城市污泥新型固化技术及其力学特性

我国城市污泥产量巨大，如果得不到妥善处理将会严重影响环境综合治理。为了研究一种高效、资源、稳定的城市污泥处理技术，对城市污泥先进行生石灰消化处理，再通过正交试验，以无侧限抗压强度为指标，优选出生石灰、原料土、城市污泥、固化剂等的最佳配比，配制成一种新型城市污泥固化土，并对其力学特性进行试验研究。试验结果表明：研制的新型城市污泥固化剂固化处理城市污泥效果很好，重金属浸出量满足国家规范要求，污泥固化土强度随着养护龄期的增加而增大，且28 d后慢慢趋于相对稳定，碱性对强度有促进作用，建议固化土初始配制含水率最高控制在45%～50%之间。三轴剪切试验得到的应力峰值和结构屈服应力随着围压和养护龄期的增大而增大，环剪试验得到的残余强度与养护龄期及有效法向应力成正比，与剪切位移成反比。

New solidification technology and mechanical properties of municipal sludge

Municipal sludge production in China is huge, and will seriously affect the comprehensive management of the environment if not handled properly. To investigate an efficient, resourceful and stable municipal sludge treatment technology, in this study, the municipal sludge is first subjected to quicklime digestion treatment, and then orthogonal test. Taking the unconfined compressive strength as the index, the optimum ratio of raw lime, soil, municipal sludge and curing agent are selected. Using this ratio, a new type of municipal sludge solidified soil is prepared and its mechanical properties are discussed. The test results show that the new municipal sludge curing agent has a good effect on the treatment of municipal sludge and the heavy metals leaching amount meets the national standard requirements. The strength of sludge solidified soil increases with the increase of curing age, and it tends to be relatively stable after 28 days. In addition, alkali has a promoting effect on the strength, and it is suggested that the initial formulation of the solidified soil is controlled to be between 45% and 50%. Furthermore, in the triaxial shear test, the stress peak and structural yield stress increase with the increase of confining pressure and curing age. In the ring shear test, the residual strength is proportional to the curing age and effective normal stress, and inversely proportional to the shear displacement.