ANALYSIS AND PRELIMINARY STUDY OF TREATMENT OF LEACHATE BY WATER HYACINTH

摘要

Sanitary landfill leachates are considered as heavily polluted industrial wastewater and not easily defined by certain characters since their compositions are characterized by their origins and their lifetimes. Chemical composition of leachates generally consists of organic matter (OM); suspended solid (SS); concentrated nutrients such as phosphorus compounds, nitrogen compounds and small amounts of metals like Fe, Pb, Zn, Sn, Cu, Ni, Cr. The leachates are known to cause pollution of surface and ground water which are revealed by over-saturations of NH_4~+ (＞ 600 mg/l), NO_3~-^s(＞ 30 mg/l), COD (＞ 1000 mg/l), BOD (＞ 100 mg/l). Therefore, treatment to reduce this pollution is required.In this research, Water hyacinth (Eichhornia crassipes) plants, being able o grow in extremely polluted environment, is used as biological treatment tool to clean up leachates. Experimental results show that about 80% of pollutants were treated. The treatment duration and plant density for each particular treatment depend on pollution level and pollutant composition of the leachate. The treated water is then usable as qualifying the industrial wastewater standard of Vietnam [6].