Leaching tests granular materials

British Standards Institute. 1996. Draft European Standard PrEN 12457 leaching compliance test for leaching of granular materials. 96/105207DC. 

EN 12457-1 (2003) Characterization of waste - Leaching - Compliance test for leaching of granular waste materials and sludges - Part 1 One-stage batch test at a liquid to solids ratio of 2 L/kg for materials with high solids content and with a particle size below 4 mm (with or without size reduction), CEN/TC292/WG2, European Committee for Standardization, Brussels. 

NEN 7343 (1995) Leaching Characteristics of Solid Earthy and Stony Building and Waste Materials. Leaching Tests. Determination of the Leaching of Inorganic Components from Granular Materials with the Column Test, Netherlands Normalization Institute, Delft, Netherlands. 

Column test (described in Dutch standard NEN 7343) is intended to simulate the percolation of (acidic) rainwater through granular materials in a road construction or landfill. The material is placed in a column with a diameter of 5 cm and height of 20 cm, and acidified demineralized water is then passed upwards through it. The eluate is collected in seven fractions at a liquid/solid ratio of between 0.1 and 101 kg-1. The leaching is calculated and expressed in mg kg 1 as a function of time, based on the analysis results. 

Cascade test (described in Dutch standard NEN 7349) provides information on long-term leaching from a granular material. In this test the material is brought into contact with acidified demineralized water five times in succession for 23 h. The cumulative L/S (liquid/solid) ratio is 100 1 kg1. This test also yields an emission, expressed in mg kg-1. 

For the purposes of describing leaching tests, the description of the leaching mechanisms hence the description of the types of tests are simplified into those which are relevant to granular materials and those which are suitable for monolithic materials. 

In leaching tests for granular materials, it is assumed that the liquid percolates through a material which comprises a mass of particles or granules. As... 

A number of reviews of available leaching tests have been carried out (Environment Canada 1990 Wallis etal. 1992 Ure etal. 1993 Quevauviller etal. 1995 CEN/TC/292/NNI 1994 Science of the Total Environmental Special Issue 1996 van der Sloot etal. 1997). Examples of leaching tests performed throughout the world are shown in Table 9.1. As shown in the table, there are more tests available for granular materials than there are for monolithic materials. 

CEN/TC 292 PrEN 12457-1 to PrEN12457-4 (2000) Characterisation of waste. Leaching compliance test for leaching of granular waste materials and sludges. 

A compliance leaching test for granular waste material has been published (prEN 12457) which describes three different procedures shake test at liquid/solid (L/S) ratio = 2, L/S = 10 and a two-step shake test at L/S = 2 and 10. The leachant used is demineralized water. It is likely that the standard will be validated. The driving force behind this standard was the draft European Directive on the landfill of waste. 

EN 12457, Characterization of Waste - Leaching - Compliance Test for Leaching of Granular Waste Materials, Determination of Leaching of Constituents from Granular Waste Materials, Comite Europeen de Normalisation, Brussels, Belgium, 2003. 

The neat and the fractionated olive residue ash samples performed in a similar to wheat straw way during the DTA/TGA tests. On the contrary, the leached olive residue sample exhibited a totally different behaviour its DTA line revealed a significant endothermic phenomenon occurring at the range of 750-850 C, which can be attributed to the dissociation of alkali carbonates, whereas no melting behaviour was observed up to the temperature level of 1000 C. Inspection at the end of the test confirmed that the heated material had kept its initial, granular form. 

Two-step (ls2, IS2-10) or one-step (Isio) agitated leaching with deionised water on granular (<4mm) materials. Tested on equivalent of 100 g dry solids after removal and quanitification of non-crushable portion. 

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