Treatment of domestic wastewater by vertical flow constructed wetland planted with umbrella sedge and Vetiver grass.

The aim of this study was to investigate the efficiency of wastewater treatment by vertical flow constructed wetland systems under different hydraulic loading rates (HLR). The comparison of two types of plants, Cyperus alternifolius (Umbrella sedge) and Vetiveria zizanioides (Vetiver grass), was also conducted. In this study, six circular concrete tanks (diameter 0.

Effect of dosing regime on nitrification in a subsurface vertical flow treatment wetland system.

In this study, the effect of dosing regime on nitrification in a subsurface vertical flow treatment wetland system was investigated. The experimental unit was composed of four circular concrete tanks (1 m diameter and 80 cm deep), filled with gravel (1-2 cm) and planted with Cyperus alternifolius L. Synthetic wastewater with average chemical oxygen demand (COD) and ammonia nitrogen of 1,151 and 339 mg/L was fed into each tank.

Response of Salvinia cucullata to high NH4(+) concentrations at laboratory scales.

Growth, morphology, NH(4)(+) uptake and mineral allocation in Salvinia cucullata Roxb. ex Bory grown with different amounts of NH(4)(+) were investigated. Plants of uniform size were grown on full strength Smart and Barko medium with different NH(4)(+) concentrations (0.

Using a compact combined constructed wetland system to treat agricultural wastewater with high nitrogen.

The objectives of this study were to find appropriate conditions for nitrogen removal by a compact combined constructed wetland system and to evaluate the removal rate constant in a tropical climate. This study will present suitable operating conditions for a combined system to treat pig farm wastewater containing high ammonia-nitrogen. Four laboratory-scale combined constructed wetland units (0.

Treatment of agricultural wastewater in two experimental combined constructed wetland systems in a tropical climate.

Two designs of experimental combined constructed wetland systems were constructed: vegetated (Scirpus grossus Linn) subsurface horizontal flow bed followed by a vegetated vertical flow bed and a vegetated vertical flow bed over an unvegetated horizontal flow sand bed. The systems were used to compare the nitrification/denitrification efficiency in a tropical climate which has temperatures above an average of 25 degrees C throughout the year. The effluent from a biogas digester of pig farm wastewater with TKN and COD concentrations of approximately 400 and 1,000 mg/L was fed every 4 hours intermittently.

Nitrogen removal in a combined system: vertical vegetated bed over horizontal flow sand bed.

Pig farm wastewater creates various problems in many areas throughout Thailand. Constructed wetland systems are an appropriate, low cost treatment option for tropical countries such as Thailand. In this study, a combined system (a vertical flow bed planted with Cyperus flabelliformis over a horizontal flow sand bed without plants) was used to treat settled pig farm wastewater.