استخدام نبات عدس الماء Lemna spp لازالة بعض الملوثات من مياه الصرف الصحي

The study examines the possibility of using one of the local aquatic plants called Lemna spp. in the treatment of waste water (sewage) for the city of Nasiriyah by removing heavy elements and nutrients (nitrate and phosphate) and some characteristics such as dissolved oxygen DO and the biological requirement for oxygen BOD5. Phytoremediation experiments were conducted Water pollution with concentrations (7,5,3,1) ppm for each of the following elements (nickel, iron and zinc). Water lentil plants were grown in the above concentrations for a period of four days, and the studied characteristics were measured daily, and the results showed that the values ​​of dissolved oxygen It increases throughout the time period, as the values ​​ranged between (1.4-2.3), (1.6-2.8) and (1.6-2.4) mg/L for each of the ponds in which (nickel, iron and zinc) are present, respectively, as the lowest values ​​were on the first day. While the highest values ​​were on the fourth day, and the results showed that the values ​​of the vital oxygen requirement during the treatment period ranged between (76-116), (82-136) and (76-126) mg / liter for each of the ponds in which it is located (nickel, iron and zinc). respectively where the values ​​were high on the first day and then It began to decrease during the four days of the experiment, and the results also showed a decrease in the values ​​of both nitrates and phosphates with the passage of the treatment period. The results showed that water lentils have the ability to withdraw heavy elements from the environment in which they live and collect these elements in the vegetative part of it. The accumulation of heavy elements increases with the length of the treatment period, as well as the accumulation increases with the increase in concentrations in the medium in which it lives. The important thing is that the concentrations of heavy elements Each of nickel, iron and zinc decreases with the passage of time in the water in which water lentils grew, and this indicates that water lentils have the ability to reduce organic pollutants and heavy elements from sewage water.