Reduction Turbidity of Water in Tikrit Drinking Water Treatment Plant by Using Alum Which was Quantified by a Jar Test Apparatus, with limnological Study of Treated and Raw Water

Tigris river is a major source of water for drinking, agricultural and industrial desires in Iraq. The quality of drinking water is very important because it is related to the health of people. For this purpose, we assess the quality of drinking water in the city of Tikrit with some physical-chemical parameters which have a significant role in determining the potability of drinking water. The obtained results were compared with the permissible limits for universal standards of drinking water Such as Environment Protection Agency (EPA), World Health Organization (WHO), etc.

In this study, two samples of water within Tikrit drinking water treatment plant were taken, the first sample was the raw water (Tigris River) which is a water source project, and the second sample represents treated water in the Tikrit drinking water project.

All the physical and chemical parameters (Conductivity, pH, Chloride and Total Alkalinity) were found to be within the safe limit values except turbidity and aluminum levels of treated water in some months.

Turbidity is a principle physical characteristic of water, excessive turbidity in drinking water is aesthetically unappealing and may also represent a health concern.

Generally, alum is the first coagulant of choice because of its lower cost and its widespread availability. The coagulation performance of alum, an inorganic chemical coagulant was used to remove the turbidity of raw water, but the problem with the use of alum as a coagulant for water treatment often leads to higher concentrations of aluminum in the treated water than in the raw water itself.

Jar tests were carried out to optimize alum dose in most months of the current study. Results showed that the efficiency of alum has been high in reducing values, but it is necessary to choose the lowest doses of alum and appropriate in reducing the values of turbidity to be within the permissible limits to avoid increasing the concentration of aluminum in treated water, especially that increasing the concentration of aluminum in drinking water has a risk to human health.

Results showed an increase in concentrations of aluminum in treated water in some months through recording values exceeded the permissible limits (Maximum Permitted Level 0.2 mg/L) according to the universal standards of drinking water due to excessive doses of alum added to sedimentation basins at Tikrit drinking water treatment plant.