REMOVAL EFFICIENCY OF NITROGEN, PHOSPHORUS AND HEAVY METALS ASSOCIATED WITH SWINE WASTEWATER USING AQUATIC MACROPHYTES

Abstract

Wastes from breeding farms have globally increased greenhouse gases and caused a serious pollution to aquatic environments. Biogas treatment polymer bags could significantly reduce organic compounds; however, they could not effectively treat other pollutants in animal wastewater. The objective of this study was to assess removal efficiency of salinity and pollutants associated with pig wastewater using aquatic macrophytes. Four macrophytes namely Acrotichum aureum, Eleocharis dulcis, Typha domengensis, and Limnophyton obtusifolium and a soil control without vegetation were randomly assigned into fifteen mesocosms (1.2 x 0.7 x 0.6m) with 3 replicates for each treatment. Pig wastewater was filled continuously into input chambers of mesocosms in every three day with 5 liters. Water samples were collected from output chambers with 60 and 120 days after treatment while soil and vegetation samples were collected at the beginning and the end of the experiment. The results showed that E. dulcis, T. domengensis, and L. obtusifolium were dominant in removal of N, P, Cu and Zn and suspended solids as well; E. dulcis and T. domengensis significantly increased the dissolved oxygen; whereas the treatment of L. obtusifolium species showed the best efficiency in salt-ion removal. Pollutants of N, P, Cu and Zn tend to accumulate more in the macrophyte roots than in their leaves. Accumulation of N, P, Cu and Zn in the L. obtusifolium’s biomass is the highest compared with other treatments. From findings, it is suggested that a combination of three aquatic macrophytes including E. dulcis, T. domengensis, and L. obtusifolium could establish a constructed wetland system to directly treat pollutants of livestock wastewaters