Visual Detection of Microplastics Derived from Plastic Mulch in Soil

Öz

This preliminary study aimed to visually investigate the presence and disturbance of microplastic particles among soil aggregate fractions (1000- 2000 µm - <0.053 μm) in a mulch applied soil. In the extraction of microplastics from the soil samples, two separate treatments were applied, by changing the order of applied solutions (NaCl-H2O2 and H2O2-NaCl), through density separation. In the first treatment, the soil sample was shaken first with a saturated NaCl solution, then filtered through the filter paper and the microplastics remaining on the filter paper were determined. Then, 30% H2O2 was added to the remaining soil sample. In the second treatment, H2O2 (30%) solution was applied first, and then saturated NaCl solution was added. Microplastics were counted and defined by stereo binocular microscope. In the first treatment 29 particles of 20g soil-1 and in the second treatment 16 particles of 20g soil-1 microplastics were found. Microplastics were found in all fractions and dominated form was “fiber” and in the form of 'round bead' were also found in the fraction smaller than 0.053 mm. As a result, in the extraction of microplastics, changing the order of application of solutions did not have a different effect on the extraction, showed that both treatments can be used for visual identification.

Anahtar Kelimeler

• Microplastics
• Soil
• Separation
• Stereo binocular microscope

Toprakta Plastik Malçtan Kaynaklanan Mikroplastiklerin Görsel Olarak Saptanması

Öz

Bu ön çalışmada, malç uygulanmış bir toprakta toprağın farklı agregat fraksiyonları (1000- 2000 µm - <0.053 µm) arasında mikroplastik partiküllerin varlığının ve dağılımının görsel olarak belirlenmesi amaçlanmıştır. Toprak örneklerinden mikroplastiklerin ekstraksiyonunda, uygulanan çözeltilerin sırası (NaCl-H2O2 ve H2O2-NaCl) değiştirilmiş ve yoğunluk ayrımı yapılarak iki ayrı işlem uygulanmıştır. İlk işlemde toprak örneği önce doymuş NaCl çözeltisi ile muamele edilmiş, ardından filtre kağıdından süzülerek filtre kağıdı üzerinde kalan mikroplastikler görüntülenmiştir. Daha sonra kalan toprak örneğine %30 H2O2 ilave edilmiştir. İkinci işlemde ise önce H2O2 (%30) çözeltisi uygulanmış ve ardından doymuş NaCl çözeltisi ilave edilmiştir. Mikroplastikler, binoküler bir mikroskopla görüntülenmiş ve görsel tanımlamaları yapılmıştır. İlk işlemde 20 g toprakta 29 parçacık, ikinci işlemde ise 16 mikroplastik parçacık bulunmuştur. Mikroplastiklerin tüm fraksiyonlarda bulunduğu ve baskın formun “lif” olduğu, ancak 0.053 mm'den küçük fraksiyonda “yuvarlak boncuk” şeklinde de olduğu belirlenmiştir. Sonuç olarak, topraktan mikroplastiklerin ekstraksiyonunda, çözeltilerin uygulama sırasının değiştirilmesinin ekstraksiyon üzerinde farklı bir etkisinin olmadığı, her iki işlemin de görsel tanımlama için kullanılabileceği ortaya konulmuştur.

Anahtar Kelimeler

• Mikroplastikler
• Toprak
• Ayırma
• Binoküler mikroskop

Kaynakça

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