Investigation of the process of adsorption of heavy metals in coastal sands containing micro-plastics, with special attention to the effect of aging process and bacterial spread in micro-plastics

The chief purpose of this study is to investigate the process of adsorption of heavy metals in sands containing microplastics due to aging and bacterial culture. For this purpose, first, the experiment’s conditions were determined by reviewing previous studies and examining the effects of factors on the duration of bacterial culture and UV radiation. Finally, the test conditions were determined as follows: 25 g of adsorbent in 250 ml solution containing 50 mg/l of lead, cadmium, copper, zinc, chromium, and nickel, 750 micrograms of microplastic, bacterial culture time two days, aging time with UV light 14 days. Results of the study show that the addition of virgin microplastics has little effected on increasing the adsorbent strength, except in the case of nickel which reduces adsorption strength. The aging process increases the absorption of all studied metals by up to 60%. Bacterial culture without an aging process reduces the absorption of nickel and cadmium. Simultaneous use of bacterial culture and aging increases the adsorption power by up to 80% for all metals.