Viable Alternatives Study for Reusing Lipids from Microalgae Biomass Present in the Generated Sludge in the Supply Water Treatment Processes

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 104 and 106 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

EMPREGO DAS SEMENTES DE MORINGA OLEIFERA LAM, COMO COAGULANTE ALTERNATIVO AO POLICLORETO DE ALUMÍNIO (PAC), NO TRATAMENTO DE ÁGUA PARA FINS POTÁVEIS

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.AbstractThis 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