Deize Dias Lopes

Geophysical technique and groundwater monitoring to detect leachate contamination in the surrounding area of a landfill – Londrina (PR – Brazil)

The aim of the present study was to define leachate plume by using two techniques: geophysical and groundwater sampling in order to evaluate groundwater contamination. After performing a topographic survey and using geophysics, the leachate plume was identified. With this data, the wells for groundwater monitoring were located. Groundwater samples were analyzed for: COD, BOD, pH, alkalinity, conductivity, TKN and heavy metals. Through the electroresistivity method it was possible to define the shape of plume contamination. This method was important to locate the groundwater monitoring wells. The results of the physicochemical parameters showed the suitability of the geophysical study. The highest values of electric conductivity and alkalinity correspond to the wells located in the area interpreted as contaminated by leachate in the map of the resistivity. Even with seasonal variations, BOD values are low if compared to Brazilian environmental regulations, but COD values are higher up to 40 times the values of BOD. The concentrations of Ni, Zn, Cd and Cu in the groundwater are below the limits established by the potable water quality standards in Brazil, except for Pb whose concentration in groundwater were higher if compared to Brazilian legislation.

Removal of COD and nitrogen from animal food plant wastewater in an intermittently-aerated structured-bed reactor.

This study evaluated the performance of a continuous flow structured-bed reactor in the simultaneous removal of total nitrogen (TN) and chemical oxygen demand (COD) in the effluent from an animal food plant. The reactor had an intermittent aeration system; hydraulic retention time (HRT) of one day; temperature of 30 °C; and recirculation ratio of five times the flow. An experimental central composite rotational delineation (CCRD) type design was used to define the aeration conditions and nitrogen load (factors) to be studied. Response surface methodology was used to analyse the influence of the factors above the results, the removal of TN and COD. It was observed that the aeration factor showed the greatest significance for the results and that the affluent TKN concentration did not have a significant effect, at a 95% level of confidence, on COD removal. Throughout the experiment, the COD/N ratio remained between 3.2 and 3.8. The best results for COD and TN removal, 80% and 88%, respectively, were obtained with 158 min of aeration on a cycle of 180 min and 255 mg L(-1) of Total Kjeldahl Nitrogen (TKN) in the substrate.

SELEÇÃO DE INDICADORES DE SUSTENTABILIDADE PARA AVALIAÇÃO DO SISTEMA DE DRENAGEM URBANA

E comum observar nas grandes cidades os efeitos negativos causados pelo processo de urbanizacao desordenado, principalmente aqueles relacionados com o escoamento pluvial. Inundacoes, erosoes da pavimentacao das vias e deslizamentos de solo sao exemplos dos problemas recorrentes em eventos chuvosos. Para mitigar tais prejuizos, surge a necessidade da utilizacao de sistemas de drenagem sustentaveis, os quais buscam nao modificar o ciclo hidrologico da regiao, bem como, nao transferir impactos decorrentes das precipitacoes pluviais para jusante. O presente trabalho teve como objetivo desenvolver uma ferramenta de avaliacao do sistema de drenagem urbana utilizando indicadores de sustentabilidade selecionados e propostos a partir de informacoes levantadas na literatura sobre o assunto. Os indicadores definidos devem ser utilizados para avaliacoes expeditas da drenagem urbana de uma area, pois nao fazem uso de levantamentos quantitativos. Os resultados alcancados com a aplicacao da ferramenta desenvolvida podem ser utilizados para organizar as informacoes relacionadas a drenagem urbana e servirem de apoio ao planejamento e tomada de decisoes com relacao as acoes a serem adotadas para solucao de problemas envolvendo o escoamento das aguas pluviais e o sistema de drenagem urbana do local. Palavras-chave: Drenagem urbana sustentavel. Indicadores de sustentabilidade. Aguas urbanas. Infraestrutura urbana.