?url_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Adc&rft.relation=http%3A%2F%2Fmiis.maths.ox.ac.uk%2Fmiis%2F671%2F&rft.title=Toxic+Chemical+and+their+Neutralising+Agents+in+Porous+Media&rft.creator=Dalwadi%2C+M.&rft.creator=Dubrovina%2C+E.&rft.creator=Eisentraeger%2C+A.&rft.creator=Lee%2C+A.&rft.creator=Maestri%2C+J.&rft.creator=Matejczyk%2C+B.&rft.creator=O'Kiely%2C+D.&rft.creator=Stamper%2C+M.&rft.creator=Thomson%2C+S.&rft.subject=Environment&rft.subject=Fluids&rft.description=The+UK+Government+Decontamination+Service+advises+central+Govern-+ment+on+the+national+capability+for+the+decontamination+of+buildings%2C+infrastructure%2C+transport+and+open+environment%2C+and+be+a+source+of+expertise+in+the+event+of+a+chemical%2C+biological%2C+radiological+and+nuclear+(CBRN)+incident+or+major+release+of+HazMat+materials.+The+study+group+constructed+mathematical+models+to+describe+the+depth+to+which+a+toxic+chemical+may+seep+into+an+initially+dry+porous+substrate%2C+and+of+the+neutralisation+process+between+a+decontaminant+and+the+imbibed+chemical.%0D%0AThe+group+recognised+that+capillary+suction+was+the+dominant+process+by+which+the+contaminant+spreads+in+the+porous+substrate.+Therefore%2C+in+the+first+instance+the+absorption+of+the+contaminant+was+modelled+using+Darcy%E2%80%99s+law.+At+the+next+level+of+complication+a+diffuse+interface+model+based+on+Richards%E2%80%99+equation+was+employed.+The+results+of+the+two+models+were+found+to+agree+at+early+times%2C+while+at+later+times+we+found+that+the+diffuse+interface+model+predicted+the+more+realistic+scenario+in+which+the+contaminant+has+seeped+deeper+into+the+substrate+even+in+the+absence+of+further+contaminant+being+supplied+at+the+surface.%0D%0AThe+decontamination+process+was+modelled+in+two+cases%3B+first%2C+where+the+product+of+the+decontamination+reaction+was+water+soluble%2C+and+the+second+where+the+reaction+product+formed+soluble+in+the+contaminant+phase+and+of+similar+density.+These+simple+models+helped+explain+some+of+the+key+physics+involved+in+the+process%2C+and+how+the+decontamination+process+might+be+optimised.+We+found+that+decontamination+was+most+effective+in+the+first+of+these+two+cases.%0D%0AThe+group+then+sought+to+incorporate+hydrodynamic+effects+into+the+reaction+model.+In+the+long+wavelength+limit%2C+the+governing+equations+reduced+to+a+one-dimensional+Stefan+model+similar+to+the+one+considered+earlier.+More+detailed+approximations+and+numerical+simulations+of+this+model+were+beyond+the+scope+of+this+study+group%2C+but+provide+an+entry+point+for+future+research+in+this+area.&rft.date=2014&rft.type=Study+Group+Report&rft.type=NonPeerReviewed&rft.format=application%2Fpdf&rft.language=en&rft.identifier=http%3A%2F%2Fmiis.maths.ox.ac.uk%2Fmiis%2F671%2F1%2FESGI100-UKGDS-Report.pdf&rft.identifier=++Dalwadi%2C+M.+and+Dubrovina%2C+E.+and+Eisentraeger%2C+A.+and+Lee%2C+A.+and+Maestri%2C+J.+and+Matejczyk%2C+B.+and+O'Kiely%2C+D.+and+Stamper%2C+M.+and+Thomson%2C+S.++(2014)+Toxic+Chemical+and+their+Neutralising+Agents+in+Porous+Media.++%5BStudy+Group+Report%5D+++++