New insights into arsenate removal during siderite oxidation by dissolved oxygen

Purification of As(iii) through oxidation of siderite and As(iii) by dissolved oxygen: behavior and mechanism

“…This was probably related to the fact that the Fe( iii ) oxides rapidly generated with a high DO concentration covered the surface of siderite and hindered further Fe( ii ) oxidation, which is in agreement with a previous study. 52 They showed that the covering constrained the oxidation of siderite. Once siderite oxidation was restricted, ·OH production would be limited because of the weakened Fenton-like reaction, which was in line with others showing that the passivation layer after mineral oxidation hindered ·OH generation.…”

“…Recently, we have investigated the effects of DO concentrations on As(V) adsorption onto siderite, and found that As(V) adsorption capacities generally increased with an increase in DO concentrations and when DO concentration was excessive (i.e., 9.0 mg L −1 ), fast oxidation of siderite constrained As(V) adsorption due to the coating of produced Fe(III) oxides on the pristine siderite preventing further oxidation of siderite. 52 Therefore, the effects of DO concentration on siderite oxidation, As(III) oxidation, and As removal need further investigation.…”

“…, 9.0 mg L −1 ), fast oxidation of siderite constrained As( v ) adsorption due to the coating of produced Fe( iii ) oxides on the pristine siderite preventing further oxidation of siderite. 52 Therefore, the effects of DO concentration on siderite oxidation, As( iii ) oxidation, and As removal need further investigation.…”