MGP WASTE STABILIZATION TREATABILITY STUDIES

摘要

In-situ stabilization/solidification is being evaluated as a component of a remedy for sludgesrnin a former quarry that had been used for the historic disposal of MGP-related wastes.rnRemedial investigations conducted at the Site under Pennsylvania’s Land Recycling Programrn(Act 2) confirmed that sludges in and impacted sediment beneath the quarry contain certainrnvolatile organic compounds (VOCs) and polycyclic aromatic hydrocarbons (PAHs) atrnconcentrations exceeding Act 2 direct contact Medium Specific Concentrations (MSCs). Thernquarry also poses a physical hazard due to its steep-sided slopes and standing water.rnA treatability study was conducted for solidification/stabilization (S/S) design and productrntesting for the quarry sludges. The treatability program evaluated several solidification agentsrnas possible additives for in-situ stabilization of composite samples of the quarry sludge. Thernselected option was shown to be cost-effective and capable of meeting the project’srnperformance requirements and compliance standards. These are: 1) identification of reagentrnsystems that facilitate rapid solidification of the sediments while providing stabilized materialsrnthat can be used as engineered fill within the quarry; and 2) control of sludge leaching to allowrnthe stabilized sediments to remain in place with reduced potential for groundwater impact.rnThe studies included both an Initial screening level evaluation and a Confirmatory levelrnevaluation. The reagents tested were: 1) Type I Portland Cement (PC); 2) Type III PC; 3)rnMgSO3 scrubber by-product; and 4) coal fired power plant fly ash. Based on an evaluation ofrnthe Initial screening data, it was determined that the sludge be tested during the Confirmatoryrnevaluation using Type III PC.rnThe Confirmatory evaluation included two different dosages on two composite samples tornconfirm the initial findings. The recommended dosages were as follows: 1) Upper Sludge- 20%rnand 22.5% Type III PC; and 2) Lower Sludge - 15% and 17.5% Type III PC. Physical andrnchemical testing of the stabilized material proved that Type III PC achieved the project goals.