Daw Nway Nway Khaing Assistant Lecturer Civil Engineering Department Yangon Technological University Yangon Convention Center (YCC) 12 th October 2018 1
Outlines Introduction Objective Methodology Results and Discussion Conclusion References 2
Introduction Population Growth of Yangon City 2012 4.9 Million 2016 6 Million 2017 6.2 Million (Estimated) Source: (Populatonof2017, 2017) Increase population Increase numbers of households and community buildings Increase amount of municipal wastewater from municipalities 3
4 Introduction (Continued) Sewage Sanitary waste from sewers Septic Wastewater Sanitary waste from septic tank Both can contain Grit, debris and suspended solids Disease causing pathogens such as virus and bacteria Decaying organic waste Nutrients such as Nitrogen and Phosphorous Some household and industrial chemicals
5 Introduction (Continued) Nitrogen and Phosphorous Pollution Responsible for eutrophication problem Can damage drinking water supplies Can degrade recreational and aesthetic values of surface water bodies Can kill aquatic lives and Can even cause public health problems Need efficient domestic wastewater treatment system
Objectives To reduce the concentration of nutrient in municipal wastewater of Yangon City using aerobic-anoxic and constructed wetland system 6
Methodology Collect MWW sample from YCDC WWTP Fabricate a lab-scaled MWW treatment system (IFAS, Anoxic and CWS) and operate it systematically Determine concentration of NH3-N, NO3-N and P of wastewater from every treatment step Evaluate organic contaminants and nutrient removal efficiency of proposed MWW treatment system 7
Collection of Municipal Wastewater Sample Sewage from six downtown townships of YGN City + Septage from other townships of YGN City Influent of WWTP Municipal Wastewater Sample for experiment Source: Jeremias, 2014 8
Treatment of Municipal Wastewater Effluent Using IFAS Process (For Nitrification) IFAS Process (For Nitrification) Aeration Tank Length = 12 in, Width = 6 in, Depth = 15 in, F.B = 4 in Volume of wastewater = 16L Volume of media = 2 L Rate of Oxygen supplied = 5.5 Lit/min Influent flow rate = 1 cu-m/day Sedimentation Tank Length = 3 ft -8 in Width = 4 in Depth = 8 in F.B = 10 in Volume of wastewater = 23.6 L Bed slope angle = 20º Influent flow rate = 0.02 cu-m/day Settling Velocity = 6.99 in/hr Horizontal Velocity = 3.22 in/hr Dimensions and Hydraulic Parameters of Lab-scaled IFAS Process 9
Treatment of Municipal Wastewater Effluent Using Anoxic Process (For Denitrification) Anoxic Process Anoxic Tank Length = 10 in Width = 10 in Depth = 14 in F.B = 4 in Volume of wastewater = 18 L Mixing speed = around 100 rpm Influent flow rate = 1 cu-m/day 10 Lab-scaled Physical Model of Anoxic Tank 10
Treatment of Municipal Wastewater Effluent Using Constructed Wetland System (For Phosphorous Removal) A h = Cross-section of surface area (sq-m) (0.28 sq-m) (3 sq-ft) Q d = Influent flow rate (cu-m/day) (0.05 cu-m/day) C i = BOD concentration of influent (mg/l) (60 mg/l) C e = BOD concentration of effluent (mg/l) (25 mg/l) Lab-scaled Physical Model of Constructed Wetland System 11
Schematic diagram of lab-scaled wastewater treatment system 12
Results and Discussion Table 1 : Different Operational Condition of lab-scaled treatment system IFAS Process Anoxic Process Experiment No. Condition Flow Rate (m 3 /d) Rate of Oxygen Supply (m 3 /day) RAS a (m 3 ) Flow Rate (m 3 /d) Mixing System (rpm) RAS b (m 3 ) Anoxic Residenc e Time (hours) 1 and 2 1 1 8 0.003 1 100 0 24 3 and 4 2 1 8 0.003 1 100 0 48 5 and 6 3 1 8 0.003 1 100 0 36 7 and 8 4 1 8 0.002 1 100 0.001 48 9 and 10 5 1 8 0.001 1 100 0.002 48 Note: RAS a Amount of returned activated sludge recycled to aeration tank and RAS b Amount of returned activated sludge recycled to anoxic tank 13
Operation of Lab-scaled VFSCW System Hydraulic Loading Rate (HLR) : 0.19 m3/m2-d Influent and Effluent Flow rate : 0.05m 3 /day Numbers of experiments: 10 nos. (After 20 days, 29 days, 36 days, 40 days, 51 days, 56 days, 65 days, 70 days, 79 days and 85 days of planting date) Macrophyte: Thysanolaena Maxima Grass (or) Tiger Grass Type of constructed wetland : Vertical Flow Subsurface Constructed Wetland (VFSCW) System Surface area of wetland : 0.28 m 2 Diameter size of the media (bed layer, inlet and outlet zones) : varied from 20 mm to 40 mm Media size for top and inner side boundary: varied from 5 mm to 10 mm. 14
Determination of Pollution Parameters Determination of Ammonia Nitrogen, Nitrate Nitrogen and Phosphorous concentration Using photometer (YSI 9300) 15
Concentration of Ammonia Nitrogen (mg/l) Results and Discussion (Ammonia Nitrogen Removal) Removal Efficiency (%) 10000 1000 100 10 120.0 100.0 80.0 60.0 40.0 20.0 1 0.0 1 2 3 4 5 6 7 8 9 10 Experiments Influent (mg/l) Effluent (mg/l) Removal Efficiency (%) Figure Efficiency of Lab-scaled Treatment System for NH3-N Removal 16
Concentration of Nitrate Nitrogen (mg/l) Results and Discussion (Nitrate Nitrogen Removal) Removal Efficiency (%) 10000 1000 100 10 1 1 2 3 4 5 6 7 8 9 10 Experiments 120.0 100.0 80.0 60.0 40.0 20.0 0.0-20.0-40.0-60.0 Influent (mg/l) Effluent (mg/l) Removal Efficiency (%) Figure Efficiency of Lab-scaled Treatment System for NO3-N Removal 17
PRR Results and Discussion Relationship between PLR and PRR 30 25 20 15 10 5 0 0 5 10 15 20 25 30 35 PLR y = 0.898x - 0.7056 R² = 0.9942 Figure Variation of PRR Depending on PLR PRR = 0.898 (PLR) 0.7 Where, PLR = Phosphorous Loading Rate of lab-scaled VFSCW system (g/m 2 -d) and PRR = Phosphorous Removal Rate of lab-scaled VFSCW system (g/m 2 -d). 18
Concentration of Phosphorous (mg/l) Results and Discussion (Phosphorous Removal) Removal Efficiency (%) 1000 120.0 100.0 100 80.0 60.0 10 40.0 1 1 2 3 4 5 6 7 8 9 10 Experiments 20.0 0.0 Influent (mg/l) Effluent (mg/l) Removal Efficiency (%) Figure Efficiency of Lab-scaled Treatment System for P Removal 19
1/U 1/SRT Results and Discussion From experiments, 9 th Experiment Optimum Treatment Efficiency IFAS Process F/M ratio: 0.1 per day SRT : 6.5 days Y : 0.05 (g VSS/g BOD) Kd : 0.12 per day Ks : 340 mg/l K : 10 per day 12.00 10.00 8.00 0.19 0.17 0.15 0.13 0.11 0.09 0.07 0.05 y = 0.0553x + 0.1214 0 0.2 0.4 0.6 0.8 1 Determination of Y and K d through the relationship between SRT and F/M ratio U 6.00 4.00 2.00 0.00 0.00 0.05 0.10 0.15 0.20 0.25 0.30 (1/S) y = 33.925x + 0.1 Determination of K s and K through the relationship between F/M ratio and Soluble BOD 5 20
SRDN (g NO3-N/g MLSS) Results and Discussion From experiments, 9 th Experiment Optimum Treatment Efficiency Anoxic Process F/M ratio : 0.3 per day SRDN : 0.27 g NO3-N / g of MLSS * SRDN = 0.171 (F/M ratio)+0.2148 0.35 0.3 0.25 0.2 0.15 0.1 0.1 0.3 0.5 0.7 0.9 F/M ratio y = 0.171x + 0.2148 Relationship between SRDN and F/M ratio in the anoxic zone 21
Raw Wastewater Effluent from Aeration Tank Effluent from Anoxic Tank Effluent from Sedimentation Tank Effluent from Constructed Wetland Physical Appearance of Wastewater from Each Treatment Step 22
Parameters Conclusion According to the results from ten experiments, the optimum treatment efficiency was obtained from the ninth experiment. P NO3-N NH3-N 75 80 85 90 95 100 Removal Efficiency (%) In order to use the land area for both environmental and economical achievement, the tiger grass was tested as the macrophyte for uptaking phosphorous from wastewater because they can be economically used for making soft brooms. 23
24 REFERENCES J. K. C. Jalal et al., Removal of nitrate and phosphate from municipal wastewater sludge by chlorella vulgaris, spirulina platensis and scenedesmus quadricauda, IIUM Engineering Journal, vol. 12, no. 4, pp. 125 132, Apr. 2011. A. M. Helmenstine, What is the chemical composition of urine?, ThoughtCo, January 21, 2018. R. Mylavarapu, Impact of phosphorous on water quality, SL 275, a series of the Soil and Water Science Department, University of Florida, 2008. B. Oram, Phosphate in water, Water Research Center, Dallas, PA 18612, 2014. S. Qomariyah et al., Use of macrophyte plants, sand & gravel materials in constructed wetlands for greywater treatment, in IOP Conf. Ser.: Materials Science and Engineering. 2017, pp. 1-6. Vymazal, Removal of nutrients in various types of constructed wetlands, Science of the total environment, pp. 48 65, Jan. 2006. PCARRD, Tiger grass farming and broom making in Bagulin, La Union [Philippines], Department of Science and Technology, University of the Philippines, 2007. APHA, Standard method for the examination of water and wastewater including bottom sediments and sludges, 12 th ed. Albany, New York, 1969, pp. 415 421. T. Katherine, Sewage Industry Fights Phosphorous Pollution, Scientific American, November 1, 2009.
25 REFERENCE Richard Sedlak, 1991. Phosphorous and Nitrogen Removal from Municipal Wastewater, Principles and Practice Principles of Biological and Physical/Chemical Nitrogen Removal. New York. Syed R. Qasim, 1985. Wastewater Treatment Plants Planning, Design and Operation Primary Sedimentation. Biological Waste Treatment. CBS Publishing Japan Ltd. UN-HABITAT, 2008. Constructed Wetlands Manual. UN-HABITAT Water for Asian Cities Programme Nepal, Kathmandu.
THANK YOU SO MUCH! 26