Designing a Decentralized Sewage Treatment Plant

Abstract

The contamination in Tigress and Euphrates Rivers in Iraq has reached a high level for several reasons; one of these reasons is the discharged of sewage treatment plant (STP) effluent in the rivers, as well as other wastewater treatment plants. But the major problem is to taker discharge of wastewater to the river directly with no treatment! Many tankers in different places in all governorates in Iraq are utilized because of the absence of sewers which collecting the domestic discharge. Wastewater discharge in the rivers increases the pollution levels and especially when the river level decreases during summer seasons. In the last few years, the pollution was dramatically exacerbated. In this paper, an optimum Design for Decentralized Sewage Treatment Plant will be presented. Discharge of sewage tanks in the Tigris River has a severe negative impact on the environment; causing a deficiency in the dissolved oxygen in the water and increasing the limits of toxicity due to the accumulation of organic and inorganic substances. Pollution has become a serious issue that directly affects the aquatic life, agriculture, and people. The design unit has good specifications for effluent water discharge. TSS (Total Suspended Solid) decreased to less than 10 ppm, BOD (Biochemical Oxygen Demand) to less than 10 ppm, and COD (Chemical Oxygen Demand) to less than 50 ppm. The designed unit showed a good and easy operation and maintenance with less chemicals used.