Due to population growth and industrial development, many environmental problems have arisen.Water is one of the problems that has become a global crisis.The pollution of water sources around the world has caused a shortage of fresh water in different regions of this planet.The discharge of wastewater containing heavy and toxic metals such as iron, manganese, zinc, etc. in the environment has had a serious impact on the lives of humans and animals as well as aquatic life.In order to solve the environmental problems of heavy metals entering the water, in the present study we have evaluated and demonstrated the potential of microalgae as a bioabsorbent in the removal of heavy metals in wastewater.After screening several types of microalgae, in this research, Chlorellavgaris microalgae was used.Heavy metals in wastewater include iron, manganese, and zinc, and in this study, the possibility of removing these metals was investigated.This research also compares the biological removal of heavy metals in wastewater in two ways, bioaccumulation and biosorption. Various parameters such as concentration of metals, contact time of adsorbent and metals, amount of adsorbent dose were investigated.After the cultivation and production of biomass on a high scale, the obtained biomass was used as a bio-adsorbent in the removal of metals.The concentration of iron metal was considered in the range of 5 to 15 mg/liter, manganese 20 to 40 mg/liter, zinc 20 to 40. The pH value was considered equal to 8.5.The contact time in bio absorption mode was 10 minutes to 120 minutes and the culture temperature was considered 23 degrees Celsius. Biomass dose was used in bio absorption mode from 0.5 to 2 grams. In the case of bioaccumulation, the period of microalgae culture was considered to be 14 days.After performing the tests and also checking the BET, SEM, FT-IR tests, in the case of biological absorption, the amount of removal under optimal conditions of iron was equal to 83%, manganese equal t