Biosorption of zinc (II) using Spirogyra species from electroplating effluent

Zinc was removed from the metal plating effluent with the biosorbent consisting of filamentous algae Spirogyra sp. The sorption was pH dependent with best adsorption at pH 2.5. The metal uptake increased from 3.9% (for no dilution) to 36.8% (for 10 times dilution), indicating that sorption increased with dilution of sample. The adsorption was faster at initial contact time, gradually decreased and remains constant after certain optimum time. Percentage removal of zinc increased from 20.3% to 63.6% with increase in the temperature from 25 degrees C to 35 degrees C but further increase resulted in the decrease in adsorption. Freundlich isotherm was applied and it holds good for the adsorption data.     

Quantification of Polycyclic Aromatic Hydrocarbons in Tea and Coffee Samples of Mumbai City (India) by High Performance Liquid Chromatography

This paper describes a method for quantification of sixteen polycyclic aromatic hydrocarbons (PAHs) in tea and coffee samples of Mumbai City with the help of reversed phase high performance liquid chromatography with UV-VIS detector. This method is based on liquid–liquid extraction followed by clean up with C-18 cartridge. Concentration of total PAHs in different brands of tea and coffee samples varied from 18.79 to 31.37 μg/L and from 16.47 to 18.24 μg/L, respectively. Mean concentration of total PAHs was 27.56 μg/L in tea and 17.20 μg/L in coffee. Recoveries at different concentration levels were higher than 68% in samples of tea and coffee. Detection limit was found to be low (0.0006 ng) for anthracene and highest (0.174 ng) for naphthalene with relative standard deviation between 0.4%–7%.     

Potable groundwater quality in some villages of Haryana, India: focus on fluoride

The fluoride concentration in ground water was determined in ten villages of Rohtak district of Haryana state (India). The fluoride concentration in the underground water of these villages varied from 0.034-2.09 mg/l. Various other water quality parameters, viz., pH, electrical conductivity, total dissolved salts, total hardness, total alkalinity sodium, potassium, calcium, magnesium, carbonate, bicarbonate, chloride and sulfate were also measured. A systematic calculation of correlation coefficients among different physicochemical parameters indicated considerable variations among the analyzed samples with respect to their chemical composition. Majority of the samples do not comply with Indian as well as WHO standards for most of the water quality parameters measured. Overall water quality was found unsatisfactory for drinking purposes. Fluoride content was higher than permissible limit in 50% samples.