Iraqi Journal of Chemical and Petroleum Engineering

Two types of adsorbents were used to treat oily wastewater, activated carbon and zeolite. The
removal efficiencies of these materials were compared to each other. The results showed that
activated carbon performed some better properties in removal of oil. The experimental methods
which were employed in this investigation included batch and column studies. The former was used
to evaluate the rate and equilibrium of carbon and zeolie adsorption, while the latter was used to
determine treatment efficiencies and performance characteristics. Expanded bed adsorber was
constructed in the column studies. In this study, the adsorption behavior of vegetable oil (corn oil)
onto activated carbon and zeolite was examined as a function of the concentration of the adsorbate,
contact time, adsorbent dosage and amount of coagulant salt(calcium sulphate) added . The
adsorption data was modeled with Freundlich and Langmuir adsorption isotherms. and it was found
that the adsorption process on activated carbon and zeolite fit the Freundlich isotherm model. The
amount of oil adsorbed increased with increasing the contact time, but longer mixing duration did
not increase residual oil removal from wastewater due to the coverage of the adsorbent surface with
oil molecules. It was found that as the dosage of adsorbent increased, the percentage of residual oil
removal also increased. The effects of adsorbent type and amount of coagulant salt(calcium
sulphate) added on the breakthrough curve were studied in details in the column studies. Expanded
bed behavior was modeled using the Richardson-Zaki correlation between the superficial velocity of the feed
stream and the void fraction of the bed at moderate Reynolds number.

This research adopts the estimation of mass transfer coefficient in batch packed bed distillation
column as function of physical properties, liquid to vapour molar rates ratio (L / V), relative
volatility (α), ratio of vapour and liquid diffusivities (DV / DL), ratio of vapour and liquid
densities (ρV / ρL), ratio of vapour and liquid viscosities (µV/ µL).
The experiments are done using binary systems, (Ethanol Water), (Methanol Water), (Methanol
Ethanol), (Benzene Hexane), (Benzene Toluene). Statistical program (multiple regression
analysis) is used for estimating the overall mass transfer coefficient of vapour and liquid phases
(KOV and KOL) in a correlation which represented the data fairly well.
KOV = 3.3 * 10-10 α
-0.7 (DV / DL)
0.65 (L / V)
3.5 (ρV / ρL) 1.25 (μV / μL)
-5.0
KOL = 2.8 * 10-6
α
-0.95 (DV / DL)
0.03 (L / V)
1.15 (ρV / ρL )
0.077 (μV / μL)
-0.9
In this research a method where the resistances to mass transfer in both phases are accounted for
separately through the use of HTU-NTU model for each phase
Z=HTUOV.NTUOV and Z=HTUOL.NTUOL
Results show that both overall vapour and liquid mass transfer coefficient are increased with
liquid to vapour molar rates ratio, vapour to liquid diffusivities ratio and vapor to liquid densities
ratio, but decreased with increasing the relative volatility and vapour to liquid viscosities ratio

The unsteady state laminar mixed convection and radiation through inclined
cylindrical annulus is investigated numerically. The two heat transfer mechanisms of
convection and radiation are treated independently and simultaneously. The outer
cylinder was kept at a constant temperature while the inner cylinder was heated with
constant heat flux. The study involved numerical solution of the governing equations
which are continuity, momentum and energy equations using finite difference method
(FDM), where the body fitted coordinate system (BFC) was used to generate the grid
mesh for computational plane. A computer program (Fortran 90) was built to calculate
the bulk Nusselt number (Nub) after reaching steady state condition for fluid Prandtl
number fixed at (Pr =0.7) (for air) with radius ratio ( =1.5, 2.6, 5.0), Rayleigh number
(0≤Ra≤103
),Reynolds number (50≤Re≤2000), dimensionless heat generation (0≤Q≤10),
Conduction-Radiation parameter (0≤N≤10), optical thickness (0 ≤
t

≤ 10) and different
annulus inclination with horizontal plane (0°≤δ≤90°). For the range of parameters
considered, results show that radiation enhance heat transfer. It is also indicated in the
results that Nu increase with the increasing of inclination angle δ, Ra, Re, and Q. The
correlation equations are concluded to describe the radiation effect.
Comparison of the result with the previous work shows a good agreement

In Iraq, water shortages and drought, especially during the hot summer months, necessitates that
municipal authorities adopt water reuse projects like reusing treated domestic wastewater for crop
irrigation. This work gives the conceptual and basic design elements for the necessary steps of
filtration, UV irradiation and chlorination to make such a wastewater fit for agricultural use. A typical
rural community of 50,000 people is considered as an example case for which functionality and relative
simplicity of the proposed designs are prime factors. The objectives are 1) to show what is required and
2) that the presented information may be utilized to embark on the following phases of detailed design
and execution of such projects.