?url_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Adc&rft.relation=http%3A%2F%2Fd-scholarship-dev.library.pitt.edu%2F37841%2F&rft.title=Control+of+Naturally+Occurring+Radioactive+Material+(NORM)+in+Produced+Water+by+Inorganic+Sorbents&rft.creator=Gusa%2C+Alen&rft.description=Produced+water+generated+during+unconventional+gas+extraction+is+characterized+by+high+total+dissolved+solids+(TDS)+and+high+concentration+(i.e.%2C+up+to+4%2C000+times+higher+than+the+drinking+water+standard)+of+naturally+occurring+radioactive+material+(NORM).+The+goal+of+this+study+was+to+evaluate+options+for+the+control+of+major+components+of+NORM+in+produced+water%2C+Ra-226+and+Ra-228%2C+and+mitigate+potential+adverse+health+and+environmental+impacts.+%0D%0ARadium+removal+capacity+of+barite+(BaSO4)%2C+one+of+the+most+cost-effective+solids+for+radium+separation%2C+was+affected+by+monovalent+and+divalent+cations+in+solution+due+to+competition+and+impact+on+barite+zeta+potential.+Molecular+dynamics+simulations+showed+a+reasonable+agreement+with+experimental+results.+The+main+discrepancy+was+due+to+dissolution-recrystallization+reactions+at+barite+surface+that+are+not+included+in+theoretical+calculations.+This+dissertation+research+provided+key+fundamental+insights+into+radium+removal+by+barite+and+enabled+accurate+estimate+of+the+effect+of+different+cations+on+radium+uptake.+%0D%0AIn+an+attempt+to+sequester+NORM+underground+and+prevent+its+accumulation+in+surface+impoundments%2C+a+novel+coated+hydraulic+fracturing+proppant+was+developed+in+this+dissertation.+Proppant+sand+impregnated+with+celestite+(SrSO4)+and+barite+using+heterogeneous+precipitation+showed+remarkable+capacity+for+Ra-226.+These+novel+proppants%2C+with+fairly+small+amount+of+impregnate+(i.e.%2C+10-30+mg%2Fg)%2C+exhibited+sufficient+capacity+for+Ra-226+even+at+high+ionic+strength+and+elevated+solution+temperatures.+It+is+also+estimated+that+this+method+can+control+Ra-226+during+the+lifetime+of+the+well+(i.e.%2C+20+years).%0D%0AIf+Ra-226+is+brought+to+the+surface%2C+co-precipitation+as+Ba-Ra-SO4+is+the+best+way+to+remove+it+prior+to+salt+recovery+or+to+prevent+accumulation+in+surface+impoundments.++Produced+water+with+high+Sr%2FBa+concentration+ratios+is+challenging+due+to+the+interference+of+Sr+with+this+process.+Optimization+of+the+treatment+process+to+achieve+requisite+effluent+quality+while+minimizing+the+total+amount+of+radioactive+sludge+involved+adjustment+of+Sr%2FBa+ratio+and+addition+of+barite+%E2%80%9Cseed%E2%80%9D.%0D%0ABased+on+the+improved+understanding+of+radium+removal+by+barite+adsorption%2Fco-precipitation%2C+this+study+offers+options+for+the+control+of+NORM+in+produced+water+by+either+sequestering+it+in+the+subsurface+or+by+treating+produced+water+above+ground.&rft.date=2020-01-29&rft.type=University+of+Pittsburgh+ETD&rft.type=PeerReviewed&rft.format=application%2Fpdf&rft.language=en&rft.identifier=http%3A%2F%2Fd-scholarship-dev.library.pitt.edu%2F37841%2F1%2Fgusaalen_etdPitt2019.pdf&rft.identifier=++Gusa%2C+Alen++(2020)+Control+of+Naturally+Occurring+Radioactive+Material+(NORM)+in+Produced+Water+by+Inorganic+Sorbents.++Doctoral+Dissertation%2C+University+of+Pittsburgh.++++(Unpublished)++