Iranian Researchers Use Native Reed Plant to Purify Urban Waste Leachate

‘Studying the effectiveness of the combined system of modified septic tank and artificial wetland with subsurface flow to treat the leachate of Hamadan waste disposal site’ is the title of Sonia Chavoshi's doctoral thesis which was completed with the support of the National Science Foundation of Iran.

“Due to the high concentration of chemical and microbial pollutants in the leachate and the health and environmental impacts caused by it, and the lack of facilities in the urban waste landfills that are often located in the suburban areas, using the natural purification methods with the help of plants (wetland) which prevent pollutants from entering the environment and are compatible with existing conditions and facilities is inevitable,” Chavoshi said.

“In this study, we made efforts to design and implement the purification process by using native reed plant (Phragmites australis) and taking advantage of the natural potential of the region with the lowest amount of energy consumption and without the need for expert personnel to manage the system,” she noted.

Phragmites australis, known as the common reed, is a species of flowering plant in the grass family Poaceae. It is a wetland grass that can grow up to 20 feet (6 metres) tall and has a cosmopolitan distribution worldwide.

Phragmites australis commonly forms extensive stands (known as reed beds), which may be as much as 1 square kilometre (0.39 square miles) or more in extent. Where conditions are suitable it can also spread at 5 metres (16 feet) or more per year by horizontal runners, which put down roots at regular intervals. It can grow in damp ground, in standing water up to 1 m (3 ft 3 in) or so deep, or even as a floating mat. The erect stems grow to 2–4 m (6+1⁄2–13 ft) tall, with the tallest plants growing in areas with hot summers and fertile growing conditions.

The leaves are 18–60 centimetres (7–23+1⁄2 in) long and 1–6 cm (1⁄2–2+1⁄4 in) broad.

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