Revista Ambiente & Água - An Interdisciplinary Journal of Applied Science

1-18

Authors: Talisson Sáteles Matos; Eduardo Morgan Uliana; Camila Aparecida da Silva Martins; Luis Miguel Castillo Rapalo

This study aimed to regionalize maximum (Qmax), minimum (Q95), and long-term mean (Qltm) streamflows in the Juruena River Basin to further water-resource planning and management, especially regarding water-use grant rights, streamflow regulation, and hydraulic designs. To do that, a traditional method was used, which relates the interest streamflows with sub-basin physiographic parameters by linear and nonlinear regressions. In summary, the traditional method was efficient for regionalization of Q95, Qltm, and Qmax streamflows for the Juruena River Basin. Moreover, the explanatory variables able to provide the best results for regionalization of Q95 and Qltm stream flows are drainage area, total watercourse length, and sub-basin mean altitude. For Qmax regionalization, the best results were provided by explanatory variables like drainage area, perimeter, and total watercourse length.

1-11

Authors: Isabela Aparecida Giordani; Eduarda Busatta; Luís Carlos Iuñes de Oliveira Filho; Dilmar Baretta; Camila Kissmann; Carolina Riviera Duarte Maluche Baretta

Pesticides are widely used in the agricultural sector to control and prevent pests and diseases. The use of these products can adversely affect non-target organisms that have a significant role in the soil, such as earthworms. This study evaluated the toxicity of the commercial formulation of the fungicide Comet® (active ingredient – a.i. pyraclostrobin) at concentrations of 0.08, 0.17, 0.35, 0.70, 1.40 and 2.80 mg of the commercial formulation kg-1 soil and the fungicide + insecticide Standak®Top (a.i. pyraclostrobin + thiophanate-methyl + fipronil) at concentrations of 0.05, 0.10, 0.20, 0.60, 1.20 and 2.40 mg of the commercial formulation kg-1 soil, plus the control treatment, to Eisenia andrei in Tropical Artificial Soil (TAS) by means of standardized tests.

1-11

Authors: Ana Paula Staben Pruchniak; Graziella dos Santos Portes Silva ; Liliane Schier de Lima ; Sueli Pércio Quináia

Activated carbon is commonly used as a material for contaminant-adsorption processes in aqueous systems. However, its use is more restricted to charcoal than to coal, for the most part, in view of the fact of the higher cost (~ 40%) if the mineral is a fossil fuel which needs to be extracted from the earth by mining. For this reason, the peach stone that comes from alimentary industrial tailings can be a good choice for the separation of pollutants from aqueous suspensions and other soluble substances. The purpose of this research was the development of a low-cost filter, using stones to remove atrazine from water. Appraisal and characterization studies were performed along with batch experiments to investigate dosing effects of the activated carbon, atrazine concentration, contact time, and adsorption pH on removal procedures. From the results of the experiment, an excellent removal of the analyte in question was observed under conditions that can be considered as close as possible to the environment, such as pH = 6.5, room temperature and 10 minutes of agitation time, always choosing the best alternative with the lowest cost of energy and time. Batch system application has been recommended as versatile for utilization in seasonal problems such as pesticide contamination.

1-11

Authors: João José da Silva Junior; Alberto Colombo; Geraldo Cézar Oliveira; Bruno Montoani Silva; José Eduardo Juliaci Eugênio

In the last few years, many studies have been published by authors from several countries offering approximations and use of the inverse method. However, the unique environmental conditions and distinct properties of the tropical soils in Brazil require extra considerations and the need to adjust these methods to tropical soil conditions. Considering the above, this determined the parameters of the van Genuchten (1980) model (θs, θr, α, n) of the water retention curve in the soils. It also determined the parameter (Ks) of the soil’s hydraulic conductivity curve by solving an inverse problem using the HYDRUS-2D model, considering cumulative infiltration data collected in the field by means of an infiltration test using the tension infiltrometer. It then compared the hydraulic properties determined by these methods in relation to the standard laboratory method. The inverse method was able to efficiently determine the water retention curves in the soils here studied; however, it was not possible to reliably determine the unsaturated hydraulic conductivity curve.

1-19

Authors: Natasha Berendonk Handam; José Augusto Albuquerque dos Santos; Antonio Henrique Almeida de Moraes Neto; Maria de Fátima Leal Alencar; Caroline Ferraz Ignacio; Adriana Sotero-Martins

The study analyzed the quality of drinking water used in Brazilian urban slum residences according to the standards established in Brazilian regulations. Bacteriological (n=231) and physicochemical parameters (n=134) were analyzed, as the Standard Methods for the Examination of Water and Wastewater establishes. The results revealed that contaminants in the water consumed, for the most part, exceed the limits of drinking water quality standards, putting the population's health at risk and reinforcing the urgency of the need for public policies.

1-19

Authors: Gustavo Willy Nagel; Evlyn Márcia Leão de Moraes Novo ; Milton Kampel

Nanosatellites and CubeSats were first developed for educational purposes. However, their low cost and short development cycle made nanosatellite constellations an affordable option for observing the Earth by remote sensing, increasing the frequency of high-resolution imagery, which is fundamental for studying and monitoring dynamic processes. In this sense, although still incipient, nanosatellite applications and proposed Earth observation missions are steadily growing in number and scientific fields. There are several initiatives from universities, space agencies and private companies to launch new nanosatellite missions. These initiatives are actively investigating new technologies to improve image quality and studying ways to increase acquisition frequency through the launch of larger constellations. So far, the private sector is leading the development of new missions, with proposals ranging from 12 to more than one thousand nanosatellite constellations. Furthermore, new nanosatellite missions have been proposed to tackle specific applications, such as natural disasters, or to test improvements on nanosatellite spatial, temporal and radiometric resolution. The unprecedented combination of high spatial and temporal resolution from nanosatellite constellations associated with improvement efforts in sensor quality is promising and may represent a trend to replace the era of large satellites for smaller and cheaper nanosatellites. This article first reports on the development and new nanosatellite missions of space agencies, universities and private companies. Then a systematic review of published articles using the most successful private constellation (PlanetScope and Doves) is presented and the principal papers are discussed.

1-12

Authors: Gabriel Luis Anibal de Oliveira; Delma de Mattos Vidal

The need to investigate viable methods to facilitate correct disposal of high-water content waste is immediate in the scenario of water source degradation. In this context, Closed Geotextile Systems (CGS) have shown promise for dewatering a variety of high water-content sediments, aiming to reduce the waste final volume, encapsulating particles, and at the same time allowing fluid drainage. Especially in Water Treatment Plants, the geotextiles generally employed in these systems have good tensile strength and rigidity to support mechanical solicitations and hydraulic properties that warrant good drainage conditions. In these applications, the geotextile element should assure the waste confinement and retention of some particles that will form a filter cake which will control internal flow conditions. The present work investigated how small portions of sand influence fine-particle retention. The sludge used consisted of a mixture of filtered water with two well-defined fractions of ground quartz: FG, a silt and CG, a fine sand. The results show that small amounts of sand are capable of leading to the formation of a pre-filter, even if the maximum diameter of the fine particles is much less than the geotextile filtration opening size. The test results indicate that the retention efficiency gradually increases as CG increases in the solution, up to a fraction of CG close to 14%, which represents only 0.7% of the total solution mass. The increase in particle retention was directly proportional to the increase in the GC fraction until reaching the filtration efficiency of approximately 72% where it stabilizes.

1-12

Authors: Marcelo Barbosa Motta; Elisabeth Neumann

Consumption of non-potable water is a relevant public health problem due to the possibility of transporting numerous chemical and microbiological contaminants. In 2005, the Brazilian Ministry of Health created the National Program of Surveillance in Environmental Health related to the Quality of Water for Human Consumption (VIGIAGUA), with the primary purpose of managing risks related to water supply to human populations in Brazilian territory. However, VIGIAGUA does not have a methodology capable of characterizing or managing risks. The objective of this research is to create a working model to transform raw data into conceptual data related to low-, medium- and high-risk levels. The data used in the application of the model were obtained through the analyses of water-quality surveillance conducted by the Regional Health Management of Itabira, a municipality with less than 10 thousand inhabitants, whose history of water contamination is alarming. Twelve samples/month were collected between May 2017 and April 2018. The results of the treated water analyses were classified according to the presence of hazards and categorized into risk levels. The results showed 83.3% contamination by total coliforms at the treatment plant and 91.6% in the distribution system. The Escherichia coli contamination was 16.7% in the treatment plant samples and 45.2% in the distribution system. The system was categorized as "High Risk". The analysis of untreated water samples was carried out for the purpose of knowing the contamination pattern of the raw water of the region, finding 100% contamination by total coliforms and 97.2% contamination by E. coli.

1-14

Authors: Polyane Ribeiro Machado; Thiago Vinícius Ribeiro Soeira; Fausto de Souza Pagan; Geoffroy Roger Pointer Malpass; Julio Cesar de Souza Inácio Gonçalves; Deusmaque Carneiro Ferreira

This study assessed the degradation of bromothymol blue in a Venturi device based on a hybrid process that combines hydrodynamic cavitation (HC) and hydrogen peroxide (H2O2). A Rotatable Central Composite Design (RCCD) was used to optimize the following variables: pressure, reaction time and molar ratio of hydrogen peroxide. Degradation efficiencies were evaluated based on Chemical Oxygen Demand (COD) and color removals before and after Venturi treatment. Maximum COD (93.42%) and color (93.28%) removals were observed at 4.0 bar inlet pressure, at a treatment time of 25 minutes and at H2O2/effluent (dye) molar ratio of 30:1. The hydrodynamic cavitation/hydrogen peroxide system has great potential to remove normally recalcitrant organic pollutants.