Assessment of the arise situation and characteristics of sewage sludge from the wastewater treatment plants in hanoi

THAI NGUYEN UNIVERSITY UNIVERSITY OF AGRICULTURE AND FORESTRY DANG XUAN HAO TOPIC TITTLE: ASSESSMENT OF THE ARISE SITUATION AND CHARACTERISTICS OF SEWAGE SLUDGE FROM THE WASTEWATER TREATMENT PLANTS IN HANOI BACHELOR THESIS Study Mode : Full-time Major : Environmental Science and Management Faculty : International Training and Development Center Batch : 2011-2015 Thai Nguyen, Sept 2015 ABSTRACT Student name DANG XUAN HAO Student ID DTN1153110019 Thesis Title Assessment of the arise situation and characteristics of sewage sludge from the wastewater treatment plants in Hanoi Supervisor (s) Prof Dr Nguyen The Dang Abstract: The sewage sludge is an object of most attention today The biological sewage sludge has the potential to re-use for various purposes because principal components of sewage sludge is the excess microbial of bioremediation processes with high content of organic, nitrogen and phosphorus The volume of sewage sludge of Hanoi city is increasing in both quantity and type The rivers and canals, in addition to the role of drainage also receive a portion of municipal and industrial wastewater One member limited liability company of Hanoi Drainage undertake of solid waste gathering, management and treatment of urban sewage sludge volumes of Hanoi but just stop at the level of sludge collected during dredging drainage ditches system, rivers and lakes Has conducted fact-finding treatment technology, sludge sources generated, sampling location at treatment plants are Kim Lien, Truc Bach and North Thang Long Concurrently, find out the management of sewage sludge in the city of Hanoi to assess the situation arising sludge from wastewater treatment plants of Hanoi and assess the characteristics of sludge components from the wastewater treatment plant of Hanoi The conclusions are i sludge from sewage treatment plants have high humidity, weak alkaline pH and nutrient contents are high; content of the heavy metal in sludge from water treatment plants are less than the threshold of the EEC (1986) and the threshold for hazardous waste according to QCVN 07: 2009 Key words: Waste treatment, sewage sludge, heavy metal content, management of sewage sludge Number of pages: 51 Date of submission: 30/09/2015 Signature of supervisor: ii ACKNOWLEDGMENT First, I would like to express profound gratitude to Prof Dr Nguyen The Dang, who has driven research, guidance, help me during the implementation and completion of this thesis I sincerely thank to dean board, teachers of Environment Faculty and International Training and Development Center of Thainguyen University of Agriculture and Forestry has been communicated, to equip for me many knowledge and valuable experience as well as create the most favorable environment to learning during four school years I would also like to thank to the staff and workers of three water treatment plants Kim Lien, Truc Bach and North Thang Long of Hanoi has help and provide for me important documents and create favorable conditions for the me in the process of gathering documents and fieldwork Finally, I would like to express deep gratitude to my family and friends, having always encourage and help me about materially and mentally during the study to I can finish this thesis Due to time and capacity is limited so my thesis is inevitable shortcomings I would like to receive the instructions, comments of teachers and friends to my thesis is more complete Student Dang Xuan Hao iii TABLE OF CONTENTS LIST OF TABLES LIST OF FIGURES TABLE OF ABBREVIATIONS PART I INTRODUCTION PART II REVIEW OF LITERATURE 1.1.The general issues of sewage sludge 1.1.1 Concept and classification of waste sludge 1.1.2 Origin, nature and characteristics of sludge 1.1.3 Regulations and standards on sludge 13 1.1.4 The impact of the sludge on the environment and human health 18 1.2 The sludge treatment method 21 1.2.1 Handling by incineration 21 1.2.2 Handling by landfilling method 21 1.2.3 Handling by composting biological method 22 1.2.4 Handling by recycling method 23 1.3 Management situation of urban sludge in the world and in vietnam 23 1.3.1 Sludge management in the world 23 1.3.2 Sludge management in Vietnam 25 1.4 An overview of the wastewater treatment technology and generated sludge at three treatment plants 26 1.4.1 Waste water input 26 iv 1.4.2 Waste water treatment technology general at three wastewater treatment stations: 30 1.4.3 Residue sludge product (sewage sludge) 34 PART III OBJECT, CONTENT AND METHODS 35 2.1 Research subjects 35 2.2 Research Content 36 2.2.1 The status of municipal sludge generated from the water treatment plant 36 2.2.2 Characteristics of sludge from the wastewater treatment plant 36 2.3 Research Methods 36 2.3.1 Collection method, synthetic material 36 2.3.2 Survey method, fieldwork 36 2.3.3 Analytical method 37 2.3.4 Methods of data processing 39 PART IV RESULTS AND DISCUSSION 40 3.1 The status of urban sludge generated from the water treatment plant 40 3.2 Physical and chemical characterization of sludge from wastewater treatment plant 41 PART V CONCLUSIONS AND RECOMMENDATIONS 48 Conclusion 48 Recommendation 48 REFERENCES 50 v LIST OF TABLES Table 1.1 Nutrient contents in sewage sludge 12 Table 1.2 Regulations of US - EPA for some heavy metals in the sludge according to intended use 13 Table 1.3 The content of organic compounds for sludge applied to agriculture of some countries 14 Table 1.4 Heavy metal content to apply sewage sludge in agriculture in some countries 15 Table 1.5 Limit values of some microorganisms in sludge as standard in some countries in the world 15 Table 1.6 Basis absolute content (H) and hazard threshold calculated according leaching concentration (Ctc) of the parameters in the sludge 17 Table 1.7 Method of sludge management in some countries 24 Table 2.1 The sampling locations and sample symbols 35 Table 2.2 The targets and methods of analysis 37 Table 3.1 Parameters of the wastewater treatment plants 40 Table 3.2: Physical and chemical characterization of sludge at wastewater treatment plants 41 Table 3.3: Heavy metal (HM) content in the sludge of plants 43 Table 3.4 Some regulations on permissible limits of heavy metal in soil 43 LIST OF FIGURES Figure 2.1 Sampling locations 36 Figure 3.1 Some of nutritional components in sludge 41 Figure 3.2 Cu content in sewage sludge 45 Figure 3.4 Pb content in sewage sludge 46 Figure 3.5 Pb content in sewage sludge 47 Figure 3.6 Cr content in sewage sludge 47 TABLE OF ABBREVIATIONS BTNMT : Ministry of Natural Resources and Environment BXD : Ministry of Construction OM : Organic matter NXB : Publishing house TCVN : Vietnam standard TCXD : Construction Standard TNHH : Limited liability QCVN : Regulation of Vietnam URENCO : Hanoi Urban Environment Company US-EPA : United States Environmental Protection Agency PART I INTRODUCTION Today, the economy - society of Vietnam is on track to grow strongly, accompanied the process of industrialization and modernization, urban is gradually expansion lead to pollution, especially the emergence of various types waste In particular, the sewage sludge is also an object of most attention today, become a burden for businesses, not only in Vietnam, but even in other countries with economy, science and technology developed in the world The collection, transportation, treatment, recycling and reuse of waste particularly sewage sludge from drainage systems and sanitation facilities in urban centers, is becoming a difficult problem for the managers most in countries of the world, particularly in countries with developing economies, including Vietnam According to US-EPA, sewage sludge disposal costs accounted for 50% of operating costs of the treatment system The disposal and burial of sewage sludge has been causing serious environmental pollution Production of sewage sludge in the United Kingdom now is up to about 1.2 million tons dry solids and in the EU generally has about 6.5 million tons of dry solids are produced annually According to recent studies, the biological sewage sludge has the potential to re-use for various purposes because principal components of sewage sludge is the excess microbial of bioremediation processes with high content of organic, nitrogen and phosphorus In Vietnam, solve the environmental pollution due solid waste, hazardous waste, especially sewage sludge is a major challenge to society, with the relevant authorities and the State Also sludge of canals, drains, sewage sludge generated from factories, industrial zones, industrial facilities, etc contains many pollutants and is discharged into the environment Analysis Targets Method Summary of methods equipment Nitrogen Kjeldahl Decompose sludge sample to convert Digestion total nitrogen into ammonium sulfate cabinets, form by boiling H2SO4 combined distillation catalyst HClO4 Distilling and titrate machine and ammonium form, which calculate the burette titrator total amount of nitrogen in sludge samples Phosphorus Kjeldahl Destroy the samples to convert Digestion total phosphorus into P2O5 forms by cabinets, mixed of H2SO4 and HClO4 boiling colorimetric Use colorimetric method of blue photovoltaic molybdenum to quantify Potassium Kjeldahl machines Destroy the sludge sample by mixed Digestion total of H2SO4 and HClO4 to convert cabinets flame potassium into K + form photometer, Quantification of potassium by flame meter photometer method Heavy Extract Extract in turn the forms of metal by Shaker, metal (Cu, analyzing the appropriate extract Then bring centrifuges, Zn, Pb, Cd, heavy the extract obtained for analysis to digestion Cr) determine the amount of heavy cabinets metals form of metals in sludge samples and atomic improved absorption Tessier spectrometry machine AAS 38 2.3.4 Methods of data processing The data were presented in the study results are the average results of the experiments are repeated after statistical processing, calculating average values The graph shows the data plotted by the Excel software 39 PART IV RESULTS AND DISCUSSION 3.1 The status of urban sludge generated from the water treatment plant Sludge generated at three treatment plants Kim Lien, Truc Bach, North Thang Long are calculated according Spinosa L and Vesilind P A (2002): the amount of sludge arising from domestic wastewater is estimated at 0.25 kg/m3 waste water treatment (Hai, 2007) According to the evaluation report about management activities of urban wastewater in Vietnam (2013), some parameters of the three treatment plants is shown in Table 3.1 below (Hai, 2007): Table 3.1 Parameters of the wastewater treatment plants Wattage (m3/day) Treatment Plant The collection Design Operate system The amount Technology of sludge process generated * (kg/day) Kim Lien 3,700 3,700 General A2O 925 Truc Bach 2,500 2,500 General A2O 625 North Thang Long 42,000 7,000 General A2O 1,750 Thus, the estimated average domestic waste sludge from three wastewater treatment plants in Hanoi after the wastewater treatment generated about 3,300 kg/day or about 1.205 tons of sludge generated annually from three wastewater treatment plants 40 3.2 Physical and chemical characterization of sludge from wastewater treatment plant 3.2.1 Physical and chemical characterization The physical and chemical characteristics of the sludge of wastewater treatment plants concentrate are shown in Table 3.2 and Figure 3.1 Table 3.2 Physical and chemical characterization of sludge at wastewater treatment plants Hum Plant pHKCl pHH2O idity (%) Kim Lien Truc Bach North TL OM Nts Ndt Pts Pdt Kts Kdt (%) (%) (mg/kg) (%) (mg/kg) (%) (mg/kg) 7.60 7.82 84.95 57.72 3.70 3798.62 5.30 4832.00 6.02 5602.11 7.43 7.64 85.17 63.18 3.37 3634.51 5.80 4801.30 6.50 5012.01 7.69 7.79 87.05 53.04 3.49 2947.11 6.35 5462.00 6.05 5901.79 Figure 3.1 Some of nutritional components in sludge 41 From the analysis results, we find: - The pH values ranged from 7.43 to 7.81 During treatment process have used more chemicals to reduce the pH but generally the pH of the sludge is relatively stable - The average humidity of the sludge of treatment plant at about 85.52% It is not significant difference between the average moisture of the wastewater treatment plants - Concentration of organic matter in sewage sludge are high, ranged from 53.04% to 63.18% Among them, the highest in Truc Bach plant (reaching 63.18%), and lowest in North Thang Long plant (53.04%) Mostly organic substances from waste, vegetable oil and animal fat, vegetable carcasses, excreta usually in sludge However, due to the retention time in the works and sewer network are long, most of the organic matter in the sludge deposition are decomposed - Nitrogen total (Nts), phosphorus total (Pts) and potassium total (Kts) in the sludge are high and not much difference between the wastewater treatment plants In which, Kim Lien treatment plant with the highest concentration of Nts is 3.7%, in North Thang Long treatment plant have Pts concentrations about 6.35% and Truc Bach treatment plant have Kts concentrations about 6.50 % is greater than the two remaining treatment plants - Concentration of Nts and Kts in plants are very high compared to the rating scale N, K in the soil This is a potential source of nutritional supplements for the soil if the sludge used for agricultural purposes Pts content in sludge at plants are also quite high However, the amount of P digestible small proportion compared with P total This is explained by the P total are rich but neutral pH so the content of Fe, Al,etc lead to P exists mainly in the form of precipitates 42 3.2.2 Heavy metals Table 3.3: Heavy metal (HM) content in the sludge of plants HM Kim Truc Lien Bach North Thang Long QCVN: 07/2009/ BTNM T QCVN:03/2008/B TNMT Agricul tural land CCME, 2005* Industr Type Type ial land A B EEC*** Italia, DPR 1982** pH < pH > Cu 57.1 82.0 674.9 - 50 100 400 757 600 1,000 1,750 Zn 367.5 424.1 2719.3 5,000 200 300 700 1,850 2,500 2,500 4,000 Pb 18.3 21.7 44.8 300 70 300 150 500 500 750 1.200 Cd 1.2 1.3 1.5 10 10 20 10 20 40 Cr 37.9 56.1 158.3 100 - - 210 1,060 - 1,000 1,500 To assess the level of heavy metal pollution of sewage sludge we compare with some standards in Table 3.4 Table 3.4 Some regulations on permissible limits of heavy metal in soil CCME, EEC* HM Italia, pH < pH > 7 Cu 1,000 1,750 Zn 2,500 Pb DPR 2005*** QCVN:03/2008/BTNMT QCVN Type Type Agricultural Industrial A B land land 600 400 757 50 100 - 4,000 2,500 700 1,850 200 300 5,000 750 1,200 500 150 500 70 300 300 Cd 20 40 10 20 10 10 Cr 1,000 1,500 - 210 1,060 - - 100 1982** 07:2009 Note: QCVN:07/2009/BTNMT: National Technical Regulation of Vietnam on Hazardous Waste Threshold QCVN:03/2008/BTNMT: National Technical Regulations of Vietnam on permissible limits of heavy metal in the soil (***)Regulations on the maximum levels of heavy metal allows for the compost of the Canada Department of Environment Canada, CCME 2005 Type A: Use unlimited Type B: Do not use in agriculture, are permitted for use in forestry, green city park (**)Italian regulations on the maximum levels of heavy metal allows for the compost Use unlimited for agriculture (*)Directive 86/278/EEC (European Community 1986), the allowed limit of heavy metal in sewage sludge can be added to soil with pH>7 or pH