Immobilization of arsenic in aqueous solution by waterworks alum sludge: prospects in China

Abstract

In this study, groups of batch experiments were designed to identify the characteristics of alum sludge for arsenic (As) adsorption. Air-dried alum sludge (moisture content 13.9%) collected from a water treatment works in Xi’an, China, was subjected to artificial As-rich wastewater adsorption tests using As₂O₃ as a model As source. Adsorption behaviours were investigated and the results have shown that the Langmuir adsorption isotherm well fits the experimental data (R² = 0.94957–0.99365). The maximum adsorption capacities range from 0.61 to 0.96 mg-As/g when the pH of the As solution was varied from 9.0 to 4.0. The prospects in China for the outcome of this study are discussed. This promising low-cost technique can eradicate As contamination in China.

Keywords:

• Al-WTRs
• Adsorption
• Arsenic removal
• Kinetics

Acknowledgements

The Key Laboratory of Water Supply and Drainage, Ministry of Housing and Urban-Rural Development and Chang’an University are also thanked for hosting some experiments.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by China Central University Funds [grant number 2013G1291073], [grant number 2013G1502043]; National Natural Science Youth Fund [grant number 41302207].