Towards the development of a better safe and environment friendly method to purify water using Moringa oleifera

Abstract

newline xvi newlineAbstract newlineThe treatment of water to make it suitable for human consumption has become a newlinemajor concern worldwide. Due to challenges related with the use of current water newlinetreatment methods, there is a great need for substitute adsorbents of natural origin. In newlinethis study, an attempt was made to analyze the various capabilities of Moringa oleifera newlineseeds (MOS) in order to use it for water treatment. Aqueous extract of MOS was newlineinvestigated for its anti-bacterial activity against selected pathogenic bacterial strains newlineby using agar well diffusion method. 100 mg/mL of MOS extract was found to be newlineeffective against the test strains. Accordingly, a portable water purification kit in the newlineform of DipBag (containing MOS powder) was developed. A single DipBag with 100 newlinemg MOS powder was able to eradicate 99.9% of the microbial load from 1 L of water newlinewithin 5 minutes. DipBag was also found to be effective for the treatment of drinking newlinewater collected from natural water sources. The feasibility of using MOS as a newlinebiosorbent to remove dye (congo red-CR) and heavy metals (Cd II, Cr VI, Pb II) from newlinewater was assessed by measuring adsorption, kinetic, and thermodynamic parameters. newlineThe optimal conditions for dye and heavy metal biosorption resulted in 91.56, 98.18, newline92.42, and 77.45% removal of CR dye, Cd II, Cr VI, and Pb II, respectively. The newlineequilibrium data for dye and heavy metal removal were found to be well represented newlineby the Langmuir isotherm, and the rate of adsorption process followed pseudo-second newlineorder kinetic model. The nature of adsorption reaction was revealed to be endothermic newlineand exothermic for biosorption of dye and heavy metals, respectively. A filter was newlinedeveloped by using MOS and activated charcoal powder for the treatment of water newlinepolluted with CR dye, which showed 96% dye removal efficiency. The toxicity profile newlineof MOS and the corresponding effect on vital organs of swiss albino mice was also newlineevaluated. Test animals were administered with 2000 and 5000 mg/kg (body weight of newlinemice) of aqueous extract of MOS as a single dose. Haematological, biochemical and newlinehistopathological indices were evaluated by standard methods. Toxicity studies newlinerevealed that the concentration of neutrophils, eosinophils, MCH (mean corpuscular newlinehaemoglobin), MCHC (mean corpuscular haemoglobin concentration), alkaline newlinephosphatase, and creatinine in the animals of test groups was closer to the normal range newlinewhen compared to the animals of control group. Level of lymphocytes, and blood urea newlinewas found to be low in the test groups when compared to the control group. The newlineconcentration of aspartate aminotransferase was found to be elevated both in the test newlinexvii newlineand control groups when compared to the normal range. Other haematological and newlinebiochemical parameters have been found to be within or very close to the normal range newlinein all the animals (test and control). Histopathological examination revealed no newlinesignificant changes in the organs (liver, kidney, and spleen) of the test animals when newlinecompared to the control. No histological abnormalities were observed in any organ. newlineHence, the present study proved that Moringa seeds could be used as a promising newlinealternative for water treatment. newlineKeywords: Water treatment, Moringa oleifera seeds, DipBag, congo red dye, heavy newlinemetals, acute toxicity.