【摘要】 为解决水泥对含有机质和重金属污染物的淤泥固化效果不佳的问题,提出采用水泥、生石灰、高铁酸钾和高分子吸水树脂作为复合固化剂对淤泥进行固化处理的方法。通过干湿循环试验和渗出液试验,从固化淤泥平均累计相对质量损失率、无侧限抗压强度和固化淤泥渗出液中重金属离子浓度等指标的变化,探究了复合固化剂对固化淤泥耐久性和稳定性的影响。试验结果表明:增加水泥掺量在一定程度上能提高固化淤泥的强度、改善固化淤泥的耐久性和固化淤泥中重金属的稳定性,但仅掺入水泥难以达到理想的固化效果;而掺入复合固化剂的固化淤泥,在干湿循环作用下能保证整体的完整性,其平均累计相对质量损失率仅为3.89%,无侧限抗压强度相比28d养护的试样提高了4.1%;在渗流作用下,掺入复合固化剂的固化淤泥末次渗出液中未检出Pb离子,而Cu、Zn离子的浓度仅为初次渗出液中的15.24%和2.25%,表明复合固化剂克服了因化淤泥体系酸碱度变化的影响,通过包裹作用和络合作用稳定了淤泥中的重金属离子,有效地降低了固化淤泥渗出液中Cu、Zn、Pb离子的浓度。更多还原

【Abstract】 In order to solve the problem that cement has poor solidification effect on sludge containing organic matters and heavy metal pollutants,this paper uses cement,quick lime,potassium ferrate and super absorbent resin as composite stabilizer to solidify sludge.The paper conducts the wetting-drying cycle test and the exudative fluid test to investigate the effect of composite stabilizer on durability and stability of solidified sludge by measuring the average cumulative relative mass loss rate and the unconfined compressive strength of solidified sludge,and heavy metal ion concentration in the solidified sludge exudate.The experimental results show that increasing the cement content can improve the strength of solidified sludge,the durability of solidified sludge and the stability of heavy metals in solidified sludge,but it is difficult to achieve the desired solidify effect only by adding cement.After wet and dry cycles,the average cumulative mass loss rate of sludge mixed with composite stabilizer is 3.89%,and unconfined compressive strength of the solidified sludge increases 4.1%in comparison to the 28-day cured sample.Besides,after multiple exudation,lead ions in the final exudative fluid of sludge treated bycomposite stabilizer fail to check out,while the concentrations of copper and zinc ions are only 15.24%and 2.25%in comparison to the initial exudative fluid.It is indicated that the composite stabilizer overcomes the influence of the pH change of the solidified sludge system;the heavy metal ions in the sludge are stabilized by the encapsulation and complexation,and the concentration of Cu,Zn and Pb ions in the solidified sludge exudate is effectively reduced.更多还原