Erratum to “An Apatite II permeable reactive barrier to remediate groundwater containing Zn, Pb and Cd” [Applied Geochemistry 21 (2006) 1288–1300]     

James L. Conca  Judith Wright 《Applied Geochemistry》2006,21(12):1288

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Mapping soil liquefaction susceptibility across Europe using the analytic hierarchy process     

Meisina  C.  Bonì  R.  Bozzoni  F.  Conca  D.  Perotti  Cesare  Persichillo  Pina  Lai  C. G. 《Bulletin of Earthquake Engineering》2022,20(11):5601-5632

Bulletin of Earthquake Engineering - Mapping the susceptibility of earthquake-induced soil liquefaction at the continental scale is a challenge. Susceptibility of soils to liquefaction is the...  相似文献   

The effect of organics on lead sorption onto Apatite II™     

W.A. Martin  S.L. Larson  D.R. Felt  J. Wright  C.S. Griggs  M. Thompson  J.L. Conca  C.C. Nestler 《Applied Geochemistry》2008

Training activities at firing ranges, both civilian and military, deliver large quantities of Pb bullets into range soils where the physical and geochemical properties of the soil can influence Pb transport. Some best management practices (BMPs) developed for range managers include the addition of phosphate amendments, such as apatite, to immobilize Pb and other metals associated with firing ranges. In this study, the effect of the organic matter content of apatite II™ on its metal sorption properties was investigated. Batch and column experiments were conducted using mechanically, enzymatically, and thermally-treated forms of Apatite II™ to sorb soluble Pb. In batch experiments, mechanically and enzymatically-treated Apatite II™ reduced soluble Pb concentrations from 29% to 96%, depending on the age of the Apatite source. Thermally-treated Apatite II™ consistently reduced soluble Pb concentrations in solution by more than 90%, regardless of aging. The mechanically and enzymatically-treated Apatite II™ produced significantly higher dissolved organic carbon (DOC) and biochemical oxygen demand (BOD) concentrations while undergoing aging. This contrasts with the thermally-treated Apatite II™ that produced very low to non-detectable levels of DOC and BOD while aging. To determine the effects of thermal treatment on performance efficiencies, studies were performed using 500 mg L⁻¹ Pb solutions in columns packed with Apatite II™ that had been preheated at various temperatures for 2 h. The column study showed Pb loading of the Apatite II™ at different thermal treatments that ranged from 10.5% to 16.8% Pb by weight of substrate. The Pb loading capacity (by weight of substrate) increased as the treatment temperature of the Apatite II™ increased.  相似文献   

Technical guidelines for the assessment of earthquake induced liquefaction hazard at urban scale     

Lai  C. G.  Bozzoni  F.  Conca  D.  Famà  A.  Özcebe  A. G.  Zuccolo  E.  Meisina  C.  Bonì  R.  Bordoni  M.  Cosentini  R. M.  Martelli  L.  Poggi  V.  Viana da Fonseca  A.  Ferreira  C.  Rios  S.  Cordeiro  D.  Ramos  C.  Molina-Gómez  F.  Coelho  C.  Logar  J.  Maček  M.  Oblak  A.  Ozcep  F.  Bozbey  I.  Oztoprak  S.  Sargin  S.  Aysal  N.  Oser  C.  Kelesoglu  M. K. 《Bulletin of Earthquake Engineering》2021,19(10):4013-4057

Bulletin of Earthquake Engineering - Microzonation for earthquake-induced liquefaction hazard is the subdivision of a territory at a municipal or submunicipal scale in areas characterized by the...  相似文献   

Megazonation of earthquake-induced soil liquefaction hazard in continental Europe     

Bozzoni  F.  Bonì  R.  Conca  D.  Lai  C. G.  Zuccolo  E.  Meisina  C. 《Bulletin of Earthquake Engineering》2021,19(10):4059-4082

Bulletin of Earthquake Engineering - Mapping large territories for earthquake-induced soil liquefaction hazard may sound like an oxymoron since soil liquefaction is by itself a spatially highly...  相似文献   

Diffusion And Flow In Gravel,Soil, And Whole Rock     

James L. Conca  Judith Wright 《Hydrogeology Journal》1992,1(1):5-24

Transport parameters (diffusion coefficients, D(/), hydraulic conductivities, K(/), and retardation factors, R_f were experimentally determined in unsaturated soil, gravel, bentonite, and whole rock over a wide range of water contents, fixed at desired levels using the Unsaturated Flow Apparatus (UFA^TM). Effective diffusion coefficients in all media were found primarily to be a function of volumeric water cintent (/) and not material characteristics, except where the characteristics affect or determine water content. At high water contents, D(/) gradually declines as water content decreases, from 10^-5cm²/s at a / of about 50% to 10^-7cm²/s at a / of about 5%, followed by a sharp decline as surface films become thin and discontinuous, and pendular water elements become very small, from 10^-7cm²/s at a / of about 5% to 10^-10cm²/s at a / of about 0,5%. The several whole rock cores studied behaved similary. In aggregate material such as gravel and soil where the particles themselves have significant porosity, only the surface water content, not the internal water of the particles, contributes to the diffusion coefficient and hydraulic conductivity under unsaturated conditions, although the internal water is very important in retardation and other chemical effects. Experimentally determined K(/) compares favorably to van Genuchten/Mualem relationships calculated from laboratory-determined water retention versus matric potential data obtained on the same soils. Experimentally determined K(/) for whole rock appears to validate capillary bundle theory. Résumé. Diffusion et écoulement dans les graviers, les sols et les roches. Les paramètres de flux (coefficient de diffusion, D(‹), conductivité hydraulique, K(‹), et facteur de retard, R_f) ont été déterminés expérimentalement dans des formations non saturées (sol, gravier, benthonite et roche consolidée) pour une large gamme de tenneurs en eau (‹); ces teneurs en eau ont été ajustées aux valeurs désirées grâce à un dispositif spécial fournissant un écoulement non saturé (UFATM). Les résultats montrent que les coefficients de diffusion efficace de tous ces milieux sont d'abord fonction de la teneur volumique en eau et non des caractéristiques du matéeriau, sauf lorsque ces caractéristiques affectent ou déterminent la teneur en eau. Pour les fortes teneurs en eau, D(‹) décroit progressivement avec la teneur en eau, de 10 ^ч cm²/s pour un ‹ de 50% jusqu'à 10^щ cm²/s pour environ 5%. Lorsque les films d'eau deviennent minces et discontinus et lorsque la fraction d'eau gravitaire devient trop faible, D(‹) diminue très brutalement de 10^щ cm²/s pour un ‹ de 5% à 10^⪞ cm²/s pour un ‹ de 0,5%. Plusieurs roches consolidées, testées sur carottes, se comportent de la même façon. Dans les agrégats, comme les graviers et les sols, où les particules possèdent une porosité propre, seule la teneur en eau intergranulaire, et non l'eau de l'intérieur des particules, contribue à la valeur du coefficient de diffusion et à la conductivité hydraulique, dans des conditions non saturées, bien que l'eau intragranulaire joue un rôle très important quant au retard et aux autres effets chimiques. Les Valeurs de K(‹) déterminées expérimentalement montrent un bon accord avec les relations de van Genuchten/Mualem calculées à partir des teneurs en eau de rétention, déterminées au laboratoire en fonction du potentiel matriciel obtenu sur les mêmes sols. Les valeurs expérimentales de K(‹) pour des roches consolidées semblent valider la théorie du faisceau capillaire.  相似文献