In recent decades, more attention has been paid to various pollutants and their negative effects on the environment. One of these pollutants are also microplastics. They can be found in all ecosystems, and municipal wastewaters are also an important source of microplastics that enter the aquatic environment. Constructed wetlands (CW) are frequently used to treat municipal wastewater, however it is unknown how efficient are CW for removal of microplastics.
In the master's thesis, a horizontal subsurface flow laboratory CW with continuous flow was used for the treatment of municipal wastewater with the addition of microplastics (microbeads and fibers). Investigated retention of microplastics and their distribution in the CW as well as the effect of treatment efficiency of municipal wastewater.
It was observed that microplastics are efficiently retained in the CW, and only 0.288 % and 0.003 % of the total amount of microbeads and fibers, respectively, were found in the effluent. Most of the microplastics were retained in the initial part of the CW. The presence of microplastics did not significantly affect the removal of carbonaceous matter, ammonium and nitrate ions, but the concentration of nitrite ions decreased, and the concentration of phosphate ions increased after the addition of microplastics.
Results indicated that CW are an efficient barrier to the release of microplastics into the aquatic environment. However, the accumulation of microplastics can lead to changes in nutrient cycling and consequently, to changes in the efficiency of the system.
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