Laboratory studies have indicated that calcite may be used in separate, exchangeable filter units in constructed wetland systems to remove phosphorus. Based on these studies we built a full-scale experimental constructed wetland with a calcite-based filter unit to study its performance, under real-life conditions. The system consists of a 2-m3 sedimentation tank and two vertical flow constructe...

Constructed wetlands are gaining increased attention for treatment of nonpoint sources of water pollution. Although constructed wetlands have been utilized for wastewater treatment in warm climates, their performance in cold climates has been questioned. A surface-flow wetland, designed to treat 2.65 m super(3) d super(-1) of milkhouse wastewater, was constructed on the University of Connecticu...

Chromium is a pollutant present in tannery wastewater, its removal is necessary for protection of the environment. Penisetum purpureum, Brancharia decumbens and Phragmites australis were grown hydroponically in experimental gravel beds to determine their potential for the phytoremediation of solutions containing 10 and 20 mg Cr dm. These concentrations, similar to tannery wastewater after initi...

Removal of nitrogen (N) is a critical aspect in the functioning of constructed wetlands (CWs), and the N treatment in CWs depends largely on the presence and activity of macrophytes and microorganisms. However, the effects of plants on microorganisms responsible for N removal are poorly understood. In this study, a three-stage surface flow CW was constructed in a pilot-scale within monospecies ...

The efficiency of a series of wetland colonized with Eichhornia crassipes and Salvinia molesta to treat the effluent of a giant river prawn (Macrobrachium rosenbergii) broodstock pond was evaluated in this study. The experimental design was completely randomized and was performed in 9 rectangular tanks (1.6 m3) with three treatments (constructed wetlands) and three replicates. The treatment typ...

A free water surface wetland treating domestic wastewater for the village of Pompia in Southern Crete was constructed in early 1999 and became operational on September 1st of the same year. The total surface area of the wetland was 5700m2, designed for 1200 people equivalent. Arundo donax (giant reed) was used for the vegetation of the bed. Approximately 4-6 plants were introduced per square me...

A horizontal subsurface flow constructed wetland was investigated after eight years of residential wastewater discharge (150 person equivalents). Twenty core samples distributed over the entire wetland were taken from the soil matrix. The distribution pattern of phosphorus (P) accumulation in the substrate of the wetland was determined using kriging technique and P sorption was related to the c...

Plants that accumulate a small percentage of metals in constructed treatment wetlands can contribute to remediation of acidic, metal contaminated runoff waters from coal mines or processing areas. We examined root and shoot concentrations of elements in four perennial wetland species over two seasons in mesocosm wetland systems designed to remediate water from a coal pile runoff basin. Deep wet...

AIMS To correlate microbial community composition and water quality changes within wetland cells containing varying plant densities and composition in a free water surface (FWS) constructed wetland. METHODS AND RESULTS Water chemistry was monitored weekly for nitrate, orthophosphate, and suspended solids, at various sites throughout the wetland for 6 months. Treatment ponds with 50% plant cov...

This paper illustrates the role of plants to assist the treatment of water pollution in man-made wetlands in tropical and temperate climates. It also considers the potential for environmental education of these wetland systems. The management and natural treatment of pollution is described in the Mai Po Marshes, Hong Kong and a wetland in London which is also an important site for birds. The de...