磷酸盐对铁锰复合氧化膜去除地表水中氨氮的影响

Effect of Phosphate on the Ammonium Removal Performance of Iron-Manganese Co-oxide Film in Surface Water Treatment

利用中试实验系统,研究磷酸盐对石英砂滤料表面负载的铁锰复合氧化膜去除地表水中氨氮的影响.结果表明,当水温为17.2~21.9℃时,随着运行时间的推移,未投加磷酸盐滤柱的氨氮去除效果有所下降;而投加5~15μg·L^(-1)磷酸盐滤柱的氨氮去除效果稳定,且去除率大于95.3%.当水温低于10.5℃时,滤柱出水氨氮浓度超标,此时通过提高磷酸盐投加量至30μg·L^(-1)或增加滤层厚度均可实现出水氨氮浓度达标.但随着系统持续运行,仅增加滤层厚度的滤柱出水氨氮浓度会再次超标.水温在6.5~10.5℃之间,投加30μg·L^(-1)磷酸盐的条件下,120 cm和80 cm活性滤层的最大安全进水氨氮浓度分别为2.34 mg·L^(-1)和1.95 mg·L^(-1).滤柱中生物灭活实验表明活性氧化膜对氨氮的去除同时包括催化氧化作用和生物作用;投加磷酸盐条件下,活性氧化膜的总活性和催化氧化活性分别是未投加磷酸盐条件的1.36倍和1.79倍,这表明磷酸盐促进了活性氧化膜的催化氧化活性.

The effect of phosphate on the ammonium removal performance of iron-manganese co-oxide film coated quartz sands in surface water treatment was investigated in a pilot-scale filtration system.The experimental results showed that the removal efficiency of ammonium decreased with reaction time without phosphate,while it stabilized at a level over 95.3% with phosphate dosing of 5-15μg·L^-1 at a temperature between 17.2-21.9℃.The effluent ammonium concentration of the filter columns exceeded the permitted limits for drinking water,when the water temperature was below 10.5℃.Fortunately,it can meet the water standards by increasing the amount of dosed phosphate to 30 μg·L^-1 or increasing the height of the filter layer.However,the ammonium concentration in the effluent of the filter when only increasing the height of the filter layer exceeded the water standards after running for several days.The maximum safe concentration of ammonium in the influent of the filters with 120 cm and 80 cm height active filter beds were 2.34 and1.95 mg·L^-1 with the condition of 30 μg·L^-1 phosphate,respectively.Microorganism inactivation experiments indicated that the ammonium removal capability of the activated oxide film included catalytic oxidation and biological nitrification simultaneously.The total activity and catalytic oxidation activity of the activated oxide film were 1.36 times and 1.79 times higher than those without phosphate,respectively,which suggested that phosphate can facilitate the catalytic oxidation activity of the activated oxide film.