A contribution towards the performance and structural understanding of copper and nickel salts as ammonia stores

The ongoing depletion of fossil fuels and the severe consequences of the greenhouse effect make the development of alternative energy systems crucially important. While hydrogen is, in principle, a promising alternative, releasing nothing but energy and pure water. Hydrogen storage is complicated and no completely viable technique has been proposed so far. This work is concerned with the study of one potential alternative to pure hydrogen: ammonia, and more specifically its storage in solids. Ammonia, NH3, can be regarded as a chemical hydrogen carrier with the advantages of strongly reduced flammability and explosiveness as compared to hydrogen. Furthermore, ammine metal salts presented here as promising ammonia stores easily store up to 50 wt.-% ammonia, giving them a volumetric energy density comparable to natural gas. The model system NiX2���NH3 ( X = Cl, Br, I) is studied thoroughly with respect to ammine salt formation, thermal decomposition, air stability and structural effects. The system CuX2���NH3 ( X = Cl, Br) has an adverse thermal decomposition behaviour, making it impractical for use as an ammonia store. This system is, however, most interesting from a structural point of view and some work concerning the study of the structural behaviour of this system is presented. Finally, close chemical relatives to the metal ammine halides, the metal ammine nitrates are studied. They exhibit interesting anion arrangements, which is an impressive showcase for the combination of diffraction and spectroscopic information. The characterisation techniques in this thesis range from powder diffraction over single crystal diffraction, spectroscopy, computational modelling, thermal analyses to gravimetric uptake experiments. Further highlights are the structure solutions and refinements from powder data of (NH4)2[NiCl4(H2O)(NH3)] and Ni(NH3)2(NO3)2, the combination of crystallographic and chemical information for the elucidation of the (NH4)2[NiCl4(H2O)(NH3)] formation reaction and the growth of single crystals under ammonia flow, a technique allowing the first documented successful growth and single crystal diffraction measurement for [Cu(NH3)6]Cl2.

Especia����o qu��mica de ars��nio inorg��nico no estu��rio da Lagoa dos Patos-RS

A polui����o das ��guas por metais, principalmente os metais pesados, vem chamando a aten����o no mundo, pois estes poluentes aqu��ticos representam um risco em potencial, devido ao seu car��ter acumulativo. Entre os metais, o ars��nio recebe destaque pelo seu potencial t��xico. O ars��nio inorg��nico ocorre na natureza em quatro estados de oxida����o: As5+, As3+, As0 e As3- . O estado de oxida����o do ars��nio tem um papel importante no seu comportamento e toxicidade nos sistemas aqu��ticos. Pelo fato do ars��nio ser extremamente perigoso e nocivo para o meio ambiente, novos m��todos anal��ticos de especia����o qu��mica no meio ambiente t��m sido publicados. Neste estudo foi otimizado e validado um m��todo para realizar a especia����o qu��mica de ars��nio inorg��nico presente em amostras de ��gua coletadas nos meses de julho e outubro de 2010 no estu��rio da Lagoa dos Patos (RS, Brasil), como parte das atividades do Programa de Monitoramento Ambiental do Porto do Rio Grande-RS. Foi usada a t��cnica de espectrometria de absor����o at��mica com gera����o de hidretos e inje����o em fluxo (FI-HG AAS), podendo ser quantificadas esp��cies de As3+ e As5+ nas amostras de ��gua estuarina. A concentra����o do ars��nio trivalente inorg��nico foi determinada, ap��s adi����o de solu����o tamp��o citrato de s��dio (0,4 mol L-1 ; pH = 6,0). A concentra����o de ars��nio inorg��nico total foi determinada, ap��s uma etapa de pr��-redu����o da esp��cie pentavalente para a forma trivalente usando uma mistura de iodeto de pot��ssio, ��cido asc��rbico em meio ��cido clor��drico concentrado. A concentra����o de ars��nio pentavalente foi calculada pela diferen��a das concentra����es de ars��nio inorg��nico total e trivalente. A interpreta����o dos resultados gerados pelo m��todo proposto usado ao analisar amostras de ��guas coletadas no estu��rio da Lagoa dos Patos foi feita pela an��lise dos componentes principais. Os dados tratados estatisticamente revelaram uma intera����o significativa neste estudo entre o ars��nio, o material em suspens��o (MS) e o NH4 + na superf��cie da coluna d�����gua no per��odo da primavera.

Effective and ecological half-lives of 90Sr and 137Cs observed in wheat and rice in Japan

Published pre-Fukushima food monitoring data from 1963 to 1995 were used to study the long-term presence of 137Cs and 90Sr in rice and wheat. Effective half-lives (T eff) were calculated for rice (137Cs: 5.6 years; 90Sr: 6.7 years) and wheat (137Cs: 3.5 years; 90Sr: 6.2 years), respectively. In rice, 137Cs exhibits a longer T eff because putrefaction processes will lead to the formation of NH4 + ions that are efficient ion exchangers for mineral-adsorbed cesium ions, hence making it more readily available to the plant. Knowledge on the long-term behavior of radiocesium and radiostrontium will be important for Japanese food-safety campaigns after the Fukushima nuclear accident.

Isolamento, sele����o e cultivo de leveduras com potencia biotecnol��gico para a produ����o de endo-xilaneses

Xilanases s��o enzimas que catalisam a hidr��lise das xilanas e t��m sido em grande parte, obtidas a partir de bolores e bact��rias. No entanto poucos estudos t��m sido relatados sobre a produ����o destas enzimas por leveduras. O presente trabalho teve como objetivo isolar leveduras de diferentes fontes vegetais visando �� produ����o de xilanases, al��m de maximizar sua produ����o, estudar o uso de diferentes fontes de nitrog��nio e cultivar as leveduras em meios contendo coprodutos agroindustriais. As amostras de alimentos e res��duos foram enriquecidas em caldo extrato de malte e levedura e isoladas em ��gar Nutriente Wallerstein, as leveduras isoladas foram, a seguir, avaliadas quanto �� capacidade de degradar xilana presente no meio e produzir halos de hidr��lise, os quais foram visualizados atrav��s do uso do corante vermelho congo. Os micro-organismos selecionados como potenciais produtores de xilanase foram crescidos em meio complexo l��quido e as atividades enzim��ticas de endoxilanase, ��-xilosidase, carboximetilcelulase, celulase total, pH e concentra����o de biomassa foram avaliadas ao longo de 96 h de cultivo. Dentre as leveduras isoladas, sete foram selecionadas, e a 18Y foi a que apresentou a maior atividade de endo- xilanase (2,7 U.mL-1 ), sendo esta isolada de chic��ria e identificada como Cryptococcus laurentii. Esta estirpe apresentou capacidade de produzir xilanase com baixos n��veis de celulase, sendo assim selecionada neste trabalho. A maximiza����o de endo-xilanase foi avaliada fazendo uso de planejamento experimental onde primeiramente foi realizado um planejamento fracion��rio 2 6-2 para verificar os efeitos do pH inicial e as concentra����es de xilana, peptona, (NH4)2SO4, extrato de levedura e KH2PO4 sobre a atividade enzim��tica. Ap��s selecionar as vari��veis xilana, peptona, pH e extrato de levedura foi realizado um delineamento composto central rotacional (24 ) onde todos os cultivos foram mantidos a 30��C, 150 rpm durante 96 h sendo retiradas al��quotas para determina����o das atividades, pH e biomassa. A produ����o m��xima foi de 6,9 U.mL-1 usando 10,0 g.L-1 de extrato de levedura, 10,0 g.L-1 de peptona, 10,0 g.L-1 de xilana, 1,0 g.L-1 de (NH4)2SO4 em pH 6,5 o que permitiu um incremento de mais de 250% sobre a atividade. Posteriormente foram realizados ensaios avaliando diferentes fontes e concentra����es de nitrog��nio org��nico e inorg��nico. A presen��a de NH4NO3 e (NH���)���SO��� usados na concentra����o de 3% proporcionaram as maiores atividades de endo-xilanase (6,2 e 6,0 U.mL-1 respectivamente). O sulfato de am��nio foi selecionado e fixado em 1 g.L-1 e logo ap��s um planejamento completo 22 foi realizado onde as vari��veis xilana e extrato de levedura foram estudadas e as demais fixadas. As condi����es ��timas estabelecidas para a produ����o da enzima foram: concentra����o de xilana de 18,6 g.L-1 , concentra����o de extrato de levedura de 10 g.L-1 atingindo 14 U.mL-1 . Ap��s a maximiza����o enzim��tica estudou-se o crescimento de Pichia pastoris NRRL Y-1603 e Cryptococcus laurentti em cinco substratos agroindustriais visando a possibilidade estes substratos substitu��rem a xilana em cultivos para a produ����o de endo-xilanase. Os ensaios foram realizados utilizando os subtratos pr��-tratados com NaOH 4% e n��o tratados. Para inser����o dos mesmos aos meios de cultivo, estes foram mo��dos e adicionados na concentra����o de 2%. O pr��-tratamento para todos as fontes de hemicelulose foi eficiente e promoveu aumento nas atividades produzidas. Cryptococcus laurentti apresentou maior atividade enzim��tica (8,7 U.mL-1 ) em farelo de arroz desengordurado e pr��- tratado enquanto que a levedura Pichia pastoris NRRL Y-1603 apresentou sua melhor condi����o para produ����o de endo-xilanase quando cultivada em meio contendo casca de aveia e o farelo de arroz pr��-tratados, alcan��ando atividades m��ximas de 7,6 e 7,5 U.mL-1 .

THE PROSPECT OF BIOGAS AMONG SMALL-HOLDER DAIRY GOAT FARMERS IN THE ULUGURU MOUNTAINS, TANZANIA

Biogas can be a clean cooking alternative where biomass is the dominant source of cooking energy and where feedstock for anaerobic digestion is available. By substituting woody biomass for energy, biogas may reduce local deforestation. Tanzania has more than 15.6 million goats. Dairy goats of different breeds are found in the mid- to high altitudes of the country. Population density has made firewood increasingly scarce and there are few energy alternatives in mountainous areas such as in the Uluguru Mountains. In Mgeta ward, Morogoro region, introduction of Norwegian dairy goats in the 1980s has improved livelihoods in the area. In this study, goat manure was assessed as feedstock for biogas and as fertilizer. Field work among small-holder dairy goat farmers in Mgeta was conducted to measure daily manure production, and to provide a basic model for prediction of the quantity of droppings which may be collected by farmers. Biogas and fertilizer potential from goat manure was compared to cow and pig manure. Buswell���s formula was used to calculate approximate methane yield. The results show that goat manure from Mgeta can yield 167 l���kg Volatile Solids-1 (VS). Compared with other substrates approximate methane yield can be ranked as pig > guatemala grass > cow > goat. The average goat of 25 kg in Mgeta leaves 61 kg Total Solids (TS) droppings per year. It was estimated that 15 goats capita-1 would be required to meet the total cooking energy needs of small-holder households in the study location. N:P:K content in goat manure (TS) is 2:1:1, similar to cow and pig manure. Goat droppings had to be macerated to reduce particle size for anaerobic digestion. Biogas from dairy goats could be combined with the year-round irrigated horticulture production in Mgeta. Vegetable gardens in the slope below the digesters could be fertilized by gravitation with the NH4+-rich bioslurry, to save labour and increase yields.

Microbiologia do ciclo do nitrog��nio em solos do cerrado

Disserta����o (mestrado)���Universidade de Bras��lia, Instituto de Ci��ncias Biol��gicas, Programa de P��s-Gradua����o em Biologia Microbiana, 2016.

Nutrients limiting the Algal Growth Potential (AGP) in the Gulf of Riga, eastern Baltic Sea, in spring and early summer 1996

In May, June and July 1996, samples wcre collected along one transect greatly influenced by river discharge (eastern side of the gulf), along one transect slightly influence by river discharge (western side), at one station Iocated in the mouth of the main river (River Daugava), at one station located in the center of the Gulf and at several nearshore locations of the western side. Ratios of rnolecular concentrations of in situ dissolved ioorganic nitrogen, phosphorus and silicon, as weIl as enrichment bioassays were llsed to dctcrrnine which nutrient (s) lirnited the potential biomass of phytoplankton. Both comparison of (NO.d-N02+NJ.L): P04 (DIN: DIP) values with Redfic1d's ratio and bioassay inspection led to the sarne conclusions. Phosphorus was clearly the nutrient most limiting for the potcntial biornass of test species in nitrogen- rich waters, which occurred in mid spring, in the upper layer of the southern-eastern part of the Gulf which is greatly influenced by river discharge. In late spring, with the decrease of the total DIN reserve, nitrogen and phosphorus showed an equallimiting role. In deeper layers of this area and out of the river plume (western side and central part of the gulf), nitrogen was the limiting nutrient. In summer, whcn river discharge was the lowest, a11 DIN concentrations but one ranged between 1.6 and 2.6 ��M, and the whole area was nitrogen-limited for both the cyanobacterial and the algal test strains. In 74% of the samples for which nitrogen was the limiting nutrient, phosphorus was recorded to be the second potentially limiting nutrient. In contrast, silicon never appeared as limiting the growth potential of either Microcystis aeruginosa or Phaeodactylum tricornutum; phosphorus was the limiting nutrient when DIN: Si03 values were >1 (in May), but DIN: Si03 was <1 when nitrogen was limiting (June and July). The authors conclude that the recently reported decrease of silicon loading in coastal waters and its subsequent enhanced importance in pushing the outcome of species competition towards harmful species may not yet be the most important factor for the Gulf of Riga. Iron appeared for 12% of the tests in the list of nutrients limiting the potential biomass. Tentative results also indicated that a significant fraction of the nitrogen (~,4 ��g-atom N 1(-1) taken up by Microcystis aeruginosa may have been in the form of dissolved organic nitrogen (DON). It is thus also suggested tentatively that more attention be paid to these nitrients during further research in the Gulf of Riga.

Environmental assessment of proton exchange membrane fuel cell platinum catalyst recycling

International audience

PHYTOPLANKTON AND NUTRIENT DYNAMICS WITH A FOCUS ON NITROGEN FORM IN THE ANACOSTIA RIVER, IN WASHINGTON, D.C. AND WEST LAKE, IN HANGZHOU, CHINA

Nutrient loading has been linked with severe water quality impairment, ranging from hypoxia to increased frequency of harmful algal blooms (HABs), loss of fisheries, and changes in biodiversity. Waters around the globe are experiencing deleterious effects of eutrophication; however, the relative amount of nitrogen (N) and phosphorus (P) reaching these waters is not changing proportionately, with high N loads increasingly enriched in chemically-reduced N forms. Research involving two urban freshwater and nutrient enriched systems, the Anacostia River, USA, a tributary of the Potomac River feeding into the Chesapeake Bay, and West Lake, Hangzhou, Zhejiang Province, China, was conducted to assess the response of phytoplankton communities to changing N-form and N/P-ratios. Field observations involving the characterization of ambient phytoplankton communities and N-forms, as well as experimental (nutrient enrichment) manipulations were used to understand shifts in phytoplankton community composition with increasing NH4+ loads. In both locations, a >2-fold increase in ambient NH4+:NO3- ratios was followed by a shift in the phytoplankton community, with diatoms giving way to chlorophytes and cyanobacteria. Enrichment experiments mirrored this, in that samples enriched with NH4+ lead to increased abundance of chlorophytes and cyanobacteria. This work shows that in both of these systems experiencing nutrient enrichment that NH4+ supports communities dominated by more chlorophytes and cyanobacteria than other phytoplankton groups.

Kinetic Analysis of Gill (Na+,K+)-ATPase Activity in Selected Ontogenetic Stages of the Amazon River Shrimp, (Decapoda, Palaemonidae): Interactions at ATP- and Cation-Binding Sites

We investigated modulation by ATP, Mg2+, Na+, K+ and NH4 (+) and inhibition by ouabain of (Na+,K+)-ATPase activity in microsomal homogenates of whole zoeae I and decapodid III (formerly zoea IX) and whole-body and gill homogenates of juvenile and adult Amazon River shrimps, . (Na+,K+)-ATPase-specific activity was increased twofold in decapodid III compared to zoea I, juveniles and adults, suggesting an important role in this ontogenetic stage. The apparent affinity for ATP ( (M) = 0.09 +/- A 0.01 mmol L-1) of the decapodid III (Na+,K+)-ATPase, about twofold greater than the other stages, further highlights this relevance. Modulation of (Na+,K+)-ATPase activity by K+ also revealed a threefold greater affinity for K+ ( (0.5) = 0.91 +/- A 0.04 mmol L-1) in decapodid III than in other stages; NH4 (+) had no modulatory effect. The affinity for Na+ ( (0.5) = 13.2 +/- A 0.6 mmol L-1) of zoea I (Na+,K+)-ATPase was fourfold less than other stages. Modulation by Na+, Mg2+ and NH4 (+) obeyed cooperative kinetics, while K+ modulation exhibited Michaelis-Menten behavior. Rates of maximal Mg2+ stimulation of ouabain-insensitive ATPase activity differed in each ontogenetic stage, suggesting that Mg2+-stimulated ATPases other than (Na+,K+)-ATPase are present. Ouabain inhibition suggests that, among the various ATPase activities present in the different stages, Na+-ATPase may be involved in the ontogeny of osmoregulation in larval The NH4 (+)-stimulated, ouabain-insensitive ATPase activity seen in zoea I and decapodid III may reflect a stage-specific means of ammonia excretion since functional gills are absent in the early larval stages.

Lixivia����o de nitrog��nio em Latossolo incubado com lodo de esgoto.

Lodo de esgoto cont��m teores elevados de N org��nico. Se for aplicado em quantidade excessiva em solos, h�� risco de polui����o de ��guas subsuperficiais com nitrato, produto da mineraliza����o do N. Por essa raz��o, um dos crit��rios agron��micos para a determina����o da taxa m��xima de aplica����o do lodo de esgoto �� a quantidade de N mineral que ser�� disponibilizada ��s culturas. Neste trabalho, s��o apresentados os resultados relativos �� lixivia����o de N mineralizado em um Latossolo Vermelho distrof��rrico incubado durante 224 dias com dois tipos de lodo de esgoto anaer��bios, um de origem urbana (Franca, SP) e outro com presen��a de despejos industriais (Barueri, SP). Cada lodo de esgoto foi aplicado em quatro doses, contendo 0,13, 0,3, 0,5 e 1,0 g kg-1 de N org��nico. Essa quantidade de substrato mineraliz��vel foi equivalente a 5, 11, 22 e 43 t ha-1 de lodo de Franca, e a 8, 15, 31 e 61 t ha-1 de lodo de Barueri. O experimento foi conduzido em colunas de percola����o, sob temperatura de 25 a 28 ��C em laborat��rio, fazendo-se lixivia����es com solu����o extratora de KCl 0,01 mol L-1. Foram determinadas as quantidades de N mineral (N-NH4 + e N-NO3 - + N-NO2 - ) extra��das nos percolados em doze ��pocas. Houve correla����o significativa entre as quantidades aplicadas de N na forma org��nica e as quantidades de N mineralizadas durante a incuba����o nos dois tipos de lodo avaliados. O potencial de mineraliza����o estimado pelo modelo exponencial simples foi de 73 mg kg-1 de N no solo sem aplica����o de lodo, e aumentou de 107 para 224 mg kg-1 e de 132 para 364 mg kg-1 nos tratamentos com o lodo de esgoto de Franca e de Barueri, respectivamente. A fra����o de mineraliza����o potencial do N org��nico dos dois tipos de lodo de esgoto decresceu com o aumento das doses aplicadas: 26, 25, 21 e 14 % para o de Franca, e 43, 39, 34 e 27 % para o de Barueri. Em consequ��ncia, o potencial de lixivia����o de N no Latossolo aumentou de 46 para 207 % com as doses do lodo de Franca, e de 81 para 399 % com as doses do lodo de Barueri.

Photocatalytic Dehydrogenative Lactonization of 2-Arylbenzoic Acids

A metal-free dehydrogenative lactonization of 2-arylbenzoic acids at room temperature was developed. This work illustrates the first application of visible-light photoredox catalysis in the preparation of benzo-3,4-coumarins, an important structural motif in bioactive molecules. The combination of photocatalyst [Acr+-Mes] with (NH4)2S2O8 as a terminal oxidant provides an economical and environmentally benign entry to different substituted benzocoumarins. Preliminary mechanistic studies suggest that this reaction most likely occurs through a homolytic aromatic substitution pathway.

Estudo comparativo de dois tipos de cultivo: monocultivo (camar��es) versus cultivo integrado (algas/camar��es)

The integrated culture of seaweed and aquatic animals is an ancient practice in Asian countries. The expansion of this practice to western countries is consequence of the recognition of this system as a sustainable alternative that allows economical diversification and mitigation of environmental impacts generated by effluents of aquaculture. This study evaluated the growth of the seaweed Gracilaria caudata and of the shrimp Litopenaeus vannamei in monoculture (shrimps) and integrated culture (shrimps and algae) systems, and accessed the effect of the seaweed in the water quality. There were two treatments in the experiment: monoculture (shrimps) and integrated culture (shrimps/ algae). The organisms were cultured in 6 aquaria (10L) filled with seawater (35.0��0.0 PSU and 28.1��0.4��C) for 28 days. The nutrients of water (PO43-, NH4+, NO2-, NO3- and DIN), the biomass and the relative growth rate (RGR, % day-1) of seaweed and shrimps were measured weekly. The parameters pH, temperature, salinity and dissolved oxygen were measured daily. The concentration of NH4+ in integrated culture (62.8��25.2��M) was lower (Mann-Whitney p<0.001) than in monoculture (85.6��24.3��M). The mean of PO4- in monoculture (10.4��4.6��M) was markedly higher (Mann-Whitney; p=0.024) than that in integrated culture (8.7��4.1��M). The level of dissolved oxygen in integrated culture (6.0��0.6mg/L) was higher (t-Student; P=0.014) than that in shrimp monoculture (5.8��0.6mg/L). The mean values of the parameters pH, NO2-, NO3- and DIN were 7.5��0.2, 10.1��12.2��M, 24.5��3.2��M and 120.17��30.76��M in monoculture, and 7.5��0.2, 10.5��13.2��M, 27.4��3.5��M and 100.76��49.59��M in integrated culture. There were not differences in these parameters between treatments. The biomass and RGR of seaweed reached 15.0��1.9g and 7.4��2.8% day-1 at the end of the experiment. The performance of shrimp was favorable in monoculture (1.5��0.8g; 5.7��1.6% dia-1) and in integrated culture (1.5��0.7g; 5.2��1.2% dia-1), and the rate of survival was 100% in both treatments. The tolerance and favorable performance of Gracilaria caudata suggest that this seaweed might be integrated into shrimp (Litopenaeus vannamei) culture systems

Efeito dos nutrientes (nitrog��nio e f��sforo) sobre o desenvolvimento da Gracilaria birdiae: crescimento e poss��vel uso como biofiltro

Marine shrimp farming has grown exponentially during the last years in Brazil. In spite of the promising economical situation, this activity is facing an increasing criticism due to its environmental impact. Thus, the necessity of alternatives to mitigate environmental degradation caused by this activity. An alternative that is being studied is the policulture that is the integrated culture of two or more organisms, normally one of them a filtering organism. Among filtering organisms, macroalgae are very practicable because they are efficient in the removal of the exceeding nutrients of the water and do not leave residues in the water. Besides, the integrated culture with macroalgae allows the economical exploration of the seaweed (for the manufacture of jelly and jam, for the dairy industry, pharmaceuticals, etc.) along with possibility of a sustainable aquaculture. In the present experiment, the development of the seaweed Gracilaria birdiae, the influence and tolerance of this species to the environmental parameters, and its absorption efficiency in relation with the three kinds of macronutrients (NH4+, NO3- and PO4-3) found in the effluents of marine shrimp farming was studied. The experiment was divided in two parts: a laboratorial part and one part carried under natural conditions. The water used in the laboratory trial was collected in the shrimp ponds of Tecnar��o farm and distributed in aquaria containing 20 g of G. birdiae. In the field trial, 0.5 kg of G. birdiae was inserted in PVC cages cultivated in the farm. The results of the study showed a modest growth of G. birdiae, probably due to its low tolerance to highly eutrophicated environments. However, the removal of nutrients was very expressive. Ammonia was reduced in approximately 34 %. Ortho-phosphate showed a reduction of 93.5 %. The capacity of biofiltration of the NO3- by the macro algae was of 100 %, showing that G. birdiae is a seaweed-filtered with a high level of removal for this nutrient under laboratorial conditions. In spite of the low growth of the macro algae in the experiment, the results in relation to the removal of nutrients of the water was encouraging, suggesting that this species can be an efficient biofilter and thus, a strong candidate to be used in a sustainable aquaculture

Estudo do crescimento, efici��ncia de biofiltra����o e cin��tica de absor����o de nutrientes (N-NH, N-NO e P-PO4��) da macroalga Gracilaria cervicornis (Turner) J. Agardh

The objective of this study was to examine the growth of Gracilaria cervicornis cultured in a shrimp (Litopenaeus vannamei) pond and to determine the absorption efficiency and the kinetics parameters (Vmax, Ks e Vmax:Ks) of this macroalgae for the nutrients N-NO3-, N-NH4+ and P-PO4-3, aiming at its use as bioremediatory of eutrophicated environments. For this study, two experiments (field and laboratory) were developed. In the field study, the seaweed was examined in relation to the growth and the biomass. In the laboratory experiment, the absorption efficiency of G. cervicornis was measured through the monitoring of the concentration of the three nutrients (N-NO3-, N-NH4+ e P-PO4-3) during 5 hours and the kinetic parameters were determined through the formula of Michaelis-Menten. The results obtained in this study demonstrated that G. cervicornis benefited from the available nutrients in the pond, increasing 52.4% of its biomass value after 30 days of culture. It was evidenced that the variability of the biomass could be explained through the salinity, availability of light (transparency and solid particle in suspension) and concentration of N-NO3- in the environment. In the laboratory experiment, the highest absorption efficiency was found in the treatments with low concentration (5 ��mol.L-1), being evidenced a reduction of up to 85,3%, 97,5% and 81,2% of N-NH4+, N-NO3- and P-PO43-, respectively. Regarding the kinetic parameters, G. cervicornis presented better ability in absorbing N-NH4+ in high concentrations (Vmax = 158,5 ��mol g-1 dry wt h-1) and P-PO43- in low concentrations (Ks = 5 ��mol.L-1 e Vmax:Ks = 10,3). The results of this study show that G. cervicornis could be cultivated in shrimp ponds, presents a good capacity of absorption for the tested nutrients and is a promising candidate for biorremediation in shrimp pond effluent