Effects Of Graphene Oxide On The Growth Of Larix Olgensis Seedlings And The Properties Of Dark Brown Forest Soil Under Cadmium Pollution

Graphene oxide is one of the most studied carbon nanomaterials.Due to its huge specific surface area and strong hydrophilicity,it has been widely used in daily production.With the wide application of graphene oxide,it naturally enters into the soil environment.The current"three wastes" of social industry,the use of pesticides and the emission of automobile exhaust have caused environmental pollution,leading to serious heavy metal pollution,especially cadmium pollution,which can have adverse effects on soil,animals and plants and even humans.Graphene oxide is likely to enter the cadmium polluted soil,which has an impact on the soil and plants.This study combined the two aspects and explored the effects of cadmium on the growth of Larix olgensis seedlings and dark brown forest soils,and the effects of graphene oxide on the growth of Larix olgensis seedlings and dark brown forest soil under cadmium contamination.Our aim is to provide a theoretical basis for comprehensive evaluation of the ecological and environmental effects of cadmium on dark brown forest soil and larch,and the effects of graphene oxide on cadmium-contaminated dark brown forest soil and larch.The main results of the study are as follows:1.Cadmium treatments affected the growth and physiological characteristics of Larix olgensis seedlings.Low concentration(?25mg/L)cadmium treatment promoted seedling growth,and high concentration(?25mg/L)had inhibitory effects on these seedlings.With the increase of Cd concentration,the root growth of Larix olgensis seedlings was inhibited.At 40 days,the MDA content of the leaves of Larix olgensis seedlings increased with the increase of cadmium concentration,and reached the maximum at 75mg/L cadmium treatment.Soluble protein and proline content decreased under low concentration(?5mg/L)cadmium treatments and increased under high concentration(?75mg/L)treatments.At 30 and 50 days,the contents of superoxide anion increased first and then decreased and then increased with the increase of cadmium concentration,while the contents of hydrogen peroxide showed the opposite trend,that is,first decreased and then increased and then decreased.With the increase of cadmium concentration,the total chlorophyll content and carotenoid content decreased first and then increased and then decreased.The above results indicated that the greater the damage to seedling growth as cadmium concentration increased.2.Graphene oxide treatment affected the growth and physiological characteristics of Larix olgensis seedlings under cadmium pollution.Low concentration(?100mg/L)graphene oxide treatments inhibited the growth of Larix olgensis seedlings and roots,and high concentration(?100mg/L)graphene oxide promoted seedling and root growth.The MDA content of the leaves increased at different times under the treatment of graphene oxide,and the variation range was:30d>20d>40d.With the increase of graphene oxide concentration,the relative electrical conductivity and MDA content of the leaves increased first and then decreased and then increased at 20 and 40 days,and decreased and then increased and then decreased at 30 days,decline first,then increase and then decrease.The content of soluble protein and proline showed a trend of decreasing first,then increasing and then decreasing.At 30 days,the content of superoxide anion and hydrogen peroxide showed a trend of first decreasing,then increasing and then decreasing.At 40 days,the total chlorophyll content and carotenoid content increased under low concentration(?50mg/L)graphene oxide treatments and decreased under high concentration(?50mg/L)graphene oxide treatments.The above results showed that low concentration(?100mg/L)of graphene oxide inhibited the growth of seedlings under cadmium contamination,but graphene oxide within a certain concentration range(100-500mg/L)could promote the growth of cadmium-contaminated seedlings.3.Both cadmium and graphene oxide treatment reduced the pH of Dark Brown Forest Soil to a certain extent,and most of them improved the availability of N,P,K nutrients in Dark Brown Forest Soils.Graphene oxide effectively reduced the content of available cadmium in Dark Brown Forest Soils with cadmium pollution,and absorbed certain cadmium in the soil,so as to reduce the impact of cadmium on Dark Brown Forest Soils and Larix olgensis seedlings.With the increase of time,the greater the change of available cadmium content in Cd-contaminated soil under the treatment of graphene oxide with different concentrations was greater.