الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
Water resources are the critical factor affecting productivity, services and sustainable development in Egypt. It is facing two main constrains with respect to its water resources, which are fixed water supply and population growth. Egypt also faces the pollution of water resources by industrial wastewater, agriculture drainage and municipal wastewater which may cause many health risks. Water scarcity became a worldwide concern so water consumption rationalization and seeking for alternative water resources became necessary. Reuse of industrial and domestic wastewater after treatment became a worldwide trend. Wastewater generated in water treatment plants from back wash of filters and alum sludge from sedimentation tanks could be treated and reused as a source of raw water for water treatment plants or other uses.
Alexandria water company AWCO is running 11 water treatment plants use an average 2.8 Mm3/day to produce an average 2.7 Mm3/day. The amount of wastewater produced daily in AWCO water treatment plants is 100000 m3/day (36.5 Mm3/year) with an average percentage of 3.57% during the period from July 2016 to June 2018. It is considerable amount of wastewater to be treated for reuse. In the summer season of 2012 the shortage in raw water supply for AWCO water treatment plants reached 500000 m3/day. In case of treatment and reuse the generated wastewater in AWCO water treatment plants, it could reduce the shortage in raw water supply at least by 20%.
The wastewater generated at El-Siouf Water Treatment Plant was analyzed physically and chemically at the entrance and outlet of the wastewater basin to assess the effect of detention in wastewater basin on the quality of wastewater. The following parameters were analyzed; turbidity, color, aluminum, TDS, TSS, settleable solids after 1 hr, pH, EC and BOD5. In addition, the wastewater samples were bacteriologically analyzed to determine the THPC, TC, FC and biologically analyzed for algae count and protozoa.
Staying of wastewater in the wastewater basin for around from 1 to 2 hours reduced the pollution indicators as follow; turbidity was reduced by 16.9%, color was reduced by 28%, TSS was reduced by and 16%. In addition, THPC was reduced by 26.9%, TC was reduced by 37.9% and FC was reduced by 38.9%.
The wastewater generated at El-Siouf Water Treatment Plant was treated using rapid sand filtration, fabric filtration and coagulation using polymer. The results showed that mean value of turbidity 1.9 NTU and maximum turbidity reduction after using cationic polymer [polyacrylamide NALCO 9907] was 97.9% reduction, fabric filtration with size 5μm 86% percent reduction and rapid sand filtration recorded the minimum efficient method with 66% reduction of the wastewater turbidity.
In addition, mean value of color 7.5 Hazen and maximum reduction in color was 90.5% after using cationic polyacrylamide which showed the best results ever among the applied methods. The mean value of treated wastewater color recorded 20% of the color of the raw water source of El-Siouf water treatment plant. Also, the maximum percent reduction in TSS was 87.5% after using cationic polymer which was the best ever among the used methods. Similar results were recorded in the reduction of settleable solids after 1hr with a maximum reduction 61% after using cationic polymer.
It was noticed clearly that reduction in EC, pH and TDS were very small after using the three methods selected in treatment as these indicators are not supposed to be reduced by filtration. The percent reductions BOD5 after application of the three treatment methods rapid sand filtration, fabric filtration and coagulation using polymer were 19.9%, 24.3% and 46.9% respectively. The BOD5 results of the raw water source of El-Siouf water treatment plant reported mean value 22 mg/l. The mean value of raw water BOD5 recorded 1.16 times of the mean value of the treated wastewater BOD5.
The results of THPC recorded that the maximum THPC reduction was 76.9% after using [polyacrylamide NALCO 9907] with medium and low cationic change. This method reported the best reduction compared to rapid sand filtration 64.7% and fabric filtration 60.9 %, the higher reduction in bacterial plate count after using cationic polymer because it contains NH2 group which increase the ability to loss protons and therefore easily attracted negatively charged bacterial cell wall, leading to its destroyed.
The total coliform TC number was reduced by the three methods with a maximum percentage reduction of 61.8% after using rapid sand filtration for treatment of wastewater generated. Faecal coliform FC was reduced by 21.6% when coagulation using polymer for treatment of wastewater generated was applied. On the other hand, the minimum percent reduction was 12.7% when rapid sand filtration was applied.
Algae count was reduced by three methods applied for treatment of wastewater generated. The maximum percent reduction was 46.4% when coagulation using polymer was applied. Fabric filtration and rapid sand filtration was 28.8% and 26.5% respectively. It was slight difference in percent reduction between rapid sand filtration and fabric filtration methods.
The results recorded that coagulation using polymer was the best method in protozoa reduction, because the percentages removal of protozoa were 0.0%. While the percentages reduction after applied rapid sand filtration and fabric filtration was 70% and 30%, respectively.
The results represents that coagulation using polymer method indicates the highest recent reduction in analyzed parameters. ANOVA test reported that there is highly significant difference in most parameters among the three methods after treatment. The most important recommendation was the application of cationic polyacrylamide in the treatment of wastewater generated from water treatment plant.
Conclusion:
It could be concluded that:
• The amount of wastewater generated during the production of Alexandria Water Company (AWCO) was around 4% of the total amount of treated water production, i.e. the quantity of wastewater generated was 100000 m3/day.
• The quality indicators of wastewater generated at El-Siouf water treatment plant at the entrance of wastewater basin were turbidity with mean value 185 NTU, color with mean value 66 Hazen, TSS with mean value 27 mg/l and BOD5 with mean value 34.
• The quality indicators of wastewater generated at El-Siouf water treatment plant at the outlet of wastewater basin were turbidity with mean value 154 NTU, color with mean value 54 Hazen, TSS with mean value 23 mg/l and BOD5 with mean value 31.
• The reduction in EC, pH and TDS were very small after using the three methods selected in treatment as these indicators are not supposed to be reduced.
• The percentage reduction in wastewater quality indicators due to staying of wastewater from 1 to 2 hours in wastewater basin were turbidity reduced by 16.9%, color reduced by 28%, TSS reduced by 16%. In addition, THPC, TC and FC reduced by 26.9%, 37.9% and 38.9%, respectively.
• Fabric filtration, rapid sand filtration and coagulation using polymer methods were applied for wastewater (generated from El-Siouf Water Treatment Plant) treatment after staying from 1 to 2 hours in wastewater basin.
• Using fabric filtration method with pre size 5 µm, the percent reduction in turbidity was 86.6%, color was 65.4%, TSS was 54.5%, settleable solids after 1 hr was 38%, THPC was 60.9%, TC was 43.6%, FC was 16%, algae count was 28.8% and protozoa was 30%.
• Also when using rapid sand filtration with effective size (0.9-1.1)mm, the percent reduction in turbidity was 66%, color was 65.6%, TSS was 52%, settleable solids after 1 hr was 38.2%, THPC was 64.7%, TC was 61.8%, FC was 12.5%, algae count was 26.5% and protozoa was 70%.
• Adding 0.5 mg/l of cationic polymer in coagulation using polymer method, the percent reduction in turbidity was 97.9%, color was 90.5%, TSS was 87.5%, settleable solids after 1 hr was 61%, THPC was 76.9%, TC was 45.6%, FC was 21.6%, algae count was 46.4% and protozoa removal was 100%.
• The results recorded that coagulation using polymer methods indicate the highest recent reduction in analyzed parameters.
• ANOVA test reported that there is highly significant difference in most parameters among the three methods after treatment.
Recommendations
The following is recommended:
• The AWCO has to fit flow measurement structures and instruments to measure the quantities of raw water consumed and wastewater generated.
• Application of cationic polyacrylamide in the treatment of wastewater generated from water treatment plant.
• Setting out on AWCO pilot plant may be used in rapid sand filtration technique with dissimilar pore size of sand and different scales in length.
• Carrying out non-weave fabric material may be used in fabric filtration technique with pore size less than 5µm.
• Undertake cost analysis for the three methods used in treatment of wastewater generated at El-Siouf water treatment plant.
• Undertake toxicological study on the use of polyacrylamide in wastewater treatment
• Further research on the use of natural polymer in treatment of wastewater generated in water treatment plans is recommended.