Abstract: The Programa Água Doce-PAD(in English: Fresh Water Program) promoted by the Brazilian Federal Government under the coordinationof the Environmental Ministry, seeks to promote sustainable use of groundwater resources and provide potable water for human consumption in areas withcriticalwater scarcity in the Brazilian Semiarid region, through the use of the Reverse Osmosis Technique. The Program is guided by the following principles: community empowerment, environmental sustainability and technicalcapacity building. The methodology that led the Program to becomea success case was conceived in 2003, through a participatory process with the contribution of public Brazilian institutions such as: Federal University of Campina Grande-UFCG (Social Engagement Procedure); Brazilian Geologic Service-CPRM (Ground Water information), Brazilian Agriculture Research Corporation ?EMBRAPA (Methodology for the reuse of desalinated water concentrate), besides 10 Brazilian State ?s Governments and the civil society. The Program was launched in 2004.Ithas, presently,more than 460 installed Desalination Plants, which, together,can producea total of approximately 1.5 million liters (around 400,000 gallons) of potable water per day (considering a 8h/per dayproduction).It has,so far,benefited about 184,000 people in over 460 rural communities spread throughout the Brazilian semiarid region, ensuring safe water access to its residents. The program has already trained more than 1,000 people, including state technicians and operators of desalination systems. The Program contributes to improving the health and life quality of people in the semiarid regionas it takesinto account the naturaland socialpotential of each communitie, ensuring ways to address the vulnerabilities to which they are subjected becauseof climate variability. Social engagement is a mandatory aspect for the Program?s success. Local communities are stimulated to gain their independence by having, through the PAD methodology, their empowerment encouraged and demanded.The ultimate goal of the first large scaleplan is to take Desalination Systems to at least 1,300 communities throughout the Brazilian Semiaridregion. The Environmental Ministry is seeking to improve the systems with solar energy and automatized machinery,looking forward to improve local communities? independence.

Abstract: A coastal karstic aquifer highly exposed to anthropogenic pollution and seawater intrusion is the main water supply source for Merida-Progreso inhabitants (Yucatan, Mexico). In this investigation fresh/ brackish water interface changes linked to precipitation events were identified and correlated with the Ghyben-Herzberg principle. Water level elevations and electrical conductivity values were manual and automatic recorded in a 26 wells monitoring network. Results indicate a fast water level increase (hours) to precipitation events, for example a 19 cm water level increase and 570 µmhos·cm-1 decrease measured at the fresh/brackish water interface were recorded in an observation well located west of Merida city less than 24 hours after a 60 mm rainfall. Predictions using the Ghyben-Herzberg principle do not correlate with in-situ measurements. Actual thickness of the freshwater lens change from rainy (33 m) to dry (31.5 m) season below Merida city, minor thickness changes along the year were identified north to Merida city (26 m freshwater lens thickness). | Resumen: La población en la región Mérida-Progreso, Yucatán, México, depende totalmente del agua subterránea que es obtenida de un acuífero kárstico costero, vulnerable a la contaminación antropogénica y natural por los efectos de la intrusión salina. El objetivo de estudio fue describir, espacial y temporalmente, el comportamiento de las interfases de agua dulce y agua salobre ante eventos de precipitación, y proponer alternativas que ayuden a explicar la respuesta observada y su relación con el principio de Ghyben-Herzberg. Se utilizó una red de 26 pozos de observación para determinar elevaciones del nivel del agua y cambios en la conductividad eléctrica en las interfases mediante mediciones manuales y una red automatizada. Los resultados indican que en general existe una respuesta rápida (del orden de horas) del nivel freático a la precipitación, por ejemplo un incremento de 19 cm en la elevación del nivel del agua al occidente de Mérida y un comportamiento irregular de las elevaciones de las interfases de agua salina (decremento de 570 µmhos·cm-1) y salobre ante eventos de precipitación (60 mm). De acuerdo con los resultados obtenidos, el principio de Ghyben-Herzberg no es aplicable para la determinación de la posición de la interfase de agua salina en la región. Finalmente, se definieron espesores de agua dulce bajo la zona urbana de Mérida para las temporadas de lluvia (33 m) y estiaje (31.5 m), y un espesor promedio de 26 m al norte de Mérida a 15 km de la línea de costa donde no hay una variación entre ambos periodos.

A total of 300 Centropomus undecimalis juveniles, with an average initial weight of 3.16 ± 0.28 g and average total length of 7.17 ± 0.22 cm, were reared for eight weeks using a recirculating system to determine the dietary protein requirement for their growth and survival. The e ect of ve experimental diets containing 40, 45, 50, 55 and 60% total protein content and two salinities (brackish water, BW at 5 UPS and marine water, MW at 36 UPS) were assessed. Fish were fed ve times per day at 2.5% of total biomass. All treatments were performed in triplicate, recording the individual weight and total length every 15 d, while weight gain and daily growth rate were recorded at the end of the experiment. Mean weight increased proportionally as protein content increased, with the greatest growth occurring with a 60% protein diet for sh reared in brackish water, and 55% for sh in marine water. We consider that the protein requirement in C. undecimalis juveniles is high; in addition, it differs depending on the salinity, which may be due to the higher energy expenditure derived from the processes of osmoregulation in fish reared in marine water.

A total of 300 Centropomus undecimalis juveniles, with an average initial weight of 3.16 ± 0.28 g and average total length of 7.17 ± 0.22 cm, were reared for eight weeks using a recirculating system to determine the dietary protein requirement for their growth and survival. The e ect of ve experimental diets containing 40, 45, 50, 55 and 60% total protein content and two salinities (brackish water, BW at 5 UPS and marine water, MW at 36 UPS) were assessed. Fish were fed ve times per day at 2.5% of total biomass. All treatments were performed in triplicate, recording the individual weight and total length every 15 d, while weight gain and daily growth rate were recorded at the end of the experiment. Mean weight increased proportionally as protein content increased, with the greatest growth occurring with a 60% protein diet for sh reared in brackish water, and 55% for sh in marine water. We consider that the protein requirement in C. undecimalis juveniles is high; in addition, it differs depending on the salinity, which may be due to the higher energy expenditure derived from the processes of osmoregulation in fish reared in marine water.

Objetivou-se com este trabalho avaliar o desenvolvimento de mudas de Aspidosperma pyrifolium Mart. sob diferentes níveis de salinidade da irrigação. | Edição dos Resumos do V Workshop de Tecnologia e Fisiologia de Sementes e Mudas, Petrolina, dez. 2014.

Este trabalho teve por objetivo avaliar a emergência de plântulas de pereiro (Aspidosperma pyrifolium) sob diferentes níveis de salinidade da água de irrigação. | Edição dos Resumos do V Workshop de Tecnologia e Fisiologia de Sementes e Mudas, Petrolina, dez. 2014.

Plants of lettuce cv. Elba were grown under two hydroponic systems, Floating and NFT, aiming to evaluate three water resources: natural brackish water (2,47 dS m-1) obtained from a deep well; fresh water (0,11 dS m-1) produced by reverse osmosis desalination; and reject brine (5,15 dS m-1), a wastewater from desalination process. These waters were combined in six treatments resulted from their alternated use to prepare nutrient solution (NS) and/or replace the evapotranspiration loss (ETc). The experiment was carried out under a greenhouse condition in the semiarid region of Pernambuco State, Brazil; 48 experimental units were used for both hydroponic systems. The lettuce yield (shoot fresh matter) was higher under Floating conditions. The single use of deep well water and reject brine decreased 22.7 and 39.6% the lettuce yield, respectively. For a better combination of fresh and brackish waters, the use of brackish water to replace ETc loss may increase the lettuce yield in comparison to use these waters to prepare the NS; this result was registered for deep well water and reject. | Plantas de alface cv. Elba foram cultivadas em dois sistemas hidropônicos, Floating e NFT, com o objetivo de avaliar três tipos de água: a água salobra natural (2,47 dS m-1) obtida a partir de um poço profundo; água doce (0,11 dS m-1) produzido por dessalinização por osmose inversa, e o rejeito salino (5,15 dS m-1), um efluente do processo de dessalinização. Estas águas foram combinadas em seis tratamentos resultantes da sua utilização alternada para preparar a solução nutritiva (SN) e/ou substituir as perdas por evapotranspiração (ETc). O experimento foi conduzido em casa de vegetação na região semiárida de Pernambuco, utilizando 48 unidades experimentais em blocos casualizados em esquema fatorial 6x2 com quatro repetições. O rendimento da alface (massa de matéria fresca) foi maior nas condições do Floating. O uso exclusivo da água do poço profundo e do rejeito de dessalinizadores diminuiu 22,7 e 39,6% a produção de alface, respectivamente. Para uma melhor combinação de águas doces e salobras, o uso de água salobra para repor a perda por ETc pode aumentar a produção de alface em relação ao uso dessas águas para preparar a SN, estes resultados foram registrados para a água do poço profundo e o rejeito.

Objetivando reduzir os impactos causados pelo rejeito da dessalinização de água salobra, no trópico semi-árido brasileiro, três alternativas de aproveitamento de água com alta salinidade, subproduto da dessalinização foram avaliadas nos campos da Estação Experimental da Embrapa Semi-Árido, em Petrolina-PE. As alternativas foram: (a) produção de tilápia rosa (Oreochromis sp); (b) produção de feno da erva-sal (Atriplex nummularia) irrigado; e (c) engorda de caprino/ovino com feno de erva-sal. A salinidade média da água usada foi de 11,38 ds/m. A tilápia atingiu o peso de 518,72 gramas em 153 dias de cultivo; o rendimento do feno da erva-sal foi de 14.900kg de matéria seca por hectare, e o ganho de peso de ovino/caprino, quando alimentado com 1,5 kg de feno da erva-sal, foi de 138 gramas/dia. Em função dos resultados obtidos com estes estudos, é possível a viabilização do uso do rejeito da dessalinização de água de poços no cristalino do semi-árido brasileiro para a geração de renda.