Microplastics effect on the physicochemical parameters and interaction with spirulina platensis microalgae in Al-Dalmaj Marsh, Iraq

Abstract

Abstract Al-Dalmaj Marsh is considered one of the important brackish water body in Iraq as it has a huge fish wealth in addition to the possibility of investment in the place for tourism due to the presence of many archeological and historical sites nearby the Al-Dalmaj Marsh such as the ancient city of Nippur that demand to monitor the water quality of Al-Dalmaj Marsh and assure to be clean and pollution-free all the time. The physicochemical properties of Al-Dalmaj Marsh water (Temperature, pH, Conductivity, and Dissolved oxygen) were changed from October 2019 to October 2020 due to the decrease in the water level. The present study showed that the water body of the Al-Dalmaj Marsh has microplastics pollution in a ratio reached to 2.6% especially in the south and east sites of the study (S1, S2, S6, S7, S8). Moreover, different types of microplastics (MPs) were characterized using FTIR spectroscopy in the collected samples from the eight sites and it is found that the transparent Polyethylene (PE) is the most abundant MPs. MPs concentrations in the collected samples were changed from (1.9 x103- 2.8 x103) in October 2019 to (2.8 x103-3.6 x103) items/km2 in October 2020. The growth and chlorophyll content of the Spirulina platensis microalgae showed a clear decrease by adding the different types of MPs and PVC showed the most adverse effect on these two parameters. Besides, Spirulina p. showed great potential to uptake and aggregate MPs particles from the culturing media and work as a bioremediation agent.