Bioplastic muab tawm kom tsis muaj teeb meem tsawg dua li qub

2024 Tus sau: Seth Attwood | [email protected]. Kawg hloov kho: 2023-12-16 16:06

Plastics raws li cog tsuas yog tsis noj qab haus huv raws li ib txwm "petroleum" plastics. Qhov no yog qhov xaus tau los ntawm cov kws sau ntawv ntawm kev tshawb fawb loj tshaj plaws ntawm cov khoom siv bioplastics rau hnub tim.

Cov ntsiab lus tau teev tseg nyob rau hauv ib tsab xov xwm tshawb fawb luam tawm nyob rau hauv phau ntawv journal Environment International.

Cov khoom siv raw rau kev tsim cov yas feem ntau yog roj, thee lossis natural gas. Tab sis nyob rau hauv xyoo tas los no, muaj kev txaus siab rau bioplastics tau los ntawm cov khoom cog.

Ib qho laj thawj yog vim li cas cov khoom siv yas xws li polyethylene thiab polypropylene tsis decompose nyob rau hauv lub sijhawm ntev heev. Yog li ntawd, lub roob ntawm cov pov tseg yas raug tsim. Txawm li cas los xij, lawv tsis nyob mus ib txhis, thiab lawv qhov kev puas tsuaj qeeb ua rau tsim cov microplastic hais tias dej nyab ib puag ncig, nkag mus rau hauv lub cev ntawm cov tsiaj thiab tib neeg.

Chemists tau siv zog los tsim cov ntaub ntawv uas, yog tias tso rau hauv ib puag ncig, yuav sai sai decompose rau hauv cov khoom tsis zoo (piv txwv li, carbon dioxide thiab dej). Ib txoj hauv kev zoo los ua qhov no yog siv cov khoom zoo sib xws hauv cov khoom sib xyaw rau ntoo, nplooj poob thiab lwm yam khoom uas paub txog lub ecosystem.

Tsis tas li ntawd, roj, thee thiab roj muaj ntau yam sib txawv, suav nrog cov tshuaj lom. Thaum lub sij hawm tsim cov yas, cov khoom no tuaj yeem nkag mus rau hauv ob qho tib si yas thiab ib puag ncig.

Thaum kawg, muaj qee tus neeg yuav khoom uas tsis tsim nyog ntseeg tias txhua yam ntuj tsim zoo dua li khoom siv. Qhov no yog, ntawm chav kawm, ib qho yuam kev: hluavtaws saccharin muaj kev nyab xeeb ntau dua thaum noj ntau tshaj li lub ntuj thiab ib puag ncig tus phooj ywg daj toadstool. Tab sis qhov kev thov rau bioplastics yog fueled los ntawm no irrational kev ntseeg thiab.

Puas yog "yas los ntawm lub vaj" tiag tiag muaj kev nyab xeeb rau tib neeg kev noj qab haus huv dua li nws cov khoom siv ib txwm? Cov lus nug no kuj tau pom los ntawm cov kws sau ntawv ntawm txoj kev tshawb fawb tshiab.

Cov kws tshawb fawb tau sim 43 hom khoom siv. Ntau ntawm lawv tau tsim los rau kev sib cuag zaub mov: cov tais diav pov tseg, chocolate wrappers, haus fwj, wine stoppers.

Cov khoom kuaj tau tsim los ntawm cuaj ntawm bioplastics nrov tshaj plaws. Ntawm lawv yog cov khoom uas tau txais lub npe zoo siab no rau ntau yam laj thawj.

Yog li, biopolyethylene tsis txawv ntawm cov polyethylene zoo tib yam hauv cov khoom lossis hauv cov cuab yeej siv los ntawm ethylene. Qhov txawv tsuas yog qhov no ethylene los ntawm (tsis yog los ntawm cov roj los yog roj, raws li niaj zaus, tab sis los ntawm ethanol ntawm cov nroj tsuag keeb kwm). Ntawm qhov tod tes, qee qhov kev sim tshuaj plastics muaj ntau txoj cai rau prefix "bio-": lawv feem ntau muaj cellulose lossis starch thiab sai sai decompose thaum lawv nkag mus rau hauv cov thoob khib nyiab.

Txawm li cas los xij, tag nrho cov khoom sib txawv no muaj ib yam zoo sib xws: lawv muaj ntau yam tshuaj- impurities. Txawm tias nyob rau hauv lub "huv" yas muaj yuav luag 190 txawv tebchaw, thiab nyob rau hauv lub "dirtiest" - ntau tshaj 20 txhiab. Yim caum feem pua ntawm cov khoom muaj tsawg kawg yog kaum txhiab (!) cov tshuaj sib txawv. Ntxiv mus, feem ntau ntawm lawv tau pom nyob rau hauv "cov hmoov txhuv nplej siab" thiab "cellulose" plastics. Tej zaum cov khoom tseem ceeb ntawm ib puag ncig zoo tsis yog qhov ua tau zoo raws li cov khoom siv, thiab cov tuam ntxhab tau tsim rau qhov no nrog ntau cov khoom ntxiv.

Tsis tas li ntawd, "pob paj" ntawm cov tshuaj ntxiv feem ntau nyob ntawm qhov tsis yog ntawm cov khoom, tab sis kuj nyob ntawm hom khoom. Yog li, lub hnab ua los ntawm biopolyethylene muaj cov impurities sib txawv li cov cawv txiv hmab los ntawm nws.

Ntawm chav kawm, ntau haiv neeg ntawm kab-up tseem tsis tau muaj laj thawj rau kev ntshai. Tom qab tag nrho, ib lub txiv apple tshiab muaj ntau yam sib txawv. Tab sis cov kws tshawb fawb tau sim nrog cov teebmeem ntawm bioplastics ntawm tib neeg cov kab lis kev cai ntawm tes nrog cov txiaj ntsig txaus ntshai.

Nws muab tawm tias feem ntau "natural thiab environmentally friendly" plastics muaj cov tshuaj lom. 67% ntawm cov qauv yog tshuaj lom, 42% ua rau oxidative kev nyuaj siab nyob rau hauv lub hlwb, 23% muaj cov nyhuv hormonal zoo li. Qee cov qauv muaj ob lossis peb ntawm cov khoom tsis zoo saum toj no ib zaug. Ntxiv mus, qhov txaus ntshai tshaj plaws yog, dua, biodegradable plastics ua los ntawm cellulose thiab starch.

Rau kev sib piv, cov kws tshawb fawb tau sim cov khoom tsim los ntawm cov yas yas thiab, feem ntau, tsis pom qhov txawv.

"Bio-raws li plastics thiab biodegradable plastics tsis muaj kev nyab xeeb dua li lwm cov yas," hais txog tsab xov xwm thawj tus sau Lisa Zimmermann ntawm Goethe University Frankfurt.

Tau kawg, qhov no tsis tau txhais hais tias lub tswv yim ntawm bioplastics yog qhov tsis zoo. Tab sis cov neeg tsim khoom yuav tsum tau them nyiaj ntau rau cov khoom uas tau ntxiv (lossis poob rau hauv) cov khoom siv thaum lub sijhawm tsim khoom, cov kws sau ntawv ceeb toom.