Pinarli Vedat, Karaca Gizem, Salihoglu Guray, Salihoglu Nezih Kamil
Uludag University, Faculty of Engineering-Architecture, Department of Environmental Engineering, Bursa, Turkey.
J Environ Sci Health A Tox Hazard Subst Environ Eng. 2005;40(9):1763-74. doi: 10.1081/ese-200068051.
Stabilization and solidification of the waste phosphate sludge (WPS) using Portland cement (PC) and fly ash (FA) were studied in the present work. The WPS content in the cement mortars varied from 5% to 15%. Setting times were measured, and unconfined compressive strengths (UCS) were determined for the mortars cured in water for 3, 7, 28, 56, and 90 days. Zinc and nickel leaching of the solidified products were measured according to the Toxicity Characteristic Leaching Procedure. Setting times were extended as the WPS content in the paste samples increased. The UCS values of the mortar containing 5% WPS solidified by using 95% PC were similar to the reference sample. Use of 10% FA as cement substitute increased the UCS values by 10% at the end of curing period of 56 days. The WPS contained initially 130.2 mg L(-1) of zinc and 22.7 mg L(-1) of nickel. The zinc and nickel leached from the 5% WPS solidified by using 95% PC were measured as 3.8 mg L(-1) and 0.4 mg L(-1), respectively. These metal concentrations were below the limits given by the U.S. Environmental Protection Agency for landfilling the solidified wastes.
本研究采用波特兰水泥（PC）和粉煤灰（FA）对废弃磷酸盐污泥（WPS）进行稳定化和固化处理。水泥砂浆中WPS的含量在5%至15%之间变化。测定了凝结时间，并测定了在水中养护3、7、28、56和90天的砂浆的无侧限抗压强度（UCS）。根据毒性特性浸出程序测定了固化产物中锌和镍的浸出量。随着浆体样品中WPS含量的增加，凝结时间延长。使用95%的PC固化含5%WPS的砂浆的UCS值与参考样品相似。在56天的养护期结束时，使用10%的FA作为水泥替代品可使UCS值提高10%。WPS最初含有130.2mg/L的锌和22.7mg/L的镍。使用95%的PC固化5%WPS时，锌和镍的浸出量分别测定为3.8mg/L和0.4mg/L。这些金属浓度低于美国环境保护局规定的固化废物填埋限值。
