At present, common methods for preparing adsorbents for arsenic removal include electrospinning, tape-casting, and the powder method, but there is still a lack of research on the differences in the adsorption properties of arsenic-removal adsorbents prepared by these three methods. In this study, nine composite adsorbents were prepared by electrospinning, tape-casting, and the powder method with ferric hydroxide as the dopant, and their properties were examined. Scanning electron microscopy, energy dispersive spectroscopy, and X-ray diffraction confirmed the existence of ferric hydroxide on the surfaces and insides of the composite adsorbents. Differential scanning calorimetry and mechanical performance tests showed that the addition of FeOOH changed the thermal and mechanical properties of the adsorbents. The arsenic(III) adsorption capacity of each composite adsorbent was also determined as well as the effects of pH and temperature. The results showed that polyacrylonitrile/ferric hydroxide (fiber) had the highest arsenic(III) adsorption capacity (11.31 mg/g) under the baseline conditions. When the pH was adjusted to approximately 9, the maximum adsorption capacity increased to 12.41 mg/g. When the control temperature was 15 degrees C, the maximum adsorption capacity was 12.07 mg/g. After three adsorption cycles, the arsenic(III) removal rate of each composite membrane reached 90%. Overall, the electrospun membranes had the highest adsorption efficiencies among the three types of adsorbents with respect to arsenic removal, and polyacrylonitrile proved to be the best base material. In comparison, polyvinylidene fluoride proved more suitable for tape-casting films and powder adsorbents. (C) 2021 Elsevier B.V. All rights reserved.
