Comparison of wastewater treatment performance: traditional vs. baffled horizontal flow constructed wetlands.

Abstract

This study investigated two lab-scale CW systems, traditional horizontal flow (HFCW) and baffled horizontal flow (BHFCW), as a treatment process in CWs filled with porous gravel and planted with Typha latifolia. BHFCW achieved average removal efficiencies of 88.65, 86.00, and 84.17% for TSS, BOD₅, and, COD, respectively. Meanwhile, in HFCW, the removal efficiencies for these pollutants were 88.48, 81.07, and 77.89%, respectively. The results demonstrated that BHFCW is a reliable alternative to enhance the treatment performance of nitrogen in CWs compared to HFCW. The BHFCW removals were the best among all units: 76.59, 86.39, and 92.22% for NH₄⁺, NO₃^-, and NO₂^-, respectively. Statistical differences were observed when comparing removal effects between HFCW and BHFCW (p < 0.05). Nevertheless, 84.15% of orthophosphate was successfully removed in HFCW. The introduction of baffles augmented the flow path of wastewater. 14% and one-day reduction in the area and HRT of BHFCW was noted relative to the HFCW respectively. The two types of flow used are suitable for wastewater treatment. This investigation of flow type showed a role in the absorption and retention of pollutants. In addition, the BHFCW could generate interest in a treatment option.