RESUMO Os sedimentos em suspensão formam compartimento ambiental especial que caracteriza os efeitos do uso do solo na bacia hidrográfica. Tal compartimento é capaz de armazenar compostos orgânicos e metais em geral, cujas variações espaciais nas concentrações podem ser associadas ao uso do solo, à composição do solo e à existência de fontes poluidoras na bacia. Aqui avaliamos a variação espacial da concentração de metais e fósforo nos sedimentos em suspensão em rio sob influência urbana. Por meio de amostradores integrados no tempo, amostras foram coletadas em três pontos com diferentes níveis de ocupação urbana: com 5,73%, 22,30% e com 54,06% de urbanização. Cada amostrador foi instalado de modo a ficar 20 cm abaixo da superfície da água, sendo coletadas amostras a cada 30 dias em cada ponto amostral. Doze amostras foram obtidas para análise de 27 elementos químicos. Dos 27 elementos selecionados para análise, 19 apresentaram taxas de variação de concentração positivas, indicando enriquecimento ao longo do trecho de rio amostrado. As maiores taxas de variação positivas foram obtidas para P (151,20%), La (117,98%), Cd (93,33%), Cr (71,43%), Na (68,75%), Ni (68,07%), Y (66,67%), Th (63,64%) e Zn (56,77%). Considerando a comparação com valores de referência locais conclui-se que Cd, Cr, Ni, P, Y e Zn aparecem associados ao aumento de urbanização na bacia; Co, Sc, Sn, Cu e Mn aparecem possivelmente associados à urbanização; Ba, La, Na, Pb e Sr demonstram comportamento inconclusivo em relação à influência urbana; e Al, Fe, Nb, Th, Ti, As, Ca, K, Mg, Va e Zr demonstram não estar associados ao aumento de urbanização.

ABSTRACT The suspended sediments are a special compartment that characterizes the effects of land use in the watershed. Such compartment is able to trap organic compounds as well as metals in general. Spatial variation of concentrations can be accounted for the land use, soil composition and pollution. In this work, we aimed to assess the spatial variation of metals and phosphorus concentration presented in suspended sediments collected in a river under urban occupation. Using time-integrated suspended sediment samplers, samples were collectec in three sites covering different levels of occupation: Almirante Tamandaré (P1) and two in Curitiba city (Tingui Park -P2 and Barigui Park - P3). The sampler was settled to be 20 cm below the water surface and it was removed after 30 days. Twelve samples were collected to examining the following elements Al, As, Ba, Ca, Cd, Co, Cr, Cu, Fe, K, La, Mg, Mn, Na, Nb, Ni, P, Pb, Sc, Sn, Sr, Th, Ti, V, Y, Zn and Zr by ICP-OES. The first site is characterized with only 5.73% of urban area; meanwhile the site P3 has the highest urban area 54.06%. Among the twenty seven elements, nineteen showed a positive variation in concentration between collected sites, giving indication that an enrichment of metals along the river. The following elements showed positive variation: P (151.20%), La (117.98%), Cd (93.33%), Cr (71.43%), Na (68.75%), Ni (68.07%), Y (66.67%), Th (63.64%) and Zn (56.77%). Considering local reference values it is concluded that Cd, Cr, Ni, P, Y and Zn appear associated with urbanization increase in the basin; Co, Sc, Sn, Cu and Mn appear possibly associated with urbanization; Ba, La, Na, Pb and Sr show inconclusive behavior in relation with urban influence ; Al, Fe, Nb, Th, Ti, As, Ca, K, Mg, Zr and Va demonstrate not be associated with urbanization.

The objective of this study was to evaluate the transport of one of the most toxic and best-selling herbicides in Brazil. The active ingredient 2,4-dichlorophenoxyacetic acid (2,4-D) was applied onto the surface of a tank-type lysimeter, filled with undisturbed soil, in Curitiba, Parana State. Samples of infiltration and runoff water were obtained during rain simulations. The concentrations of the active ingredient 2,4-D showed a rapid decrease in the environment, with mass losses of 29.12% by infiltration and 0.87% by runoff.