Drying And Extraction of Moringa Oleifera And Its Application In Wastewater Treatment
Abstract Conventional coagulants such as aluminum sulfate and ferric sulphate have proved to be harmful to human health as it may cause neurological diseases like Alzheimer and percentile dementia. These health concerns have led to the use of natural coagulants which are environmental friendly and not harmful to human health. In this study, Moringa Oleifera seeds are selected to study the preparation of the natural coagulant and further use it in dye wastewater treatment. The two important steps used in preparing the natural coagulants are drying of the raw materials and extraction of the protein content. Moringa Oleifera seeds were oven dried at 40°C, 50°C and 60°C and the drying data was recorded. The recorded data was then fitted into five thin layer kinetic models to obtain the most suitable drying temperature and its corresponding drying time. Using Microsoft Excel Solver 2011, values of (R2), (RMSE) and chi-square (X2 ) were calculated. Based on the highest value of (R2 ) and lowest value of (RMSE), Page kinetic model was selected. Moreover, for the selected Page kinetic model, values of (R2) and (X2) were also compared for all three temperatures and the temperature with the highest (R2) value and lowest chi-square value (X2) was selected as the most optimum drying temperature. The most optimum drying temperature for drying Moringa Oleifera seeds was obtained as 50°C as the seeds dried at this temperature holds the maximum protein content concentration which enhances its coagulation properties. Furthermore, the corresponding drying time of about 6.5 hours for seeds dried at 50°C was also taken as the most optimum drying time. In the next step, Moringa Oleifera seeds which have been dried at 50°C for 6.5 hours were used for protein extraction. Solid to solvent ratios of 0.5:100, 1:100, 2:100 and 5: 100 (g of dried Moringa oleifera seeds: ml of distilled water) were used to extract the protein by using a domestic blender for 2 minutes. Using the Bradford method, the absorbance for each solid to solvent ratio solution was recorded and the protein content concentration was further calculated. The highest protein content concentration of 0.0017 ug/uL was obtained in the best solid to solvent ratio which is 5.0: 100. Therefore, this solid to solvent ratio was used in the jar test. The jar test was based on three process parameters which includes coagulant dosage, pH and initial concentration of dye wastewater. The coagulant dosage of 300 mg/L, initial concentration of dye wastewater of 50 ppm and pH of 7 were selected as the most optimum process parameters for a maximum turbidity removal of 70.4% and a maximum color removal of 44.54% in the dye wastewater treatment with Moringa Oleifera seeds.
