EFFICIENCY OF DUCKWEED (LEMNA MINOR L.) IN PHYTOTREATMENT OF WASTEWATER POLLUTANTS FROM BASRAH OIL REFINERY

This study involved a laboratory experiment on the efficiency of the plant duck weed (Lemna minor L.) in improving the quality of wastewater of Basrah Oil Refinery. The efficiency was tested by measuring some of physicochemical characteristics of the control and plant treatments after each seven days. The experiment lasted for a month, and recorded the rates of reduction. The highest rates of reduction were for heavy metals, accounting 99.8%, 99.6%, 98.7% and 72% for Copper, Cadmium, Lead and Zinc, respectively, followed by Turbidity and Nitrate recorded 64% and 57.1% respectively. The percentage reduction of BOD5 was 49.6 %, while for COD 32.7%, either the rest of the physicochemical characteristics as follows: 48.9% for Soluble Solids and 43% of Oils and Grease, 41% of Total Alkalinity, 40% for Phenols, 39.1% for Sulfide, 38% of Suspended Solids and 30% of Phosphate. Lower rates of reduction were recorded of each Temperature (17.2%), pH and Sulfate (13.4%). The results showed that this aquatic plant can be successfully used for wastewater pollutants removal.