models. Although there is a great deal of academic literature estimating T90, no standard methodology has been validated so far. Estimation of die-off rates should consider many other biological, chemical and physical processes. Over the last three decades, while a great deal of new knowledge about microbial biology and ecology has become available, it has not been fully incorporated into the overall research. Consequently, hydrodynamic models of sewage plumes lack consistency with environmental dynamics and frequently do not fully reproduce processes. This article scrutinized the relevant works that could improve T90 assessment using the most robust and realistic approaches. The most important related literature since the 1990s was considered, together with earlier relevant works. The research focused on techniques and methodologies, especially their ecologic and cellular biology aspects. A brief discussion of the methods applied to evaluate the T90 of bacteria examined aspects like representativeness of incubation, incubation scale, measurement procedures and models’ representations of bacterial decay. The factors affecting population decay, such as solar radiation, salinity and interaction with solids, were considered in the light of the very large literature registry. Finally, biological aspects affecting decay, like predation and genetic resistance, were also analyzed. The resulting updated understanding of T90 may contribute to better managerial procedures that could improve water quality in freshwater and coastal systems, and consequently improve human health outcomes.

1-9

Authors: Valdiney José da Silva; Cláudio Ricardo da Silva; Leandro da Silva Almeida*; Claudionor Ribeiro da Silva; Hudson de Paula Carvalho; Reginaldo de Camargo

The “heat island” phenomenon is one of many serious problems caused by rapid urban growth. This study therefore sought to characterize and quantify heat islands in Uberlandia, to evaluate the seasonality of these islands (winter-summer) and to identify the effect of surface coverage on their intensity. To identify intra-urban heat islands in Uberlandia, air temperature data were collected in two seasons (winter and summer) using mobile and fixed transects seasons. Transition measurements were recorded automatically every 0.5 seconds using a car-mounted thermos-hygrometer moving at an average of 40 km h-1. GPS was used to select approximately ten data points every 500 meters of each transect. Fixed weather stations measured air temperature at three sites in the region. Transect data analysis showed that the intra-urban heat islands were more intense in winter (ΔT = 2.2ºC) than in summer (ΔT = 1.2ºC) mainly because by reduction in atmospheric vapor in winter (dry season) and by higher rate of radiative cooling that is favored in permeable areas. The methodology used in the present study proved to be a quick and efficient way to carry out this type of monitoring.

1-13

Authors: Gladis Maria Backes Bühring*; Vicente Celestino Pires Silveira

Human demand for the provisioning services of the ecosystem has been rising and shows the existence of trade-offs in their generation. Brazil is a great producer of agricultural commodities and animal protein, which generates a large amount of residual biomass throughout the production process, especially animal highly polluting waste concentrated in small areas. Ecosystems provide a wide range of services that are of fundamental importance to the well-being, health, subsistence and survival of human beings. The impacts of the waste generated by confined animals can degrade the ecosystem and reduce the services it can supply. Using waste to generate biogas does not require direct resources from the ecosystems to generate energy. In this context, it is an energy product classified as a provisioning service and, at the same time, an ecosystem regulating service, as it mitigates undesirable effects in the environment. The main goal of the classification of biogas as an ecosystem service is to explore its contributions to the ecosystem and to human well-being.

1-10

Authors: Adriele Santos Van Der Maas; Nazareth Jordelina Ribeiro da Silva; Alexandre Sylvio Vieira da Costa; Aruana Rocha Barros; Cleide Aparecida Bomfeti*

Fungi have a large capacity to produce enzymes that are capable of degrading compounds. In this regard, soluble dyes are often used as a means of evaluating and selecting strains with potential for biodegradation. This study verified the capacity of the strains of Pleurotus sp. in degrading methylene blue dye, in order to identify the strains with potential for the bioremediation. For this reason, a total of seven strains of Pleurotus sp. were grown in a potato liquid medium with the methylene blue dye at the concentrations of 0.02 g L-1 and 0.04 g L-1. The results of the absorbances showed that all the isolates were visibly able to reduce the media staining following seven days of growth. However, a reduction of approximately 80% in the staining was observed for the strains named ERY, HI, and SB compared to the control. Thus, it was observed that these strains could be used in the color removal bioprocesses and in the biodegradation of pollutant compounds.

1-10

Authors: Juliana Chagas Rodrigues*; Izildinha Souza Miranda; Adriano Marlisom Leão de Sousa

Changes in land use alter regional microclimate. This study compared the microclimate in understories of a mango orchard and a degraded area in the municipality of Salinópolis, in the northeast of the Brazilian State Pará, eastern Amazon. In both environments, the microclimate was monitored through collecting data on the following variables: maximum, minimum and average air temperature, air thermal amplitude and vapor pressure deficit. The microclimate was monitored daily during four seasons: early rainy season, late rainy season, early dry season and late dry season, between December 2015 and November 2016. Vegetation coverage was the most important factor to soften maximum and average air temperature in the understories. Lower values of meteorological variables were observed in the mango orchard understory, especially during late rainy season and late dry season, except for minimum air temperature, which was lower in the understory of the degraded area, especially during the late rainy season. The microclimate in the understory differed between both environments, and mango orchards may ameliorate the understory microclimate more efficiently than degraded areas; therefore, the mango orchard can be used as an alternative for the rehabilitation of degraded areas.

1-10

Authors: Thaís Andrade de Sampaio Lopes*; Luciano Matos Queiroz; Asher Kiperstok

Life Cycle Assessment (LCA) was applied to estimate and analyze the environmental impacts from the construction and operation phases of a full-scale wastewater treatment plant (WWTP) located in the municipality of Lauro de Freitas, Bahia, Brazil. The WWTP process consists of the association of an Upflow Anaerobic Sludge Blanket (UASB) reactor followed by four constructed wetlands (CWL) and a disinfection step. The functional unit was defined as one cubic meter of treated effluent during the useful life of this WWTP (20 years). The LCA was carried out using SimaPro® software and the Centre of Environmental Science (CML) assessment method. The environmental impacts during construction phase were mainly from the wooden forms for concrete and the use of reinforcing steel. During the operation phase, the chlorine used as effluent disinfectant caused the greatest impacts in the abiotic depletion and acidification categories. Macronutrient concentrations present in the treated effluent and the methane generated also caused significant environmental impacts during the WWTP’s useful life. The results obtained highlight the importance of the application of a methodology like LCA to assist in decision-making with regard to the implementation, construction and operation of a WWTP.