Print ISSN: 1681-6900

Online ISSN: 2412-0758

Keywords : Coagulation


Oil Removal from Oilfield Produced Water, North Rumaila by Combination CoagulationFlocculation and Microfiltration Technique

Thamer J. Mohammed; Eman Sh. Awad; Thabit A. Ahmed

Engineering and Technology Journal, 2019, Volume 37, Issue 2C, Pages 204-208
DOI: 10.30684/etj.37.2C.1

The Southern Oil Company, which is operated in North Rumaila oilfield in Basrah/ Iraq, is one of the important companies which produced huge amounts of produced oilfield water. The aim of this study is to treat the produced water by hybrid methods: the process of coagulation-flocculation and microfiltration technique (ceramic membrane) to remove the oil content and improve the water quality to meet the allowable limit of reinjection into the reservoir. Poly-aluminum chloride (PAC), and Ferric Chloride (FeCl3.6H2O) coagulants were used separately and in combination with cationic polyelectrolyte (PE). After produced water was treated with different doses of coagulant, it was passed through the Microfiltration technique/ ceramic membrane (0.5µm) to reach the allowable limit for reinjection. It was found that the best value of oil content after passing through ceramic membrane is 0.2 mg/L at FeCl3.6H2O dose (10 mg/L) combined with PE dose (0.6 mg/L), which was less than the allowable limit for re-injection, (5) ppm.

A Mathematical Model to Determination of Alum Amount Added for the Purpose of Coagulation in Water Purification Plants

Hassan A. Omran; Mizher A. Kadhim

Engineering and Technology Journal, 2018, Volume 36, Issue 4A, Pages 456-460
DOI: 10.30684/etj.36.4A.13

Chemicals are used to increase the settling velocity for suspended deposition colloids which are not settled in sedimentation tanks in water purification plants . For this purpose, the alum is used in wide spread across the water purification projects in Iraq. This research contains studying the factors that effect on alum amount added by conducting laboratory tests of water samples from Euphrates river at the purification plant in AL-Musayyab city over ten years (with monthly rate). It was noted that the amount added depends heavily on the turbidity of water entering the purification plant, in addition to water temperature and its pH. The results of laboratory tests have been approved, which included the measurement of the turbidity, pH, temperature, and the value of alum added. Since this method is applicable in all water purification plants. The results during the period of ten years are accredited, and subjected to multi -regression analysis. A mathematical model was conducted to calculate the alum dose, which must be added depending on the raw water turbidity, temperature, and pH. This model also has been examined by using data of another years and gave satisfactory results to be up to 91% each. This model compensates the use of the Jar-test of raw water to determine the amount of alum that must be added and sufficient by measuring the turbidity, temperature, and pH of the raw water only, and then calculating the value of the required dose of alum.

Improve Coagulation Process To Control The Disinfection By- Products In Water Treatment Plant

Alaa H. Wadie Al-Fatlawi

Engineering and Technology Journal, 2014, Volume 32, Issue 13, Pages 3228-3240

This paper describes a laboratory study comparing three coagulants (alum, ferric chloride, and ferric sulfate) to determine which coagulant would not only remove NOM but DBP precursors as well. Experiments were conducted to compare the effectiveness of three coagulants in removing DBPs precursors from raw water samples. The results show that the removal of total organic carbon (TOC) which is mean NOM here, was dependent on the coagulant type and was enhanced with increasing coagulant dose, but ferric chloride, and ferric sulfate have no further considerable effect in case of increasing to high levels. For all the treated samples coagulation with ferric chloride proved to be more effective than alum and ferric sulfate at similar doses and the mean values of treatment efficiencies were 30%, 37%, and 45% by ferric sulfate, alum, and ferric chloride respectively. The range of TOC removal rates obtained using ferric sulfate (18-48%), (14-50%) for alum, and (21-59%) for ferric chloride. Ferric chloride was therefore considered the better chemical for enhancing the coagulation process.Fair removals of turbidity were observed (86%) for ferric chloride, (78%) for alum, and 65% for ferric sulfate. Mean TOC removal using alum was determined to be 61% and much more than results of water coagulation by ferric sulfate which was reported to be 53% in experiments performed for treating Euphrates river water.
Among the Trihalomethanes compounds, chloroform was the common detected Trihalomethanes in the samples collected from Euphrates Riverwere generally below the guideline values, but some samples displayed levels which exceeded the level of WHO Standards for chlorinated compounds. Based on preliminary jar test experiments, ferric chloride at concentrations of 20-30 mg/L was found as an efficient coagulant for disinfection by- products and turbidity reduction.

Boron Removal from Shat Al-Arab River Water Using Electrocoagulation

Saadi K. Al-Naseri

Engineering and Technology Journal, 2012, Volume 30, Issue 13, Pages 2175-2185

Shat Al-Arab is a river located at the south of Iraq. Boron concentration has
increased significantly recently due to the drought season which makes water from
the Arabian Gulf pour into Shat Al-Arab. Boron concentration, as high as 5 mg/l,
was detected in this river. This is 10 times the allowable drinking water concentration
for boron according toWHO and the Iraqi drinking water guidelines, i.e. 0.5 mg/l.
Experiments were conducted to determine the ability of electrocoagulation
technique to reduce boron concentrations in synthetic water of 5 mg Boron/l and
conductivity of 2000 μS/cm to the required level in drinking water. Experimental
setup was prepared to determine the effects of several operating parameters on the
optimum operation for the electrocoagulation. In addition, the technique was
compared with chemical coagulation, using Poly-Aluminum-Chloride, Aluminum
Sulphate, and Ferric Chloride.
The experiments revealed that chemical coagulation has a very low efficiency
(about 12%) that renders it unsuitable as a pretreatment for existing (or for the future)
desalination units. On the other hand, electrocoagulation experiments showed a
maximum boron removal efficiency of 40% at a current density of 5 mA/cm2,
operating time of 30 minutes, and pH of 8.

Compromise Study Between The Hydrate And Dehydrate Coagulate (Alum ,Ferrous sulfate and Ferric Chloride )

Engineering and Technology Journal, 2011, Volume 29, Issue 6, Pages 291-305

This research focuses on the use of hydrate and dehydrate aluminum sulfate (Alum) ,ferrous sulfate and ferric chloride ,Which burnt in different temperatures degrees ,or use U.S.Pat.NO.4105747 to dehydrate of ferric chloride, and compare the result and selected the batter coagulate to remove the turbidity from the water sampling light 6NTU ,medium 55NTU ,high 150NTU turbidity use the jar test to find
the change in PH and turbidity at the same condition .
The study revealed the efficiency of the gradually dehydrate coagulant in reducing the turbidity from prepared samples by continuous burnt when using alum and ferrous sulfate, and when use ferric chloride in continues change from hydrate to dehydrate coagulant.
The hydrate and dehydrate alum is batter coagulant for removal turbidity. The final turbidity from the light sample less than 1NTU and less than 2NTU from the medium samples, less than 3NTU from high samples.
There is no change in the cost by using hydrate or dehydrate alum.
It appears high increase of removal ratio between hydrate and dehydrate alum i.e from 64% to 85% for light samples and from 94% to 98% for medium samples, 91% to 98% increasing removing ratio from high turbidity samples.