Mu Ogasiti, akatswiri a zamankhwala adalengeza kuti akhoza kuchita zomwe zakhala zikuwoneka zosatheka kwa nthawi yayitali: kuphwanya zina mwa zinthu zodetsa zachilengedwe zomwe zimakhala zolimba kwambiri pansi pa mikhalidwe yofatsa. Zinthu za Per- ndi polyfluoroalkyl (PFAS), zomwe nthawi zambiri zimatchedwa mankhwala osatha, zikusonkhana m'chilengedwe ndi m'matupi athu pamlingo woopsa. Kulimba kwawo, komwe kumachokera ku mgwirizano wolimba wa carbon-fluorine, kumapangitsa PFAS kukhala yothandiza kwambiri ngati zokutira zosalowa madzi komanso zosamata komanso thovu lozimitsa moto, koma zikutanthauza kuti mankhwalawa amakhalapo kwa zaka mazana ambiri. Ena mwa mankhwala akuluakuluwa amadziwika kuti ndi oopsa.
Gululo, lotsogozedwa ndi katswiri wa zamankhwala ku Northwestern University William Dichtel komanso wophunzira womaliza maphunziro Brittany Trang, linapeza kufooka kwa perfluoroalkyl carboxylic acids ndi mankhwala a GenX, omwe ndi gawo la gulu lina la PFAS. Kutenthetsa mankhwala mu solvent kumachotsa gulu la mankhwala a carboxylic acid; kuwonjezera kwa sodium hydroxide kumachita ntchito yotsala, kusiya ma fluoride ions ndi mamolekyu achilengedwe osavulaza. Kusweka kumeneku kwa mgwirizano wamphamvu kwambiri wa C-F kumatha kuchitika pa 120 °C yokha (Science 2022, DOI: 10.1126/science.abm8868). Asayansi akuyembekeza kuyesa njira iyi motsutsana ndi mitundu ina ya PFAS.
Ntchitoyi isanachitike, njira zabwino kwambiri zothetsera PFAS zinali kuchotsa mankhwalawo kapena kuwaphwanya pamalo otentha kwambiri pogwiritsa ntchito mphamvu zambiri—zomwe sizingakhale zogwira ntchito konse, akutero Jennifer Faust, katswiri wa zamankhwala ku College of Wooster. "Ndicho chifukwa chake njira yochepetsera kutentha iyi ndi yodalirika kwambiri," akutero.
Njira yatsopanoyi yowerengera zinthu inalandiridwa makamaka poganizira zomwe zapezeka mu 2022 zokhudza PFAS. Mu Ogasiti, ofufuza a Stockholm University otsogozedwa ndi Ian Cousins adanenanso kuti madzi amvula padziko lonse lapansi ali ndi milingo ya perfluorooctanoic acid (PFOA) yomwe imaposa mulingo wa upangiri wa US Environmental Protection Agency wa mankhwala amenewo m'madzi akumwa (Environ. Sci. Technol. 2022, DOI: 10.1021/acs.est.2c02765). Kafukufukuyu adapezanso milingo yambiri ya PFAS ina m'madzi amvula.
“PFOA ndi PFOS [perfluorooctanesulfonic acid] zakhala zikulephera kupanga kwa zaka zambiri, kotero zikusonyeza momwe zimakhalira zolimba,” akutero Faust. “Sindinkaganiza kuti zingakhalepo zambiri chonchi.” Iye akutero, ntchito ya asuweni ake, “ndiyo mfundo yaikulu kwambiri.” Faust wapeza mitundu yatsopano ya PFAS—yomwe simayang'aniridwa nthawi zonse ndi EPA—m'madzi amvula aku US okhala ndi kuchuluka kwakukulu kuposa mankhwala akale awa (Environment. Sci.: Processes Impacts 2022, DOI: 10.1039/d2em00349j).
Nthawi yotumizira: Disembala-19-2022