Effect of hydrodynamic characteristics on flotation treatment erocess of oily wastewater

Dissertant

Muhammad, Shahd Salim

Thesis advisor

Muhammad, Thamir J.

University

University of Technology

Faculty

-

Department

Department of Chemical Engineering

University Country

Iraq

Degree

Master

Degree Date

2012

English Abstract

In the North Oil Company (Kirkuk) which represents one of the important companies in Iraq that consumes a large quantity of water, the oily wastewater discharges from this company represent a great threat to the agricultural lands.

The aim of the present work is to select the efficient systems for treating oily wastewater using different flotation techniques.

Two flotation techniques were carried out: Induced Air Flotation (IAF), and Modified Induced Air Flotation (MIAF) with a coagulation processes.

The experimental work was carried out using flotation bubble column of Perspex glass (10cm I.D, 150cm height).

A liquid depth of 70cm was kept constant throughout the study.

Different two types of gas distributors namely Perspex perforated plate of diameter of 0.002m was drilled with (70) holes and the second one is a porous ceramic plate of 0.09m diameter with pore size (120m).

In order to achieve effective mixing and to modify the flotation column (MIAF), stirrer was used with a rotational speed of (50-250) rpm.

A monometer was used to measure the local gas hold up; also a high speed camera was used to measure the bubble rise velocity and bubble size.

The variables that affects the removal efficiency (R%) of oil from wastewater is hydrodynamic characteristics, such as gas velocities (0.00636- 0.0636) m/sec, oil concentration (30-800) ppm, surfactant concentration(SLS, Camper) and the addition of alum, pH (4.3-8.5), speed of stirrer (50-250) rpm, have been studied.

The study has showed that the removal efficiency of oil, COD and BOD were related to the additive dose of Alum and SLS.

It was found that the flotation rate increases when using alum and surfactant together, the fastest removal rate was obtained when pH 4.3 and also, when a stirrer speed 200 rpm was used, the removal efficiency was about 98%(residual oil <10 ppm) when the initial oil concentration was 800 ppm.

The kinetics of flotation bubble column was studied and it was found that the removal rate constant increases with increasing oil concentration and with dosage of surfactant (SLS).

The results showed that the order of the kinetics flotation process changes between half to first order.

The interfacial area (a) obtained experimentally from the bubble hydrodynamic parameters and the velocity gradient (G), have been proven to be important parameters for controlling the flotation process efficiency.

The experimental results of the removal efficiency are represented in two and three dimensional graphs.

An empirical correlation for gas hold up using MIAF has been developed as follows:g =0.39 (Ug) 0.0163 (H/D) 0.157 (N/L) 0.473 Statistical analysis showed that the average absolute error and correlation coefficient are 2% and 0.98 respectively.

And general correlation for the removal efficiency (R %) using dimensionless groups was found to be: R% = 1.67 (CA/ l )145.7 (CS/L)161 (C/Co)0.0624(1/Re)1.48(1/We)1.54 (1/Fr)1.096 The correlation obtained gave an average absolute error and correlation coefficient 0.053%, 0.9999 respectively.

Main Subjects

Engineering & Technology Sciences (Multidisciplinary)

Topics

• Water resources
• Fluid dynamics
• Water

• APA
• MLA
• AMA

Language

English

Data Type

Arab Theses

Record ID

BIM-419289