添加SDS对剩余污泥水解系统中硫的影响

Effect of Sodium Dodecyl Sulfate Addition on Sulfur in Hydrolysis System of Excess Sludge

添加表面活性剂十二烷基硫酸钠(SDS)对剩余污泥水解有促进作用,但由于其本身含有硫,因此可能对污泥水解系统的硫形态和组成产生影响。对比研究了添加SDS对剩余污泥水解系统中不同形态含硫物质的影响。结果表明:添加SDS可促进剩余污泥水解释放溶解性碳、氮、磷,但同时会引起污泥水解系统中总硫绝对量的增加以及污泥中有机硫向溶解硫的快速转化。添加SDS的污泥水解系统,液相中S^(2-)、SO_4^(2-)-S、有机硫和总硫的浓度均明显升高,其中SO_4^(2-)-S增量最大,高达液相总硫增量的61.45%,固相总硫中有机硫占比降低而使硫化物占比升高,因此,添加SDS对污泥水解产生的(重)金属固定可能起到一定作用。此外,添加SDS的第1天,水解系统的气相中H_2S浓度即大幅升高,其浓度为控制反应器的3.04倍,为《城镇污水处理厂污染物排放标准》中H_2S气体一级排放限值的4 600倍。

The addition of sodium dodecyl sulfate （SDS） would promote the hydrolysis process of excess sludge from the wastewater treatment plant （WWTP）. However, the form and composition of sulfur in the hydrolysis system may be affected by SDS addition because SDS contains sulfur element itself. The effect of SDS addition on different forms of sulfur-containing substances in the sludge hydrolysis system was investigated. The results showed that the addition of SDS could promote the release of soluble carbon, nitrogen and phosphorus, but it could also cause the increase in total sulfur and the fast transformation of organic sulfur into soluble sulfur in the hydrolysis system. At the same time, SDS addition led to the increase in concentrations of S^2- , SO4^2- - S, organic sulfur and total sulfur in the liquid phase of sludge system, among which SO4^2- - S accounted for 61.45% of the increment of the total sulfur. On the other side, SDS addition caused the abatement of organic sulfur and the increase in sulfide in the hydro- lyzed sludge, which may contribute to the fixation of the （heavy） metals from hydrolysis process. In addition, the concentration of H2S in the SDS addition reactor on the first day was 3.04 times of that in the control one and 4 600 times of that in the first class discharge standard specified in the Discharge Standard of Pollutants for Municipal Wastewater Treatment Plant.