Hauv cov ntsiab lus ntawm cov khoom siv roj av ntau zuj zus thiab kev txhawb nqa thoob ntiaj teb ntawm kev tiv thaiv ib puag ncig tsawg-carbon, bioplastics muaj qhov zoo sib xws ntawm cov khoom siv niaj hnub xws li kev siv cov peev txheej thiab degradability. Kev lag luam thiab tsoomfwv tab tom pib tawm tswv yim "degradable plastics" ua lwm txoj rau cov khoom siv yas. Txawm li cas los xij, nyob rau hauv lub ntsej muag ntawm kev sib xyaw ntawm cov yas degradable nrog ntau lub npe ntawm lub khw, cov pej xeem, thiab cov kws kho mob feem ntau tsis meej pem.
Cov ntaub ntawv yas uas tau tshaj tawm no puas tuaj yeem decomposed tag nrho hauv ib puag ncig?
Hauv lub Peb Hlis 2019 xyoo tas los,EU tau tshaj tawm ntau qhov kev thov rau cov khoom siv yas ib zaug, suav nrog kev txwv tsis pub oxidatively degradable plastics (Oxo-degradable plastics). /904, uas suav nrog kev txwv tsis pub siv cov khoom siv yas ib zaug ua los ntawm oxo-degradable plastics hauv EU cov tswv cuab. Vim li cas EU txwv cov yas degradable no?
Qhov tseeb, thaum ntxov li 2017, ib qho kev pib los ntawm Ellen MacArthur Foundation rautxwv tsis pub oxidatively degradable yas ntimtau txais kev txhawb los ntawm ntau tshaj 150 lub tuam txhab thiab cov koom haum, suav nrog cov npe nrov: Unilever, Nestlé, thiab Pepsi, ib puag ncig NGOs Greenpeace thiab WWF, thiab M&S.
Yog li, vim li cas thiaj muaj kev hu mus tas li txwv tsis pub oxidatively degradable plastics thoob ntiaj teb nyob rau xyoo tas los no?
01
Dab tsi yog oxidatively degradable yas?
Raws li ib tug rechaw nres nkoj los ntawm European Plastics Association (Plastic Europe) [2],oxidatively degradable plastics (Oxo-degradable plastics) yog raws li traditional plastics, ntxiv chemical additives los ua kom lawv degrade nyob rau hauv aerobic tej yam kev mob, Thiab ceev decomposition nyob rau hauv lub teeb thiab / los yog kub, nws kuj tau hais tias ib tug tsim nyog lub npe rau oxidative degradable plastics tej zaum yuav thermo- lossis photo-fragmentable plastics.
Ib puag ncig kev siab hlub Ellen MacArthur Foundation tau hais hauv nws cov lus hais tias oxidatively degradable plastics thiab cov ntaub ntawv zoo sib xws tau muag hauv ntau lub npe, suav nrog oxidatively biodegradable, yees duab / thermal degradable, Plastics uas tuaj yeem oxidatively tawg los yog muaj cov tshuaj tiv thaiv oxidative, thiab lwm yam. cov ntsiab lus tuaj yeem tsis meej pem.Raws li cov ntaub ntawv pov thawj muaj, cov ntim yas uas lees tias muaj cov tshuaj ntxiv (ob qho tib si organic thiab inorganic) uas ua kom cov biodegradation, nrog rau cov enzyme-mediated degradable plastics, kuj tuaj yeem tsim teeb meem zoo ib yam li oxidatively degradable plastics.
02
Kev phom sij ntawm oxidatively degradable plastics
Raws li United Nations Environment Programme's "Biodegradable Plastics thiab Marine Litter" qhia [3],Qhov pib degradation ntawm oxidatively degradable plastics tuaj yeem tsim ntau qhov me me (piv txwv li microplastics), tab sis txoj hmoo ntawm cov khoom me me no tsis paub. .Raws li nrog rau tag nrho cov degradation, tus nqi thiab qhov luaj li cas ntawm cov yas tawg thiab hloov los ntawm cov kab mob yog nyob ntawm ib puag ncig ib puag ncig.Txawm li cas los xij, tsis muaj pov thawj pom tseeb rau pej xeem tias, tshwj tsis yog muaj kev sib xyaw ua ke, oxidatively degradable plastics tuaj yeem ua tiav mineralized thiab degraded nyob rau hauv ib puag ncig ntuj.
Daim duab. Cov khib nyiab yas hauv dej hiav txwv
Ib qhov kev ntsuam xyuas tsoomfwv UK xyoo 2010 tau xaus qhov ntawdKev cuam tshuam ib puag ncig ntawm oxidatively degradable plastics tsis tau txo qis piv rau cov khoom siv niaj hnub. Cov kev xaiv pom zoo rau kev pov tseg cov khoom pov tseg oxidatively degradable plastics yog incineration (nyiam dua) lossis pov tseg. "Cov oxidatively degradable plastics tsis degrade rau 2-5 xyoo, thiab lawv tseem pom cov pov tseg kom txog thaum lawv degrade."
Thaum lub Plaub Hlis Ntuj xyoo no, ib tsab ntawv tshawb fawb tau tshaj tawm los ntawm University of Plymouth tau qhia tias ntau hom hnab yas uas tau thov kom degradable tau muab tso rau hauv qhov chaw qhib, av, dej hiav txwv thiab chaw kuaj mob, thiab lawv cov kev cuam tshuam degradation raug saib xyuas rau 3 xyoos.Cov txiaj ntsig tau pom tias ntxiv nrog rau kev sib xyaw ua ke, kev degradation ntawm cov yas degradable yog qhov txaus siab, thiab cov yas kho los ntawm lwm txoj kev (xws li oxidative biodegradation) tsis txaus siab.
Daim duab qhia tau hais tias oxidative biodegradable hnab yas khaws cia rau hauv seawater ib puag ncig (daim duab sab saum toj) thiab av ib puag ncig (duab hauv qab) rau 3 xyoos,
Nws tsis muaj teeb meem los nqa cov khoom hnyav 2.25 kg (Duab: Pab pawg tshawb fawb ntawm University of Plymouth)
Tsis tas li ntawd, oxidatively degradable plastics tsis haum rau composting ib puag ncig.Composting yuav tsum tsis tsuas yog cov ntaub ntawv uas biodegradable, tab sis kuj hais tias cov ntaub ntawv no nws thiaj li los ua ib feem ntawm cov chiv thiab muab cov as-ham rau cov av. Kev tshawb fawb tau pom tias oxidatively degradable plastics tsis haum rau txhua hom kev sib xyaw lossis anaerobic digestion thiab tsis ua raws li EU cov qauv ntim khoom ntim tam sim no. Cov khoom seem ntawm cov yas thiab cov microplastics ntawm oxidatively degradable plastics yuav cuam tshuam qhov zoo ntawm composting.