污水污泥对染料废水的吸附脱色性能研究

A Study on Dye Adsorption by Sewage Sludge in Dye Wastewater

为探讨污泥的资源化利用和开发新型的染料废水吸附剂 ,在对污水污泥吸附处理染料废水的工艺条件进行优化的基础上 ,得到污水污泥对 3种染料 (中性橙、中性黑BL ,元青 )的最大吸附量及其吸附类型。结果表明 ,污泥焙烧温度、废水pH值和吸附时间对吸附效果有影响 ,而废水温度的变化则不会引起脱色率的较大改变。在最佳工艺条件 (污泥经 40 0℃焙烧 ,废水pH值为 1,吸附时间为 3 0min ,水温为 3 0℃ )下 ,3种染料废水的脱色率均达到 98% ,其最大吸附量都在 2 9mg·g-1左右 ,与活性炭的效果相当 ,而高于其它种类的吸附剂。焙烧后的污泥对中性黑BL的吸附符合Langmuir方程 ,对中性橙和元青的吸附符合Henry方程。焙烧污泥的优良脱色性能使其在染料废水处理方面具有较好的应用前景。

On the basis of optimizing the operation conditions for dye adsorption by sewage sludge in dye wastewater, the maximum capacity and the adsorption patterns for sewage sludge adsorbing 3 kinds of dye, Neutral Black BL(NB-BL), Neutral Orange(NO) and Acid Black(AB), were studied. It was shown that, the percent removal of dyes in wastewater depended not only on the temperature at which the sewage sludge was baked, but also on the pH of wastewater and the absorbent time. However, the change in wastewater temperature was somewhat less effective. The optimal operation conditions were found to be as follows: the sewage sludge was baked at 400℃ as an absorbent, the pH value and temperature of the wastewater were 1.0 and 30℃, respectively, and the adsorption time was 30min. A maximum adsorption of dyes of about 29mg·g -1 by sewage sludge could be obtained under the optimal conditions mentioned above, with a percentage color removal of 98% in wastewater. This removal was higher than that of other absorbents and close to that of active charcoal. The pattern for sewage sludge adsorbing NB-BL fits well to the Langmuir Equation; whereas, the other two dyes were adsorbed based on the Henry Equation. The excellent decolor ability of sewage sludge made it possible to be applied extensively in dye wastewater treatment.