Avaliação do potencial fitorremediador da mamona (Ricinus communis L.) e girassol (Helianthus annuus L.) quanto à remoção de chumbo e tolueno em efluentes sintéticos.

The development of research that aim to reduce or even eliminate the environmental impacts provided by anthropogenic actions. One of these main action is the discard of industrial waste in the biotic compartments such as soil, water and air, gained more space in academic settings and in private. A technique of phytoremediation involving the use of plants (trees, shrubs, creepers and aquatic) and their associated microorganisms in order to remove, degrade or isolate toxic substances to the environment. This study aimed to evaluate the potential for phytoremediation of castor bean (Ricinus communis L.) and sunflower (Helianthus annuus L.), wild crops suitable region of Rio Grande do Norte, to reduce concentrations of lead and toluene present in synthetic wastewater that simulate the characteristics of treated water production originated in the petrochemical Guamaré. The experiment was accomplished in randomized blocks in four replicates. Seeds of BRS Energy for the development of seedlings of castor beans and sunflower for Catissol 01, both provided by EMPARN (Empresa de Pesquisa Agropecuária do Rio Grande do Norte) were used. Lead concentrations tested were 250, 500 and 1000 mg/L called T2, T3 and T4, respectively, for toluene the concentrations used were 125, 256 and 501 μg/L, called T5, T6 and T7, respectively. The data for removal of lead in relation to sewage systems applied in castor bean and sunflower were 43.89 and 51.85% (T2), 73.60 and 73.74% (T3) and 85.66 and 87.80 % (T4), respectively, and toluene were approximately 52.12 and 25.54% (T5), 55.10 and 58.05% (T6) and 79.77 and 74.76% (T7) for castor and sunflower seeds, respectively. From the data obtained, it can be deduce that mechanisms involved in reducing the contaminants were of phytoextraction, in relation to lead and phytodegradation for toluene. However, it can be concluded that the castor bean and sunflower crops can be used in exhaust after-treatment of industrial effluents that have this type of contaminant

Alterações morfofisiol��gicas e moleculares em resposta a estresses abióticos em mamona (Ricinus communis L.)

The use of fossil fuels has been considered one of reason for the increase of pollution in the atmosphere and it may be related to the climate changes. Then, the research of the new sources of fuels will be important. Considering this, the use of biodiesel has been considered not as bad as petrol. The castor bean (Ricinus communis L.) is an important oilseed, which belongs to Euphorbiaceae family, and the oil found in the seed has important characteristics for biodiesel. This plant is considered as “rustic” as it does not need so much water for its development and oil production. Due to this, this plant has been considered to be ideal in semi-arid regions, such as the Northeast of Brazil. The aim of his study is to better understand the responses to abiotic stresses (drought and salinity) from castor bean plants using morphological, physiological and molecular tools. In order to do this, the castor bean plants were subjected to salt stress (50, 100, 150 and 200 mM NaCl) in a controlled environment and drought stress (5, 10, 15 days and 10 days cyclic). After these treatments, these plants were subjected to different analyzes: a) the expansion and retention of water from leaves; b) anatomy using leaves and roots. Based on these results, we found that castor suffered decrease in leaf area with increase drought stress, however restricted water loss, probably by accumulation of compatible solutes in the leaves. The anatomy data showed modifications in the vascular system. These modifications observed suggested that castor bean plant may be resistant to stress as it was verified in 5 days of drought as well as in 100 mM NaCl. In both conditions, these plants were fine. Probably these plants keep some solutes in the cell and then maintain the cell tugor. The data obtained in this study gave a better idea how castor bean plant responds to abiotic stress conditions - drought and salt stress