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Abstract

Meaningful waste use aimed at conservation of resources and lowering the amount of pollution is now inevitable. In the present study, the potential of tendu (Diospyros melanoxylon) leaf waste from a local beedi (cigarette) industry to remove dye from aqueous solution was studied after its pretreatment with phosphoric acid. The carbon prepared was characterized by analysis of porosity, surface area, scanning electron micrograph, cation exchange capacity, iodine, and methylene blue number. Feasibility of employing this carbon for the removal of Janus Green, a diazine dye, from aqueous solution was investigated. Dye removal was compared simultaneously with commercial carbon. The adsorption was evaluated in a batch process with different concentrations of dye as well as with different adsorbent doses, at a range of pH values, temperature, and contact time. The kinetic parameters were determined and found to follow the Lagergren pseudo first order model. The suitability of the adsorbent was tested by fitting the adsorption data with Langmuir and Freundlich isotherms. The Langmuir maximum adsorption capacity was found to be 51 mg/g, which approached the value 57 mg/g obtained for commercial carbon. The changes in standard free energy, standard entropy and standard enthalpy were calculated. The results showed that adsorption of dye onto phosphoric acid treated tendu biomass was spontaneous and found to be physical and exothermic in nature.

Kinetic, equilibrium and thermodynamic study of 2-chlorophenol adsorption ontoRicinus communispericarp activated carbon from aqueous solutions

“…The maximum uptake of adsorbate was the highest at pH of 6.0, with the adsorption capacity of 24.69 mg/g of RCAC and 98.75% of adsorption. A significant decline in removal efficiency was observed with further increase in pH above 6.0, which may be attributed to formation of phenolate anions (20). The pKa of 2-chlorophenol is 8.3, thus at optimum conditions of pH 6 the neutral species predominates, and appears to be more readily adsorbed on the negatively charged surface of the carbon.…”

Study of Adsorption of Janus Green B and Methylene Blue on Nanocrystalline Cellulose

“…MB is a basic dye that has different applications such as pH indicator, photodynamic therapy, 12 treatment of malaria, 13 staining of cells, 14 etc. A number of compounds, such as agro-industrial waste, 15 magnetite nanoparticles-modified activated carbon, 16 crystalline silica, 17 trisyl silicas, 18 activated carbon, 19 silica gel, 20 wool fiber, 21 sludge-adsorbents, 22 low-cost adsorbents 23 and zeolites 24 have been used for adsorption of these dyes. On the other hand, cellulose is the most abundant organic compound on the earth 25 and is cheap, renewable, and biodegradable.…”

Solute Uptake, Isotherm and Kinetic Studies for Distillery Wastewater Treatment for Removal of Organic Matter by Low Cost Adsorbent

“…At higher pH the OH -ion hinder the adsorption of organic matter on the adsorbent. pH value of 7-8 was found to be optimum in the investigations for COD removal by waste leaves [22]. At lower pH, the adsorption is expected to be high because of positive charge of H + ions from acids.…”