Preparation and performance of arsenate (V) adsorbents derived from concrete wastes.
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.
Department of Materials and Life Science, Faculty of Science and Technology, Seikei University, 3-3-1, Kichijoji-kitamachi, Musashino, Tokyo 180-8633, Japan.
Takeshi
T
Sasaki
Research Center for Sustainable Science and Engineering, Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, 2-1-1, Katahira, Sendai, Miyagi 980-8577, Japan.
Atsushi
A
Iizuka
Department of Materials and Life Science, Faculty of Science and Technology, Seikei University, 3-3-1, Kichijoji-kitamachi, Musashino, Tokyo 180-8633, Japan.
Masayuki
M
Watanabe
School of Creative Science and Engineering, Faculty of Science and Engineering, Waseda University, 3-4-1, Okubo, Shinjuku, Tokyo 169-8555, Japan.
Teruhisa
T
Hongo
Department of Materials and Life Science, Faculty of Science and Technology, Seikei University, 3-3-1, Kichijoji-kitamachi, Musashino, Tokyo 180-8633, Japan. Electronic address: akihiro@st.seikei.ac.jp.
Akihiro
A
Yamasaki
D000327:Adsorption; D001149:Arsenates / Q000737:chemistry*; D001151:Arsenic / Q000737:chemistry; D017610:Calcium Compounds / Q000737:chemistry; D007220:Industrial Waste / Q000032:analysis; D014874:Water Pollutants, Chemical / Q000737:chemistry*; D018508:Water Purification / Q000379:methods*
D001149:Arsenates; D017610:Calcium Compounds; D007220:Industrial Waste; D014874:Water Pollutants, Chemical; C045817:calcium arsenate; D001151:Arsenic; C025657:arsenic acid
Adsorption; Arsenate removal; Waste cement; Waste concrete; Water pollution