a b s t r a c tWaste molding and core sands from the foundry industry are successfully being used around the world in geotechnical and soil-related applications. Although waste foundry sands (WFSs) are generally not hazardous in nature, relevant data is currently not available in Argentina. This study aimed to quantify metals in waste molding and core sands from foundries using a variety of metalebinder combinations. Metal concentrations in WFSs were compared to those in virgin silica sands (VSSs), surface soils and soil guidance levels. A total analysis for Ag, Al, Ba, Be, Cd, Co, Cr, Cu, Fe, Mg, Mn, Mo, Ni, Pb, Sb, Te, Tl, V, and Zn was conducted on 96 WFSs and 14 VSSs collected from 17 small and medium-sized foundries. The majority of WFSs analyzed, regardless of metal cast and binder type, contained metal concentrations similar to those found in VSSs and native soils. In several cases where alkyd urethane binder was used, Co and Pb concentrations were elevated in the waste sands. Elevated Cr, Mo, Ni, and Tl concentrations associated with VSSs should not be an issue since these metals are bound within the silica sand matrix. Because of the naturally low metal concentrations found in most WFSs examined in this study, they should not be considered hazardous waste, thus making them available for encapsulated and unencapsulated beneficial use applications.Published by Elsevier Ltd.

As part of the casting process, foundries create sand molds and cores to hold the molten metal to specifi c dimensional tolerances. Although most of the waste foundry sands (WFSs) from this process are land fi lled, there is great interest in diverting them for use in agricultural and geotechnical applications. One potential limitation to their benefi cial use is concern that the WFSs will leach high levels of trace metals. Th e aim of this study was to quantify Ag, Ba, Cd, Cr, Cu, Ni, Pb, and Zn in leaching extracts from 96 waste molding and core sands from ferrous and nonferrous foundries. Th e procedures used to assess leaching in the WFSs were the Extraction Procedure, the Toxicity Characteristic Leaching Procedure, and the American Society for Testing and Materials water extraction procedure. Th e metal extract concentrations were compared with those found in virgin silica sands and Argentinean and U.S. hazardous waste laws to determine if the WFSs met toxicity limits. Regardless of metal cast and sand binder type, the majority of the WFS extracts analyzed contained metal concentrations similar to those found in virgin sand extracts and were below levels considered hazardous. However, 4 of 28 sands that used alkyd urethane binder were deemed hazardous because Pb concentrations in these sands were found to exceed regulatory thresholds. Although other regulated metals, such as As, Hg, and Se, were not analyzed in the extracts, this dataset provides additional evidence that many WFSs have a low metal leaching potential. Use of Standardized Procedures to Evaluate Metal Leaching from Waste Foundry SandsRoberto E. Miguel, James A. Ippolito, Atilio A. Porta, Roxana B. Banda Noriega , and Robert S. Dungan* F errous and nonferrous foundries produce metal castings to supply a variety of large markets, including the automotive, mining, petroleum, and marine industries. As part of the casting process, foundries create molds and cores using sand (e.g., silica, olivine, chromite, zircon) as refractory materials. Th e molds are made of virgin or reclaimed sand and binding agents such as clays or organic resins. Molding sands made with calcium and/or sodium bentonite clay are called green sands, which also contain lesser quantities of bituminous coal and cellulosic materials to prevent casting defects. Core sand grains are almost exclusively bound with organic resins such as phenolic urethane, furan, and novolac (Dungan and Reeves, 2005), although natural protein-, oil-, and polysaccharide-based binders are also available (Roa, 2003;Yu et al., 2009). When assembled, molds and cores form a cavity that holds the molten metal to specifi c dimensional tolerances.Aft er the molten metal has solidifi ed, the mold is broken to retrieve the casting. Depending on the technology used within the foundry, the sands can be reclaimed to make new molds or cores. However, a fraction of a foundry's system sand must be regularly discarded and replaced with virgin sand to avoid casting defects as a result of poor sand quality. Th e discarded...

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Este trabajo tiene por objetivo el análisis de la calidad del agua del arroyo Langueyú para determinar el estado de situación y su relación con la gestión de los recursos hídricos superficiales a nivel local. Se tuvieron en cuenta antecedentes hidrológicos regionales. Se efectuaron recorridos siguiendo el cauce del arroyo desde la cuenca alta, al Sur de la ciudad de Tandil incluyendo sus tributarios Blanco y Del Fuerte, hasta la intersección con la Ruta Provincial Nº 30. Se seleccionaron 9 sitios en los que se realizaron muestreos de calidad de agua en el período 2009-2011. Se complementó el estudio con un ensayo ecotoxicológico referido al desarrollo y crecimiento de bulbos de cebolla y de peces. Además, se identificaron los usos del suelo lindantes al cauce y sus afectaciones. Se detectó que los efluentes de impacto en el recurso son en su mayoría las descargas provenientes de las plantas de tratamiento de aguas residuales de Obras Sanitarias de Tandil (OST) y de las industrias alimenticias. Los resultados revelan un aumento significativo de los parámetros físicoquímicos en agua a partir de la descarga de una de las plantas de OST. Se detectó la inhibición en el crecimiento de las raíces de las cebollas y una disminución en el porcentaje de sobrevivencia en peces en los puntos de descarga. Los resultados microbiológicos y la materia orgánica, medida a través de DBO5 y DQO, denotan el impacto de la descarga cloacal. Se propone a futuro el monitoreo y análisis detallado del agua del arroyo y de los distintos efluentes antrópicos.   Abstract This work aims to analyze water quality of Langueyú stream, in order to determine its state and relationship with surface water management at local level. Regional previous studies were taken into account. Several itineraries were done along Langueyú stream channel, since the high part of the basin at the south, to the Provincial Route Nº 30 at the north. Two tributary streams were included, called Blanco and Del Fuerte. During the period 2009-2011, water quality sampling was executed in 9 selected places. An ecotoxicological test was done using onion bulbs and fish, in order to evaluate their development and growth. Besides, land uses near the stream and their impacts on water were identified. The main impact on surface water is caused by discharges from waste water treatment plants belonging to Obras Sanitarias Tandil (OST) and by food industries. Results show a significant increasing of physicochemical water parameters starting from one of the treatment plants. Growth inhibition in onions roots and decreasing in survival percentage of fish were detected in discharge points. Microbiological results together with DBO5 y DQO show the impact of waste water discharge. Detailed monitoring and analysis of Langueyú stream water and human discharges is recommended.