Long-term performance of wastewater gardens: follow-up on the status of the wastewater garden in Temacine – Algeria

ABSTRACT This work investigated the long-term performance of a small wastewater garden (WWG) system for treating municipal wastewater, which has been operating continuously since 2007. The studied system consisted of a horizontal subsurface flow (HFCW) and treated a flow rate of 15 m3/day. Results from 15 years of operation showed that the system has an average removal efficiency of 90.76, 85.12, 89.43, 66.87, 94.74, and 94.74% for total suspended solids (TSS), chemical oxygen demand (COD), biochemical oxygen demand (BOD5), nitrites (NO2–), nitrates (NO3–), and orthophosphates (PO43−), respectively. The high efficiency of the WWG plant was achieved during 2018–2022 compared to the two first years of operation (apart from the TSS). It was noted that the removal of BOD5, NO2–, NO3–, and PO43− has been improved in the last years of operation. The elimination COD remained relatively consistent between the initial and present period of operation. The finding confirms the high efficiency in the long-term operation of municipal wastewater treatment. Thus, it can serve as a suitable solution for small communities, especially in arid climate areas.