Zhang Qian, Lu Haijun, Liu Junzhu, Wang Weiwei, Zhang Xiong
a Institute of Poromechanics , Wuhan Polytechnic University , Wuhan , People's Republic of China.
b Beijing Geo. & Inv. Engineering Institute , Beijing , People's Republic of China.
Environ Technol. 2018 May;39(10):1307-1315. doi: 10.1080/09593330.2017.1329348. Epub 2017 May 24.
Sewage sludge ash (SSA) produced by municipal sludge can be used as a modified additive for clay liner, and improves the working performance of landfill clay liner in contact with leachate. Under the action of landfill leachate, the permeability, shear strength, phase composition, and pore structure of the modified clay are investigated through the flexible wall permeability test, triaxial shear test, thermal gravimetric and differential thermal analysis, and low-temperature nitrogen adsorption test, respectively. The hydraulic conductivity of the modified clay containing 0-5% SSA is in the range of 3.94 × 10-1.16 × 10 cm/s, and the pollutant concentration of the sample without SSA was higher than others. The shear strength of the modified clay is more than that of the traditional clay liner, the cohesion rate of modified clay increases from 32.5 to 199.91 kPa, and the internal friction angle decreases from 32.5° to 15.6°. Furthermore, the weight loss rates of the samples are 15.69%, 17.92%, 18.06%, and 20.68%, respectively, when the SSA content increases from 0% to 5%. The total pore volume and average pore diameter of the modified clay decrease with the increase in the SSA content, respectively. However, the specific area of the modified clay increases with the increase in the SSA content.
城市污泥产生的污水污泥灰（SSA）可作为黏土衬层的改性添加剂，提高垃圾填埋场黏土衬层与渗滤液接触时的工作性能。在垃圾渗滤液作用下，分别通过柔性壁渗透试验、三轴剪切试验、热重与差热分析以及低温氮吸附试验，对改性黏土的渗透性、抗剪强度、相组成和孔隙结构进行了研究。含0-5%SSA的改性黏土的水力传导率在3.94×10-1.16×10 cm/s范围内，不含SSA的样品的污染物浓度高于其他样品。改性黏土的抗剪强度高于传统黏土衬层，改性黏土的黏聚力从32.5kPa增加到199.91kPa，内摩擦角从32.5°减小到15.6°。此外，当SSA含量从0%增加到5%时，样品的失重率分别为15.69%、17.92%、18.06%和20.68%。改性黏土的总孔体积和平均孔径分别随SSA含量的增加而减小。然而，改性黏土的比表面积随SSA含量的增加而增大。
