الفهرس 
IntroductionOnly 14 pages are availabe for public view
 |  | from | 154 |  |  |
| | | from | 154 | | |
Abstract
In this work , achieve optimal coagulation is very vital in water treatment which increase the quality of drinking water, decrease of chemicals consumption and their residual on human health .The current study could be summarized in the following three main chapters:-
The first chapter:-
Introduction contains a general introduction about water nature, water pollution and water treatment processes with a detail of stages of water treatment processes pre-treatment, coagulation, flocculation, filtration and disinfection. Many factors affect on
09
coagulation unit such as alkalinity, turbidity, pH, suspended matter, natural organic matter, temperature, coagulant dose and pre-chlorine dose.
The second chapter:-
Experiment, represents the experiment part of the study shows, using the Jar test simulation for coagulation and flocculation processes to determine the coagulant doses which simulation coagulation step by rapid speed of turbines and flocculation step by low speed of turbines, pH Meter used to measure acidity and alkalinity of water (raw and treated water). To determine inorganic elements such as (Mn, Fe, No3, Al and No2) by using Spectrophotometer. Turbidity meter used to measure the Turbidity. The electrical conductance and total dissolved solids (TDS) by using conductivity meter. All experiments have a relationship between Turbidity, pH, conductivity and a coagulant dose.
The third chapter:-
Results and discussion is devoted to illustrate results and interpretate the discussion of these results .this chapter revealed the following remarks:-
Conventional running treatment method was developed to achieve upgraded optimal coagulation that reduces: NTU; disinfection dose by-products (DBPs); heavy metal levels. On the contrarily; it increases filtration time duration and to reduce running cost of the treatment. Although the theoretical value of Zeta potential is proposed to be Zero at the neutralized point, but in the actual experimental levels, the reaction doesn’t fulfill the Zero value. Results showed that the potential of raw water ranged between 45 and 35 mV, that will achieve the highest removal levels of colloidal matters; wide range of pH (8.5–7.8) of raw water that is very limited. This has no remarkable effect on coagulation process. Moreover, results showed that the reaction temperatures were widely affected the consumed alum doses due to the big variation of temperatures from
14 to 30 oC during winter to summer, passing by autumn and spring seasons, respectively. The 33% alum doses were fluctuated between 30 to 45 mg/l, this is due to the highly wide range of temperature from 14 to 28-30 oC; that decrease alum dose. In fact, this paper represents a real trial for saving chemicals, reduces chlorinated bi-products by reducing the pre-chlorination to the minimum. Some modifications may be needed on the treatment sequence.
Due to the low levels of algal growth with noticeable DBPs reduction during summer and spring seasons, the required pre-chlorination decreased from 1.5 to 0.5 mg/l, which led to corresponding variation of Z-potential of the raw water from 45 to 35 mV, and achieved a high removal of colloidal matters. Although the sludge produced from alum was higher than PAC; but, alum was highly effective than PAC.
The optimum operating conditions for the chosen factors that fulfilling the final turbidity 0.3NTU, were pH range 7.8-8.5, and coagulant dose 30-45 mg/I, respectively.