Adsorption of some acid dyes from aqueous solutions onto neutral alumina

938-944The kinetics and isotherm studies on the adsorption of five acid dyes, viz., Acid Orange 6, Acid Orange 7, Ethyl Orange, Acid Red 88 and Acid Blue 113 on neutral alumina have been carried out spectrophotometrically. In each case the absorption process follows first order kinetics. For all the five dyes the rate of adsorption shows an increase with increase in dye concentration (0.5 - 6.0 x 10-5M), decrease in pH (4 - 8.5), decrease in temperature (30 - 50°C) and amount of adsorbent (0.1 - 0.6g). The adsorption shows the order: Acid Orange 6> Acid Orange 7 > Ethyl Orange> Acid Red 88 > Acid Blue  113. The dye adsorption follows the Langmuir and Freundlich isotherms; the various isotherm constants and thermodynamic parameters for the adsorption of dyes have been calculated and discussed

An Unusual Complex Odontoma

Odontoma, complex type is an agglomerate of all the dental tissues that are characterized by normal histodifferentiation but abnormal morphodifferentiation producing little or no resemblance to normal tooth form. They are usually asymptomatic but often associated with eruption disturbances. An interesting case of unusually large complex odontoma that was associated with pain and an impacted as well as missing molar is reported