Crystalline Hydrous Ferric Oxide: An Adsorbent for Chromium(VI)‐Contaminated Industrial Wastewater Treatment

Abstract

Synthetic crystalline hydrous ferric oxide (CHFO) (particle size 0.14 to 0.29 mm) has been used systematically for adsorptive chromium(VI) removal from contaminated water. Batch experiments were performed as a function of pH, contact time, solute concentration, and regeneration of adsorbents. Column experiments were performed for breakthrough points in the presence and absence of other ions and treatment of industrial effluent. The optimum pH range was 2.0 to 4.0. The adsorption kinetic data could be described well by both second-order and pseudo-firstorder models. The isotherm adsorption data at 30 6 28C obeyed the Langmuir model best. The monolayer adsorption capacity was 35.7 mg/g. Chromium(VI)-rich CHFO could be regenerated up to 89 6 1% with 2.0 M sodium hydroxide. Regenerated column reuse showed a decrease (10 to 12%) in breakthrough capacity. Finally, the CHFO-(dried at 3008C) packed column was used for the recovery (98.5 6 1.0%) of chromium(VI) from contaminated industrial waste effluent of Hindustan Motor Limited (Hooghly, West Bengal, India). Water Environ. Res., 78, 986 (2006).

Kinetics, isotherm and thermodynamics for Cr(III) and Cr(VI) adsorption from aqueous solutions by crystalline hydrous titanium oxide

“…The removal and recovery of Cr(VI) from the industrial waste water had been reported from our laboratory using synthetic hydrous zirconium oxide [19], titanium oxide [20], stannic oxide [21], and ferric oxide [22].…”

Magnetic adsorption separation (MAS) process: An alternative method of extracting Cr(VI) from aqueous solution using polypyrrole coated Fe 3 O 4 nanocomposites

“…A lot of literature is available on removal of Cr(VI) from aqueous solution yet none has attempted to perform a continuous combined process. For example Goswami and Ghosh [53] achieved 3.48 mg Cr(VI)/g of hydrous stannic oxide (HSO), Ghosh et al [54] used hydrous titanium oxide (HTO) to remove 84 lg/0.1 g of HTO, while Goswami et al [55] extracted 35.7 mg Cr(VI)/g crystalline hydrous ferric oxide (HFO). Thus, our study gives promising results despite using a scaled-up process unlike other works where separation studies were done using fixed-bed configuration.…”

Polymers for the Extraction of Chromium—Role of Polymers in the Removal and Recovery of Chromium from Wastewater

“…In +III oxidation state, chromium remains as hex aqua ion [Cr(H 2 O) 6 ) 3+ in aqueous solution (11). The aqua ion is acidic (pK a = 4), and the hydroxo ion condenses to give a dimeric hydroxo bridged species (11).…”

“…E-mail: pranesh 02@yahoo.co.in of the conventional treatment are lengthy process, high chemical cost, significant sludge production and higher disposal cost. As a result, emphasis in recent years has been given on methods for recovery and reuse of metals rather than disposal (6)(7)(8). The solid phase extraction (SPE) and ion exchange process based on reactive polymers play a vital role in removal and recovery of chromium from waste water in recent years (9)(10).…”