Microscale Constructed Wetlands with Different Particulate Matters in their Substrates Exhibit Opposite Nitrogen Removal Performances

Excess suspended particulate matter (PM) in constructed wetland (CW) substrates may reduce the substrate porosity and thus affect pollutant removal performance. However, it remains unclear how different PMs nitrogen performance CWs. In this study, kaolin polystyrene (PS) were selected as two model added to CW at a concentration of 100 mg/L. Four CWs constructed, designated C-CW without PM addition, K-CW with M-CW mixed addition PS, PS-CW PS addition. The or showed no significant difference terms NH4+-N efficiency (p > 0.05), while NO3−-N TN was significantly improved but, contrast, considerably inhibited < 0.05). reduced substrates. There total solid quality among but had highest volatile content. mg/L increased activities nitrite reductase (NIR) nitrate (NAR) much higher relative abundance denitrifying bacteria, ammonia monooxygenase (AMO) oxidoreductase (NXR) four enzymes degrees M-CW, which nitrifying bacteria than that C-CW. conclusion, noteworthy effect on qualitatively (i.e., enhanced vs. inhibited) types PMs. This interesting important new finding could provide valuable information for better understanding evaluation role process during operation.