Over groundwater exploitation owing to population, urbanization and industrialization make the groundwater unfavorable for living beings. This study deals with the assessment of groundwater quality in Gudiyattam and Vaniyambadi blocks of Vellore district, Tamil Nadu, India where groundwater is the major source of drinking due to deficiency in surface water. The significant physicochemical parameters such as pH, conductivity, total dissolved solids, chlorides, total alkalinity, calcium hardness, magnesium hardness and sulphate were assessed. Correlation matrix, box plot, multivariate statistical tools such as cluster analysis and principal component analysis were applied to groundwater quality analysis. The groundwater samples were assessed for its applicability in irrigation and drinking purposes and geographic information system techniques are used for mapping consequence. The parameters analyzed were compared with Bureau of Indian Standards (BIS) and WHO standards. Box plot analysis revealed that total dissolved solids and electrical conductivity was strongly correlated. Correlation analysis exhibits strong correlation (R 2 >0.7) between total dissolved solids and electrical conductivity, anions such as Ca 2+ and Mg 2+ for both the study areas.

Bicarbonate source for cultivation of microalgae is an alternate method mainly to avoid CO 2 loss. The main aim of the work is to assess the bio-fixation ability of CO 2 from ammonium bicarbonate by Chlorella pyrenoidosa under mixotrophic condition. Furthermore, statistical optimization has been carried out to study the influence of pH, concentration and inoculum size and identify best conditions for CO 2 removal. The results revealed that maximum removal of CO 2 was obtained at pH 6.0; with ammonium bicarbonate concentration, 6.66 g LG 1 and inoculum size, 36.81%. The obtained results were statistically analyzed and the results were obtained with regression co-efficient R 2 value of 0.94 for CO 2 removal and 0.86 for corresponding chlorophyll content. From the study, it can be concluded that microalgae could able to grow in ammonium bicarbonate source which indicates that microalgae could assimilate ammonium and CO 2 in to their cells even at high concentration. Bicarbonate captured CO 2 proves to be a significant method for cultivation of microalgae supports commercial production.