Winery and distillery wastewater treatment by constructed wetland with shorter retention time

摘要

The rationale for using constructed wetlands for treating wastewater is that wetlands arennaturally among the most biological active ecosystem on earth. The aim of the study wasnto determine the impact of shorter retention time on the performance of constructed wetlandnin terms of Chemical Oxygen Demand (COD) and other elements removal. The application ofnwastewater with retention time of seven days as well as the evaluation of water quality afterntreatment at Goudini experimental wetland was carried out throughout the year. The resultsnhad shown an overall average COD removal of 60% throughout the year. Results also showednreasonable removal of other elements namely; potassium, pH, nitrogen, electrical conductivity,ncalcium, sodium, magnesium and boron from the wastewater by constructed wetlands.nThe results showed low COD removal during July until September after which it improvedntremendously. The reason for low COD removal during first three months could be attributednto the fact that there was no gradual increase of wastewater application to the wetlandsni.e. from 4,050 litres per day to 8,100 litres per day. The results had showed that constructednwetland as a secondary treatment system is effective in terms of COD and other elementsnremoval from winery and distillery wastewater. COD removal throughout the year was 60%nwith seven days retention time. When compared with previous studies that showed 80%nCOD removal within 14 days retention time, therefore the 60% removal is very criticalnto wine industries as more wastewater will be applied to the system.