Sample records for greases
from WorldWideScience.org

Sample records 1 - 2 shown.



1

Tratamento de efluente de refinaria de óleo de soja por sistema de flotação por ar dissolvido/ Treatment of efluents of soybean oil refnery by dissolved air flotation

Cecchet, Juliana; Gomes, Benedito M.; Costanzi, Ricardo N.; Gomes, Simone D.
2010-01-01

Resumo em português Propôs-se, neste trabalho, avaliar o desempenho de coagulantes combinados a três tipos de polieletrólitos (aniônico, catiônico e não iônico), através de Flotação por Ar Dissolvido (FAD), no tratamento de efluentes de refinaria de óleo de soja. O experimento, conduzido em escala de laboratório, ensejou não apenas encontrar, pelos diagramas de coagulação, a melhor faixa de pH e a melhor concentração de coagulante mas, também, as dosagens e os tipos de floc (mais) ulante, culminando em sua dosagem ótima. Para tanto, parâmetros, como tempo e gradiente de mistura rápida (1 min / 150 s-1), tempo e gradiente de mistura lenta (10 min / 40 s-1 - 5 min / 20 s-1), pressão na câmara de saturação (450 kPa) e velocidade ascensional (1,67 cm min-1) foram usados para a fase da flotação nos ensaios. Após o término dos ensaios, amostras do efluente tratado foram utilizadas para comparativo com o efluente bruto, obtendo-se um grau de remoção de demanda química de oxigênio (DQO) de 93,7 e 95,1% e de óleos e graxas (O&G) de 94,2 e 99,8% para os ensaios 1 e 2, respectivamente. Apesar de sua excelente eficiência de remoção, o efluente tratado não apresentou características de reúso em torres de resfriamento, haja vista que sua DQO ficou muito acima de 75 mg L-1 O2. Resumo em inglês The aim of this work was to evaluate the performance of coagulants combined with three polyelectrolytes (anionic, cationic and non ionic) using dissolved air flotation (DAF) in the treatment of effluents of the soybean oil refinery. This study was conducted at laboratory-scale to find, through the coagulation diagram, the best limits of pH and coagulant concentration. With those limits, the dosage of flocculants was varied to achieve the optimum dosage. For that, some par (mais) ameters were fixed: time and rapid mix gradient (1 min and 150 s-1), time and slow mix gradient (10 min and 40 s-1 - 5 min and 20 s-1), pressure in saturation chamber (450 kPa) and ascension velocity (1.67 cm min-1) for two flotation tests. After the flotation tests, samples of treated effluent were collected for comparison with crude effluent. The removal percentage obtained of chemical oxygen demand (COD) was 93.7 and 95.1% and of oil and greases (O&G) was 94.2 and 99.8% for the test 1 and 2, respectively. Despite excellent efficiencies of removal, the treated effluent did not present characteristics for reuse in cooling towers, because the COD was above 75 mg L-1 O2.

Scientific Electronic Library Online (Portuguese)

2

Avaliação do processo eletrolítico em corrente alternada no tratamento de água de produção/ Evaluation electrolytic process in alternate current in treatment of water production

Cerqueira, Alexandre Andrade; Marques, Monica Regina da Costa; Russo, Carlos
2011-01-01

Resumo em inglês The main objective was to study the treatment of wastewater generated by the oil industry. This work consisted of tests of electroflocculation with alternate current (AC), and chemical coagulation. The removal efficiencies of organic load were evaluated by the removal of oils and greases, color and turbidity. The parameters investigated were the change in alternate current frequency, the initial pH, the distance between electrodes, the applied potential and time lapse. Fr (mais) om the results, one may conclude that the electroflocculation process is potential applicability to the effluent studied, while chemical coagulation was not successful.

Scientific Electronic Library Online (Portuguese)