Toxic Effects Of Single And Combined Pollution Of Graphene-sulfadiazine On Wheat

Because of its unique physical and chemical properties,nano-materials are widely used in materials,electronics,pollution remediation,cosmetics,medicine and other fields.With the increasing use of nano-materials,which in the environment will inevitably produce complex effects with other pollutants.Sulfonamides are one of the most widely produced and used antibiotics in China.Studies have shown that they have certain residues in the environment and have certain toxicity to plant growth.In order to assess the potential risks to the ecosystems of nanomaterials and sulfadiazine in the environment,two different nanomaterials of graphene and graphene oxide were selected,combined with sulfadiazine,to investigate the single and combined ecological toxicity to plant germination and growth.The main findings are as follows:The single and combined eco-toxicological of rGO/GO-SD on the germination and growth of wheat were studied by acute toxicity experiment and plant growth experiment.The results showed that under the single pollution,the growth inhibition rate of plant was increased with the increase of SD concentration.Under the single stress of rGO,the growth of the plant was promoted.When the rGO concentration was 200 mg/ L,Plant root growth was slightly inhibited.Under GO single pollution,the elongation inhibition rate of crop was slight decreased with the increase of GO concentration,the root elongation inhibition rate and the growth inhibition rate of roots and shoots increased with the increase of GO concentration,inhibition rate increases.Under the combined pollution,SD plays a primary role,that is,at the same rGO/GO concentration,with the increase of SD concentration,the inhibition effect was enhanced.The existence of rGO reduces the toxic effect of SD on plant growth while GO increases the toxicity of SD to plant growth effect.The toxicity of GO to plant growth is greater than that of rGO.The possible reason is that GO is adsorbed at the root of the plant and affects the growth of plant roots.The changes of MDA content and antioxidant enzyme system in different stages of rGO-SD single and combined pollution were different.The content of MDA in plant roots and shoots increased with the increase of SD concentration,while the content of MDA in shoot increased first and then decreased.The content of MDA in root increased with the increase of rGO concentration.Under the condition of compound pollution,the content of MDA in roots was the highest when the concentration of SD was 50 mg/L.The concentration of antioxidant enzymes in the plant with the concentration of pollutants,the overall changes are not obvious.Under the single and combined pollution conditions of SD and GO-SD,the content of MDA in the roots were significantly lower than that in the aerial part.Under the single stress,the content of MDA in roots and shoots were significantly lower than that in the roots.The activity of POD in roots and shoots increased with the increase of GO concentration,its activity increased first and then reduced.Under the effect of compound pollution,the content of MDA in the contaminated roots increased with the increase of SD concentration,while the MDA in the shoots and shoots were opposite.Whether it is SD single or SD-GO compound pollution,the activities of SOD activity in the plant were activated,and the activities of POD were in the active state of the plant germination period,and the activity of SOD was increased with the increase of SD concentration,while the activity of POD in the shoots of the growing season was lower than that of the control,in the state of suppression.