Hybrid wastewater treatment system using anaerobic microorganisms and reed (Phragmites communis)

A small hybrid wastewater treatment system consisting of a settling tank in series with an anaerobic filter-reed (Phragmites communis) treatment cell was evaluated and compared with a similar plant-free system. Data demonstrated that by combining anaerobic filters, also referred to as attached film filters, and vascular aquatic plants a synergistic effect is produced which increases the treatment efficiency of each individual system. The plant-free system reduced the BOD₅ from 114 to 31 mg/l in 6 h as compared to a reduction of 110 to 9 mg/l in the anaerobic filter-reed system in the same length of time. The BOD₅ and TSS after 24 h in each component of plant-free system were reduced from 114 mg/l to 14 mg/l and 51 to 15 mg/l, respectively. Under the same conditions, the hybrid system reduced the BOD₅ from 110 to 3 mg/l and the TSS from 68 to 6 mg/l. The hybrid system also reduced the total Kjeldahl nitrogen (TKN) from 16.1 to 2.9 mg/l, total phosphorus (TP)from 4.4 to 2.0 mg/l, and the ammonia (NH₃-N)from 12.4 to 0.6 mg/l after 24 h of exposure while the plant-free system demonstrated insignificant reduction of these components.