AUTOMATION OF COMMON EFFLUENT TREATMENT PLANT AT AURANGABAD

Abstract

Water is the basic human need for survival of life. To fulfill the increasing water demand due to rapid growth in population, treating different types of wastewater i.e., domestic and industrial wastewater effectively and reusing it is very important. CETP is an approach for the treatment of wastewater from different small and medium scale industries at a common facility in the same way as municipal sewage treatment plant which treats the wastewater from different houses. Due to the lack of space, non availability of trained staff and economical problems for installation costly pollution control equipments, small and medium scale industries cannot be able to establish the individual treatment plant at their own facility. CETP solves this problem by treating the wastewater of different industries at common place and also protects the environment and help to the society at large. Automation is an ideal tool to improve the quality of treated water. But most of the CETPs in the country are operating manually due to the costs involved in implementation of automation without focusing on its benefits. Implementation of automation in CETPs not only improves the quality of treated water, but also reduce the costs of energy, chemical, labour, operational and maintenance. If it is not possible to automate the total treatment plant with the sophisticated automation tools due to economical reasons, automation can be implemented at least in the areas where there is a major contribution of the total annual costs. Usage of online measurement devices will also reduce the labour cost since there is no necessity of sampling and testing in laboratory for several quality parameters and to adjust the controls according to that. Treated water quality will also be improved due to the accuracy in measurements of quality parameters and timely controlled operation of different equipments. Extent of automation which gives the economical benefits can be chosen by doing life cycle cost analysis before selecting any automation scheme. CETP, Aurangabad is selected for the study of manual operation and to understand the problems involved in that operation. An automation scheme is prepared for the CETP under study in the areas of raw water pumping, coagulation, flocculation, sedimentation, DO control, filtration, back wash process, chlorination and treated water pumping since these areas contribute to major annual costs mainly in terms of energy cost and chemical cost. ILN From the life cycle cost analysis it is obtained that total cost for the implementation of the proposed automation scheme is Rs 1.0 crore and total expected benefit from automation is 1.8 crore. Benefit to cost ratio is 1.74 (i.e. >1) and NPV is Rs.77 lakh (i.e. -1-ye). Payback period of the project is 5 years that means total capital cost invested on automation project will regenerate within 5 years after implementation of project. Implementation of automation is reducing annual costs by 25%. So all these parameters indicate that the implementation of automation at CETP, Aurangabad is economically feasible and profitable.