Sudy On The Removal Of Microplastics Form Water Bu Polymeric Aluminum Chloride

In recent years,microplastics have been frequently detected in water bodies around the world,and even in many animals and human bodies.After decomposition of plastics into microplastics,their surface area ratio increases,which can attach to microorganisms and have hydrophobic properties,so that microplastics can adsorb toxic substances with hydrophobic properties,and the microplastics attached to toxic substances are ingested by aquatic organisms and enriched through the biological chain,and the microplastics themselves can cause mechanical damage to small organisms.Microplastics can also affect marine ecology by influencing the population size and structure of aquatic organisms.As a new type of pollutant,the removal of microplastics is an urgent task.In this study,the flocculation method was used to remove microplastics by using polymerized ferric sulfate and polymerized aluminum chloride to flocculate polyethylene,polypropylene,polystyrene,polyvinyl chloride and polyethylene terephthalate,which are present in the environment.The flocculants were characterized before and after flocculation with the help of transmission electron microscopy and nano-particle size potentiometry,respectively,to explore their flocculation mechanisms,and the studies were as follows.(1)The correlation coefficients R~2 between the concentration and absorbance of polyethylene,polypropylene,polystyrene,polyvinyl chloride and polyethylene terephthalate were 0.9950,0.9995,0.9990,0.9996 and 0.9980,respectively,after the interference of flocculants in solution was removed by the background difference method,and UV spectroscopy can be used as an effective method to detect the concentration of microplastics.(2)The flocculation and precipitation of microplastics by polymerized ferric sulfate will be affected by the solution pH,the starting concentration of microplastics,the concentration of polymerized ferric sulfate,and the concentration of inorganic ions in the water column.The optimum flocculation and precipitation effect of polymerized ferric sulfate is 50mg/L of microplastics,500 mg/L of flocculant,and 5.0 pH.Increase of pH will lead to decrease of removal effect;too high or too low concentration of microplastics will weaken the flocculation and precipitation effect;too high concentration of flocculant will inhibit the flocculation and precipitation effect,and too low will lead to weaken the flocculation and precipitation effect;inorganic ion concentration in ambient water will also promote the flocculation and precipitation effect.The concentration of ions in the environmental water body will also promote the flocculation and precipitation effect.The removal of microplastics by polymeric aluminum chloride is influenced by the pH of the solution and the concentration of polymeric aluminum chloride.The best flocculation and precipitation effect of polymeric aluminum chloride is the starting concentration of microplastics at 75 mg/L or 50 mg/L,the flocculant concentration at 500mg/L,and the pH at 9.0.The increase of solution pH will promote the flocculation and precipitation effect;too high flocculant concentration will inhibit the flocculation and precipitation effect,and too low will lead to the weakening of the flocculation and precipitation effect;the inorganic ions in the water body and the starting concentration of microplastics will affect the flocculation and precipitation effect of polymeric aluminum chloride.Aluminum chloride flocculation and precipitation of microplastics does not have a significant effect.(3)The removal rate of polyethylene,polypropylene,polystyrene,polyvinyl chloride and polyethylene terephthalate in ambient water was shown as seawater>river water>lake water,and the removal rate was above 85%,and the ion concentration in water had a facilitating effect on the flocculation and precipitation of microplastics by polymerized ferric sulfate.Polymeric aluminum chloride flocculation on polyethylene,polypropylene,polystyrene,polyvinyl chloride and polyethylene terephthalate in environmental water bodies removal rate are above 95%,the ions in the water body has little effect on the removal rate.The effect of polymeric aluminum chloride flocculation and precipitation in environmental water bodies is better than that of polymeric ferric sulfate.