RESUMOObjetivou-se, neste trabalho, avaliar a capacidade extratora de duas espécies vegetais quando cultivadas em sistemas alagados construídos (SAC) utilizados no tratamento de águas residuárias de laticínios (ARL Extraction capacity of plants grown in constructed wetland systems used for treatment of dairy wastewater ABSTRACT The objective of this research was to evaluate the extraction capacity of two plant species when grown in constructed wetland systems (CWS) used for dairy wastewater (DW) treatment. The experimental units were formed by five CWS grown with Pennisetum purpureum schum grass and five CWS cultivated with grass tifton 85 (Cynodon spp.), with horizontal subsurface flow. The DW was applied at an average flow of 60 L d -1 and hydraulic residence time of 4.8 days, and subjected to organic loading rates (ORL) of 66, 130, 190, 320 and 570 kg ha -1 d -1 of BOD. The grass tifton 85 extracted more nitrogen and sodium, while the elephant grass extracted a larger amount of potassium from the DW, when grown under the evaluated organic loading rates (ORL). The concentration of phosphorus in aerial parts of plants and extraction capacity were similar in the two grasses, however, there is evidence of an increase in the extraction this nutrient, by the grass tifton 85, with the increase of the ORL applied in the CWS.

In this study, the role of Cyperus sp. was evaluated for removal of pollutants from swine wastewater. Vertical-flow pilot scale constructed wetlands (CWs) operating with a hydraulic retention time (HRT) of 72 h were monitored in a greenhouse, located in Viçosa, Brazil. Significant differences were observed for the following parameters: Kjeldahl nitrogen, total phosphorus, alkalinity and electric conductivity, with averages removals of 37.5 and 28.5%, 55.9 and 44.4%, 30.2 and 25.6 and 26.1% and 22.9% (for planted and unplanted CWs, respectively). The rate of dry matter yield from Cyperus sp. was 7.5 gm −2 day −1 , and the nutrient uptake capacities were 21.8, 2.1, 14.0 and 0.9 gm −2 of N, P, K and Na, respectively. Evapotranspiration (2.7 mm day −1 ) was statistically higher in the planted CWs. Plants in the CWs are important for achieving high nutrient removal.

RESUMO: A caracterização das chuvas intensas para utilização em projetos de engenharia é fundamental, especificadamente no que tange à obras hidráulicas. O estudo das chuvas intensas é feito por meio da relação entre a intensidade, a duração e a frequência das mesmas. Este artigo trata da determinação de tais relações para o município de Ipameri, Goiás, devido à falta de estudos relacionados a esta localidade. Foi feito o ajustamento à distribuição estatística de Gumbel de forma a obter os valores de precipitação máxima para os períodos de retorno de 2, 5, 10, 15, 20, 25, 50 e 100 anos. Para verificação do ajuste dos dados observados a distribuição de Gumbel, realizou-se os testes de aderência de Kolmogorov-Smirnov, Anderson-Darling e Qui-Quadrado, ao nível de significância de 1%. A desagregação dos valores de precipitação máxima em durações menores que 24 horas foi feita utilizando o método das Relações de Durações. Os parâmetros K (881,7487), a (0,1333), b (10,5332) e c (0,7519) da equação de chuvas intensas foram obtidos utilizando o método do Gradiente Reduzido Generalizado. Para avaliação da equação obtida foi utilizado o coeficiente de determinação (R²), o índice de concordância de Willmott (d) e índice de confiança (Ic), com resultados respectivos de 0,9986, 0,9997 e 0,9990. Assim esta pesquisa contribuiu para a determinação da equação de chuvas intensas, permitindo seu uso no dimensionamento de estruturas hidráulicas do local.ABSTRACT: Heavy rains characterization for use in engineering design projects is essential, specifically with regard to the hydrological researches and structures. In this way the study of heavy rains is done relating the intensity, duration and frequency of the events. This paper deals with the determination of such relations for the city of Ipameri, Goiás - Brazil, due to lack of studies related to the municipality. Adjusting the statistical Gumbel distribution in order to obtain maximum precipitation values for return periods of 2, 5, 10, 15, 20, 25, 50 and 100 years is made. To check the adjustment of the data observed distribution of Gumbel, we held the adherence tests (Kolmogorov-Smirnov, Anderson-Darling and Chi-Square) at a significance level of 1%. The disaggregation of the maximum precipitation values in smaller duration than 24 hours were made using the method of durations relations. The parameters K (881.7487), a (0.1333), b (10.5332) and c (0.7519) of equation heavy rains were obtained using the Generalized Reduced Gradient method. To validate the obtained equation was used the coefficient of determination (R²), the concordance index of Willmott (d) and confidence index (Ic) with the results of 0.9986, 0.9997 and 0.9990. Thus, this research contributes to the determination of the intense rainfall equation, allowing its use in the design of local hydraulic structures.

This study aimed to evaluate the influence of hydraulic retention time (HRT) and cultivated species in vertical-flow constructed wetlands (CW) on the removal of pollutants found in swine wastewater. The applied organic loading per unit area was 20 g m(-2) d(-1) of COD in nine cylindrical CW planted with Cyperus sp., Heliconia rostrata and Hedychium coronarium, and three controls containing only gravel. The HRT tested were 24, 48, 72 and 96 h. The following parameters of the CW influent and effluent were analysed: pH, ORP, turbidity, alkalinity, COD, TN, TKN, NH(x), N-NO3(-), TP, K and Na. Statistical analysis was performed at a 1% level of probability according to the Tukey test. It was noted that the greatest reductions were observed when CW were operated at higher HRT. TKN removals were 1.3 times greater than in unplanted CW. The best combination was CW planted with Cyperus sp. operating with a 72 h HRT, presenting the highest average mass removals with values of 69.1% (COD), 56.5% (TKN), 61.7% (NH(x)), 64.3% (TP) and 55.0% (K).