摘要
研究了针铁矿、赤铁矿、磁铁矿和钢渣4种铁氧化物表面结合铁系统对硝基苯的还原转化,并对不同pH值下的还原机制进行了分析.在pH为6.5～7.0时,赤铁矿、磁铁矿和钢渣通过吸附Fe(Ⅱ)形成的表面结合铁系统,对硝基苯具有较强的还原能力,还原效果由高到低依次为磁铁矿、赤铁矿和钢渣,磁铁矿、赤铁矿还原率随着pH值升高而升高,而钢渣组还原率差别不大.针铁矿虽然吸附的Fe(Ⅱ)量最多,但没有还原活性.在pH值为6.0时,赤铁矿和磁铁矿对Fe(Ⅱ)吸附量较少,对硝基苯没有还原效果,而钢渣在pH6.0时仍可吸附大量Fe(Ⅱ),对硝基苯的还原率与pH7.0时相当.在pH超过7.5时,溶解性Fe(Ⅱ)转化为Fe(OH)2,Fe(OH)2成为系统的还原动力,铁氧化物的存在反而抑制了Fe(Ⅱ)系统的还原能力.
Batch tests were conducted to investigate the reductive transformation of nitrobenzene by goethite, hematite, magnetite and steel converter slag bound Fe（ Ⅱ ） system. And the reduction mechanism was explored at different pH values. Experimental results showed that hematite, magnetite and steel converter slag could adsorb Fe（ Ⅱ ） on surfaces and form iron oxides bound Fe（ Ⅱ ） system at pH from 6.5 to 7.0. The systems had strong reductive capacity and could reduce nitrohenzene to aniline. The reduction efficiency of nitrobenzene in surface bound Fe（ Ⅱ ） system followed the sequence of magnetite, hematite and steel converter slag from high to low. The reduction efficiency of hematite and magnetite system increased with pH increasing. While it was almost pH independent in steel converter slag system. Although goethite adsorbed most of Fe（ Ⅱ ） in solution, the adsorbed Fe（Ⅱ ） had no reductive activity for nitrobenzene. At pH 6.0, small amount of Fe（ Ⅱ ） was adsorbed on magnetite and hematite and the systems did not show reductive activity for nitrobenzene. However, steel converter slag could adsorb Fe（ Ⅱ ） at pH 6.0 and reduction efficiency almost equaled to the value at pH 7.0. When pH was above 7.5, dissolved Fe（ Ⅱ ） could be converted to Fe（OH）2 and the newly formed Fe（OH）2 became the main redactor in the system. Under alkali condition, the presence of iron oxides inhibited the reduction capacity of system.
出处
《环境科学》
EI
CAS
CSCD
北大核心
2009年第7期1937-1941,共5页
Environmental Science
基金
国家自然科学基金项目(50608056)
同济大学污染控制与资源化研究国家重点实验室开放课题项目(PCRRF06005)
关键词
铁氧化物
表面结合铁
还原转化
硝基苯
iron oxides
surface bound Fe（ Ⅱ ）
reductive transformation
nitrobenzene
