Revista Ambiente & Água - An Interdisciplinary Journal of Applied Science

239-249

Authors: Christian Luiz da Silva; Nádia Solange Schmidt Bassi; Weimar Freire da Rocha Junior

Brazil has the highest water availability of any country in the world. Nearly 20% of all the world’s rivers flow on Brazilian soil. Brazil’s herds of cattle, pigs and poultry are among the largest in the world, and the country uses irrigated agriculture extensively, which accounts for most water consumption (approximately 70% of the water consumed in the world). The Brazilian Agricultural Research Corporation (Embrapa), the largest and most important public institution of Brazilian agricultural research, has attempted to develop environmental technologies in order to minimize the impact caused by the scarcity and pollution of water resources. This paper describes the technologies this institution offers to different regions. For this purpose, a descriptive and exploratory study was conducted in various Embrapa research units. The results showed that research on the rational use of water in agriculture has intensified since the early 2000s. However, the pace of growth in agricultural activities and their impact is much greater than that of the generated technologies, demonstrating the difficulty in striking a balance in this relationship. Furthermore, it is clear that that water scarcity and the increasing pollution of shallow and deep waters are complex issues with no short-term solution.

268-278

Authors: Oscar Orlando Ortiz Rodriguez; Raquel Amanda Villamizar-Gallardo; Rafael Guillermo García

There is currently great concern about the processes that directly or indirectly contribute to the potential for global warming, such as stratospheric ozone depletion or acidification. In this context, and provided that treated water is a basic public utility in urban centers around the world as well as in some rural areas, its impact on the environment is of great interest. Therefore, this study applied the environmental methodology of Life Cycle Assessment (LCA) to evaluate the environmental loads of four potable water treatment plants (PWTPs) located in northeastern Colombia following the international guidelines delineated in ISO 14040. The different stages of the drinking water process were thoroughly assessed, from the catchment point through pumping to the distribution network. The functional unit was defined as 1 m3 of drinking water produced at the plant. The data were analyzed through the database Ecoinvent v.3.01, and modeled and processed in the software LCA-Data Manager. The results showed that in plants PLA-CA and PLA-PO, the flocculation process has the highest environmental load, which is mostly attributable to the coagulant agent, with a range between 47-73% of the total impact. In plants PLA-TON and PLA-BOS, electricity consumption was identified as the greatest impact source, with percentages ranging from 67 to 85%. Treatment processes and techniques, bioclimatic conditions and culturally driven consumption behavior varied from region to region. Furthermore, changes in treatment processes and techniques are likely to affect the environment during all stages of a plant’s operational cycle.

291-303

Authors: Celso Maran de Oliveira; Ozelito Possidônio de Amarante Junio;Celso Antonio Pacheco Fiorillo; Pedro Luciano Colenci

This work discusses the regulatory standardization among countries that are party to MERCOSUR. This standardization forms the legal and institutional framework for maintaining important and strategic water resources, which require such regulation in order to be preserved and protected for present and future generations. Due to the lack of general legislation relating to MERCOSUR’s water resources, it was necessary to study the main multilateral agreements among the MERCOSUR countries, such as the Amazon Cooperation Treaty and the River Plate Basin Treaty relating to surface water, and also the legal points included in a recent joint statement of the presidents of the Mercosur States regarding the Guarani Aquifer, which is an important resource for current and future generations of the MERCOSUR. The survey was developed using the hermeneutical method, based upon surveys and analysis of international legislation involving MERCOSUR member states, multilateral treaties relating to transboundary waters and groundwater zones and also included a search of bibliographic materials, books, journals, thematic maps, information and documents available on the Internet. The combination of the sparse legal rules covers most legal relationships between MERCOSUR member states relating to water.

316-326

Authors: Fábio Campos; Roque Passos Piveli

This study used acute toxicity tests on the marine bacteria Allivibrio fischeri and on microcrustaceans Daphnia similis to evaluate the reduction of acute toxicity in effluent generated by the IFAS (Integrated Fixed Film Activated Sludge) hybrid process, treating landfill leachate with domestic sewage. In order to evaluate the treatment’s ability to lessen the toxicity of the effluent, three experimental stages were developed with leachate contributions of 5, 10 and 20% of the total load of BOD in the effluent composition. In general, the results show that, even with the greatest contribution of leachate, no significant alterations were observed in the behavior and efficiency of the biological process; however, with regard to the degree of acute toxicity observed in the affluent, the classification of the effluents changed from Very Toxic to Toxic in three phases of operation, even reaching the reduction levels around 70% in the last stage of the study, highlighting the need for greater control and evaluation of this variable. The methodology of using the Microtox® technique proved to be more sensitive to compounds present in the samples when compared to the technique using the microcrustaceans D. similis.

339-349

Authors: Milton César Costa Campos; Marcelo Dayron Rodrigues Soares; Mailson Ferreira Nascimento; Douglas Marcelo Pinheiro Silva

Land use and management systems are factors that can influence carbon stock and its aggregate stability. This study assessed the carbon stock and aggregate stability of Inceptisols under different land use and management systems. The study was conducted on five properties located in the southern region of Amazonas state. Five areas were selected with different traditional land use systems (agroforestry, cassava, sugarcane, pasture and native forest). On each site, grids of 50 m x 50 m, with regular spacing of 10 by 10 meters were outlined for a sampling of 36 points in each mesh at a depth 0.00-0.10 m. We determined the bulk density, aggregate stability, total organic carbon and carbon stock. Data were subjected to analysis of variance (F test) and means were compared by Tukey test at 5% probability. We found that the highest values of carbon stocks were found in areas under sugar cane and pasture, followed by the areas under cassava, agroforestry and native forest. Carbon stocks and aggregate stability were significantly altered by land use management systems.

362-376

Authors: Poliana Nascimento Arruda; Aline Souza Carvalho Lima; Paulo Sérgio Scalize

The characteristics of services provided and the regulations governing their cost both contribute to the satisfaction of the consumer. Therefore, the aim of the study was to analyze the quality of public water and sewage services in 21 municipalities of Goiás, to include billing procedures and consumer satisfaction, and taking into account whether or not the operations were regulated. To accomplish this, we conducted on-site visits to complete questionnaires relating to our interviews with managers to obtain technical information and with consumers to determine their level of satisfaction. It was observed that systems are managed by local authorities in ten municipalities, four by city hall departments or appointed officials, and seven did not have any specific regulatory oversight. Seven municipalities had no water treatment; of those, six had no specific regulatory oversight, revealing the lack of a planned management system. In 57.1% of the municipalities, there was no sewage treatment and sewage was dumped in soak pits. These had no governing body, and the price-charging adjustments were established in three ways: i) approval of the project by the Town Hall councilors; ii) decree by the mayor; and iii) analysis by the Municipal Sanitation Council (CMS). The satisfaction of the consumers was related to economic, cultural and, especially, political factors, and the existence of a management system improved infrastructure conditions.

387-401

Authors: Karla Santos de Araújo; Raissa Antonelli; Beatriz Gaydeczka; Ana Claudia Granato; Geoffroy Roger Pointer Malpass

Contamination of water by toxic and/or recalcitrant species has great environmental impacts. In this context, Advanced Oxidation Processes (AOPs) - technologies that principally use the hydroxyl radical (HO●) for oxidation - have emerged as promising alternatives in treating urban and industrial wastewaters. This study reviewed the literature on POAs and presented data regarding the efficiency of these processes in pollutant degradation, comparing the theoretical reasoning and its industrial applications. The fundamentals and major applications of AOPs (chemical, photochemical, electrochemical, sonochemical and ozone-based processes), as well as their advantages and disadvantages, are described in this review. AOPs have been considered an effective alternative from a technical, economic and environmental viewpoint for the degradation of pollutants in effluents and industrial wastewater, despite having limitations such as high cost of available energy sources, development of new low-cost catalytic materials and construction of full-scale reactors. It is greatly important to the industrial application of AOPs to optimize the effectiveness of these factors.

414-427

Authors: Ermeton Duarte do Nascimento; Claudio Marcio de Medeiros Maia; Magnólia Fernandes Florêncio de Araújo

Water contamination in the semi-arid section of Northeast Brazil is a current concern for the country’s researchers, since this region is considered one of the poorest in Brazil and the water in these locations is a primary vehicle for disease transmission. We collected physical and chemical data as well as water samples from four semiarid potiguar reservoirs during the dry and rainy seasons of 2013 and 2014. These samples were prepared in a laboratory at the Federal University of Rio Grande do Norte (UFRN) and their physical, chemical and microbiological characteristics were evaluated. The procedures of microbial isolation and identification followed the Standard Methods for Examinations of Water and Wastewater. Then Vitek II system (Bio-Merieux®) was used to identify the microbial specimens and we calculated the frequency of specimens’ occurrence. Altogether, 168 bacteria were isolated and identified; 97% were Gram-negative and only 3% were Gram-positive. Within the Gram negatives, 73.2% were identified as belonging to the Enterobacteriaceae family and, in general terms, the most constant genera in the water reservoirs were Vibrio and Aeromonas. Among the Enterobacteriaceae family, the species Escherichia coli, Enterobacter cloacae complex and Klebsiella pneumoniae were the most frequent. There was no statistical difference between the number or morphotype groups found in the periods, p=0.255 and p=0.237, respectively. The analyzed data indicate possible contamination of these water reservoirs by human and/or animal fecal material.

439-447

Authors: Larissa Imaculada da Costa Sobrinho; Francine Alves da Silva Coelho; Matheus Diniz Gonçalves Coelho

Giardia duodenalis is the main water-transmitted protozoan in developing countries. This study evaluated the effectiveness of ceramic filters in capturing G. duodenalis cysts and verified the porosity size needed to remove cysts from contaminated water. The study was conducted in the Laboratory of Parasitology at the University of Taubaté, where each filter unit was made by joining two Pet gallons, latex hose and a ceramic filter. Two porosity sizes were selected: 0.5-1.0 μm and 5-15 μm with or without activated carbon, and the assays were run in triplicate. Approximately 60 μL (53 cysts) of G. duodenalis cysts were placed in 2 liters of distilled water. After the preparation of the contaminated water, this solution was run through the filter until the completely filtered. Afterwards, the filtrate was processed according to the methodology described by De Faria (2006), in order to concentrate parasitic elements. The results were statistically evaluated using ANOVA and Tukey tests, showing that the 0.5- 1,0 μm porosity filter candles (with and without activated carbon) were able to retain 100% of cysts of G. duodenalis. This is a result significantly superior to the results obtained in the control group (p<0.05). On the other hand, for the candles with porosity of 5 15 μm, total retention occurred only in candles with activated carbon. Based upon our results, it can be concluded that, in candles with both porosity sizes with activated carbon, all filters showed a satisfactory efficacy for filtration of G. duodenalis cysts.

462-471

Authors: Erbia Bressia Gonçalves Araujo; Francisco Vanies da Silva Sá; Fernanda Andrade de Oliveira; Lauter Silva Souto; Emanoela Pereira de Paiva; Maria Kaline do Nascimento Silva; Evandro Franklin de Mesquita; Marcos Eric Barbosa Brito

The melon crop is normally developed in semiarid regions, where water resources are limited. This scarcity of water is a strong stressor on the crops, and requires the supplementation of existing water supplies with poor quality water, especially saline water. This can impede the growth and production of plants; however, the use of tolerant genotypes may minimize this problem. Thus, a greenhouse experiment was developed at the Federal University of Campina Grande - UFCG, Pombal Campus, Paraiba State, Brazil, in order to study the emergence, initial growth, and tolerance of melon cultivars irrigated with waters of different salt content. We studied three melon cultivars (Gaúcho Redondo, Gaúcho Casca de Carvalho and Halles Best Jumbo) irrigated with five levels of saline water (0.6; 1.2; 1.8; 2.4; and 3.0 dS m-1), arranged in a 3 x 5 factorial scheme, with the treatments distributed in a randomized block design with four replications. The plants seeds were monitored for 30 days after sowing, and at 30 days the growth and salinity tolerance index was evaluated. Cultivar Halles Best Jumbo was the most tolerant to saline water during initial stage of growth, while the Gaucho Redondo was more sensitive to salinity. It was found that saline waters up to 1.8 dS m-1 were suitable for irrigation of melon plants round Gaucho and waters up to 2.4 dS m-1 could be used for irrigation of Gaucho Casca de Carvalho and Halles Best Jumbo crops during the initial growth phase.