NEERIMREC CONTENTS Introduction Preamble Wastewater and its Impact Wastewater Treatment Objectives and Methods Need for WWTP Design Software Basic Considerations Nature of Pollutants Wastewater Characteristics Some Wastewater Treatment Methods and their Characteristics Discharge Standards NEERIMREC CONTENTS Theoretical Considerations for Design Description of Unit Operations and Processes Details of ASP & Other Processes ASP Operational Problems The WWTP Software General Considerations Framework for WWTP Software Detailed Description of Software Augmentation of Jaipur STP Conclusion NEERIMREC INTRODUCTION Water is important resource because it is essential for survival its use underlies all agriculture and industrial processes it can not be substituted for technologically It is becoming increasingly scarce resource warranting careful engineering & management NEERIMREC INTRODUCTION Industrialization & urbanization have polluted the watercourses created a growing demand for large quantities of protected water for public & industries Analysis of the available information reveals that two-thirds of all illnesses in India, are related to water-borne diseases (cholera, typhoid, diarrhea, infectious hepatitis, dysentery, etc.)NEERIMREC INTRODUCTION In most developed countries honey wagon method was used city residents used to put night soil in buckets along the streets where workers emptied the waste into honey wagon tanks waste was transported for disposal over agricultural lands For rural communities in many under developed countries, this method is still in use NEERIMREC INTRODUCTION Development of flush toilet in nineteenth century, which produced large volumes of wastewater, overtaxed agricultural lands as a final receptor of the waste. This induced people to use natural channels to convey the large volumes of liquids generated by flush toilets into the nearest watercourse. This practice resulted in gross pollution of these receiving water bodies. NEERIMREC INTRODUCTION In India, the situation so worsened that the government had to launch large-scale projects of the order of Ganga Action Plan, for improvement of water quality of major rivers at a cost of several crores of Rupees. Thus, the need for development and proper management of water resources can not be emphasized more.NEERIMREC WASTEWATER & IMPACT Main sources of wastewater are domestic sewage industrial wastewaters agricultural runoff storm water & urban runoff Estimated wastewater generation from 212 Class-I cities of India is 12,145 MLD of which only 2485 MLD (about 20%) receives treatment, in some cases only partially. NEERIMREC WASTEWATER & IMPACT An estimated 1298 MLD of wastewater is generated from 241 out of 270 Class-II towns in India. Further, it is reported that less than 5% of total wastewater is collected and only 2% is receiving some kind of treatment. E.g. an estimated 900 ML sewage is discharged into the river Ganga everyday and this accounts only for 75% of total pollution reaching the river. NEERIMREC METHODS & OBJECTIVES Treatment methods were first developed in response to concern for public health adverse conditions caused by discharge of WW limited land available for treatment & disposal Purpose of developing other methods was to accelerate the forces of nature under controlled conditions in treatment facilities of comparatively smaller size. NEERIMREC METHODS & OBJECTIVES Treatment objectives were concerned with removal of suspended and floatable material treatment of biodegradable organics elimination of pathogenic organisms Since 1980, because of increased scientific knowledge and an expanded information base, wastewater treatment has begun to focus on the health concerns related to toxic and potentially toxic chemicals released to the environmentNEERIMREC METHODS & OBJECTIVES Contaminants in wastewater (pollutants) are removed by: physical, chemical, biological or other means WTP utilizes a number of treatment processes to achieve the desired degree of treatment NEERIMREC METHODS & OBJECTIVES The environmental design engineer must evaluate numerous other important factors in selection of the treatment processes:constituents treated, effluent limitations, proximity to build-up areas, hydraulic requirements, sludge disposal, energy requirements, and economics Collective arrangement of various treatment processes is called a flow scheme, flow diagram, a flow sheet or a process trainNEERIMREC METHODS & OBJECTIVES Choice of proper treatment processes anddevelopment of flow scheme is not simple. It requires understanding of the unit operations & processes, operational capabilities and environmental effects of various treatment components Laboratory and pilot plant studies are often necessary to develop design parameters for physical, chemical, and biological treatment processes used for treatment of wastewaterNEERIMREC NEED FOR DESIGN S/W Over a period of time several techniques and processes have been developed for wastewater treatment These methods encompass from low-cost wastewater treatment methods such as stabilization ponds, to advanced wastewater treatment methods such as activated carbon adsorption, reverse osmosis, etc.NEERIMREC NEED FOR DESIGN S/W Design of wastewater treatment plant is the solution of a very complex problem for several reasons : Probabilistic nature of flow and composition Restricted knowledge of the behavior of biological system in regard to adaptation Strong influences of future developments during long lifetime of equipment and construction Different definitions of effluent quality standards NEERIMREC NEED FOR DESIGN S/W Restricted knowledge of influences of probabilistic effluent quality on the receiving waters Restricted knowledge of technical reliability of different process configurations Influences of operational decisions on the treatment efficiency Different cost calculation procedures (investment, capital, operation costs) NEERIMREC NEED FOR DESIGN S/W Thus, to ensure that quality of our watercourses is maintained at desirable levels, it is necessary to treat the wastewater before discharging into water bodies It is only in last few years that the design approach for these plants has changed from empirical to sound engineering basis NEERIMREC NEED FOR DESIGN S/W While much work is reported on development of mathematical models for treatment processes such as ASP, no or little work is devoted to development of computer based efficient tools for design of treatment plants

It was towards this end that development of a computer software for use by design engineers was thought as a timely and apt action NEERIMREC OBJECTIVES OF S/W It was envisaged to develop a computer software which would help in the design of a new treatment plant augmentation of an existing treatment plant operation of treatment plant through troubleshooting guide NEERIMREC ACTIVATED SLUDGE PROCESS Enzyme Kinetics c s c eE oduct Complex S Ekkk) (Pr321+ +s Kesskk kescc k c k s c e km equilibriu Atc k c k s c e km +=++=+ = ((((((

13 23 2 13 2 1) ( ) ( ) )( () ( ) ( ) )( (Eq Menten Michaeliss Ksv ve k v Velocity Maximums Kes kc k vis Velocity Overallmm +=+= ==max3 max33NEERIMREC ACTIVATED SLUDGE PROCESS Enzyme Kinetics (((

+=ssKsmax In Wastewater Treatment microbial growth is more important and can be done by using Monods expressionand noting that rate of change in microbial concentration is proportional to concentration (x) xdtdxe i = . .(((

+=ssKsxdtdxmaxThis is related to substrate removal through yield constant (Y); dsdxY =(((

+((

= ssKsYxdtdsThereforemax, Mathematical Model for Bio-oxidation NEERIMREC CHOICE OF PLATFORM IBM PC Compatible Computer System - Pentium Pro processor @ 266 MHz - 64 MB RAM, 6 GB Hard disk space - 14 VGA color monitor - User interface is perhaps the most important part of an application; its certainly the most visible. To users, interface is the application. No matter how much time and effort is put in writing and optimizing the code, the usability of the application depends on the interfaceNEERIMREC CHOICE OF PLATFORM Why Windows has become so Popular Device Independent Programs Pre-installed Code Standard User Interface Microsoft Visual Basic Offers An Object Oriented Programming language An integrated development environment Powerful tools for creating GUI; Application as a standalone executable program Crystal Reports to create customized reportsNEERIMREC FRAMEWORK FOR S/W Commensurate with objective of the research, WWTP Design software was conceptualized to comprise the following three modules: Design Module Augmentation Module Troubleshooting Module S/W comprises a No.of VB Forms; data files- ASCII or MDB; and report formats NEERIMREC FRAMEWORK FOR S/W Static data- information on mechanical aerator parameters; properties of water as a function of temperature; compiled from literature are stored in files Dynamic data- specific for a particular unit operation; is restricted to forms only A set of linked forms is dedicated to each task obtaining Input Data from user presenting the design results on screen carrying out the design in an interactive mode NEERIMREC FRAMEWORK FOR S/W Input data and Design details are stored in Access Database consisting of Tables corresponding to respective units. Summary reports for each units are developed using Crystal Reports instead of creating plain ASCII files. The approach offers the advantage of pre-designed report format and efficient linking with the database. A menu of reports is displayed to select the report to be printed/saved. NEERIMREC Fig 4.7: System Flow Chart for Design of Augmentation Module WWTP Software Introductory Display MAIN MENU DDesign ofNew System AAugmentation of Existing System TTroubleshooting of ASP System EExit START Design ModuleAugmentation Module Troubleshooting Module A A NEERIMREC DESIGN MODULE WTP flow-sheet comprises a No. of treatment unit processes / unit operations connected in series Choice of units depends on several factors: influent type, flow and characteristics, available skilled manpower, process reliability, available land area, mode of final disposal, governing rules and local laws, etc. NEERIMREC pH:8.4 SS: 60 mg/L BOD: 26 mg/L COD: 164 mg/L Raw Waste Water Screen Chamber GritChamber FlowMeasuring Device Equalization Tank Flash Mixer pH:8.5 SS: 125 mg/L BOD: 85 mg/L COD: 300 mg/L SAMPLE FLOW SHEET OF TREATMENT SCHEME pH:6.7 SS: 1110 mg/L BOD: 200 mg/L COD: 620 mg/L ABCA Chemicals Sand Filter CarbonColumn ClariflocculatorAeration TankSecondary Clarifier Treated Effluent pH: 8.1 SS: