Preparation and performance of arsenate (V) adsorbents derived from concrete wastes

Waste Manag. 2014 Oct;34(10):1829-35. doi: 10.1016/j.wasman.2014.01.001. Epub 2014 Jan 25.

Abstract

Solid adsorbent materials, prepared from waste cement powder and concrete sludge were assessed for removal of arsenic in the form of arsenic (As(V)) from water. All the materials exhibited arsenic removal capacity when added to distilled water containing 10-700 mg/L arsenic. The arsenic removal isotherms were expressed by the Langmuir type equations, and the highest removal capacity was observed for the adsorbent prepared from concrete sludge with heat treatment at 105°C, the maximum removal capacity being 175 mg-As(V)/g. Based on changes in arsenic and calcium ion concentrations, and solution pH, the removal mechanism for arsenic was considered to involve the precipitation of calcium arsenate, Ca3(AsO4)2. The enhanced removal of arsenic for the adsorbent prepared from concrete sludge with heat treatment was thought to reflect ion exchange by ettringite. The prepared adsorbents, derived from waste cement and concrete using simple procedures, may offer a cost effective approach for arsenic removal and clean-up of contaminated waters, especially in developing countries.

Keywords: Adsorption; Arsenate removal; Waste cement; Waste concrete; Water pollution.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adsorption
  • Arsenates / chemistry*
  • Arsenic / chemistry
  • Calcium Compounds / chemistry
  • Industrial Waste / analysis
  • Water Pollutants, Chemical / chemistry*
  • Water Purification / methods*

Substances

  • Arsenates
  • Calcium Compounds
  • Industrial Waste
  • Water Pollutants, Chemical
  • calcium arsenate
  • Arsenic
  • arsenic acid