The role of Sand, Marble chips and Typha latifolia in domestic Wastewater Treatment - A Column Study on Constructed Wetlands

The relative importance of sand, marble chips and wetland plant Typha latifolia is evaluated in constructed wetlands (CWs) for the treatment of domestic wastewater intended for reuse in agriculture. The prototype CWs for the experiments are realized in polyvinyl chloride (PVC) columns, which are grouped into four treatments viz. sand (<2 mm) + Typha latifolia (cattail), sand, marble chips (5-20 mm) + cattail, and marble chips. The removal percentage of organic and nutritional pollutants from the wastewater is measured at varying hydraulic retention time (HRT) in the columns. The statistical analysis suggests that, the main effects of sand and cattail are found to be significant (p<0.05) for the removal of biological oxygen demand (BOD) and chemical oxygen demand (COD) from the wastewater. The presence of cattail significantly (p<0.01) contributes for the conversion of total nitrogen in wastewater into NO3(-) by fostering the favorable microbes for the nitrification. The rem...