<p align="justify">Este trabalho avaliou a eficiência das sementes de Moringa oleifera Lam como coagulante natural no processo de coagulação/floculação/sedimentação (C/F/S), seguido de ultrafiltração (UF), para a obtenção da remoção de cor, turbidez, coliformes totais, Escherichia coli e pH da água tratada. Para os ensaios, foi utilizada água bruta com turbidez na faixa de 150 à 550 uT proveniente do Rio Pirapó. O processo C/F/S foi realizado com o coagulante natural Moringa oleifera (MO) extraído em solução salina de KCl e NaCl (1M) e com o coagulante químico Policloreto de Alumínio (PAC), nas dosagens de 25 à 300 mg.L-1. Para os ensaios de UF foi utilizada uma membrana de poli (éter sulfona) à pressão de 3 bar. Pode-se observar que a Moringa não influencia o pH do meio, o qual manteve-se estável em todas as dosagens. O processo combinado C/F/S+UF se apresentou eficiente, pois os parâmetros analisados atingiram os valores estabelecidos pela Portaria nº 2914 do Ministério da Saúde. PALAVRAS-CHAVE: Coagulação/floculação/sedimentação, ultrafiltração, Moringa oleífera.</p><p align="justify">Abstract</p><p align="justify">This study investigated the efficiency of Moringa oleifera seeds as natural coagulant in coagulation/flocculation/sedimentation (C/F/S) process, followed by ultrafiltration (UF) for color, turbidity, total coliforms and Escherichia coli removal and pH of the treated water. For the tests a raw water with turbidity 150-550 uT, from the River basin Pirapó was used. The C/F/S process was performed using the Moringa oleifera extracted in saline solution of KCl and NaCl (1M), and Poly Aluminum Chloride (PAC) as chemical coagulant, in dosage from 25 to 300 mg.L-1 . In UF process, it was used a membrane of poly (eter sulfone) in a working pressure of 3 bar. In the results, one can observe that the Moringa does not influence the pH of the medium, which remained stable at all dosages. The combined process C/F/S+UF showed efficient, because the analyzed parameters reach the values established by Regulation nº 2914 of the Ministry of Health.</p>
The aim of this study was to evaluate the coagulation, flocculation, and dissolved air flotation (C/F/DAF) process using four types of coagulants based on Moringa oleifera (MO) seeds for the removal parameters of colour, turbidity, UV 254 nm, dissolved organic carbon (DOC), chlorophyll-a, and microcystin-LR. Tests were performed using water contaminated with Microcystis aeruginosa in a concentration of 10 4 cells mL À1 . The coagulants analyzed were fractionated proteins (albumin and globulin), proteins extracted from saline solution, and the integral powder of MO seeds. The results obtained presented the same optimum dosage for globulin and albumin removal (1.5 mg L À1 ), in which globulin reached removal percentages of 83.87 and 80.88 % for chlorophyll-a and microcystin-LR, respectively, and in which albumin reached removal percentages of 79.44 and 48.14 % for chlorophyll-a and microcystin-LR, respectively. The optimal dosage of proteins extracted from the saline solution was 8.0 mg Á L À1 , which achieved removal percentages of 74.80 and 73.52 % for chlorophyll-a and microcystin-LR, respectively. For the DOC, removal was only observed after the use of fractionated proteins, which emphasizes the need for methods based on the use of active purified agents of MO seeds involved in flocculation. Therefore, it is concluded that globulin, as a coagulant, is the most suitable for the present study, since it improves the C/F/DAF process efficiency in Microcystis aeruginosa and microcystin-LR reduction in addition to removing other analyzed parameters.
RESUMO: Esta pesquisa teve como objetivo o estudo de filtros de carvão ativado modificados com nanopartículas de prata e cobre. Para a impregnação dos metais na superfície do carvão ativado foi utilizado o método de impregnação por excesso de solvente nas concentrações de
<p align = "justify">Materiais antibacterianos para aplicação na purificação de água foram produzidos a partir de carvão ativado suportados com nanopartículas (NPs) de prata (Ag) e cobre (Cu). Os materiais foram produzidos utilizando-se o método de impregnação a vácuo com soluções aquosas dos sais metálicos de nitrato de prata (AgNO3) e sulfato de cobre (CuSO4.5H2O) em diferentes concentrações, seguido da etapa de decomposição térmica para síntese das NPs de Ag e Cu no carvão ativado. A caracterização textural dos materiais foi realizada através de técnicas de medidas de área superficial específica BET, área de microporos (método t) e volume e diâmetro de poros (método HK); a caracterização estrutural foi realizada por análises de Difratometria de Raios-X (DRX) e a caracterização morfológica por Microscopia Eletrônica de Transmissão (MET). Os materiais produzidos em diferentes concentrações: C/Ag 0,3 % Cu 1,0 %, C/Ag 0,3 % e C/Cu 1,0 %, foram avaliados em relação à atividade antibacteriana contra as bactérias Escherichia coli em filtros de purificação de água, conforme estabelecido pela norma ABNT NBR 16098:2012, nas condições de 5 % e 95 % da vida útil do filtro. Os materiais modificados somente com NPs de Ag (C/Ag 0,3 %) e NPs de Cu (C/Cu 1,0 %) mostraram uma atividade antibacteriana inferior a 2 log de remoção de (1,36 log/1,07 log) e (1,31 log/0,94 log), respectivamente. Em contrapartida, o material produzido com a combinação de NPs de Ag e Cu (C/Ag 0,3 %Cu 1,0 %) mostrou uma elevada atividade antibacteriana (4,91 log/ 3,75 log), inibindo completamente o crescimento bacteriano e, por conseguinte, este pode ser considerado como potencial material antibacteriano na purificação da água.</p>
This chapter aims to evaluate the microalgae species' removal efficiency, using Moringa oleifera powder seeds as a natural coagulant with subsequent lipid profile characterization. For the tests were used deionized water artificially contaminated with cell cultures of Anabaena flos-aquae and Chlorella vulgaris, with a cell density in the order of 10 4 and 10 6 cells mL-1 , respectively. Coagulation/flocculation/dissolved air flotation (C/F/DAF) tests were conducted using 'Flotest' equipment, using M. oleifera powder seeds in the dosage range of 50-1000 mg L −1. For fatty acid profile analyses, a gas chromatograph equipped with a flame ionization detector was used. Variations of the coagulant dosages showed that there was a difference between dosages and that 100 mg L-1 provided the best removal efficiency for A. flos-aquae (96.5, 80.5 and 78.1%) and 140 mg L −1 for C. vulgaris (90.5, 78.34 and 70%) of the tested parameters of chlorophyll, color and turbidity, respectively. In relation to the produced sludge, it was observed that the use of this coagulant in the treatment of water contaminated with microalgae produces a biodegradable sludge, rich in lipids, especially oleic acid (>60%). Thus, these results indicate that the sludge's reutilization could be a good alternative to biodiesel production, as it represents an environmentally viable method for reusing residual biomass produced in the water treatment process.
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