Simultaneous removal of arsenic, fluoride, and manganese from synthetic wastewater by Vetiveria zizanioides.

Main aim of the present research is to explore the potential use of Vetiveria zizanioides L. for phytoremediation of arsenic, fluoride, and manganese simultaneously from synthetic wastewater in a batch scale floating platform unit. Half strength Hoagland's nutrient solution spiked with arsenic, fluoride, and manganese concentrations of 1, 20, and 10 mg/L, respectively has been used. The effects of pH and treatment time on simultaneous removal of arsenic, fluoride, and manganese have been performed. V. zizanioides has exhibited optimum growth at pH 8 and the removal of arsenic and fluoride is observed to be 59.6 and 38.1%, respectively. This plant has successfully removed all of the manganese (99.3%). The uptake of manganese is found to be faster than the arsenic and fluoride. The trend of arsenic, fluoride, and manganese accumulation in various parts of V. zizanioides is found as roots > stems > leaves. Result showed that the use of V. zizanioides would be appropriate to treat arsenic, fluoride, and manganese contaminated wastewater.

Pyrolysis of wood sawdust: Effects of process parameters on products yield and characterization of products.

The aim of present research was to study the pyrolysis of wood sawdust in a semi batch reactor and explored the influence of pyrolysis process parameters on the products yield. Pyrolysis process parameters such as temperature, heating rate, nitrogen (N2) flow rate and particle size of wood sawdust were varied as 350-650 °C, 10 and 50 °C/min, 50-200 cm3/min and <0.25 to >1.7 mm, respectively. The maximum bio-oil yield was found as 44.16 wt% at temperature of 500 °C, heating rate of 50 °C/min and nitrogen flow rate of 100 cm3/min for particle size range of 0.6 < dp < 1 mm. The composition and characteristics of bio-oil and bio-char were determined. Different methods such as ultimate analysis, Fourier transformed infrared spectroscopy (FTIR), Gas chromatography-mass spectroscopy (GC-MS), and Nuclear magnetic resonance spectroscopy (1H NMR) were used to characterize bio-oil. Boiling point range of bio-oil was found in between 63 and 360 °C. Bio-char and original biomass were analyzed by physicochemical, thermogravimetric as well as analytical methods using sophisticated instruments such as Field emission scanning electron microscope (FESEM), and X-ray diffractometer (XRD).