Lutz Makowsky Bewertung der Schwermetall-Mobilität von Stadtböden aus technogenen Substraten bei Elution von Bodensäulen im Dynamischen Batchtest ISBN: 978-3-8322-8349-0 Preis: 48,80 € / 97,60 SFR |
|
Rezension |
|
2Odem, pH4-solution, artificial precipitation) does not reveal any significant differences in HM mobility, respectively, since the Substrate properties dominate the leaching conditions. According to the current soil column test Standard (DIN 19528) the contact time is set to 5 h. The results of this study show that the contact time should be chosen individually for each Substrate as follows to obtain equilibrium conditions: 5 h for construction nibble and coal mining waste, 10 - 50 h for ashes, dredged sludge and household waste and to 450 h for Substrates which are characterized by fine texture and a. platy structure type (e.g. industrial sludge). In comparison with the batch leaching test (DIN 38414-4) the DB shows lower HM mobility derived from near-natural Liquid/Solid ratios. On the contrary, higher HM source concentrations (HMsc) are detected in the DB leachates. Mean and 90%-percentile HMsc scenarios are calculated from aqua regia extractable HM resources and HM mobility. Occasionally, HMsc of site samples exceecl the marginal threshold values in case of ash (Cr), coal mining waste (Zn) and household waste (Cu). The trigger values are only exceeded in material samples regarding Cr and Cu. Finally, the site samples reach the > Z0 to < Z2 level only in case of coal mining waste and aerobic dredged sludge compared with material samples which are assessed on the > Z2 level. In summary, this study reports a method key for a Substrate specific soil column leaching procedure based on column filling teclinique and contact time. Consequently. an applicable tool for an optimized assessment of the mobility and source concentration of heavy metals in Technosols is provided. | Tills study aims at tlie assessment of the mobility and source concentration of heavy metals (HM) in urban soils, which are dominated by the admixture of technogenic Substrates (Technosols). The assessment is based on assignment criteria (Z-values)(LAGA), trigger values (BBodSchV) and marginal threshold values (LAWA). The Dynamic Batchtest (DB) is applied to leach soil columns at laboratory scale. Near-natural conditions are simulated compared with the DIN 38414-4 batch leaching test. The DB is based on the principles of soil column percolation followed by a batch phase (= circulation), which is continuously monitored at equilibrium conditions (EC, pH, Eh and temperature). The analyses comprise Cd, Cr, Cu, Ni, Pb and Zn in the leachates as well as in the aqua regia extracts. Six Technosol sites are sampled which are dominated by ashes, coal mining waste, household waste or sludges are investigated. Additionally, two miaterial samples consisting of construction nibble and one MSWI bottom ash are included. Equilibrium conditions are of concern for the meaningful comparison of HM mobilities of different kinds of technogenic Substrates. They are easier obtained by using undisturbed compared with disturbed filled soil columns. Moreover, soil column leaching of Substrates which show structural units or clayey to silty texture (e.g. dredged sludge and coal mining waste) is restricted to the undisturbed filling. The comparative investigation of soil column filling techniques as well as varying leachates (H|
Quelle: | ETDE - Energy Database des Leibniz-Instituts für Informationsinfrastruktur (FIZ Karlsruhe), production no.: DE10G2885|
weiter zum Buch ... |
Lutz Makowsky Bewertung der Schwermetall-Mobilität von Stadtböden aus technogenen Substraten bei Elution von Bodensäulen im Dynamischen Batchtest ISBN: 978-3-8322-8349-0 Preis: 48,80 € / 97,60 SFR |
|
Rezension |
|
This study aims at the assessment of the mobility and source concentration of heavy metals (HM) in urban soils, which are dominated by the admixture of technogenic substrates (Technosols). The assessment is based on assignment criteria (Z-values)(LAGA), trigger values (BBodSchV) and marginal threshold values (LAWA). The Dynamic Batchtest (DB) is applied to leach soil columns at laboratory scale. Near-natural conditions are simulated compared with the DIN 38414-4 batch leaching test. The DB is based on the principles of soil column percolation followed by a batch phase (= circulation), which is continuously monitored at equilibrium conditions (EC, pH, Eh and temperature). The analyses comprise Cd, Cr, Cu, Ni, Pb and Zn in the leachates as well as in the aqua regia extracts. Six Technosol sites are sampled which are dominated by ashes, coal mining waste, household waste or sludges are investigated. Additionally, two material samples consisting of construction rubble and one MSWI bottom ash are included. Equilibrium conditions are of concern for the meaningful comparison of HM mobilities of different kinds of technogenic substrates. They are easier obtained by using undisturbed compared with disturbed filled soil columns. Moreover, soil column leaching of substrates which show structural units or clayey to silty texture (e.g. dredged sludge and coal mining waste) is restricted to the undisturbed filling. The comparative investigation of soil column filling techniques as well as varying leachates (H{sub 2}O{sub dem,} pH4-solution, artificial precipitation) does not reveal any significant differences in HM mobility, respectively, since the substrate properties dominate the leaching conditions. According to the current soil column test standard (DIN 19528) the contact time is set to 5 h. The results of this study show that the contact time should be chosen individually for each substrate as follows to obtain equilibrium conditions: 5 h for construction rubble and coal mining waste, 10 - 50 h for ashes, dredged sludge and household waste and to 450 h for substrates which are characterized by fine texture and a platy structure type (e.g. industrial sludge). In comparison with the batch leaching test (DIN 38414-4) the DB shows lower HM mobility derived from near-natural Liquid/Solid ratios. On the contrary, higher HM source concentrations (HMsc) are detected in the DB leachates. Mean and 90%-percentile HMsc scenarios are calculated from aqua regia extractable HM resources and HM mobility. Occasionally, HMsc of site samples exceed the marginal threshold values in case of ash (Cr), coal mining waste (Zn) and household waste (Cu). The trigger values are only exceeded in material samples regarding Cr and Cu. Finally, the site samples reach the > Z0 to {<=} Z2 level only in case of coal mining waste and aerobic dredged sludge compared with material samples which are assessed on the > Z2 level. In summary, this study reports a method key for a substrate specific soil column leaching procedure based on column filling technique and contact time. Consequently, an applicable tool for an optimized assessment of the mobility and source concentration of heavy metals in Technosols is provided. (orig.) | |
Quelle: | ETDE - Energy Database-production no.: DE10G2885|
weiter zum Buch ... |