MnO₂によるヒ素の除去および沈殿物の溶離

廃水中のヒ素の除去に関する基礎的研究 (第2報)

抄録

In the previous paper the co-precipitation process with ferric hydroxide was investigated to remove As contained in waste water.Since fine MnO₂powder obtained by electrolysis at lowtemperature was fou nd effective to remove the As ions, the optimum conditions were studied in this paper for both arsenous and arseni c solutions.
When the solution containing 10ppm As wastreated with MnO₂2g/l, the minimum content of As in the solution such as 0.15ppm was reached at pH 2 regardless of As³⁺or As⁵⁺. The As absorbed on MnO₂may be leached out by 2N-NaOH solution with a yield of high As content solution and the active MnO 2 applicable tof urther treatment. In the same way the iron precipitate in low As contentand high As solution were obtained by treating the precipitate of ferric hydroxide containing As with 0.5N-N_aOH solution.
As the co-precipitation process with ferric hydroxide suggested that the better result was expected when As in the solution was oxidized to As⁵⁺ion, the oxidizing effect for As³⁺was studied by using N_aOCI and C_a (OCl) ₂.