Facile preparation of polyethyleneimine modified activated sludge-based adsorbent for hexavalent chromium removal from aqueous solution

ABSTRACT

Polyethyleneimine modified activated sludge (AS-PEI) was prepared and used for the removal of Cr(VI) in wastewater. Characterized results exhibited that PEI was successfully anchored on the surface of activated sludge. At 25 ºC and pH = 5.0, the maximum adsorption amount of Cr(VI) on AS-PEI was 86.96 mg/g. The adsorption amount of AS-PEI for Cr(VI) decreased as the pH values increased. The existence of Cl-, SO₄^2- and PO₄^3- decreased the Cr(VI) adsorption, and HA enhances the Cr(VI) adsorption. The electrostatic interaction combined reduction was the main mechanism of Cr(VI) adsorption. Cr(VI) loaded adsorbent can be regenerated in alkaline solution and AS-PEI can be reused.

KEYWORDS:

• Polyethyleneimine modified activated sludge
• adsorption
• hexavalent chromium

Novelty Statement

In this study, polyethyleneimine modified activated sludge (AS-PEI) was prepared and used as an adsorbent to remove Cr(VI) in wastewater. Characterized results exhibited that PEI was successfully anchored on the surface of activated sludge. Adsorption experiments show that AS-PEI possess high adsorption amount for aqueous Cr(VI), and Cr(VI) loaded adsorbent can be readily regenerated in NaOH and the adsorbent can be reused. the main mechanism of Cr(VI) adsorption on AS-PEI was described. The results highlight that AS-PEI is an effective and recyclable adsorbent in water treatment for the removal of Cr(VI) from aqueous solution. This results also provide the method for the utilization of spent activated sludge. Thus, we believe that this paper will be of interest to many readers of Separation Science and Technology.

Additional information

Funding

This work was funded by the National Natural Science Foundation of China (21677092), and the Scientific Research Program Funded by Shaanxi Provincial Education Department (15JK1095), Xi’an, China.