A solidification/stabilization process for wastewater treatment sludge from a primary copper smelter

作者：Ivsic Bajceta Dragana^*; Kamberovic Zeljko; Korac Marija; Gavrilovski Milorad

来源：Journal of the Serbian Chemical Society, 2013, 78(5): 725-739.

DOI：10.2298/JSC1207161251

• fly ash
• lime
• heavy metals
• unconfined compressive strength
• leaching tests

Wastewater treatment sludge from a primary copper smelter is characterized as hazardous waste that requires treatment prior to disposal due to its significant contents of heavy metals and arsenic. The aim of the presented study was to investigate the feasibility and the effectiveness of a solidification/stabilization process of the sludge using fly ash and lime as binders. The effectiveness of the process was evaluated by Unconfined Compressive Strength (UCS) testing, leaching tests (EN 12457-4 and Toxicity Characteristic Leaching Procedure (TCLP)) and Acid Neutralization Capacity (ANC) tests. All the samples reached the target UCS value of 0.35 MPa. The calcium to silicon concentration ratio (c(Ca)/c(Si)), determined by X-ray fluorescence analysis, was identified as main factor governing strength developrrient. Inductively coupled plasma-optical emission spectrometry analyses of solutions after leaching tests showed excellent stabilization of Cu, Ni, Pb and Zn (above 99 %) and arsenic (above 90 %) in samples with high Ca(OH)(2) content. Results of the ANC test indicated that the buffering capacity of solidified material linearly depended on Ca concentration in FA and lime. Samples with 20 % of binder having 50 % of FA and 50 % of lime met all the requirements for safe disposal.

• 出版日期2013