RCAAP Repository

Abstract Urbanization is directly linked to the process of impermeabilization of the soil in urban areas that contributes to the emergence of flood risks. The purpose of this study was to determine the hydrodynamic properties of the public squares in a flood-prone Brazilian city and determine to what extent they could contribute to the reduction of flooding. The Beerkan method was used to determine the hydrodynamic properties of the soil in nine squares located at critical flooding points in the city of Recife. This method uses simple ring infiltration and the collection of soil samples to obtain the soil granulometric distribution, thereby generating the soil water retention curve θ(h) and the hydraulic conductivity K(θ). The squares studied have similar hydrodynamic characteristics because of their similar soil texture classes, such as Loamy Sand and Sandy Loam. This made it possible for eight of the nine squares studied to be able to contribute positively to the reduction of flood risks by adapting them into micro infiltration basins that can receive the surface flows that overload the drainage network.

Abstract Granular activated carbon was loaded with 0.5% manganese and 1.0% iron (m/m) for glyphosate removal from aqueous solutions. The adsorbent material was characterized by scanning electron microscopy, dispersive energy spectrometry, nitrogen adsorption techniques and zeta potential analyses. Batch studies were performed to investigate the adsorption equilibrium, kinetics mechanisms and to obtain thermodynamic information. Glyphosate adsorption increased with the contact time and achieved equilibrium within 24 h, with a maximum adsorption capacity of 9.19 mg g-1 at 45°C. Batch kinetic experimental data obeyed the pseudo-second-order model with R2>0.99. Adsorption isotherm experiments were carried out at 5, 15, 25, 35 and 45°C. The adsorption isotherms presented a better fitting using the Freundlich model (R2>0.98), indicating a multilayer adsorption of glyphosate. Thermodynamics studies showed that the adsorption of glyphosate onto granular activated carbon loaded with manganese and iron was spontaneous and feasible with negative values of ΔG°, endothermic with ΔH° of 20.924 kJ mol-1 and ΔS° of -73.250 J mol-1 K-1, suggesting a decrease in randomness at the solid-liquid interface between glyphosate and the adsorbent. The experimental results demonstrated that activated carbon loaded with manganese and iron may be an alternative for glyphosate removal in water, wastewater treatment and purification processes.

Abstract This study evaluated the production of Paiaguás grass (Urochloa brizantha) as a function of wood-ash doses and water availability in the Cerrado Oxisol. The experiment was carried out in a greenhouse with a randomized block design in a fractioned 5x5 factorial scheme, corresponding to five wood-ash doses (0; 8; 16; 24 and 32 g dm-3) and five soil water-availability scenarios (4; 8; 16; 32; 64 kPa) with four repetitions. The experimental design was based on the modified central compound and consisted of 13 treatments of wood-ash doses (g dm-3) and soil water-availability scenarios (kPa): 0-4; 0-16; 0-64; 8-8; 8-32; 16-4; 16-16; 16-64; 24-8; 24-32; 32-4; 32-16; 32-64. Soil volumetric moisture was monitored daily by means of the Diviner 2000 Capacitance Probe® for soil water replenishment according to the treatments. In 30-day intervals, three cuts were performed in the aerial part of the plants evaluating dry mass of leaves, stems, aerial part, number of leaves and of tillers. Data were subjected to analysis of variance and when significant to regression analysis, both up to 5% of error probability, through the statistical program SISVAR and response surface study using SAS. The combinations of wood ash doses with water soil tensions influence the productive characteristics of Paiaguás grass. Fertilization with wood ash reduces the effect of water stress on Paiaguás grass and this residue may be a viable alternative to partial replacement of mineral fertilization and safe disposal in the environment.

Abstract Industrial development has made new products available to people to make their lives easier. Items such as food, cleaning, personal care and health products, among others, are processed, sold and consumed daily by all age groups. These products include in their formulation inorganic and organic chemicals with the purpose of improving or increasing some of their properties, making them more attractive to the consumer. These substances are strictly controlled during production so that the final product may be safely consumed. In most cases, the constituents of commercial products end up in wastewater, where they are not controlled. These uncontrolled pollutants of differing chemical natures are known as “Emerging Contaminants” (ECs). Research worldwide has found ECs in various environmental matrices, especially water. To understand this problem, four fundamental aspects must be addressed: 1) the analytical methods for its determination; 2) the occurrence in environmental matrices; 3) the treatments for the removal of ECs in wastewater and drinking water plants; and 4) the risks to health and the environment. This document reviews these four aspects with regard to 14 ECs commonly found in the studies around the world and addresses the state of these ECs in trans-American waters.

Abstract Debris flows are geophysical phenomena, caused by torrential rain, which occur in mountainous areas, characterized by the detachment of slope and riverbed materials and their consequent dislodge through watersheds and streams. Debris flows usually carry sludge, water and rocks, and can destroy everything in their path. On February 8th, 2019, an event of this type occurred and destroyed Mirave’s community in Peru, which was located in the areas of transport and deposition of debris flows. This research presents the modeling and numerical simulation to reproduce the transport and deposition processes of the debris flow that occurred in Mirave. The initiation process of the debris flow in streams was represented by hydrographs obtained from the estimated rain runoff volumes and solid materials found at each evaluated micro watershed. The numerical simulation results show acceptable results in terms of reproduction of the extension of the affectation and deposition areas of solids related to the studied debris flow. The resulting velocity field shows an adequate representation of the erosion zones observed in the area. The model used for evaluating the disaster risk by debris flows can predict and delimit, with acceptable accuracy, the potentially dangerous areas for a mudslide event. The application of the proposed methodology for assessing the disaster risk due to debris flows at watersheds and streams is useful to understand the extent of debris flow affectation during extreme weather events, as well as to develop emergency plans, and to formulate disaster management policies in Peru or in other countries with similar conditions.

Abstract In agricultural regions where there is insufficient rainwater for cultivation, understanding the dynamics of surface water and groundwater is critical to assess the impact of increased well pumping on the water balance. The western region of the state of Bahia-Brazil, the largest area of agribusiness in the state, has experienced progressive occupation since the 1980s, resulting in pressure on water resources - mainly after the introduction of irrigation - and conflicts among water users. This study analyzed the effects of groundwater extraction by wells in a portion of the Urucuia Aquifer System. The methodology used was the simulation of groundwater flow in steady-state for three scenarios: i) without withdrawal of water by pumping wells; (ii) with current withdrawal rates; and (iii) with 60% additional extraction. After defining well production rates from field surveys (4.6 m3 s-1) and modeling of the aquifer base geometry (maximum thickness of 535 m), the steady-state models with and without pumping show that, in the long term, groundwater storage decreases by 2 km3 (0.8 m on average in the aquifer) without interference in the regional flow direction. The mass balance shows that the base flow of the main rivers is reduced by approximately 6% after current groundwater extraction and an additional 2.5% after additional extraction. The results point to a greater impact on surface water caused by a reduction in groundwater storage and related river base flow. This indicates the importance of maintaining and expanding the groundwater-level monitoring network.

Abstract The objective of this work is to explore the implementation of a low-cost real-time monitoring and control of water consumption together with a user feedback interface. Water usage information will be available in a cloud storage and can be accessed through a mobile application. The collected data allows access and supervision of both client- and water concessionaire. Project feasibility is analyzed in terms of hardware and software, as well as each element required for the design. The simulations were carried out with the purpose of verifying system operation, considering the following metrics: transmission rate, signal strength and transmission quality. After the simulations, the hardware and software were integrated, and the final result was presented through a mobile application. This work presents and applies a design and development methodology of Wireless Sensor Network (WSN) using Internet of Things (IoT) technologies and Smart City in water-distribution systems.

Abstract Shewanella xiamenensis G5-03 isolated from contaminated landfill soil efficiently decolorized five textile azo dyes under static conditions. One of them, Reactive Red 239 (RR239), was completely decolorized at a pH range of 7 to 11 (at 35°C) within 3-6 h. The bacterium was also efficiently decolorized RR239 in a wide temperature range of 25-40°C (at pH 8). The kinetics of RR239 decolorization by G5-03 fitted to the Michaelis-Menten Model (K m = 443.3 mg L-1, V max = 166.7 mg L-1 h-1). The decolorization of RR239 was monitored by UV-Vis and FTIR spectroscopy, which showed significant changes in peak positions when compared to the dye spectrum. Overall, the ability of S. xiamenensis G5-03 to decolorize textile azo dyes in a wide range of temperatures and pH (neutral-alkaline) indicate that this strain is a potential candidate for treating dye-containing effluent.

Abstract Land-use intensification in the "Zona Bragantina" region, an area in the eastern Brazilian Amazon, has accelerated landscape changes from primary forest to a mixture of different land uses: native forest (riparian vegetation), secondary forest, pasture, annual cropland, perennial cropland, bare soil and fallow vegetation, with negative consequences for the stability and equilibrium of river systems. This study examined the temporal and spatial variation of dissolved organic carbon (DOC) and metal concentrations in stream water of the Cumaru (ICU) and São João (ISJ) watersheds from May 2014 to April 2015, to understand the chemical changes in forests and agro-ecosystems during one year. In both watersheds, higher concentrations of dissolved metals (aluminum, sodium, barium, calcium, iron, potassium, magnesium, copper and zinc) and DOC were measured in the rainy season, with considerable variability due to precipitation events. Furthermore, strong spatial variation was observed, with lower conductivity, higher pH, and higher concentrations of DOC and dissolved metals in the downstream reaches, especially for DOC in a small reservoir below a dam in ISJ. Significant human intervention was located in these downstream areas, including nearby agriculture and pasture, and use of stream resources for domestic activity. Sandy soil in these areas likely facilitated leachate processes, mainly in deforested areas, supporting the increased movement of metals from the land to the stream.

Abstract The objective of this study was to evaluate the water balance in a Red-Yellow Latosol covered by a regenerating rainforest for 30 years in the Una River Basin between April 2016 and March 2017. Field capacity (FC) and permanent wilting-point values (PWP) used to calculate the available water capacity (AWC) in the soil were determined by the soil moisture characteristic curve obtained in pots, which made it possible to determine the soil residual water content (g / g) from the measurement of water tension in 15 Watermark (TM) sensors installed at depths of 40, 60 and 120 cm. Precipitation during the period (1962 mm) was obtained from the automatic weather station located 300 m from the experimental area. Soil surface runoff was obtained from 5 collectors distributed in the experimental area. Precipitation was characterized by a maximum of 454 mm in January 2017 and no rain in July 2016. The actual evapotranspiration was 744 mm. There were 56 runoff events (SR) totaling 60 mm. The average soil water tension remained below 37 kPa in 67% of the studied period, a condition that kept the soil moisture content high. The soil water balance of the tropical forest area, up to 120 cm deep, kept soil water content near its maximum capacity (173 mm) 49% of the time and saturated 51% of the time, so that it generated deep drainage beyond 120 cm deep and 1023 mm deep.

Abstract Intensive rainfall is an important meteorological variable that is of technical interest in hydraulic projects. This study therefore generated Intensity-Duration-Frequency equations (IDF) for 14 weather stations in Mato Grosso State, based on pluviograph analysis. Annual maximum rainfall data regarding 10-to-1440-minute long rainfall events were collected from digitized daily pluviographs. Data adherence to the generalized extreme value distribution (GEV) was checked through the Kolmogorov-Smirnov test at a 20% significance level. Next, the maximum probable rainfall for return periods such as 2, 5, 10, 20, 30, 50 and 100 years was calculated and the IDF equations were adjusted. The performance of the IDF equations was evaluated based on mean absolute error (MAE), root mean square error (RMSE), bias, Willmott's concordance index and Nash-Sutcliffe efficiency index (ENS). Adjusting the IDF equations was only possible for rainfall durations ranging from 10 to 360 min at each station due to the low frequency of longer rainfalls. High variation was present in parameters of the IDF equation and in maximum rainfall intensity between stations. The satisfactory performance of the models, as attested to by statistical indices, allows using IDF equations adjusted for rainfall durations from 10 to 360 min, and return periods from 2 to 100 years, in the regions of the Mato Grosso weather stations.

Abstract The objective of this study was to identify and evaluate the variables responsible for contributing to possible natural and/or human contamination in groundwater of the semiarid region of the state of Bahia, seeking to subsidize water quality monitoring and management actions in the area. To do so, multivariate analysis techniques regarding factorial analysis in principal components and cluster analysis were used. The factorial analysis allowed the grouping of variables into two principal factors that explained 93% of total accumulated variance. Variables were strongly related to concentrations of metals and salinity in the water. The cluster analysis was used to classify water sources according to the quality of waters into three clusters in each factor. The natural background of the rocks of the municipality of Boquira was shown to influence water resources. A continuous (during dry and rainy seasons) monitoring of water quality from wells and springs located upstream and downstream from contamination sources is recommended, even if these waters are not used for public supply, to determine possible contamination plumes from contaminated material.

Abstract Brazilian Native Vegetation Protection Law (Law n. 12.651/2012) brought flexibility related to the sizing of Permanent Preservation Areas (PPAs) along watercourses when there was anthropogenic occupation before July 22, 2008 (consolidated rural area), which may vary according to the size of the property. To better understand the effects of this law, we analyzed land use and land occupation in PPAs along watercourses in a portion of Grande River drainage basin. Scenarios were also developed to compare the effects of the reduction of PPA limits, allowing us to discuss measures to avoid water quality deterioration. We obtained the drainage network and individualized the study area through images available in Google Earth TM, and we extracted information about land use and land occupation from a vector provided by the Laboratory of Studies and Projects in Forest Management from Federal University of Lavras. Recovery scenarios were estimated according to Article n. 61-A from the Native Vegetation Protection Law. There was a significant reduction of environmental liability compared to previous legislation. In the more restrictive scenario, there may be a 31% deficit in recovery areas, where watersheds with a strong presence of small rural properties will be the most affected. Although the reduction of recovery areas is characterized as a retrogression in the protection of native vegetation, complementary strategies could be implemented, such as economic incentive mechanisms.

Abstract Reactive Black 5 (RB5) is one of the synthetic reactive dyes most used in the textile industry, due to its solubility in water and reactive groups which form covalent bonds within the fiber. In the process of dyeing fabrics, however, it is estimated that 12-14% of dyes are released into the effluent. This work evaluated the biodegradation of RB5 dye, adsorbed in polyurethane foam, by basidiomycetes (Phanerochaete chrysosporium ATCC 24725, Pleurotus ostreatus and Pleurotus floridae). Results were evaluated considering the partial- or total medium discoloration, the adsorption capacity of the dye in the polyurethane foam (PUF) and the respirometric measurements. The results showed that Phanerochaete chrysosporium was able to partially degrade 50 mg L-1 of RB5 in pH 6.0, when cultivated in Petri dishes. When this microorganism was cultivated in PUF cubes saturated with RB5 solution (50 mg L-1, pH 6.0), CO2 production reached an accumulated value of 2.16 mg on the fifteenth day, revealing the growth of the microorganism and consequently the contaminant degradation, which was used as the source of nutrients.

Abstract Phytoremediation has been used as an alternative for removal of heavy metals in aquatic environments, but plant residence time and toxicity reduction need to be studied. Ecotoxicological bioassays and root anatomic studies were conducted in order to validate the phytoremediation of Echinochloa crus-galli L. at three different ages. The experiment was conducted using E. crus-galli seeds with processing factorial experimental design (2x3) and four replicates. Cadmium presence and absence (0.8 and 0 mg L-1) at three times (20, 30, and 45 days after germination). Cd levels were quantified by flame atomic absorption spectroscopy on both aerial parts and roots. A bioassay was performed testing both acute and chronic effects using microcrustacean Daphnia similis with the purpose of evaluating phytoremediation efficiency. Regardless of biomass, E. crus-galli L. can be used for 16 to 19 days for 45 days after germination (DAG), tolerating the phytotoxicity of this metal. The residual solution after phytoremediation had chronic effect on D. similis, indicating that the time taken was not sufficient to reduce the toxicity of the solution. Thus, ecotoxicological essays are important tools in evaluating the efficiency of this type of process. While E. crus-galli L. is a valuable tool in Cd phytoremediation programs, exposure time must be higher than 19 days to reduce concentrations of this metal in the water to conform to the CONAMA 357/2005 e 430/2011 standards.

Abstract The implementation of sewage collection systems alone does not guarantee public health, since households must be correctly connected to the network in order to derive any benefit from these public works. In order to ensure an environmental and social return on investments in sanitation, a) population must be instructed concerning the role of each citizen, and b) companies responsible for the provision of water and sewage services must be managed in a coordinated and participative manner. This study sought to understand why many households do not respond promptly to the “Connect to the Network” program in the state of Parana and how much the further efforts cost to the sanitation company to regularize this problem. The methodology consisted of analyzing the program’s socio-environmental intervention strategies, interviews and service reports for 17 projects (13,286 household connections). The results: no projects achieved 100% of household connections; total connections were less than 80% in 40% of the projects; the additional cost of re-implementing social and environmental initiatives was R$ 680,000.00. We recommend that user representatives be allowed to participate in the network-deployment process, that social awareness and mobilization strategies be expanded and diversified, and that free home connections be completed for low-income families. This study may aid development agencies to arrive at a standardized methodology for the objective evaluation of socio-environmental initiatives that are to be carried out within the community; it may also aid in the fulfillment of Sustainable Development Goals (SDG), particularly Goal 6 (sanitation services for the entire population).

Abstract This article presents the first detailed geochemical data of the water from Camaquã das Lavras and Hilário Streams from Lavras do Sul-RS. Geochemical and statistical analyses were used in this study to establish the anthropogenic or natural influence on the region. The results classified the waters as soft and intermediate with acidic and neutral pH. The electrical conductivity varies from 37.2 to 62.9 μs cm-1 and the total alkalinity ranges from 4 to 30 mgL-1. The distribution patterns and ratios indicate that clay mineral weathering is dominant on the investigated samples. It is followed by feldspar weathering in an environment under temporary hardness conditions. Cu, Rh, and Cd enrichment is associated with the many mineral deposits of the region, lithological diversity and human activities. All the measured values conform with the standards set by Brasil-Ordinance nos. 2914/2011, 36-GM/1990 and 1469/2000.

Abstract Effluents generated by the food industry have become a serious environmental concern. Bioremediation is a biological process developed as an alternative for the treatment of contaminated areas. In current research, the biodegradation of fat, Biochemical Oxygen Demand (BOD5), Chemical Oxygen Demand (COD) and total solids were evaluated in dairy waste employing enzymatic extract of Yarrowia lipolytica ATCC 9773 as biological agents. All the variables were determined following the specifications of the Standard Methods of the American Water Works Association. Enzymatic extract of Y. lipolytica at different concentrations (8, 12 and 16.0%) was used in a fermentative medium at two pHs (5.0 and 6.5) for 32 h. The highest percentages (%) of fat (82.88), BOD (43.32), COD (44.3) and total solids (13.58) removal were obtained using an inoculum concentration of 16% at pH 5.0 for 32 h of fermentation. These results may have industrial relevance for the reduction of contamination of industrial effluents with high levels of fat and other contaminants.

Abstract This study evaluated the impact of diet as a mitigation action to improve the water efficiency of lactating cows. An intensive pasture dairy system was considered to calculate direct and indirect water use. Group 1 was fed with a diet containing 20% crude protein content. The crude protein content of Group 2 was adjusted according to milk production, ranging from 23% to 14.5%. The total water footprints had a value of 502.4 L kg-1 fat protein corrected milk for Group 1 and 451.2 L kg-1 fat protein corrected milk for Group 2. The diet with the adjusted protein provided a reduction of 10% in the footprint value. The green water footprint was the most representative of consumption in the total value of the water footprint, 86.4% and 85.5% for Groups 1 and 2, respectively. The animals in Group 1 had a mean total drinking water consumption of 83.3 L animal-1 day-1 and those of Group 2, 80.4 L animal-1 day-1. This study demonstrated that high crude protein content in the diet provided a greater water footprint, therefore lower water efficiency. The proposed nutritional practice proved viable as a water-mitigating action, making the ratio of liters of water per liter of milk more advantageous. The results of this study could be considered a validation of a nutritional mitigation practice to improve water efficiency and could be used as best management for the dairy supply chain.

Abstract This study evaluated genotoxic and cytotoxic potential of water samples through the analysis of Allium cepa root cells exposed to samples from five urban lakes of Alta Floresta, state of Mato Grosso. The samples were obtained in the dry and rainy periods, October 2014 and April 2015, respectively, at five distinct points. The collection points were as follows: Lake 01, located in MT 206; Lake 02, in Avenida Perimetral Rogério Silva; Lake 03, in Sector C; Lake 04 on Teles Pires Avenue; and Lake 05, in the Cidade Bela District. Bioassays using Allium cepa bulbs were taken from the water at each point, and comparisons were made with the negative and positive controls. The results found the presence of genotoxic and cytotoxic activities on the roots of A. cepa, indicating high potential in cell cycle inhibition. This result may also be caused by the influences of seasonal periods, taking into account that in the rainy season there is a greater transport of cytotoxic substances by rainwater, and in the dry season, a higher concentration of pollutants due to the reduction of water volume, resulting in a greater interaction of the concentrators as well as a greater concentration of the elements found in the water of these lagoons.