Yen So Sewage Treatment Plant - Operations and Maintenance Manual Volume I 2 TABLE OF CONTENT 1 INTRODUCTION 4 2 SYSTEM DESCRIPTION 6 2.1 Design Criteria – 6 2.2 Process Description 6 3 SYSTEM OVERVIEW AND FLOW SCHEMATICS 9 3.1 System Overview and Flow Schematics 9 4 HEALTH AND SAFETY 36 4.1 Mechanical Hazards 36 4.2 Electrical Hazards 37 4.3 Falling Hazards 37 4.4 Chemical Hazards 37 4.5 Gas Hazards 37 4.6 Noise Pollution 38 4.7 Odour Pollution 38 4.8 Infection Hazards 39 4.9 Fire Hazard 40 4.10 Basic Health Measures 40 1.1 GENERAL PLANT SAFETY 40 5 PERSONNEL 42 5.1 O&M Personnel 42 5.2 Personal Responsibiliies 51 6 SEWAGE QUALITY SAMPLING AND TESTING 53 6.1 Process Control & Laboratory Testing 59 6.2 Laboratory Quality Control Program 65 Yen So Sewage Treatment Plant - Operations and Maintenance Manual Volume I 3 6.3 Laboratory Safety 67 7 ELECTRICAL AND SCADA SYSTEM 69 7.1 SCADA SYSTEMS 69 7.2 ELECTRICAL SYSTEM 90 Yen So Sewage Treatment Plant - Operations and Maintenance Manual Volume I 4 LIST OF APPREVIATION O&M Operation & Maintenance B.O.D Biological Oxygen Demand C.O.D Chemical Oxygen Demand TSS Total Suspended Solid NH4-N Nitrogen Ammonia TKN Total Kjeldahl Nitrogen TP Total Phosphorous WWTP Waste Water Treatment Plant NO3-N Nitrogen- Nitrate STP Sewage Treatment Plant UV Ultra Violet KN Kim Nguu MIPS Main Inlet Pumping Station PTW Preliminary Treatment Works SBR Sequential Batch Reactor RAS Returned Activated Sludge WAS Waste Activated Sludge HFMS Hollow Fiber Membrane Filtrate FSBR Filtrate Sequential Batch Reactor MLD Milion liter per day H2S Hydrogen sulfide CO2 Carbon dioxide NH3 Ammonia JIT Just-In-Time P&ID Process and Instrumentation Diagram PLC Programmable Logic Control SCADA Supervisory Control And Data Acquisition I&C Instrumentation and Control HR Human Personel D.O Dissolved Oxygen MLSS Mixed Liquor Suspended Solid OUR Oxygen Uptake Rate OFG Oil, Fat and Grease NO3 Nitrate NO2 Nitrite Org-N Organic Nitrogen SVI Sludge Volume Index EPA Environmental Protection Agency ICV Initial Calibration Verification CCV Continuing Calibration Verification LCS Laboratory Control System MB Method Blank QCS Quality Control System DMR Discharge Monitoring Report Yen So Sewage Treatment Plant - Operations and Maintenance Manual Volume I 5 1 Introduction The objective of this operation and maintenance (O&M) manual is to contribute to the objective of implementing new sanitation facilities for sewage flowing from rivers / canals to Yen So Park of Hanoi. This O&M manual covers primarily the facility for treatment of the wastewater that is collected from Kim Nguu River, Set River and future sewer network from Yen So Park Development. The proper use of this manual together with sufficient resources (manpower and annual operation budget) will help to ensure the following:  compliance of the effluent quality according to Vietnamese standards  cost-efficient operation of the facility  sustainable maintenance of the facility  proper health and safety for employees The manual is a guiding tool in the operation of the facilities. It gives explanations about:  the process design  the design of the individual parts of the facilities  procedures for operating the facilities  procedures for servicing and maintaining the facilities  procedures for monitoring the performance of the facility  Personnel requirement. Further the manual includes suppliers‟ technical documentation, which gives more detailed and precise explanations about maintenance and safety which are specific to the equipment. The O&M manual is divided into following volumes:  Volume 1 provides an introduction and general overview of the system, the personnel requirements, and safety procedures to be implemented.  Volume 2A describes Yen So liquid line and STP equipment, operation and its routine preventative maintenance.  Volume 2B describes Yen So Solid line and STP equipment, operation and its routine preventative maintenance.  Volume 3 contains equipment O&M manuals and data sheets that supplement the information from the suppliers about equipment maintenance. Inspection records for each piece of equipment are included. The basic understanding of the system and its design provided in this O&M manual will assist facility personnel in coping with different conditions as they occur. This O&M manual describes the most probable operating conditions at the facility; however, conditions not described here can occur. Therefore, it will be necessary to amend these procedures as different conditions are encountered during the operation of the Yen So STP. O&M personnel should use industry standards and manufacturer‟s literature to supplement the operating instructions and procedures described in the following volumes. The manual is bound in such a manner to facilitate this updating. This manual should remain on site and be located in a place that is easily accessible to operating and maintenance personnel at all times. Yen So Sewage Treatment Plant - Operations and Maintenance Manual Volume I 6 2 System Description 2.1 Design Criteria – 2.1.1 Design Flow and Loads – Yen So Sewage Treatment Plant is designed to treat a maximum of 200,000 m 3 /day with following consideration Hourly Peak Factor 2.1 Normal Diurnal Peak 1.3 Average dry weather flow 200,000m3/d 2.1.2 Design Wastewater Characteristics 2.1.2.1 STP Wastewater Influent Characteristics– Water Quality Parameter Max Design Value [mg/l] Min Design Value [mg/l] Start-up [mg/l] BOD 250 100 50 COD 500 200 162 TSS 300 120 71 NH 4 -N 30 15 30 TKN 40 20 32 TP 6 4 4 Alkalinity 170 170 170 2.1.2.2 WWTP Effluent Discharge Standards – The Vietnamese Effluent Standards applied is QCVN24:2009/BTNMT Water Quality Parameter QCVN24:2009/BTNMT [mg/l] pH 6-9 BOD5 30 COD 50 TSS 50 NH 4 -N 5 Total Nitrogen 15 Total Phosphorus 4 Total Oil & Grease 10 Mineral Oil & Grease 5 2.2 Process Description The project is for the design and build of a new Sewage Treatment Plant (STP) at Yen So Park located in Hanoi, Vietnam. The proposed new treatment works comprise of new river debris removal systems, grit chambers, 25mm coarse screens, main inlet pumping stations, 6mm fine screens, grit and grease removal tanks, sequential batch reactor (SBR) basins, UV disinfection units, tertiary filtration plant, filtrate treatment plant , sludge storage Column A Yen So Sewage Treatment Plant - Operations and Maintenance Manual Volume I 7 facilities, gravity belt thickeners, sludge digesters, gas holders, centrifuge dewaterers, odour removal systems, polyelectrolyte dosing systems, carbon dosing system and alkalinity dosing system. The Sewage Treatment Plant at Yen So Park receives flows from Kim Nguu River, Set River and the future sewerage network from the Yen So development. The works is designed to treat a maximum of 200,000 m3/ day with a peak hourly flowrate of 2.1 times this. Inlet System is protected by a log boom (from floating debris) which diver the debris to a debris removal system mounted on the bank of river. Floating debris is removed and collected in skip for disposal. The river level is raised by two sets of radial weir gate mounted in the river. The flow to treatment passes through river intake screens mounted in the riverbank; three for Kim Nguu and two for Set. Screenings are collected and disposed of in skips. Each screen can be isolated by wall mounted actuated penstocks. After river screening, the flow passes to two sets of two number grit chambers. Grit is removed and is classified prior to disposal to skips for removal. The liquor from the grit classifiers is returned to the common inlet channel and each grit chamber can be isolated by wall-mounted penstocks. After grit removal, the flow is piped to the main inlet pumping stations where it passes through 25mm coarse screens. The Kim Nguu river flow passes through three parallel screens and Set river flow passes through two screens. The Kim Nguu flow will in future be augmented by a further flow from the Yen So development. Each screen is channel mounted and complete with actuated isolation penstocks and emergency bypass hand raked screens. After coarse screening, each river stream is pumped via dedicated main inlet pumping stations (MIPS) to the combined 6mm fine screening stage. Kim Nguu and Set River pump stations each comprise of 6 No. fixed speed submersible pumps operating on 4 No. duty and 2 No. standby configuration. The combined fine screen process includes 4 parallel channel mounted 6mm screens and an emergency bypass hand raked screen. Each screen can be isolated by actuated penstocks. The screenings are transferred to a skip for disposal. Following fine screening, the combined flow passes to a grit/ grease removal stage. There are four grit/ grease removal tanks. Grit is removed from the front hopper of the tank by dedicated grit pumps and pumped to 2 No. grit classifiers. Grit is disposed via skip and effluent drained to the Kim Nguu main inlet pump station. Grease is floated by air to the surface of the tank and removed by scraper to an outlet hopper for removal by skip. The air is introduced to the base of the tank via a common header supplied by four number air blowers. After the grit/ grease removal tanks, the flow gravitates to the sequential batch reactor (SBR) basins. There are eight treatment basins operating in two modules. The SBR basins in each module will treat sewage in batches, with the operation of basins staggered to allow continuous acceptance of sewage and continuous discharge of effluent. Each SBR basin inlet can be isolated by actuated weir penstocks. Each SBR undergoes a treatment cycle that consists of the fill, react, settle and decant sequences. During the fill sequence, the SBR basin is filled with untreated sewage. Once the SBR basin is filled, aeration commences which is known as the react sequence. After the treatment process is complete, the aeration is stopped and biomass will be allowed to settle to the bottom of the tanks (settle sequence). When the biomass has settled, a layer of clear treated water at the top of the SBR basin is removed by two decanters during the decant sequence. Each SBR module has 6 No. air blowers, operating in a 4 No. duty and 2 No. standby configuration. Excess biomass from each of the SBR basins is removed during the settle sequence by 2 No. waste activated sludge (WAS) pumps and directed to the sludge holding tanks. Return activated sludge (RAS) is returned to the bioselectors for simultaneous nitrification denitrification and enhanced biological phosphorus removal by 2 no. RAS pumps. A carbon dosing system and alkalinity dosing system are provided and doses upstream of the SBR basins for adjustment of nutrient and alkalinity levels in the influent. Yen So Sewage Treatment Plant - Operations and Maintenance Manual Volume I 8 About third of treated effluent from the SBR basins is channelled into UV disinfection units and the remaining treated effluent from the SBR basins is discharged back into the Kim Nguu River. After UV disinfection, 3,000m3/ d of the treated effluent undergoes tertiary treatment before being recycled for plant usage. Tertiary treatment comprises 2 No. hollow fibre membrane filtration (HFMS) units operating in parallel. The remaining water after UV disinfection shall be discharged directly into the Yen So Lake. Sludge holding tanks are provided to store the SBR waste sludge. From the sludge holding tanks, the sludge is transferred to 4 No. gravity belt thickeners for thickening process. Sludge is fed into a static flocculator tank by means of 6 No. thickener feed progressive cavity pumps (4 duty/ 2 standby). Polymer is dosed into the sludge prior to the thickeners to flocculate fine particles. Filtrate produced from the sludge thickeners will flow to the Kim Nguu main inlet pump station. The thickened sludge from the sludge thickeners is stored in the 2 No. thickened sludge storage tanks to allow a continuous flow to the sludge digesters. A macerator is installed in each of the thickened sludge holding tank outlet to macerate any solids left in the sludge before being fed to the sludge digester. The thickened sludge is fed to 2 No. anaerobic digesters to reduce the thickened sludge volatile suspended solids content. The gas generated by the digesters is stored in 2 No. double membrane type gas holders. Part of the gas shall be used to mix the sludge in the digesters, part of the gas shall be used for the heating of digester sludge and the excess gas shall be flared off. The digested sludge gravitates to the 2 No. digested sludge storage tanks. Digested sludge will be fed to 4 No. centrifuge dewaterers to dewater the digested sludge via 6 No. fixed speed progressive cavity dewaterer feed pumps (4 duty/2 standby). The sludge cake is conveyed to sludge storage area and transfer to skips for disposal off site. Centrate from the dewatering units will flow to the works liquor tank. Polymer is dosed into the sludge prior to the dewaterers to flocculate fine particles to increase dewatering efficiency.The polymer dosing system is designed to accept powder supply. Powdered dry polymer is stored in big bags and is transferred to a hopper. The hopper discharges into the powder feeder that feeds the polymer mixing tank. Service water from the service water booster pumps is added to the polymer mixing tank to make up the polymer solution. Polymer solution is drawn from the storage tank by 4 No. dosing pumps and is dosed into each thickener feed pump delivery. There are separate polymer dosing systems provided for the thickening and dewatering plant. Filtrate from sludge dewatering centrifuges gravitates into the filtrate holding tank before being fed to the Filtrate Sequential Batch Reactors (FSBRs). A bypass shall be provided from this holding tank back to manhole MH26B from where filtrate could be returned directly to the main SBR process in case that the FSBRs are only partially or not operational during maintenance activities, or in case that the influent sewage and operational conditions do not require utilisation of the FSBRs. Potentially odorous air is drawn from the main inlet pumping stations, coarse screens, 6mm screens, grit and grease removal tanks, grit handling plant, works liquor tank, sludge holding tanks, sludge thickening units, thickened sludge holding tank, digested sludge storage tank, sludge dewatering units, collection skip for Kim Nguu and Set River debris removal to 4 No. odour control facilities. Yen So Sewage Treatment Plant - Operations and Maintenance Manual Volume I 9 3 System Overview and Flow Schematics 3.1 System Overview and Flow Schematics Sewage treatment plant using Sequence Batch Reactor (SBR) including: Process Flow Diagram 3.1.1 Intake Works The Sewage Treatment Plant (STP) at Yen So Park receives flows from both the Kim Nguu and Set rivers. Each river intake system is protected by a log boom and debris removal system to prevent any floating debris entering the inlet works. The trapped debris is directed towards a diversion channel mounted on the side of the riverbank. The debris is removed by a mechanical 50mm screen which is cleared by a motor driven rake upon detection of high differential level. The debris is deposited into a skip via a screenings conveyor. The Kim Nguu debris removal area is connected to odour control unit 3. The Set debris removal area is connected to odour control unit 4. The debris removal systems can be isolated by stop logs. The level in the river is maintained by two sets of 2 No. radial weir gates mounted downstream of the log boom and a level transmitter. The radial weir gates can be isolated by stop logs. In the future, 10 MLD sewage from the Yen So Park Development will be introduced to the STP. Yen So Sewage Treatment Plant - Operations and Maintenance Manual Volume I 10 Typical Log boom for Kim Nguu & Set River Typical Radial Gate for Kim Nguu & Set River Typical Trash Rake for Kim Nguu & Set River Yen So Sewage Treatment Plant - Operations and Maintenance Manual Volume I 11 Yen So STP- Flow to Inlet Works 3.1.2 Inlet Chamber Incoming flow from the Kim Nguu River and Set River flows into the intake screens. Each screen channel has a motorised inlet and outlet penstock. The screens are cleared by a motor driven rake upon detection of high differential level measured by a level transmitter. The screenings are deposited via a screw conveyor compactor into a skip. [...]... Manual Volume I Thickener Feed Pumps 3 .1. 12 Sludge Thickener Sludge from the thickener feed pumps enters 4 No gravity belt thickener units Each thickener unit is controlled by a local control panel Each thickener unit consists of a flocculator tank and fixed speed main drive which rotates the belt Belt Thickeners 27 Yen So Sewage Treatment Plant - Operations and Maintenance Manual Volume I 3 .1. 13 Polymer... Operations and Maintenance Manual Volume I Compressors 3 .1. 14.2 Hot Water Pumps The digesters are maintained at 35-37°C by passing sludge streams through 2 No heat exchangers and returning it back to the digesters Hot water, with normal temperature of around 70°C, also is passed through the exchangers 3 .1. 14.3 Digester Mixing Compressors Each gas mixing system is dedicated to 1 digester and comprises draw... provide in volume 2A Flow to Sequential Batch Reactors 20 Yen So Sewage Treatment Plant - Operations and Maintenance Manual Volume I Air Blowers Blower Cooling System Air pipes Air Diffusers SBR Aeration System 21 Yen So Sewage Treatment Plant - Operations and Maintenance Manual Volume I SBR Aeration and Dosing System 22 Yen So Sewage Treatment Plant - Operations and Maintenance Manual Volume I WAS... process water pumped to odour control units 1, 2 & 3, dewaterer polymer dosing plant, thickener polymer dosing plant, sludge dewatering units, membrane chemical cleaning plant, Kim Nguu grit chamber, thickener washwater pumps, site hydrants and hose points 25 Yen So Sewage Treatment Plant - Operations and Maintenance Manual Volume I Memberane Treatment Plant 3 .1. 11 Sludge Holding Tanks Waste activated sludge... Pumped flows are subject to in-pipe flow measurements Kim Nguu and Set pumping stations are odour controlled 14 Yen So Sewage Treatment Plant - Operations and Maintenance Manual Volume I Kim Nguu-Set River Coarse Screens 15 Yen So Sewage Treatment Plant - Operations and Maintenance Manual Volume I 3 .1. 7 Preliminary Treatment Works  Fine 6mm screens + wash-compactors  Combined aerated grit + grease removal... baffle boards and scraped into the grease sump by the grease scraper to chute to skip grease tank 18 Yen So Sewage Treatment Plant - Operations and Maintenance Manual Volume I Air Blowers Grit Scraper Odour Control Traveling Bridge 19 Yen So Sewage Treatment Plant - Operations and Maintenance Manual Volume I 3 .1. 8 Sequential Batch Reactor (SBR) Flow from the grit/ grease removal tanks is split between two... off pipework, duty / standby gas compressors, 12 gas mixing points and associated instrumentation, valves and ancillary plant 3 .1. 14.4 Waste Gas Burner Occasionally, the digester may produce more biogas than can be used by the boiler in heating the sludge for digestion Under these circumstances, the surplus gas is destroyed in the waste gas burner 3 .1. 14.5 Desulphurisation Scrubber Gas collected will... digester gas 3 .1. 14.6 Hot water boiler The digesters are heated indirectly by means of a hot water heat exchanger The heat required is raised using a duty only hot water boiler set The boiler is fed with gas, from the gas holders, or standby fuel The fuel is kept in a storage tank 30 Yen So Sewage Treatment Plant - Operations and Maintenance Manual Volume I Digester Building Layout 3 .1. 15 Gas Holding... coarse screens are connected to odour control unit 1 3 .1. 5 Set River Coarse Screens Incoming flow from Set River grit chambers flows to 2 No 25mm coarse screens The sewage passes through the screens for screening of large objects, rags and debris to prevent clogging of the pumps 13 Yen So Sewage Treatment Plant - Operations and Maintenance Manual Volume I Each screen channel can be isolated by an inlet... removed and the remaining liquid flows to the SBRs for secondary treatment Preliminary treatment includes fine screens, grit/grease removal system including blowers 16 Yen So Sewage Treatment Plant - Operations and Maintenance Manual Volume I 3 .1. 7 .1 Fine Screen: Sewage from main inlet pumping station is pumped to fine screens inlet chamber, before passing through 6mm fine screen, prior entering to the 4 . Value [mg/l] Start-up [mg/l] BOD 250 10 0 50 COD 500 200 16 2 TSS 300 12 0 71 NH 4 -N 30 15 30 TKN 40 20 32 TP 6 4 4 Alkalinity 17 0 17 0 17 0 2 .1. 2.2 WWTP Effluent. Hazard 40 4 .10 Basic Health Measures 40 1. 1 GENERAL PLANT SAFETY 40 5 PERSONNEL 42 5 .1 O&M Personnel 42 5.2 Personal Responsibiliies 51 6 SEWAGE QUALITY SAMPLING AND TESTING 53 6 .1 Process. Nguu & Set River Yen So Sewage Treatment Plant - Operations and Maintenance Manual Volume I 11 Yen So STP- Flow to Inlet Works 3 .1. 2 Inlet Chamber Incoming flow from the Kim Nguu