تعاني محطات معالجة مياه الصرف الصحي كثيرا من مشكلة ادارة ومعالجة الحمأة الناتجة عن المعالجة إذ تشكل عمليات معالجة وطرح الحمأة حوالي (30-40) % من كلفة التاسيس لمحطات المعالجة
The determination of sludge characteristics of wastewater treatment process has the
primary role in the treatment and disposal. This research aims to determine the sludge
characteristics by studying specific resistance factor of the sludge on the f
iltration at Merge
Maarban station, so we took samples of sludge from the station and made several
laboratory experiments and we got the time of intensify sludge, moisture and The
concentration of the solid substances. we calculated specific resistance factor values of the
sludge when the moisture values are ( 97.5 , 95.5 , 94 , 92 , 91 , 88 ) %. The research
results showed a decrease in resistivity factor value of sludge on the filtration as its
moisture become less and the sludge drying time takes tow weeks.
The study was conducted to determine the efficiency of the aerobic treatment of primary sludge resulting from sewage sedimentation and to determine the optimum residence time by measuring the indicators of total solids, chemical oxygen demand, organic content and dewatering ability of the sludge.
The sludge of wastewater used in agriculture processes, in order to knew the effect of
its application on soil and plant contents from zinc and cadmium, Hordeum vulgare L. was
planted by using graded amounts of sludge to the soil for two years, fou
r treatments were
used: o kg/pot (control), 2, 4, 6 ton/ha (with 5 erplicates for each treatment), concentrations
of zinc and cadmium in soil, roots, straw, and grain in all treatments were measured.
Results showed that the application of sludge improve the physical and chemical
properties of the soil, the concentration of zinc and cadmium in the soil were 164.66 μg/g,
324.22 ng/g, respectively, in 60 ton/ha treatment.
Concentration of Zn increased significantly and showed positive correlation with the
amount of sludge, the highest concentration of Zn was in root of plant in comparison with
other parts of plant, in all treatments, it was 69.3 μg/g in the root while it was 45.15, 38.2
μg/g in straw and grain respectively, in 0.6 kg/pot treatment.
Concentration of cadmium increased significantly in 0.6 kg/pot treatment in
comparison with control, the highest concentration was in the root of plant in comparison
with other parts of plant.
This study showed that Hordeum vulgare L. doesn't accumulate zinc and cadmium
because it´s concentration in roots was higher than in straw and grain.
Concentration of Zn and Cd still within permissible limits in the soil and plants in all
treatments.
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 study was performed at three plants for sewage treatment in Syrian coastal
villages: al-Hara, Murj-Muairban, and Hibbeat. Dry sludge samples were collected from
drying sludge basins monthly, during the period October 2011-September 2012. We
d
epended on different global ways to isolate the eggs from the sludge (flotation,
sedimentation, filtration through special sieves).
The microscopic study results of the sediment showed the presence of 5 different
species of the parasitic worm-eggs, belonged taxonomically to five different species of
parasitic worms, two species belonged to Nematoda: Ascaris lumbricoides and Trichuris
trichura, and three species belonged to Platyhelminthes: one species of them belonged to
Trematoda: Schistosoma mansoni, and the other two species belonged to cestodes: Taenia
saginata, and Diphyllobothrium latum.
The average number of worms eggs isolated from the dry sludge resulting from the
three studied sewage treatment plants (al-Hara, Murj-Muairban, and Hibbeat) recorded
relatively close values, the most number in the dry sludge resulting from the treatment
plant in Hibbeat with an average 97.16% eggs/50g, then al-Hara with an average
75.08egg/50g dry sludge. Also the results showed that the isolated eggs were more
diversed in Hibbeat treatment plant, this an indicator of the health status of the population
in the studied sites.
Study showed that the number and diversity of parasitic worm – eggs use more
observed in Summer and Autumn than in Winter and Spring.
The study was conducted during the period 2010-2012 in the Faculty of agriculture at the University of Tishreen, with a view to obtain organic fertilizer (sludge with plant waste), through
compost it in the form of a pile within an isolated device.
The changes have been monitoring with some physical and chemical properties of the fermented substance for the duration of fermentation, by taking samples each month and analyzed them in the laboratory.
The study has included change physical and chemical residue during the fermentation process, where the temperature has reached in the center of pile to 70 degrees Celsius and the device temperature exceeded 70 degrees Celsius to 72 degrees Celsius, and either of the pH in the fermented substance had arrived to the 7.4in the pile and 7.45 in the device, the percentage had
dropped C/N from 30/1 to 18/1 of the pile and 17/1 of the device, showing the death of 99% of the huminth eggs of the intestinal worms after 26 days from the beginning of the composting process by crumpling and 97% of the huminth eggs intestinal worms had died after 10 days from the beginning of the composting process in the device.
The corrosion of biogas pipes and equipments damage as generators, boilers and coprocessors is one of
the most real important problems in Damascus wastewater treatment plant (at Adra region). These
problem caused high financial losses and costs , t
hat it required studying and solving. Biogas is the result
of an aerobic digestion process of sludge, it contains about 50-70% of methane as a main resource of
power, where the biogas considers free when it release spontaneity. Different analysis have been occurred
on the biogas to show its components, tests on the pipes material and analysis of sediment material inside
the pipes that caused by biogas.
