The activated sludge is one of the most common methods of sewage treatment , which has been studied through to find the relation between sedimentation properties and the performance of aeration units. sedimentation experiments were applied on a highl
y- aerated activated sludge experimental treatment plant .Also, another experiments were applied on Marj Maerban treatment plant which is operated using the extended aeration method in order to find the Factors influencing the settling of activated sludge . These experiments were done using the Sludge volume index (SVI) ,the maximum velocity sedimentation rate (UMAX) and the time corresponding to the maximum velocity of sedimentation (TUMAX).In experimental treatment plant. We found that the sedimentation experimental parameters (Vo, n) are very sensitive and can be changed significantly with changing the values of suspended solids (MLSS) in the aeration tank. The mathematical relationships can be used to predict the value of (Vo, n) as well as designing and selecting the operating system of sludge without resorting to a conventional sedimentation tests . We also found in the extended aeration the maximum velocity sedimentation rate (UMAX) is the most important in settling process as we got some good correlation coefficients (R2) between UMAX and (TUMAX, MLSS, SVI) was at a temperature (20OC) were respectively (98, 96,98%), and when the temperature (17 OC) respectively (97,96,97%) which is almost the same values. We noticed that the sludge volume index (SVI) is closely associated with the settling parameters (UMAX, TUMAX) with the correlation coefficients were respectively (98,99%) on the temperature of (20OC) and (98,97%) on the temperature of (17OC) . Velocity sedimentation rate (UMAX) was the largest and deposition time (TUMAX) was smaller on the temperature of (20OC) Indicating an improved sedimentation with higher temperatures . Subsequently, temperature is an influential factor on deposition and It is necessary to be taken into account in the design and operation of activated sludge treatment plan.
This research includes monitoring the distribution of DO concentrations in the Marj Maarban and AL Ruyemih WWTPs which use different types of aeration systems (surface aerators and diffusers). Research has shown a remarkable increase in the values of
DO concentrations in the studied aeration basins above 2 mg/l which means an increased electricity consumption and operational problems, in addition to the role of the natural aeration process in reducing the number of aerators operation hours. This will reflect positively on the performance of the plant and the investment cost.
As a result of increased environmental awareness and interest in the effective protection
of the environment from pollution, the restrictions have increased on the disposal of
wastewater, and the need to the treatment plants has arisen to treat the
wastewater prior to
disposal in water bodies, whether water from either large or small communities. As a result of
the importance of these facilities and cost of material massive construction, operation and
maintenance. In order to facilitate the design process and calculate the initial cost it was issued
some software that helps engineer in the design of the various parts of the station, and in order
to choose the equipments and comparison between several alternatives in objective ways to
choose the most appropriate. Some of these programs are dynamics. It has the ability to
simulate the work of the treatment plant along the time and predict its efficiency and
performance. STOAT is a software that aims to model and simulate wastewater and industrial
wastewater treatment plant, and it is one of the newest technology that uses the latest
developments in process modelling, simulation and a wide range of tools that simplifies the
model building and simulation and give the results in graphics and tables, allowing us to
examine the complex interactions between the various units within the station by interactive
and dynamic methods and this is important for the effective design, operation and management
of wastewater treatment plants. Hence, we take the coastal area as a case study where there are
number of modern wastewater treatment plants of small agglomeration and is being work, as
Kherbet al-Maaze wastewater treatment plant in Tartous. Using STOAT, the study shows a
good efficiency and performance of Kherbet al-Maaze WWTP using (ASM1,ASAL1) models,
and we could build several scenarios like arrival of high pollution load to the station in order to
evaluate and predict its performance.
