Heber Martins de Paula

Qualidade da água residuária de usina de concreto para fins de aproveitamento

Efficient water use is one of the most important requirements of cleaner production, and the use of the wastewater from concrete production can be an important means to this end. However, there are no Brazilian studies on the quality of concrete plant wastewater and the activities in which such water can be used. This paper aims to evaluate the quality of concrete plant wastewater and to propose guidelines for its treatment for non-potable applications. Wastewater samples were collected from three points in the studied treatment system, and tests were later performed in the laboratory to evaluate the water quality. The results obtained were compared with the limit values for the quality parameters that have been used for the analysis of the non-potable water supply in Brazil. The results indicate a need to at least add coagulation and pH correction processes to the treatment system.

Combined use of coagulation (M. oleifera) and electrochemical techniques in the treatment of industrial paint wastewater for reuse and/or disposal

In this work, water-based paint (WBP) wastewater was treated using a natural coagulant, Moringa oleifera aqueous extract (MOAE), fortified with Ca2+ (from nitrate and chloride salts). In order to improve the quality of the treated wastewater and render it suitable for disposal, an electrolytic flow process was associated with the wastewater treatment using a filter-press reactor with a boron doped diamond (BDD) electrode. The feasibility of the treatment was evidenced by the reuse of the treated wastewater in the production of a new paint (manufactured by the company supplying the raw wastewater), whose quality was compatible with the water used by the manufacturer. The best conditions for the coagulation-flocculation process involved the use of 80 mL of MOAE (50 g/L of MO and 0.125 mol/L of Ca2+) for every 1.0 L of wastewater at pH 6.5. The limiting current density (35 mA/cm2) and an electrolysis time of 90 min (charge passed of 3.68 A h/L) were used in the electrochemical treatment. Biotoxicity assays using the brine shrimp Artemia salina revealed that the mortality (in %) of microcrustaceans was reduced from 100% (raw wastewater) to only 11% at the end of the electrolysis process, in addition to eliminating the strong odor and 85% of the organic load. Moreover, microbiological tests showed that the number of mesophiles decreased by more than six orders of magnitude and there was no growth of thermotolerant coliforms (TC).

DISPONIBILIDADE HÍDRICA E O USO DA ÁGUA NA BACIA HIDROGRÁFICA DO RIBEIRÃO PARI/SAMAMBAIA

Neste trabalho analisou-se a disponibilidade hidrica do manancial superficial na area de abrangencia do Ribeirao Pari/Samambaia. Para tal efetuaram-se estudos da oferta hidrica da regiao, com base em dados hidrologicos e climaticos, realizou-se a medicao in loco da vazao do Ribeirao Pari/Samambaia, bem como estudos e previsoes de uso urbano e agricola da regiao. Considerando a vazao minima determinada e a vazao necessaria de agua para o abastecimento publico, acredita-se que o abastecimento de agua para a cidade de Catalao para os proximos anos podera ser comprometido. Avaliando, ainda, o crescimento urbano da cidade, acima da media nacional, sera de suma importância a implantacao do gerenciamento e monitoramento da Bacia do Ribeirao Pari/Samambaia.