Gamal El-Din Mohamed, Smith Daniel W, Al Momani Fares, Wang Weixing
Department of Civil and Environmental Engineering, University of Alberta, Edmonton, Alta., Canada T6G 2W2.
Water Res. 2006 Jan;40(2):392-400. doi: 10.1016/j.watres.2005.11.003. Epub 2005 Dec 27.
The ozonation of resin and fatty acids (RFAs) found in pulp mill effluents was investigated using rapid-scan stopped-flow spectrophotometry. RFAs oxidation (i.e., degradation) efficiency increased with increasing the amount of used ozone and temperature. The degradation process with respect to the acid was found to follow first-order kinetics. The ozonation of RFAs was modeled as an overall second-order reaction for both reactants. The apparent overall second-order rate constants were calculated based on the pseudo first-order rate constants obtained from the kinetic data fitting for the acid degradation. The apparent overall second-order rate constant was affected by pH and temperature. At 20 degrees C and when pH increased from 8 to 11, the apparent overall second-order rate constant increased almost by a factor of 5 (from 3.9 x10(3) to 1.8 x10(4)M(-1)s(-1)) for 9 mgL(-1) resin acid and a factor of 4 (from 9.6 x10(3) to 3.9 x10(4)M(-1)s(-1)) for 8 mgL(-1) fatty acid. At pH 8 and as temperature increased from 10 to 20 degrees C, the apparent overall second-order rate constant increased almost by a factor of 5 (from 8.2 x10(2) to 3.9 x10(3)M(-1)s(-1)) for 9 mgL(-1) resin acid and a factor of 3 (from 3.5 x10(3) to 9.6 x10(3)M(-1)s(-1)) for 8 mgL(-1) fatty acid. Microtox bioassay tests were completed to evaluate the toxicity of RFAs samples before and after ozonation. For the resin acid, there was an increase in toxicity as a result of ozonation. Meanwhile, toxicity of fatty acid samples decreased as a result of ozonation.
采用快速扫描停流分光光度法研究了纸浆厂废水中树脂和脂肪酸（RFAs）的臭氧化过程。RFAs的氧化（即降解）效率随着臭氧用量和温度的升高而增加。发现酸的降解过程符合一级动力学。RFAs的臭氧化被模拟为两种反应物的整体二级反应。基于从酸降解的动力学数据拟合中获得的伪一级速率常数，计算了表观整体二级速率常数。表观整体二级速率常数受pH值和温度的影响。在20℃时，当pH值从8增加到11时，对于9mgL(-1)的树脂酸，表观整体二级速率常数几乎增加了5倍（从3.9×10(3)增加到1.8×10(4)M(-1)s(-1)），对于8mgL(-1)的脂肪酸，增加了4倍（从9.6×10(3)增加到3.9×10(4)M(-1)s(-1)）。在pH值为8时，当温度从10℃升高到20℃时，对于9mgL(-1)的树脂酸，表观整体二级速率常数几乎增加了5倍（从8.2×10(2)增加到3.9×10(3)M(-1)s(-1)），对于8mgL(-1)的脂肪酸，增加了3倍（从3.5×10(3)增加到9.6×10(3)M(-1)s(-1)）。完成了Microtox生物测定试验，以评估臭氧化前后RFAs样品的毒性。对于树脂酸，臭氧化导致毒性增加。同时，脂肪酸样品的毒性因臭氧化而降低。
