Abstract

In this experiment, we have used the soil profile as a biological filter that can to absorb pollution and microbes in the domestic wastewater at Iran during 2009. In this experiment, we had 15 lysimeters, that were planted canola (Brassica napus L.) in 1 to 5 lysimeters and were irrigated by domestic wastewater with BOD₅ about 150 mg/lit and primary drainage water were accumulated. In the 6 to 9 lysimeters was planted alfalfa (Medicago sativa L.) and were irrigated by primary drainage water and then, were accumulated secondary drainage water. We have irrigation 10, 11 and 12 lysimeters by secondary drainage water that was planted inside the basil (Ocimum basilicum L.). In order to compare plants characteristics, in 13, 14 and 15 lysimeters were planted canola, alfalfa and basil respectively and were irrigated by agronomical water. The results showed that the soil could reduce BOD₅ and COD from 150 and 232 mg/lit to 11 and 18 mg/lit respectively in secondary drainage water. The essential oil yield of basil 17% increased under irrigation by secondary drainage water intoirrigation by agronomical water. Therefore, the use of secondary drainage water can be increase the quantity and quality yields in plants and the other hand, protects sweet water resources.

Key words: Domestic wastewater, agronomical water, essential oil yield, basil.