Iraqi Journal of Chemical and Petroleum Engineering

Isobaric Vapor-Liquid-Liquid equilibrium data for the binary systems ethyl acetate + water, toluene +
water and the ternary system toluene + ethyl acetate + water were determined by a modified
equilibrium still, the still consisted of a boiling and a condensation sections supplied with mixers that
helped to correct the composition of the recycled condensed liquid and the boiling temperature readings
in the condensation and boiling sections respectively. The VLLE data where predicted and correlated
using the Peng-Robinson Equation of State in the vapor phase and one of the activity coefficient
models Wilson, NRTL, UNIQUAC and the UNIFAC in the liquid phase and also were correlated using
the Peng-Robinson Equation of State in both the vapor and liquid phases.

Corrosion experiments were carried out to investigate the effect of several operating
parameters on the corrosion rate and corrosion potential of carbon steel in turbulent flow
conditions in the absence and presence of sodium benzoate inhibitor using electrochemical
polarization technique. These parameters were rotational velocity (0 - 1.57 m/s), temperature
(30oC – 50oC), and time. The effect of these parameters on the corrosion rate and inhibition
efficiency were investigated and discussed. It was found that the corrosion rate represented by
limiting current increases considerably with increasing velocity and temperature and that it
decreased with time due to the formation of corrosion product layer. The corrosion potential
shifted to more positive with increasing temperature and velocity while it shifted to more
negative with time. Sodium benzoate gave good inhibition efficiency for the whole
investigated range of temperature and velocity. Its efficiency was high on clean surfaces and
decreased with time in stationary and flow conditions. No noticeable effect of temperature on
the inhibition efficiency was noticed.

Phosphorus and dye (direct black) removal for small – scale wastewater applications
were investigated using oven dried alum sludge (ODS).The use of alum sludge not
only provides a low cost technique but also reduces the hazard and the cost related to
the disposal of large amount of alum sludge. Phosphorus and dye removal exceeds
90% for all operating conditions applied in the research.
The residuals generated during the treatment of wastewater were further tested to
study the possibility of aluminum leaching from oven dried alum sludge during the
adsorption of phosphorus and dye. These tests observed a reduction in aluminum
leaching indicating a lower risk imposed on land and surface water based on disposal
options rather than on alum sludge disposal.
The leaching of aluminum was observed to be mostly below 1 mg/l for a pH
solution of 6 and 7 for both processes of phosphorus and dye removal. However, the
pH of 5 seemed to have a concentration of more than 1mg/l of aluminum.