Application of ferrate for the treatment of organic matters in wastewater

摘要

Fe(VI) was evaluated to treat municipal secondary effluents derived from wastewater treatment plants. Organic matter and reactive phosphate compounds in wastewater was oxidized by Fe(VI)l, and the formation of adsorbable organic haloids (AOX) as by-products in this study. Additionally, the most probable number (MPN) of cultivable heterotrophic bacteria was also determined. In every case for 100% bacterial inactivation a low Fe(VI) concentration (5 mg L.1)was enough and by this concentration 40% chemical oxygen demand (COD) and 20% total organic carbon (TOC) removal could be obtained on average. Higher Fe(VI) concentration (7–15 mg L.1) resulted in an even higher organics reduction (depending on the water matrix up to 79% COD and 45% TOC removal). Monitoring AOX concentration during Fe(VI)-treatment, it could be stated that AOX formation was in linear relationship with the applied Fe(VI) concentration, but at higher than about 10 mg L-1 Fe(VI) concentration this increase became much less than at lower Fe(VI) concentration.