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).

Simultaneous arsenic and fluoride removal from synthetic and real groundwater by electrocoagulation process: Parametric and cost evaluation.

Co-existence of arsenic and fluoride in groundwater has raised severe health issues to living being. Thus, the present research has been conducted for simultaneous removal of arsenic and fluoride from synthetic groundwater by using electrocoagulation process with aluminum electrode. Effects of initial pH, current density, run time, inter electrode distance and NaCl concentration over percentage removal of arsenic and fluoride as well as operating cost have been studied. The optimum experimental conditions are found to be initial pH: 7, current density: 10 A/m2, run time: 95 min, inter electrode distance: 1 cm, NaCl concentration: 0.71 g/l for removal of 98.51% arsenic (initial concentration: 550 µg/l) and 88.33% fluoride (initial concentration: 12 mg/l). The concentration of arsenic and fluoride in treated water are found to be 8.19 µg/l and 1.4 mg/l, respectively, with an operating cost of 0.357 USD/m3 treated water. Pseudo first and second order kinetic model of individual and simultaneous arsenic and fluoride removal in electrocoagulation have also been studied. Produced sludge characterization studies also confirm the presence of arsenic in As(III) form, and fluoride in sludge. The present electrocoagulation process is able to reduce the arsenic and fluoride concentration of synthetic as well as real groundwater to below 10 µg/l and 1.5 mg/l, respectively, which are maximum contaminant level of these elements in drinking water according to WHO guidelines.

Multivariate statistical approach for the assessment of groundwater quality in Ujjain City, India.

Groundwater quality assessment is an essential study which plays important role in the rational development and utilization of groundwater. Groundwater quality greatly influences the health of local people. The variations of water quality are essentially the combination of both anthropogenic and natural contributions. In order to understand the underlying physical and chemical processes this study analyzes 8 chemical and physical-chemical water quality parameters, viz. pH, turbidity, electrical conductivity, total dissolved solids, total alkalinity, total hardness, chloride and fluoride recorded at the 54 sampling stations during summer season of 2011 by using multivariate statistical techniques. Hierarchical clustering analysis (CA) is first applied to distinguish groundwater quality patterns among the stations, followed by the use of principle component analysis (PCA) and factor analysis (FA) to extract and recognize the major underlying factors contributing to the variations among the water quality measures. The first three components were chosen for interpretation of the data, which accounts for 72.502% of the total variance in the data set. The maximum number of variables, i.e. turbidity, EC, TDS and chloride were characterized by first component, while second and third were characterized by total alkalinity, total hardness, fluoride and pH respectively. This shows that hydro chemical constituents of the groundwater are mainly controlled by EC, TDS, and fluoride. The findings of the cluster analysis are presented in the form of dendrogram of the sampling stations (cases) as well as hydro chemical variables, which produced four major groupings, suggest that groundwater monitoring can be consolidated.