title: Removal of direct red 12B and methylene blue from water by adsorption onto Fe (III)/Cr (III) hydroxide, an industrial solid waste.
abstract: Removal of direct red 12B and methylene blue by adsorption onto Fe (III)/Cr (III) hydroxide was studied using various parameters such as agitation time, dye concentration, adsorbent dose and pH. Equilibrium adsorption data followed both Langmuir and Freundlich isotherms. Adsorption followed second-order rate kinetics. The Langmuir adsorption capacity (Qo) was found to be 5.0 and 22.8 mg dye per g of the adsorbent for direct red 12B and methylene blue, respectively. Acidic pH was favorable for the adsorption of direct red 12B and basic pH for methylene blue. Desorption studies showed that chemisorption seems to be the major mode of adsorption.
authors.affiliation: Environmental Chemistry Division, Department of Environmental Sciences, Bharathiar University, Marudamalai Road, Coimbatore 641 046, India. cnamasi@vsnl.com
authors.forename: C
authors.initials: C
authors.lastname: Namasivayam
authors.forename: S
authors.initials: S
authors.lastname: Sumithra
mesh_terms: D000327:Adsorption; D000892:Anti-Infective Agents, Urinary / Q000302:isolation & purification*; D001391:Azo Compounds / Q000737:chemistry / Q000302:isolation & purification*; D017608:Chromium Compounds / Q000737:chemistry; D004396:Coloring Agents / Q000302:isolation & purification*; D005290:Ferric Compounds / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D007220:Industrial Waste; D008751:Methylene Blue / Q000737:chemistry / Q000302:isolation & purification*; D013696:Temperature; D014874:Water Pollutants, Chemical / Q000302:isolation & purification*; D018508:Water Purification / Q000379:methods*
chemical_list: D000892:Anti-Infective Agents, Urinary; D001391:Azo Compounds; D017608:Chromium Compounds; D004396:Coloring Agents; C501278:Direct Red 12B; D005290:Ferric Compounds; D007220:Industrial Waste; D014874:Water Pollutants, Chemical; C021024:ferric hydroxide; D008751:Methylene Blue