Mune dzimwe nzvimbo dzemunda, ivhu repapurazi raMark Chitley kuNorth Dakota rinopa dambudziko: Munyu unokonzera kusagadzikana kwemakemikari kunoomesa ivhu kwenguva yakareba, kufamba zvishoma nezvishoma kwemvura, kutadzisa midzi kupinda, uye pakupedzisira kuderedza goho. Ichi chiitiko chinonzi "Rings of Death".
Sekureva kwaTom DeSutter, purofesa wesainzi yevhu kuNorth Dakota State University (NDSU), munyu unowanzo pinda muvhu kubva padombo revabereki (kubva panoumbwa ivhu) uye kubva pasi pemvura. Kuchamhembe kwakadziva kumabvazuva kwedunhu, munyu unoumbwa kubva kushale uye nekukwira kwemvura kubva kuDakota Formation aquifer, nepo kumaodzanyemba kwakadziva kumadokero kweNorth Dakota inoumbwa zvakanyanya kubva kune sedimentary zvinhu.
“Kana muvhu muine sodium yakawandisa uye munyu muine munyu wakaderera, zvidimbu zvevhu zviri muvhu zvinodzingana,” inodaro DeSutter. “Mumamiriro ezvinhu echisikigo, nekufamba kwenguva, zvidimbu zvevhu zvakaparadzirwa zvinodzika pasi pevhu uye zvinogadzira mbiru inogona kunetsa kuti midzi yezvirimwa ipinde. Saka ivhu harina zvibereko zvakanyanya.”
Kugadzirisa nyaya idzi, Cheatley akabatana neNDSU Extension kudzoreredza ivhu nekubatanidza flue gas desulfurization gypsum, ne-chigadzirwa chekupisa kwemarasha. “Chinetso chacho chiri kuramba chichiwedzera, uye ndiri kutarisira kuona gypsum ichichinja maitiro aya,” anodaro Chitley.
Gypsum ndeye-chigadzirwa chemarasha-anobatidzwa magetsi emagetsi kumadokero North Dakota. Kana yaiswa muvhu, nhevedzano yemakemikari anoitika umo calcium “inoita sezambuko pakati pezvikamu zvevhu uye inosimudzira kuunganidzwa kwemakemikari,” anotsanangura kudaro Naeem Kalvar, nyanzvi yevhu yeNDSU Extension, anobatsira Cheatley kudzorera ivhu rakaoma. "Izvi zvinoita kuti ivhu rive nani, porosity yevhu uye kupinda mumvura."
Kushandiswa kwegypsum — pamwe nemimwe nzira yekupodza ivhu sembesa dzekuvharisa, iyo Chitley ichange ichiyedza kekutanga gore rino — yakanangana nekurwisa masoneti, madhaka emunyu nevhu resaline, pamwe nekuvandudza hutano hwevhu.
Kuedza uku kunogona kuchengetedza varimi vedunhu mamirioni emadhora, Kalvar akadaro, kunyanya muzvirimwa zviri panjodzi zvakanyanya sesoya, chibage, gorosi rechirimo uye canola. Zvichatora makore kuti Chitley nevavakidzani vake vaone kubatsira kwezvigadzirwa nemitoo yavari kuunza.
Papurazi reChitley, Kalvar akakurudzira kuisa matani manomwe kusvika gumi egypsum paeka. Chitley akatenga Chandler spreader kuti ishandiswe munzvimbo dzine saline uye anotenga gypsum nemadhora mana patani kubva kune chirimwa chiri muStanton, North Dakota. Chigadzirwa chacho chine "kuenderana kwehupfu hwakanyorova uye hahuparadziri zvakanaka kubva kune yakajairwa fetireza michina," Chitley anoti.
Kune dzimwe nzira dzekupfavisa ivhu resaline. Pakati pavo, kudyara huswa husingagumi hunotsungirira munyu munzvimbo umo zvirimwa zvegore negore zvisingangokuri. Varimi vanogona kuchengetedza pakati pemadhora makumi masere nemaviri nemadhora zana nemakumi masere nemanomwe paeka, Kalvar akadaro. Kunyangwe varimi vachifanira kubhadhara kumberi kweuswa gore rekutanga, ivo vanozozvikurira vega mumwaka unotevera.
"Nekupa chivharo chakanaka chezvinomera, huswa husingagumi hunoderedza kubuda kwemhepo, asi kukura midzi kuchabatsira kuderedza tafura yemvura uye kuderedza kukwira kwecapillary," anodaro Kalvar. “Varimi vanokwanisa kucheka huswa kana kufudza huswa uhu uye vanokwanisa kuwana mari kwete kungorasikirwa nemari mumaeka anenge atambura. Kana huswa hukachekwa panguva yakakodzera, huswa uhwu hunoita huswa hwakanaka.”
Parizvino, Chitley haidyari uswa husingagumi. Akanangana nekuongorora mabhenefiti egypsum nezvirimwa zvekuvharisa achienderera mberi nekuvandudza budiriro yevhu repurazi rake.