Microalgae have become popular absorption materials; therefore many studies have been conducted in order to deeply understand the metal absorption characteristics and growth rate of microalgae in water. Hence, the removal of metal elements, such as iron, manganese and copper, by four common cyanobacteria and green algae were investigated in this study. The results showed that all microalgae could grow normally, and Microcystis aeruginosa grew best. Furthermore, during the growth of microalgae, the pH values of the four groups gradually increased to 10 and then maintained. Different microalgae can remove iron, manganese and copper in water to some extent, while, Microcystis aeruginosa showed the best removal effect. The new observation is that with the increase of time, the treatment effect gradually becomes better, and it is the best on the 4th day. However, this study provides a scientific basis for the simultaneous treatment of microalgae culture and heavy metal polluted wastewater.

Microcystis aeruginosa is a common microalgae in nature. It is also the dominant algae species to form freshwater blooms. Water bloom will do harm to water environment, so this paper studies the growth law of Microcystis aeruginosa. Single factor experiment and orthogonal experiment were carried out by changing the influencing factors such as photoperiod, initial dosage and initial pH. The results showed that within a certain range, the larger the photoperiod, the larger the initial dosage, the higher the initial pH, the better the growth of Microcystis aeruginosa and the greater the increase of pH value. This study is to deepen the understanding of the growth law of Microcystis aeruginosa. It provides a scientific basis for controlling the growth of Microcystis aeruginosa.