Estudo da oxidação do metabissulfito de sódio contido no efluente da carcinicultura

The shrimp farming is a process of creation of shrimp that has been growing rapidly in the country, occupying a meaningful space in the Brazilian exporting. In 2003, this activity presented a volume of 60 millions of tons and 220 millions of dollars, being the main generator of employment and income of the primary sector of the northeast economy. However, it is a new activity with c.a. five years in the Rio Grande do Norte State and therefore needs investment in the technological area. Among the wastewaters of this activity, the sulphite solution is being usually applied in the process of fishing, i.e. retrieval of the shrimps from the farming. The aim of this work is to present the oxidation experimental results of the sulphite that may be and to determine what it s the most efficient method, trough laboratory experiments. The measurements were carried out in a mixing reactor inserting air and with hydrogen peroxide addition with and without UV light. The solutions were prepared synthetically with concentrations found in the wastewater of fishing and also collected in locu. The oxidation process using air was monitorated by iodometric analysis for the sulphite and the oxidation using hydrogen peroxide was evaluated with turbidimetric analysis for sulphate, by spectrophotometer. The sulphite was totally oxidized in both processes. The experimental results permit to conclude that the oxidation by hydrogen peroxide is more efficient and allowed to determine the optimum operational conditions in terms of concentration and time of treatment

Análise hidrodinâmica e morfodinâmica do complexo estuarino do Rio Piranhas-Açu/RN, Nordeste do Brasil

The aim of this study was the seasonal characterization of the morphology, sedimentology and hydrodynamic of the Açu, Cavalos and Conchas estuaries. These estuaries are inserted in a semi-arid climate area and form the mouth of the hydrographic basin of the Piranhas-Açu river, that represent the discharge of the largest watershed in the state. They are embedded in an environment consisting of a fluvial-marine floodplain, mangrove ecosystem, sandbanks, fields of dunes, spits and sandy beaches. Adjacent to the natural units are the main local socioeconomic activities (oil industry, salt industry, shrimp farming, fishing and tourism) are dependent on this river and its conservation. The environmental monitoring is necessary because it is an area under constant action of coastal processes and at high risk of oil spill. The acquisition and interpretation of hydrodynamic, sonographic and sediment data was conducted in two campaigns, dry season (2010) and rainy season (2011), using respectively the current profiler ADCP Doppler effect, the side-scan sonar and Van Veen sampler. In these estuaries: Açu, Cavalos and Conchas were identified the following types of bedforms: flatbed and Dunes 2-D and 3-D (small to medium size), generated at lower flow regime (Froude number <1). Structures such as ripples were observed in the Açu estuary mouth. The higher values of flow discharge and velocity were recorded in the Açu estuary (434,992 m³.s-¹ and 0,554 m.s-¹). In rainy season, despite the record of highest values of discharge and flow velocities at the mouth, the energy rates upstream did not differ much from the data of the dry season. However, in all estuaries were recorded an increase in speed and flow, with reservation to the flow in the Açu estuary and flow at the mouth of the Conchas estuary. Sediment grain sizes tend to increase towards the mouth of the estuary and these ranged from very fine sand to very coarse sand, medium sand fraction being the most recurrent. Based on the data acquired and analyzed, the estuaries Açu, Cavalos and Conchas are classified as mixed , dominated by waves and tides. According to their morphology, they are classified as estuaries constructed by bar and according to the classification by salinity, estuaries Conchas and Cavalos were ranked as hypersaline estuaries, and Açu as hypersaline and vertically well mixed type C

O território das novas economias e suas implicações socioambientais na comunidade pesqueira de Barra do Cunhaú

This dissertation aims to analyze the territory of the new economies and their social implications in the district of Barra do Cunhaú / Canguaretama. We used techniques of qualitative research (document analysis, interviews and observations in situ). It was found that the changes occurring in the territory are linked to the pressures caused by factors internal and external orders, such as the deployment and expansion of projects for development of tourism and shrimp in place, which led to the advancement of real estate speculation and intensification of the deforestation of areas of mangroves along the estuary of the river Curimataú / Cunhaú, contributing to the abandonment of fishing and agriculture for livelihood in this community, therefore, the loss of traditional knowledge applied in the conduct of this activity. It was also found that changes in the use of territory and resources threaten biodiversity and have contributed to the reduction of fish stocks of the Municipality of Canguaretama and thus bar the Cunhaú, especially the stock of crab, Uca (ucides cardatus ). The results indicated that the production in large scale in a market economy, as is the shrimp, ignores the search for balance in regional settings. Thus the environmental disturbances resulting from the shrimp and tourism have consequences for social and cultural aspects, directly affecting the livelihood of the residents of Barra do Cunhaú. Companies of shrimp and related to tourism have absorbed the fishermen who are leaving the fishing activity. However, the low level of education associated with age are factors that make them far outside the framework of employees of these companies. Therefore, it is necessary to create conditions that allow the development of the shrimp and tourism without putting at risk the sustainability of the region

Pesca artesanal entre mudanças socioambientais: estudo de caso na APA Bonfim-Guaraíra/RN-Brasil

Artisanal fishing is one of the important economic activities of Rio Grande do Norte (RN), becoming the main form of survival and income for many families. The southern coast of RN has strong fishing tradition, both in exploitation of fish as in the collection of mollusks on the banks of Guaraíra Lagoon (APA Bonfim-Guaraíra). In recent years, fishing communities have become more vulnerable to outside influences, since the socio-economic and environmental changes are exposed. These changes require adjustments to the fishermen to different environmental conditions, as the social and natural systems are driven by reorganization and upgrading processes. The living conditions in fishing communities are objective and necessary in different ways, according to a selection that is cultural, so adaptable. This study has the general objective to analyze the main environmental changes in fishing communities, based on the understanding of fishermen and mollusk fisherwomen about this problem. The specific objectives searched to: describe the socioeconomic profile, prospects and difficulties of fishermen and mollusk fisherwomen; investigate the major social and environmental changes in the fishing communities of Patané and Camocim (Arez/RN). The methodology was qualitative-quantitative with the techniques of observation in the field and open and semistructured interviews applied to representatives of Cologne fishing, fishermen and mollusk fisherwomen. Between the months of January to July 2014 were applied semistructured interviews with 41 interlocutors in Patané and 23 of Camocim; totaling 64 people. The results indicated that the interlocutors are aged 40 to 60 years; have only completed elementary school level; are married and have children; survive on less than a minimum wage income and they are not receiving employment insurance. The case study also revealed that the socioeconomic and environmental problems reflected in changes in reproduction, organization and social division of labor, which generates adaptive changes of families to external influences, resulting directly from other economic activities and market pressure and indirectly from tourism. Therefore, adaptations to changes scenario presented as favorable to economic aspects and unfavorable to the social and environmental aspects. In short, the fishery develops on technical, bureaucratic and financial obstacles, in the everyday needs of men and women is the determining factor in willingness to continue exercising fishing and shell fishing on Guaraíra Lagoon, space representing relations social, practices and customs transmitted in the course of local history through social memory of the oldest to the youngest.