Removal of crystal violate dye from aqueous solution by adsorption on mixture of activated carbon: A kinetic & equilibrium study

 The kinetics and equilibrium study of crystal violate dye adsorption on mixture of activated carbon (PWCAC) and (CSAC) was studied. The use of low cost ecofriendly adsorbent has been investigated as an ideal alternative to the current expensive methods of removing of dye from aqueous solution. This study was done by batch adsorption techniques. The quantitative adsorption kinetic and equilibrium parameter for crystal violate dye were studied using uv-visible adsorption spectroscopy. The effect of initial dye concentration, pH,adsorbent dose, temperature, particle size were determined to find the optimal condition for adsorption. The percentage removal of dye was found to be most effective at pH10and contact time 120 min and at an adsorbent dose 4 g/L of dye. The study indicates that’s, the percentage removal of dye increases with increasing initial dye concentration, adsorption dose and contact time and attains equilibrium at optimum conditions.The equilibrium study of adsorption of crystal violate dye on to mixture of activated carbon was investigated using pseudo first order and pseudo second order kinetic models. The adsorption kinetics was found to follow pseudo second order kinetic model. The equilibrium adsorption data of crystal violate dye on PWCAC and CSAC mixture was analyzed by Langmuir and Freundlich adsorption model. The results show that the Langmuir model provides the best correlation

Removal of hazardous dye Ponceau-S by using chitin: An organic bioadsorbent

There are numbers of applications of chitin for the removal of basic dyes and other colored organics from industrial effluents. In present research article there is focus on the preparation of bioadsorbent chitin and its application for the removal Ponceau-S dye from the aqueous solution by using chitin as an organic bioadsorbent. Chitin was characterized by scanning electron microscopy (SEM). Different parameters have been studied such as initial dye concentration, pH, contact time and adsorbent dose etc. In experimental study it is seen that the higher percent removal of Ponceau-S dye at optimum pH 3.5. Kinetics and equilibrium studies were also carried out by using the chitin which fit for Freundlich and Langmuir isotherm and kinetic study follows second order mechanism.Key words: Chitin, Ponceau-S, organic bioadsorbent, colored organic, industrial effluents

Geomagnetic storm dependence on the solar flare class

Content. Solar flares are often used as precursors of geomagnetic storms. In particular, Howard and Tappin (2005) recently published in A&A a dependence between X-ray class of solar flares and Ap and Dst indexes of geomagnetic storms which contradicts to early published results. Aims. We compare published results on flare-storm dependences and discuss possible sources of the discrepancy. Methods. We analyze following sources of difference: (1) different intervals of observations, (2) different statistics and (3) different methods of event identification and comparison. Results. Our analysis shows that magnitude of geomagnetic storms is likely to be independent on X-ray class of solar flares.Comment: 3 pages, 1 tabl