典型表面活性剂对焦化污泥中富集多环芳烃的解吸

焦化废水中的多环芳烃(Polycyclic Aromatic Hydrocarbons,PAHs)由于其亲脂性极易转移至污泥相中,此过程成为微生物降解污泥中PAHs的传质受限步骤.基于表面活性剂解吸焦化污泥中富集的PAHs以利于微生物降解的构想,采用两种典型的表面活性剂—Triton X~(-1)00和十二烷基硫酸钠(Sodium Dodecyl Sulfate,SDS)来考察其对菲、芘和苯并a]芘的增溶作用,对比了不同浓度的菲、芘和苯并a]芘在焦化污泥上的吸附特征,探讨了表面活性剂对焦化污泥中富集多环芳烃的解吸行为.结果发现,表面活性剂对菲、芘和苯并a]芘的增溶能力与三者的亲脂性存在负相关的关系,它们在焦化污泥上的吸附特征可用Freundlich等温吸附模型来描述,影响吸附容量的因素包括PAHs的亲脂性和焦化污泥的理化性质;SDS与Triton X~(-1)00共同作用时对芘和苯并a]芘的增溶更明显;以两者混合质量计的1 g表面活性剂在16 d内可以解吸1.12mg的总PAHs.上述研究可以作为焦化污泥生物修复的增溶工艺中表面活性剂需求量计算的参考依据.

Enhanced desorption of enriched polycyclic aromatic hydrocarbons from coking sludge using typical surfactants

Polycyclic aromatic hydrocarbons (PAHs) in coking wastewater easily transfer to the sludge due to their lipophilicity, and this process becomes the committed step for the biodegradation of PAHs in coking sludge. To improve the biodegradation of PAHs in the sludge, two typical surfactants-Triton X-100 and sodium dodecyl sulfate (SDS) were selected to investigate the enhanced solubilization of phenanthrene, pyrene and benzoa]pyrene. Adsorption characteristics of the three chemicals with different initial concentrations and desorption characteristics of enriched PAHs from coking sludge by surfactants were explored. Results show that the surfactant-enhanced solubility of phenanthrene, pyrene and benzoa]pyrene were negatively related with their lipophilicity. Adsorption characteristics of the three PAHs on coking sludge could be described by Freundlich adsorption isotherm, and factors that influenced the adsorption capacity were the lipophilicity of PAHs and physicochemical property of coking sludge. Moreover, the solubilization for pyrene and benzoa]pyrene by mixed Triton X-100 and SDS were better than that of the single surfactant, and the mixed surfactants (1 g) could desorb 1.12 mg PAHs in 16 days. This report can be used for calculating the surfactants demand in the enhanced solubilization process employed for the bioremediation of coking sludge.