Influence of Aquatic Plants and Flow Rate on Physico-chemical Characteristics of Sewage Effluent Treated through Constructed Wetland Technology

Aims: To evaluate the influence of aquatic plants and flow rate on physico-chemical properties of sewage effluent with constructed wetland technology.

Study Design: Randomized block design

Place and Duration of Study: Department of Environmental Sciences, Tamil Nadu Agricultural University, Coimbatore - 03 and June 2020 – Dec 2020

Methodology: Constructed wetland (CW) model was designed and three different aquatic plants viz., Canna indica, Arundo donax, and Xanthosoma sagittifolium were used for the study. Two different flow rates viz., 5ml/min and 10 ml/min were compared for assessing their influence in treating sewage effluent in the constructed wetlands.

Results: Among the aquatic plants, the pollutants like BOD, COD,TDS and TSS in the sewage effluent were declined and found to be 320, 1220, 666, 22 mg L-1 in Canna indica and 340, 1380, 866, 36 mg L-1 in Xanthosoma sagittifolium and 340, 1380, 866, 36 mg L-1 in Typha angustifolia utilized treatments at flow rates 5 ml/min respectively during 7th day retention time. Similar decreasing trend was observed in BOD, COD, TDS and TSS of the sewage effluent at flow rates of 10 ml/min.

Conclusion: Based on the study, it was evident that constructed wetland (CW) with Canna indica, Xanthosoma sagittifolium and Typha angustifolia found to perform better under flow rate of 5 ml/min for treating sewage effluent at the retention time of 7 days.