Adsorption of Phosphate from Aqueous Solution Using Activated Red Mud

Pradhan, Jyotsnamayee; Das, J.; Das, S. N.; Thakur, Ravindra Singh

doi:10.1006/jcis.1998.5594

Cited by 136 publications

(74 citation statements)

References 20 publications

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“…Thus, in recent years, considerable attention has been paid to the investigation of different types of low-cost adsorbents, such as alum sludge (Galarneau and Gehr 1997), red mud (Pradhan et al 1998), goetite (Buerge-Weirich et al 2002), birnesite (Manning et al 2002), zeolite (Tillman et al 2005) and other waste materials (Agyei et al 2000). However, as a result of their lower adsorption capacities and poor adsorption kinetic properties, these adsorbents cannot be widely used.…”

Section: Introductionmentioning

confidence: 99%

Phosphate Ion Removal from Aqueous Solution Using an Iron Oxide-Coated Fly Ash Adsorbent

Yao

Shi

2009

Adsorption Science & Technology

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ABSTRACT:The ability of an iron oxide/fly ash composite adsorbent prepared with municipal solid waste fly ash and iron nitrate to remove phosphate ions from aqueous solutions has been tested. The characteristics and physicochemical performances of the composite were investigated via nitrogen adsorption and scanning electron microscopy (SEM) studies. The comparative adsorption of phosphate ions by the composite adsorbent and fly ash was investigated using batch experiments.It was found that the adsorption properties of the composite adsorbent towards phosphate ions depended on the pH value of the solution and the anion concentration in the same. The equilibrium data were analyzed using the Langmuir and Freundlich isotherms, from which it was shown that the adsorption capacities for phosphate ions at pH 3.0 were 27.39 mg/g for iron oxide/fly ash and 18.90 mg/g for fly ash. The results showed the adsorption patterns for phosphate ions with fly ash and iron oxide/fly ash composite adsorbent showed a better match to the Freundlich model rather than the Langmuir model. The adsorption kinetic data could be well described by the Lagergren pseudo-secondorder kinetic equation. The effect of temperature on the adsorption phenomena was investigated, the results indicating that phosphate ion removal by iron oxide/fly ash composite adsorbent was endothermic in nature.

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Section: Introductionmentioning

confidence: 99%

Phosphate Ion Removal from Aqueous Solution Using an Iron Oxide-Coated Fly Ash Adsorbent

Yao

Shi

2009

Adsorption Science & Technology

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“…However, activated carbon remains an expensive material since its high cost, which restricted its widespread use. In recent years, considerable attention has been paid based on economic and environmental concerns to the study of using different types of low-cost sorbents such as alum sludge [3], red mud (RM) [4][5][6], fly ash (FA) [7] and other waste materials [8,9] as alternative adsorbents for sorption of phosphate from water. Therefore, the sorbent with the best sorption capacity should be selected to satisfy both economic efficiency and convenience.…”

Section: Introductionmentioning

confidence: 99%

Phosphate removal from aqueous solutions using raw and activated red mud and fly ash

Liu

Luan

et al. 2006

Journal of Hazardous Materials

303

136

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The effect of acidification and heat treatment of raw red mud (RM) and fly ash (FA) on the sorption of phosphate was studied in parallel experiments. The result shows that a higher efficiency of phosphate removal was acquired by the activated samples than by the raw ones. The sample prepared by using the RM stirred with 0.25 M HCl for 2 h (RM0.25), as well as another sample prepared by heating the RM at 700• C for 2 h (RM700), registered the maximum removal of phosphate (99% removal of phosphate). This occurred when they were used in the phosphate sorption studies conducted at pH 7.0 and 25• C with the initial PO 4 3− concentration of 155 mg P/l. The FA samples treated in the same way described above can achieve 7.0 and 8.2 mg P/l phosphate removal for FA0.25 and FA700 respectively, corresponding to 45.2% and 52.9% removal. The activated materials performed higher phosphate removal over broader pH range compared with the raw ones. The influences of various factors, such as initial pH and initial phosphate concentration on the sorption capacity were also studied in batch equilibration technique. Solution pH significantly influenced the sorption. Each sample achieved the maximal removal of phosphate at pH 7.0. The amount of phosphate removal increased with the solute concentration. The Freundlich and Langmuir models were used to simulate the sorption equilibrium. The results indicate that the Langmuir model has a better correlation with the experimental data than the Freundlich model.

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“…Adsorption is one of the techniques which would be comparatively useful and economical for phosphate removal. In recent years, considerable attention has been paid to low-cost adsorbents such as alum sludge (Galarneau and Gehr, 1997), red mud (Shiao and Akashi, 1977;López et al, 1998;Pradhan et al, 1998), fly ash (Oguz, 2005) and other waste materials (Agyei et al, 2000(Agyei et al, , 2002 as adsorbents for adsorption of phosphate from wastewater economically.…”

Section: Introductionmentioning

confidence: 99%