Li Chun-juan, Ma Jun, Liang Tao
School of Municipal and Environmental Engineering, Harbin Institute of Technology, Harbin 150090, China.
Huan Jing Ke Xue. 2008 Jun;29(6):1550-4.
The preoxidation of polluted surface water with ferrate was conducted with respect to its impact on the following coagulation. It can be seen that UV254-absorbance, turbidity and TOC substantially decreased by 36.7%, 80.2%, 31.1%, respectively, after coagulation, without ferrate preoxidation, and by 63.3%, 89.6%, 37.0%, respectively, after coagulation, with ferrate preoxidation. It is noted that NH4+-N concentration is increased by 17% after coagulation with ferrate. This phenomenon can be explained by the fact that organics containing nitrogen in raw water were partly oxidized to inorganic nitrogen by ferrate preoxidation. After coagulation, AOC and AOC/TOC are increased from 998 microg x L(-1) to 1241 microg x L(-1), from 28.4% to 38.7%, respectively, by ferrate preoxidation. AOC-P17/AOC after coagulation is up to 83% with ferrate preoxidation. These suggest that preoxidation with ferrate promoted the biodegradation of organics with substantial increases of AOC, AOC/TOC. The results indicate that the concentration of organics with relative molecular mass (Mr) of 10000-100000 and less than 500 were substantially increased after the raw water was coagulated with ferrate preoxidation, which suggested that some high molecular weight organic substances were broken into smaller ones during ferrate preoxidation. After coagulation, organics of less than Mr = 500 in TOC are increased up to 65.0% with preoxidation from 38.9% without ferrate preoxidation. These oxidation products are biodegradable.
针对高铁酸盐对污染地表水预氧化及其对后续混凝的影响展开了研究。可以看出，在未进行高铁酸盐预氧化的情况下，混凝后UV254吸光度、浊度和总有机碳（TOC）分别大幅下降了36.7%、80.2%、31.1%；而在进行高铁酸盐预氧化后，混凝后它们分别下降了63.3%、89.6%、37.0%。值得注意的是，高铁酸盐混凝后铵态氮（NH4+-N）浓度增加了17%。这一现象可以解释为原水中含氮有机物被高铁酸盐预氧化部分氧化为无机氮。高铁酸盐预氧化混凝后，可生物同化有机碳（AOC）和AOC/TOC分别从998 μg·L-1增加到1241 μg·L-1，从28.4%增加到38.7%。高铁酸盐预氧化混凝后AOC-P17/AOC高达83%。这些结果表明，高铁酸盐预氧化促进了有机物的生物降解，AOC、AOC/TOC大幅增加。结果表明，原水经高铁酸盐预氧化混凝后，相对分子质量（Mr）为10000 - 100000及小于500的有机物浓度大幅增加，这表明在高铁酸盐预氧化过程中一些高分子量有机物质被分解为较小的物质。高铁酸盐预氧化混凝后，TOC中Mr小于500的有机物从无预氧化时的38.9%增加到65.0%。这些氧化产物是可生物降解的。
