Soil contamination from film debris following the prolonged application of mulching film has emerged as a worldwide concern.However,the extent that mulching films contribute to soil microplastics,and the spatial distr...Soil contamination from film debris following the prolonged application of mulching film has emerged as a worldwide concern.However,the extent that mulching films contribute to soil microplastics,and the spatial distribution of soil contamination from film debris remain unclear.In this study,the cotton field in Xinjiang(China),which underwent film mulching for a prolonged period of 5−30 years,was selected as the research location.A total of 360 soil samples were collected,aiming to study the spatial distribution characteristics of mulching film debris pollution.The samples were extracted using the density flotation method combined with stereomicroscopic;the source,composition,abundance,and distribution characteristics of soil MPs were identified by the scanning electron microscopic,and Fourier transform infrared spectroscopic analyses.In soil mulched for a 30 year period,the abundance of microplastics across the studied soil depth(0−60 cm)was 78.51±2.57 n/(100 g).Theμ-FTIR analyses revealed that the composition of the microplastics matched that of polyethylene materials.Therefore,plastic mulching could be inferred as a major contributor to microplastic pollution in agricultural lands.Overall,it is necessary to study the distribution characteristics of plastic film remaining for further study of plastic pollution in farmland soils.展开更多
The corrosion product films of two kinds of B30 tubes(similar to CDA 715)exposed to seawat- er for various periods of time were investigated by SEM,AES and XPS.The results show that the pro- tective corrosion product ...The corrosion product films of two kinds of B30 tubes(similar to CDA 715)exposed to seawat- er for various periods of time were investigated by SEM,AES and XPS.The results show that the pro- tective corrosion product film is thin,uniform and adherent.FeOOH is found to be present in the film surface,which confirms the hypothesis that iron hydroxide segregates at the surface of the film.The FeOOH promotes Ni enrichment in the corrosion layer by preventing Ni from running off.The corro- sion product film with no protectiveness is of lay- ered structure,loose and bad adherence.The for- mer film is formed through direct oxidation and the latter by precipitation and redeposition from dis- solved species.展开更多
基金The authors acknowledge the financial support by the National Natural Science Foundation of China(Grant Nos.32060288 and 32160300)the Bingtuan Science and Technology Program(Grant No.2021CB010).
文摘Soil contamination from film debris following the prolonged application of mulching film has emerged as a worldwide concern.However,the extent that mulching films contribute to soil microplastics,and the spatial distribution of soil contamination from film debris remain unclear.In this study,the cotton field in Xinjiang(China),which underwent film mulching for a prolonged period of 5−30 years,was selected as the research location.A total of 360 soil samples were collected,aiming to study the spatial distribution characteristics of mulching film debris pollution.The samples were extracted using the density flotation method combined with stereomicroscopic;the source,composition,abundance,and distribution characteristics of soil MPs were identified by the scanning electron microscopic,and Fourier transform infrared spectroscopic analyses.In soil mulched for a 30 year period,the abundance of microplastics across the studied soil depth(0−60 cm)was 78.51±2.57 n/(100 g).Theμ-FTIR analyses revealed that the composition of the microplastics matched that of polyethylene materials.Therefore,plastic mulching could be inferred as a major contributor to microplastic pollution in agricultural lands.Overall,it is necessary to study the distribution characteristics of plastic film remaining for further study of plastic pollution in farmland soils.
文摘The corrosion product films of two kinds of B30 tubes(similar to CDA 715)exposed to seawat- er for various periods of time were investigated by SEM,AES and XPS.The results show that the pro- tective corrosion product film is thin,uniform and adherent.FeOOH is found to be present in the film surface,which confirms the hypothesis that iron hydroxide segregates at the surface of the film.The FeOOH promotes Ni enrichment in the corrosion layer by preventing Ni from running off.The corro- sion product film with no protectiveness is of lay- ered structure,loose and bad adherence.The for- mer film is formed through direct oxidation and the latter by precipitation and redeposition from dis- solved species.
